Scholarly article on 5-(5-methyl-1-phenyl-1H-4-pyrazolyl)-1,3,4-oxadiazol-2-yl hydrosulfide 816429-52-4 from Bioorganic Chemistry

Bioorganic Chemistry 114 (2021) 105122

Contents lists available at ScienceDirect

Bioorganic Chemistry

journal homepage: www.elsevier.com/locate/bioorg

Optimization of pyrazole-based compounds with 1,2,4-triazole-3-thiol

moiety as selective COX-2 inhibitors cardioprotective drug candidates:

Design, synthesis, cyclooxygenase inhibition, anti-inﬂammatory,

ulcerogenicity, cardiovascular evaluation, and molecular modeling studies

,

Khaled R.A. Abdellatif^{a *}, Eman K.A. Abdelall^a, Heba A.H. Elshemy^a, John N. Philoppes^a,

Emad H.M. Hassanein^b, Nesma M. Kahk^a

^aDepartment of Pharmaceutical Organic Chemistry, Beni-Suef University, Beni-Suef 62514, Egypt

^bDepartment of Pharmacology & Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 7152, Egypt

A R T I C L E I N F O

A B S T R A C T

Keywords:

The cardiovascular side effects associated with COX-2 selective drugs were the worst for coxibs leading to their

withdrawal from the market a few years after their discovery. Therefore, the design of new series of pyrazole (4a,

b 5a,b, 7a,b, 9a,b, 10a-h, and 11a-f) substituted with a triazole moiety as selective COX-2 inhibitors with car-

dioprotective effect was aimed in this paper. The target compounds were prepared and evaluated in-vitro against

COX-1 and COX-2 enzymes. Compound 5-(5-Methyl-1-phenyl-1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-thiol (7a)

showed the highest selectivity towards COX-2 enzyme (S.I. = 27.56) and was the most active anti-inﬂammatory

agent. Interestingly, its cardiovascular proﬁle showed the cardiac biomarkers (ALP, AST, CK-MB, and LDH), as

Pyrazole

Triazole

Selective COX-2 inhibitor

Celecoxib, Cardiotoxicity

Anti-inﬂammatory

Histopathology

well as inﬂammatory cytokines named (TNF-α and IL-6) nearly similar to the control. Besides, a histopathological

study of the heart muscle and the stomach was also included. The results conﬁrmed that compound 7a has a more

favorable cardio proﬁle than celecoxib. Moreover, docking simulation for the most selective compounds 4b, 7a,

10e, 11c, and 11e inside COX-2 active site was performed to explain their binding mode. Finally, an ADME study

was applied and proved the promising activity of the new compounds as a new oral anti-inﬂammatory agent. In

conclusion, the newly developed compound 7a represents a potential selective COX-2 NSAID candidate with

minimum cardiovascular risks.

1. Introduction

2 inhibitors as coxibs to limit those side effects. Despite coxibs’ gastro-

intestinal safety, they are implemented redoubtable cardiovascular side

The non-steroidal anti-inﬂammatory drugs (NSAIDs) exert their anti-

inﬂammatory activity by inhibiting the production of the pro-

inﬂammatory prostaglandins (PGs) mediated by cyclooxygenase

(COX) enzymes [1,2]. Prolonged administration of traditional NSAIDs

such as aspirin (I) (IC₅₀= 0.30 and 2.40 uM against COX-1 and COX-2 in

order [3]), indomethacin (II) and ibuprofen (III) (IC₅₀= 2.9 and 1.1 uM

against COX-1 and COX-2, respectively [4]). (Fig. 1) leads to obstacles

like kidney damage, gastric ulcer, and hepatotoxicity [5–7]. The

dissimilarity in the structure of COX-1 and COX-2 isoenzyme (COX-2 has

a bigger binding pocket due to the presence of the smaller amino acid

Val523, Arg513, and Val434 as compared with Ile523, His513, and

Ile434 in COX-1 [8–10]), resulting in the development of selective COX-

effects. That’s why certain coxibs have been restrained from the market

as rofecoxib (IV) (Fig. 1) [11,12]. However, Celecoxib (V) (Fig. 1) with a

central pyrazole core are the most commonly used selective COX-2

NSAID despite the warnings of its cardiovascular side effects [12,13].

The answer to this dilemma was found to be one of three strategies: i)

design of novel drugs selectively targeting COX-2 with safer proﬁle, ii)

using dual LOX/COX inhibitors, iii) using hybrid molecules of selective

or nonselective COX inhibitors together with either hydrogen sulﬁde

(H₂S) or nitric oxide (NO) releasing groups [14] as found in the reported

nitric oxide-releasing pyrazole derivative (VI) (Fig. 1), that was reported

to exert IC₅₀= 10.95 and 1.28 uM against COX-1 and COX-2 iso-

enzymes, respectively [15]. Accordingly, our previous work developed

* Corresponding author.

E-mail address: khaled.ahmed@pharm.bsu.edu.eg (K.R.A. Abdellatif).

https://doi.org/10.1016/j.bioorg.2021.105122

Received 4 May 2021; Received in revised form 9 June 2021; Accepted 22 June 2021

Available online 25 June 2021

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

several new selective COX-2 inhibitors, nitric oxide-releasing NSAIDs,

and dual COX/LOX inhibitors [15–23]. Additionally, triazoles especially

the thiol derivatives are pronounced of substantial interest as anti-

inﬂammatory agents with minimum toxicity [14,23–26]. Furthermore,

they are reported as hydrogen sulﬁde donating moiety that is incorpo-

rated into NSAIDs to lower their gastrointestinal problems and enhance

their cardiovascular safety proﬁle similar to the ibuprofen analog (VII)

(Fig. 1) with a good % of edema inhibition (59.8%) compared to the

standard ibuprofen (76.6%) and much lower ulcer index (13.37),

compared to the standard ibuprofen (21.26) [14].

isoenzymes, respectively [23] (Fig. 1).

Guided by the aforementioned data and as a continuation of our

research interest in the scope of synthesis and biological evaluation of

celecoxib analogs, we designed new compounds as a hybrid structure of

pyrazole core substituted with triazole-3-thione moiety and either the

phenyl or 4-methyl sulphonyl phenyl group as selective COX-2 phar-

macophore to provide new selective NSAIDs with overall successful

outcomes of being selective COX-2 inhibitor with minimum gastroin-

testinal and cardiovascular risks (see Fig. 2).

Recently, several pyrazole /triazole hybrid has been reported as

potent and selective COX-2 inhibitors as in the nitric oxide donating

hybrid (VIII) with IC₅₀= 9.81 and 0.91 uM against COX-1 and COX-2

Fig. 1. Structure of non-selective NSAIDs: Aspirin (I), indomethacin (II) and ibuprofen (III), selective COX-2 inhibitors: Rofecoxib (IV) and Celecoxib (V), the

selective COX-2 inhibitor nitric oxide donating pyrazole derivative (VI), ibuprofen analog containing triazole derivative as hydrogen sulﬁde donating moiety (VII),

and pyrazole /triazole hybrid as selective COX-2 inhibitor (VIII).

2

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

F₃C

Br

R₁

H or CH₃

N

S

N

Structure

N

S

extension

O

N

CH₃

N

R

SO₂NH₂

H

Celecoxib (V)

R₂

N

SH

N

H

OR

OCH₃

H

N

R₂

CH₃

H or SO₂CH₃

Cl

Target Compounds

Ibuprofen analog (VII)

Hit Compounds

Fig. 2. Rational design of the target compounds.

2. Results and discussion

at room temperature in the presence of sodium metal as a base (Scheme

1). The alkylation process was conﬁrmed by ¹H NMR through the

presence of singlet peaks integrating three protons at δ 3.33, 3.37 ppm

indicating SCH₃group. Also, ¹³C NMR charts proved S methylation

through the presence of SCH₃carbons at δ 38.70, 39.16 ppm.

2.1. Chemistry

The synthesis of novel derivatives of 1, 2,4-triazole-3-thione (thiol)

was carried out following the reaction sequences illustrated in (Scheme

1- 3).

New 1,2,4-triazoles 7a,b were synthesized through the reaction of

the carbohydrazide 2a,b with ammonium thiocyanate in a mixture of

isopropanol and hydrochloric acid under reﬂux for 10 h to get the novel

thiosemicarbazide 6a,b, followed by intramolecular dehydrative cycli-

zation of the formed thiosemicarbazide 6a,b via heating under reﬂux in

ethanolic sodium hydroxide solution. The ¹H NMR spectra of 6a,b

exhibited a singlet deuterium exchangeable signal representing two

protons at δ 6.58, 6.64 ppm due to NH₂protons. Furthermore, it showed

additional two deuterium exchangeable singlets each integrating one

proton at δ 9.33, 9.35 ppm, and δ 10.08, 10.14 ppm due to two NH

protons. The charts of ¹³C NMR of 6a,b showed peaks at δ 162.58,

Starting compounds ethyl pyrazole-4-carboxylate 1a and its 4-meth-

ylsulfonylphenyl derivative 1b were prepared according to reported

procedures [27,28] and their structures were conﬁrmed by their phys-

ical and spectral data.

Hydrazinolysis of pyrazole esters 1a,b with hydrazine hydrate giving

the key acid hydrazide intermediates 2a,b (Scheme 1). The structure of

acid hydrazide derivative 2b was conﬁrmed by its spectral data. IR

spectrum showed a stretching band at 3432 cm^{ꢀ 1}due to NH group,

forked band at 3296, 3265 cm^{ꢀ 1}due to NH₂group, and strong stretching

band at 1625 cm^{ꢀ 1}was attributed to the amidic carbonyl group. ¹H

NMR spectrum showed two deuterium exchangeable singlets at δ 4.41

ppm and δ 9.47 ppm integrating two protons and one proton which were

accounted for NH₂and NH protons, respectively.

–

162.82 ppm and δ 182.68, 182.73 ppm corresponding to C O and C

S

–

groups, respectively (Scheme 2).

The Cyclization of the thiosemicarbazides 6a,b into 1,2,4-triazole

derivatives 7a,b was proved by their spectral and elemental analysis.

The IR spectra showed absorption bands at 2661, 2675 cm^{ꢀ 1}detecting

SH groups. ¹H NMR charts showed singlet deuterium exchangeable

peaks at δ 13.58, 13.62 ppm and 13.66, 13.71 ppm each accounted for

one proton revealing NH and SH, respectively. ¹³C NMR spectra showed

N-phenylhydrazine-1-carbothioamide derivatives 3a,b were ob-

tained in a good yield (70–78%) by subjecting the carbohydrazide 2a,b

to react with phenylisothiocyanate through heating under reﬂux in ab-

solute ethanol in the presence of triethylamine. The structures of the

formed carbothioamides were conﬁrmed by their IR spectra which dis-

played absorption peaks at 3432, 3261, 3192 cm^{ꢀ 1}for 3 NH groups.

Their ¹H NMR spectra showed three characteristic singlet deuterium

exchangeable peaks each accounted for one proton at δ 9.70, 9.73 ppm,

–

the disappearance of the peaks of the C O and C S in the thio-

–

semicarbazides 6a,b with the presence of new peaks at δ 145.83, 146.14

ppm and at δ 166.14, 166.22 ppm for C-5 and C-3 in the formed triazole

ring, respectively.

at δ 9.81, 9.83 ppm, and δ 10.22, 10.29 ppm indicating 3 NH groups. The

In an attempt to synthesize diamino-1,2,4-triazole derivatives A, the

thiosemicarbazides 6a,b were heated under reﬂux with hydrazine hy-

drate for 4 h, however the thiosemicarbazides 6a,b were broken down

into the starting acid hydrazides 2a,b.

13

–

C NMR spectra showed peaks for C O at δ 162.89, 163.12 ppm and

–

peaks for C S at δ 181.71, 181.76 ppm.

Intramolecular cyclization of the formed carbothioamides 3a,b was

achieved by heating under reﬂux with methanolic KOH solution to get

the new 1,2,4-triazole-3-thiol 4a,b. Cyclization of the carbothioamides

1,3,4-Oxadiazoles 8a,b were synthesized through treatment of hy-

drazides 2a,b with carbon disulﬁde in the presence of potassium hy-

droxide in alcoholic solution followed by acidiﬁcation (Scheme 3). The

IR spectrum of the novel 5-(5-methyl-1-(4-(methylsulfonyl)phenyl)-1H-

pyrazol-4-yl)-1,3,4-oxadiazole-2(3H)-thione (8b) revealed a band at

2738 cm^{ꢀ 1}region attributed for SH group. The absence of a band

assignable for the carbonyl group at the 1625 cm^{ꢀ 1}region is evidence

1

was proved by the H NMR spectra which showed replacement of the

three deuterium exchangeable peaks of the three NH groups at the

carbothioamides 3a,b by one singlet deuterium exchangeable peak at δ

14.08 ppm indicating SH group. Their IR charts revealed absorption

bands at 2730, 2862 cm^{ꢀ 1}indicating the presence of the SH group.

S-methyl derivatives 5a,b were prepared using iodomethane as an

alkylating agent via stirring with a methanolic solution of triazoles 4a,b

1

for the cyclized form structure. Also, the H NMR spectrum displayed

only one deuterium exchangeable SH proton as a singlet signal at δ

3

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Scheme 1. Synthesis of compounds 5a,b.

14.69 ppm and the ¹³C NMR spectrum revealed new peaks at δ 157.13

and 176.95 ppm for C-2 and C-5 oxadiazole, respectively.

in absolute ethanol under reﬂux, and then intramolecular ring closure

was done to generate the target triazolothiadiazine compounds 11a-f in

good yields (82–90%). Their IR spectra revealed absorption bands at the

The 4-amino-1,2,4-triazole- 3-thione derivatives 9a,b were prepared

starting from the 1,3,4-oxadiazole derivatives 8a,b by treating them

with hydrazine hydrate under reﬂux. The structure of 9b was in agree-

ment with spectral and analytical data. Its IR spectrum of revealed sharp

absorption bands at 3433, 3316, and 2776 cm^{ꢀ 1}representing forked

NH₂and SH groups, respectively. Moreover, the singlet deuterium

exchangeable signal integrating two protons seen at δ 5.81 ppm in the ¹H

NMR spectrum conﬁrmed the presence of the NH₂group.

range of 1680–1688 cm^{ꢀ 1}corresponding to the C O group. The ¹H

–

NMR charts of the novel compounds 11a-f showed triplet peaks repre-

senting one proton at the range of 5.04–5.23 ppm and doublet peaks

integrating one proton at the range of 5.83–5.85 ppm indicating tri-

azolothiadiazine H-6 and H-7, respectively. Moreover, additional two

doublet peaks, integrating two protons for each, were found at the

ranges of 7.82–7.84 and 8.01–8.13 ppm of the ¹H NMR spectra repre-

senting aromatic protons of the bromophenyl ring.

A novel series of Schiff bases 10a-f were prepared, with an excellent

yield (85–94%), by the reaction of 4-amino-1,2,4-triazole-5-thiol de-

rivative 9a,b with different aryl aldehydes in reﬂuxing ethanol con-

2.2. Biological activity:

1

taining a few drops of glacial acetic acid as a catalyst. Their H NMR

spectra showed one singlet signal at the range of δ 9.61–9.93 ppm

attributed to N = CH. The ¹³C NMR spectra of the novel Schiff’s bases

10a-h showed a signal at the range of δ 161.56–161.68 ppm corre-

sponding to N = CH carbon.

2.2.1. In-vitro cyclooxygenase (COX-1/2) inhibition assays

Evaluation of all the synthesized pyrazole/ triazole hybrids 4a,b, 5a,

b, 7a,b, 9a,b, 10a-f, and 11a-f, indomethacin, and celecoxib for their

in-vitro inhibition of human COX-1 and COX-2 enzymes using colori-

metric enzyme immunoassay (EIA) kits was achieved to screen the

The newly synthesized Schiff’s bases 10a-f derivatives were

substituted by 4-bromophenacyl bromide using triethylamine as a base

isozyme-speciﬁc inhibition. Serial concentrations in the range (100 μM-

4

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Scheme 2. Synthesis of compounds 7a,b.

0.001

μ

M) were used for each compound in the assay kit to determine

safe gastric proﬁle than that of celecoxib. Among all compounds, the 4H-

1,2,4-triazole-3-thiol derivative 7a has the highest S.I. (27.57).

the minimum dose that makes 50% inhibition (IC₅₀) of both enzymes to

evaluate the effectiveness of the synthesized hybrids. Furthermore, the

COX-2 selectivity index (S.I.) values were calculated as [IC₅₀(COX-1)/

IC₅₀(COX-2)] and compared to the standard drugs: indomethacin as a

non-selective COX-inhibitor and celecoxib as a selective COX-2 inhibitor

to predict the gastrointestinal safety proﬁle of the newly synthesized

drug (Table 1).

2.2.2. In-vivo anti-inﬂammatory activity

2.2.2.1. Carrageenan-induced rat paw edema assay. To explore the anti-

inﬂammatory activity of the most promising compounds in COX-1 and

COX-2 inhibition assay, we employed a carrageen-induced rat foot paw

edema model for the most selective compounds 4b, 7a, 10e, 11c, and

11e using celecoxib as a reference drug. The efﬁcacy of the compounds

was expressed as the decrease in edema paw volume and calculated

edema inhibition percentage (EIP) after 1, 3, and 5 h of carrageenan

injection compared to the standard drug celecoxib (Table 2). The results

elicited that compounds 4b, 7a, 10e, 11c, and 11e showed EIP values

(35.62%, 44.52%, 43.83%, 39.04% and 35.31%, respectively) in com-

parison with reference drug celecoxib (EIP = 38.35%) after 1 h of

carrageenan injection. After 3 h, compounds 4b, 7a, 10e, 11c and 11e

resulted in inhibition by (47.92%, 63.31%, 59.17%, 54.56 and 52.89%,

respectively), while celecoxib inhibited the paw edema by 51.24%. After

5 h, all compound showed anti-inﬂammatory effects (EIP range 27.15%-

42.90%) exceeded that of celecoxib (EIP = 22.90%).

All the tested compounds inhibited COX-1 enzyme at higher con-

centrations (IC₅₀= 8.45–593.5 uM) than indomethacin (IC₅₀= 6.58 uM)

that would introduce compounds with good safety proﬁles. The 4H-

1,2,4-triazole-3-thiol derivative 7a displayed the lower afﬁnity towards

COX-1 enzyme inhibition with IC₅₀= 593.5

μM compared to that of

indomethacin (IC₅₀= 6.58 μM) and celecoxib (IC₅₀= 21.53 μM).

On the other hand, three of the synthesized compound 5b, 10b, and

11b revealed high potency towards COX-2 enzyme inhibition with IC₅₀

= 2.75, 3.60, and 2.94 μM, in order compared to celecoxib (IC₅₀= 3.33

μ

M). While most of the prepared compounds showed moderate potency

towards COX-2 enzyme inhibition with IC₅₀range (5.82–13.88 M). Six

of the prepared compounds 7a, 9a, 10c, 10d, and 11f were weak COX-2

inhibitors with IC₅₀range (19.58–36.38 M), relative to that of indo-

methacin (IC₅₀= 17.42 M) and celecoxib (IC₅₀= 3.33 M).

μ

Regarding COX-2 selectivity index values, most of the tested com-

pounds were more selective to COX-2 enzyme than COX-1, all of them

showed greater S.I. (0.71–27.57) than indomethacin (S.I. = 0.378). Four

compounds 4b, 7a, 10e, and 11c exhibited superior selectivity index

values (9.97, 27.56, 14.43, 9.05, respectively); than celecoxib (S.I. =

6.46), while compounds 10b, 11a, and 11e displayed selectivity to-

wards COX-2 enzyme (S.I. = 4.67, 5.49, and 6.13 in order) comparable

to that of celecoxib (Table 1).

2.2.2.2. Ulcerogenic liability. The ulcerogenic effect was detected for the

most selective compounds 4b, 7a, 10e, 11c, and 11e compared with

that of the reference drug celecoxib and ulcerogenic non-selective COX-

2 inhibitor indomethacin; using 50 mg/kg dose for three successive days

to ensure their gastrointestinal safety proﬁle. The obtained results are

shown in (Table 3). Our data showed that all tested compounds have less

ulceration effect than that of both reference drugs celecoxib and indo-

methacin as indicated by the smaller number of ulcers with ulcer index

range (U.I. = 2.17–6.93) when compared to that of celecoxib ((U.I. =

Accordingly, 4b, 7a, 10e, 11c, and 11e may be expected to have a

5

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Scheme 3. Synthesis of compounds 11a-f.

6.93) and indomethacin (U.I. = 20.25). The 4H-1,2,4-triazole-thiol de-

rivative 7a, the highest selective compound, was the least ulcerogenic

one (U.I. = 2.17). Also, the 4-phenyl-1,2,4-triazole derivative 4b and the

4-(benzylidene amino)-1,2,4-triazole-3-thiol derivative 10e showed

perfect ulcer index (3.13, 3.95, respectively) compared to that of cele-

coxib (U.I. = 6.93). On the other hand, the pyrazole/fused triazole hy-

brids 11c and 11e resulted in comparable ulcerogenicity (U.I. = 6.79,

6.19, in order) to that of celecoxib.

aiming to determine and compare the severity of lesions to those

induced by the standard drugs; celecoxib and indomethacin, and to the

lesions in the control negative group. Normal control rats showed

average superﬁcial mucosa with preserved mucous layer (black arrow)

with an average distribution of parietal cells (yellow arrow) (Figs. 3-1A);

another view in deep mucosa revealed average parietal cells (black

arrow), average chief cells (yellow arrow), and average muscularis

mucosa (blue arrow) (Figs. 3-2A).

On the other hand, Celecoxib administration showed superﬁcial

mucosal ulceration (black arrow) with loss of mucous layer (red arrow)

and mildly congested mucosal blood vessels (yellow arrow) (Figs. 3-1B);

another view indicated complete ulcer (black arrow) with intact

2.2.2.3. Stomach histopathological examination. Evaluating the ulcero-

genic effect of tested compounds on different stomach portions via

examination of variable histopathological lesions was carried out

6

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Table 1

Table 3

In-vitro COX-1/COX-2 inhibition result and S.I. of the newly synthesized pyr-

azole/ triazole hybrids, 4a,b, 5a,b, 7a,b, 9a,b, 10a-f, and 11a-f with celecoxib

and indomethacin as a reference drugs.

Ulcerogenic liability for the highest S.I. 4b, 7a, 10e, 11c, 11e and reference

drugs celecoxib and indomethacin.

Ulcer index

Ulcer no.

Compound no.

Compound

COX-1

COX-2

S.I.

3.13 ^a

2.17 ^a

3.95 ^a

6.79 ^a

6.19 ^a

6.93^b

20.25

5.12 ± 0.23 ^a,b

3.01 ± 0.15 ^a,b

4.34 ± 0.19 ^a,b

8.01 ± 0.28 ^a,b

7.36 ± 0.34 ^a,b

10.12 ± 0.37^b

13.0 ± 0.42

4b

IC₅₀(uM)^a

Ratio COX-1/COX-2^b

7a

10e

4a

9.668

82.26

22.19

10.58

593.5

34.73

47.49

13.1

13.62

8.247

13.88

2.752

21.53

36.38

28.04

9.056

10.78

3.6

0.709838

9.974536

1.598703

3.844477

27.56619

0.954645

1.693652

1.446555

1.076994

4.672222

3.171441

0.810521

14.4316

11c

4b

11e

5a

Celecoxib

Indomethacin

5b

7a

7b

Values represent means ± SE of 6 animals for each group.

9a

a

means the signiﬁcant difference from celecoxib,

9b

b

means the signiﬁcant difference from indomethacin (p < 0.05).

10a

11.61

16.82

70.85

15.87

107.4

20.87

73.28

8.454

52.72

31.04

75.86

31.34

21.53

6.589

10b

10c

22.34

19.58

7.442

25.61

13.33

2.946

5.82

In conclusion, celecoxib administration resulted in multiple com-

plete ulcers and superﬁcial mucosal erosions with intact muscularis

mucosa, excess parietal and average chief cells in deep mucosa, mildly

congested mucosa blood vessels, moderately edematous submucosa

with scattered inﬂammatory cells, and destructed musculosa.

10d

10e

10f

0.814916

5.497374

2.869654

9.058419

3.932599

6.13754

11a

11b

11c

While indomethacin administration viewed the edge of an ulcer with

necrotic tissue (black arrow), and viable area showing excess parietal

cells in superﬁcial mucosa (yellow arrow), and scattered inﬂammatory

inﬁltrate (red arrow) (Figs. 3-1C); another view showed the edge of an

ulcer with markedly necrotic tissue and marked inﬂammatory inﬁltrate

(black arrow), and viable area showing excess parietal cells in superﬁ-

cial mucosa (yellow arrow) (Figs. 3-2C); the view in the ﬂoor of an ulcer

showing marked inﬂammatory inﬁltrate (red arrow) and excess parietal

cells (yellow arrow), and thickened muscularis mucosa with scattered

inﬂammatory inﬁltrate (black arrow) (Figs. 3-3C); the view of the mu-

cosa adjacent to an ulcer revealed marked inﬂammatory inﬁltrate with

excess eosinophils (yellow arrow), thickened muscularis mucosa with

scattered inﬂammatory inﬁltrate (blue arrow), and edematous submu-

cosa with inﬂammatory inﬁltrate (red arrow) (Figs. 3-4C).

11d

7.893

12.36

28.63

3.332

17.42

11e

11f

1.094656

6.46

Celecoxib

Indomethacin

0.378243

a

The concentration of test compound produces 50% inhibition of COX-1,

COX-2 enzyme, the result is the mean of three values obtained by assay of

enzyme kits obtained from (cayman chemicals Inc., Ann Arbor, MI, USA) and the

deviation from the mean is < 10% of the mean value.

b

The in-vitro COX-2 selectivity index (COX-1/COX-2)

Table 2

In-vivo anti-inﬂammatory activity of the most selective compounds 4b, 7a, 10e,

11c, and 11e and the reference drug celecoxib.

In conclusion, indomethacin administration resulted in multiple

complete and perforating ulcers and superﬁcial erosions, marked in-

ﬂammatory inﬁltrate with granulation tissue formation in the ﬂoor of

ulcers, adjacent mucosa showed marked inﬂammatory inﬁltrate with

scattered eosinophils, excess parietal cells in adjacent mucosa and ﬂoor

of ulcers, markedly thickened muscularis mucosa with scattered in-

ﬂammatory cells, markedly edematous submucosa with moderate in-

ﬂammatory inﬁltrate and mildly dilated blood vessels, and average

musculosa.

Compound

No.

Mean value of paw edema

thickness (cm) SE

% of inhibition

1 h

3 h

5 h

1 h

35.62 ^a

3 h

47.92 ^a

5 h

4b

0.470

±

0.440

±

0.652

±

27.15

a,b

0.002*

0.405

±

0.026

0.310

±

0.031

0.511

±

7a

44.52 ^a,b

43.83 ^a,b

39.04 ^a

63.31 ^a,b

59.17 ^a,b

54.56 ^a

42.90

a,b

0.013*

0.410

±

0.008

0.345

±

0.030

0.533

±

10e

40.45

a,b

2.2.2.4. Scanning the stomach of the rats treated with the tested compounds

showed the following. For compound 4b: mild superﬁcial erosion (black

arrow), and excess parietal cells in superﬁcial mucosa (yellow arrow)

were indicated (Figs. 3-1D); another view in the superﬁcial mucosa

revealed excess parietal cells (black arrow), and average chief cells (red

arrow) (Figure‘3-2D); the deep mucosa view showed excess parietal

cells (black arrow), average chief cells (red arrow), mild inﬂammatory

inﬁltrate with scattered eosinophils (yellow arrow), and average mus-

cularis mucosa (blue arrow) (Figs. 3-3D).

0.022*

0.445

±

0.012

0.384

±

0.012

0.617

±

11c

31.06

a,b

0.012*

0.470

±

0.012

0.398

±

0.031

0.630

±

11e

35.31 ^a

52.89 ^a

29.60

a,b

0.090*

0.730

±

0.011

0.845

±

0.021

0.895

±

Carrageenan

Celecoxib

————

38.35 ^a

————

51.24 ^a

———

0.002

0.450

±

0.012

0.412

±

0.004

0.690

±

22.90

In conclusion, administration of the 4-phenyl-1,2,4-triazole-3-thiol

derivative 4a resulted in partial loss of mucous layer with mild super-

ﬁcial erosions, excess parietal cells in superﬁcial and deep mucosa with

average chief cells, mild inﬂammatory inﬁltrate in deep mucosa with

scattered eosinophils, average muscularis mucosa, and mildly edema-

tous submucosa with mild inﬂammatory inﬁltrate.

a

0.023

0.011

0.021

Values represent means ± SE of 3 animals for each group.

a

means the signiﬁcant difference from carrageenan,

b

means the signiﬁcant difference from celecoxib (p < 0.05).

For compound 7a: mild superﬁcial erosion with an average distri-

bution of parietal cells in superﬁcial mucosa (black arrow) were indi-

cated (Figs. 3-1E); another view in the superﬁcial mucosa indicated

average parietal cells (red arrow), and average chief cells (yellow arrow)

with few scattered inﬂammatory cells (black arrow) (Figs. 3-2E); the

view in the deep mucosa revealed the average distribution of parietal

cells (red arrow), average chief cells (yellow arrow), mild inﬂammatory

muscularis mucosa (red arrow), excess parietal cells in deep mucosa

(yellow arrow), and mildly edematous submucosa (blue arrow) (Figs. 3-

2B); Also the view in deep mucosa revealed excess parietal cells (black

arrow) with average chief cells (yellow arrow), intact muscularis mu-

cosa (red arrow) and mildly edematous submucosa (blue arrow) (Figs. 3-

3B).

7

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Fig. 3. Effects of celecoxib, indomethacin, and the highest selective compounds 4b, 7a, 10e, 11c, 11e, on the stomach histology (H & E X 400).

inﬁltrate with scattered eosinophils extending to muscularis mucosa

(black arrow) and mildly in edematous submucosa (blue arrow) (Figs. 3-

3E).

with superﬁcial erosions and excess parietal cells in superﬁcial and deep

mucosa of the gastric wall, average chief cells, average muscularis mu-

cosa, mildly edematous submucosa with mild inﬂammatory inﬁltrate,

and average musculosa.

In conclusion, administration of the 4H-1,2,4-triazole-3-thiol deriv-

ative 7a resulted in partial loss of mucous layer with mild superﬁcial

erosions, average distribution of parietal and chief cells in superﬁcial

and deep mucosa, mild inﬂammatory inﬁltrate in deep mucosa with

scattered eosinophils extending to muscularis mucosa and in mildly

edematous submucosa, and average musculosa.

For compound 11c: The view in the superﬁcial mucosa indicated

erosion (red arrow) with excess parietal cells in superﬁcial mucosa

(yellow arrow) (Figs. 3-1G); another view showed complete ulcer

reaching muscularis mucosa (red arrow), and the edge of ulcer showing

excess parietal cells (yellow arrow) (Figs. 3-2G); also mucosa with excess

parietal cells (black arrow) and marked inﬂammatory inﬁltrate in deep

mucosa (yellow arrow) and extending to the submucosa (red arrow)

were indicated (Figs. 3-3G).

For compound 10e: erosion (red arrow) with excess parietal cells in

superﬁcial mucosa (black arrow) in the superﬁcial mucosa appeared

(Figs. 3-1F); deep mucosa view indicated excess parietal cells (black

arrow), average chief cells (red arrow), and average muscularis mucosa

(blue arrow) (Figs. 3-2F); another view in deep mucosa showed excess

parietal cells (black arrow), average chief cells (red arrow), average

muscularis mucosa (blue arrow), and mildly edematous submucosa with

mild inﬂammatory inﬁltrate (green arrow) (Figs. 3-3F).

In conclusion, administration of compound 11c resulted in the loss of

mucous layer with perforating ulcers and superﬁcial erosions, excess

parietal cells in superﬁcial and deep mucosa, destructed muscularis

mucosa, markedly edematous submucosa, and marked d inﬂammatory

inﬁltrate in deep mucosa extending to muscularis mucosa and submu-

cosa, and markedly edematous musculosa in the gastric walls.

For compound 11e: The view in the superﬁcial mucosa

In conclusion, administration of the 4-benzylidene amino-1,2,4-

triazole-3-thiol derivative 10e resulted in partial loss of mucous layer

8

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Fig. 4. Effects of compound 7a and the reference drug celecoxib on the heart histology.

demonstrated healed erosion (black arrow), and adjacent mucosa

showing the average distribution of parietal cells (yellow arrow)

(Figs. 3-1H); another view in deep mucosa showed average parietal cells

(yellow arrow), and marked inﬂammatory inﬁltrate (red arrow)

extending to the submucosa (blue arrow) (Figs. 3-2H); also excess pa-

rietal cells (yellow arrow), mildly congested mucosal blood vessels (blue

arrow), average muscularis mucosa (red arrow), and mildly edematous

submucosa with mildly dilated congested blood vessels (black arrow)

were showed in deep mucosa (Figs. 3-3H).

2.2.3. Cardiovascular evaluation for compound 7a versus celecoxib:

2.2.3.1. Assessment of the cardiac function biomarkers and inﬂammatory

cytokines. It has been previously noted that celecoxib has cardio-toxicity

in experimental rats [29,30]. In the current study, the response of the

heart towards the most active and highest selective compound 7a; was

evaluated through assessment of the heart function biomarkers in sera,

including alkaline phosphatase (ALP), aspartate aminotransferase

(AST), Creatine kinase-MB (CK-MB), and lactate dehydrogenase (LDH),

In conclusion, administration of compound 11e resulted in an intact

mucous layer with healed superﬁcial erosions in the gastric wall, excess

parietal cells in deep mucosa, marked inﬂammatory inﬁltrate in deep

mucosa extending to the submucosa and mildly congested mucosal

blood vessels, average muscularis mucosa, mildly edematous submucosa

with mildly dilated congested blood vessels, and average musculosa.

as well as inﬂammatory cytokines named tumor necrosis factor-α (TNF-

α

), and Interleukin 6 (IL-6). Also, the study of changes of histopatho-

logical parameters of the evaluated compounds compared to celecoxib

as a reference standard was performed.

All the obtained results were shown in (Table 4). The results revealed

that the administration of celecoxib resulted in a signiﬁcant elevation in

the serum cardiac biomarkers levels of ALP, AST, CK-MB, and LDH

9

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Fig. 5. Binding interactions of the ligand SC-558 inside COX-2 active site. (A) 2D binding mode of the ligand SC-558 into the active site of COX-2 showing two H-

bonds with His 90 and Tyr 355 amino acids; (B) 3D ﬁtting of SC-558 into COX-2 active site pocket.

compared to normal control rats. On the other hand, the serum levels of

these biomarkers in the rats treated with compound 7a signiﬁcantly

lower than that of celecoxib treated rats. These results proved that

compound 7a has a much low risk of cardiovascular toxicity compared

to celecoxib. Furthermore, the serum levels of inﬂammatory cytokines

distinct cell borders (black arrow) and central oval\elongated nuclei

(blue arrow), and average blood vessels (yellow arrow) (Figs. 4-1C);

another view revealed scattered cardiac muscle ﬁbers with indistinct

cell borders (black arrow), bright eosinophilic cytoplasm and pyknotic

nuclei (blue arrow) (H & E X 400) (Figs. 4-2C)

TNF-

strated that celecoxib signiﬁcantly increased serum levels of both TNF-

and IL-6 in comparison with the normal rats. On the other side, the

α and IL-6 were assessed in rat sera. The results obtained demon-

α

2.3. Molecular docking

group of rats given compound 7a showed serum levels of TNF-α and IL-6

The docking study was carried out using Molecular Operating

Environment (MOE) (version 2015.10) as the computational software.

The X-ray crystallographic structure of murine COX-2 isoenzyme

completed with the ligand SC-558 (bromocelecoxib) (PDB ID: 1CX2),

was obtained from protein data bank (https://www.rcsb.org/struc

ture/1CX2) to investigate binding afﬁnities, modes, and interactions

of compounds towards the COX-2 receptor site. 1CX2 was selected due

to the structure similarity of the target compounds with the ligand SC-

558.

near to that of the normal control rat and much lower than that of the

celecoxib-treated rats, prooﬁng its protective cardiovascular activity.

2.2.3.2. Histopathological examination of the heart. Histopathological

examination of the heart muscle of the normal control group showed

viable cardiac muscle ﬁbers with distinct cell borders (black arrow) and

central oval\elongated nuclei (blue arrow), and average blood vessels

(yellow arrow) (Figs. 4-1A); another view indicated transverse section of

viable cardiac muscle ﬁbers with distinct cell borders (black arrow) and

central oval\elongated nuclei (blue arrow) (H & E X 400) (Figs. 4-2A).

On the contrary, the heart section obtained from rats exposed to

celecoxib showed viable cardiac muscle ﬁbers (black arrow), and

markedly congested blood vessels (blue arrow) with mild mono-nuclear

inﬁltrate (yellow arrow) (H & E X 200) (Figs. 4-1B); another view

revealed scattered apoptotic cardiac muscle ﬁbers (black arrow) and

others with edematous cytoplasm and pyknotic nuclei (blue arrow), and

markedly congested blood vessels (red arrow) (Figs. 4-2B); also, scat-

tered cardiac muscle ﬁbers with bright eosinophilic cytoplasm and

pyknotic nuclei (black arrow) were detected (Figs. 4-3B); moreover,

scattered cardiac muscle ﬁbers with indistinct cell border (black arrow)

and bright eosinophilic cytoplasm and pyknotic nuclei (blue arrow), and

markedly congested blood vessels (red arrow) with mild peri-vascular

edema (yellow arrow) (H & E X 400) were showed (Figs. 4-4B). In

conclusion, prolonged administration of celecoxib resulted in scattered

apoptotic cardiac muscle ﬁbers with distinct cell borders and central

oval\elongated nuclei, with edematous cytoplasm and pyknotic nuclei,

and markedly congested blood vessels in the heart muscle.

The crystal structure of the ligand SC-558 (bromocelecoxib) boun-

ded with COX-2 isoform is showed to form H-bond between His90 amino

acid and SO₂NH₂with a distance of 2.95 A^owhere it acts as a hydrogen

donor and H-bond between Tyr355 and N-2 of pyrazole ring with a

distance of 3.10 A^owhere it acts as a hydrogen acceptor (Fig. 5). The

energy score for SC-558 inside the COX-2 isoform was ꢀ 11.9919 Kcal/

mol.

It is worth mentioning that the secondary pocket found in the crystal

structure of COX-2 isoenzyme and responsible for selective COX-2 in-

hibition originates from the main channel that leads to COX active site

and is more accessible in COX-2 due to the replacement of Ilu523 amino

acid in COX-1 isoenzyme with Val523 amino acid in COX-2. The smaller

Val523 in addition to conformational changes at Tyr355 allows the

presence of the secondary hydrophobic pocket consists of Leu352,

Tyr355, Phe518, Val523, and Ser353 amino acids that interact with

phenylsulfonamide moiety of SC-558 ligand. Furthermore, His513 and

Ser516 amino acids in COX-1 are replaced with Arg513 and Ala516 in

COX-2 which were reported to play a role in COX-2 selective inhibition

[10].

Alternatively, cardiac histopathological examination of the 4H-

1,2,4-triazole-3-thiol derivative 7a treated group revealed little or no

toxic effects on the heart and showed viable cardiac muscle ﬁbers with

Molecular docking simulation for the most selective compounds 4b,

7a, 10e, 11c, and 11e in the COX-2 isoenzyme was established to gain

more insights into the probable nature of their respective binding with

10

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Fig. 6. A): 3D visualization of the new pyrazole / free triazole hybrids 4b (in purple color), 7a (in green color), and 10e (in brown color) overlaid in the COX-2 active

site indicating nice ﬁtting in the pocket. B): 2D binding mode of compound 4b in the COX-2 active site showing one H-bond interaction with His90 amino acid and

one

and one

Arg120 and one

π-H interaction with Ser353 amino acid. C): 2D binding mode of compound 7a in the COX-2 active site showing two H-bond interactions with His90 and Gln192

π

-H interaction with Ser353 amino acid. D): 2D binding mode of compound 10e in the COX-2 active site showing two H-bond interactions with His90 and

π-H interaction with Leu531 amino acid.

the active site residues. Docking scores, amino acid residues responsible

for the interaction between the synthesized pyrazole/triazole hybrids

and the active site, and the lengths of these interactions were summa-

rized in (Table 5).

the new compounds could be attributed to their large molecular volumes

that allowed them also to occupy more space in the hydrophobic pocket

(Fig. 7a). In addition to the formation of H-bonds with the key amino

acids Arg120, Ser530, and Ala516 are reported to be essential for

selectivity. The 2D binding modes of compounds 11c and 11e showing

different types of interactions were provided in (Fig. 7b and c).

In conclusion, the impact of different substituents in the prepared

triazole derivatives 4–11 on the anti-inﬂammatory activity, COX-2

selectivity, and mode of binding of COX-2 active site were summa-

rized based on the biological results (Fig. 8).

The results of the docking study revealed perfect ﬁtting of the most

selective pyrazole / free triazole hybrids 4b, 7a, and 10e into the active

site of COX-2 enzyme (Fig. 6a) Molecular docking analyses of these

compounds revealed the formation of an important H-bond interaction

with His90. Moreover, the three compounds exhibited hydrophobic π-H

interactions with the key amino acids Ser353 and Leu531 in the active

site pocket. The 2D binding modes of compounds 4b, 7a, and 10e

showing different types of interactions were provided in (Fig. 6b, 6c,

6d).

2.4. ADME proﬁling

The new pyrazole / fused triazole hybrids 11c and 11e exhibited

higher afﬁnities (SE = -18.7027 and ꢀ 17.0581 kcal/mol) compared to

the reference SC-558 (SE = -11.9919 kcal/mol). The higher afﬁnities of

It is known that the absorption, distribution, metabolism, and

excretion (ADME) properties of a molecule are one of the fundamental

causes of its washout in clinical trials during drug development [31,32].

11

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Fig. 7. A): 3D visualization of the new pyrazole / fused triazole hybrids 11c (in purple color) and 11e (in blue color) overlaid in the COX-2 active site indicating their

ﬁtting in the pocket. B): 2D binding mode of compound 11c in the COX-2 active site showing one H-bond interaction with Arg120 amino acid and one -H interaction

with Ser353 amino acid. C): 2D binding mode of compound 11e in the COX-2 active site showing two H-bond interactions with Ser530 and Ala516 amino acids and

one -H interaction with Ser353 amino acid.

π

Whilst the spectrum of in-vitro and in-vivo anti-inﬂammatory activity,

ulcerogenicity, and cardioprotective effects associated with some of the

synthesized compounds are promising, it should be further checked

whether these compounds have the required bioavailability.

than 140 Å²and more than ten rotatable bonds are thought to have low

oral bioavailability [35,36].

The most selective 1, 2, 4-triazole-3-thiol derivatives 4b, 7a, and 10e

fulﬁlled all Lipinskis’ rules, similar to the clinically used drug celecoxib,

including molecular weight range (257.31–468.55 Da) compared to

molecular weight of celecoxib = 381.73 Da, only one hydrogen bond

donor group similar to that in celecoxib, hydrogen bond acceptors

ranging from (3–6) compared to seven hydrogen bond acceptors in

celecoxib, and MlogP values (2.01–2.80) compared to 2.65 in celecoxib.

Also, tested compounds 4b, 7a, and 10e showed the number of

rotatable bond values (2–6) compared to 4 rotatable bonds in celecoxib,

indicating acceptable molecular ﬂexibility with consequent expected

good permeability and oral bioavailability. Additionally, the evaluated

compounds 4b and 7a, showed TPSA (<140 Å²) 126.04 and 98.19 Å²,

respectively, compared to TPSA value 86.36 Å²in celecoxib, indicating

good permeability and transport of the compounds in the cellular

plasma membrane. While compound 10e showed TPSA slightly 147.63

Å²higher than the ideal reported range 140 Å². Moreover, the

bioavailability scores for the free triazole derivatives 4b, 7a, and 10e

were 0.55, similar to that of celecoxib, which means that all ligands

The physicochemical properties of the most selective compounds 4b,

7a, 10e, 11c, and 11e and the reference drug celecoxib were assessed

using the SwissADME free web tool, developed by the Molecular

Modeling Group of the Swiss Institute of Bioinformatics [33] (Table 6).

In particular, we calculated the compliance of compounds to tradi-

tional Lipinski’s ‘‘rule of ﬁve” which indicates if a chemical substance

can be orally active in humans by estimating molecular properties which

are important for drug’s pharmacokinetics [34]. This simple rule states

that orally active drug has no more than one violation of the following

criteria: molecular weight (MW) less than 500 Da; no more than ﬁve

hydrogen bond donors (HBD); no more than 10 hydrogen bond accep-

tors (HBA); and calculated octanol–water partition coefﬁcient (c logP)

not greater than 5 (or MlogP not greater than 4.15) [34]. Also, topo-

logical polar surface area (TPSA) and the number of rotatable bonds are

other critical properties that have been linked to the drug bioavailability

[29,30]. The reports suggested that compounds with a TPSA of more

12

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

Fig. 8. SAR of the most selective pyrazole / triazole hybrids 4b, 7a, 10e, 11c and 11e indicating their COX-2 selectivity anti-inﬂammatory activity, and their mode

of binding in the docking study.

reach the systemic circulation.

Table 4

On the other hand, the most selective triazolothiadiazine derivatives

Cardiac effects of 7a and the reference drug celecoxib.

11c and 11e were violated from Lipinski’s rule of ﬁve by two repre-

IL-6

(pg/

ml)

TNF-

α

LDH

CK-MB

(IU/L)

AST

ALP

Compound

sented by molecular weight (589.94 and 663.61 D, respectively) and

MlogP values (6.46 and 4.55, respectively), that’s why these tri-

azolothiadiazine derivatives have lower bioavailability score (0.17)

compared to that of the reference drug celecoxib (0.55). However, the

tested triazolothiadiazines 11c and 11e showed acceptable TPSA values

(85.86 and 137.61, respectively) and rotatable bonds numbers (5 and 7,

respectively).

(pg/ml)

(IU/L)

6.75 ±

0.03

2.44 ±

0.01

134 ±

12.35

102 ±

6.72

35.3 ±

1.21

65 ±

2.15

Normal

8.67 ±

4.3 ±

315 ±

236 ±

58.3 ±

136 ±

Celecoxib

0.03

0.07 ^a

12.17 ^a

10.11 ^a

3.15 ^a

6.25 ^a

a

7.41 ±

2.7 ±

148 ±

129 ±

37.4 ±

79 ±

7a

In conclusion, ADME studies support the discovery of the prepared 1,

2, 4-triazoles 4b, 7a, and 10e as active oral bio-available anti-inﬂam-

matory candidates. However, the triazolothiadiazine 11c and 11e de-

rivatives have less oral bioavailability than the reference standard

celecoxib.

0.31^b

0.05^b

9.01 ^a

5.98 ^a,b

1.67^b

3.36^b

Values represent means ± SE of 6 animals for each group.

a

means the signiﬁcant difference from normal control rats,

b

means the signiﬁcant difference from celecoxib (p < 0.05).

13

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

4. Experimental protocols

Table 5

Molecular data outcomes from modeling of prepared compounds and SC-558

during docking in the COX-2 active site:

Compound

4.1. Chemistry

Docking

score

Main

Functional group

Type of

residue

Distance

interaction

Melting points were determined on a Grifﬁn apparatus and are un-

corrected. Infrared (IR) spectra were recorded as ﬁlms on KBr disc using

a Nicolet 550 Series II Magna FT-IR spectrometer. ¹H NMR and ¹³C NMR

spectra were measured on a Bruker Avance III 400 MHz (Bruker AG,

Switzerland) with BBFO Smart Probe and Bruker 400 AEON Nitrogen-

Free Magnet, Faculty of Pharmacy, Mansoura University, Egypt using

DMSO‑d₆as a solvent and TMS as the internal standard, where J

(coupling constant) values were estimated in Hertz (Hz) and chemical

shifts were recorded in ppm on δ scale. Mass spectra (MS) were deter-

mined on Hewlett Packard 5988 spectrometer at the regional center for

mycology & biotechnology, Al-Azhar University, Egypt. Microanalyses

for C, H, and N were carried out on Perkin-Elmer 2400 analyzer (Perkin,-

Elmer, Norwalk, CT, USA) at the regional center for mycology &

biotechnology, Al-Azhar University, Egypt, and all compounds were

within ± 0.4% of the theoretical values. Progress of the reactions was

monitored using thin-layer chromatography (TLC) sheets that were

precoated with UV ﬂuorescent silica gel MERCK 60F 254 that was

visualized by the UV lamp. The solvent system was chloroform: meth-

anol (in different ratios). All chemicals purchased from the Aldrich

Chemical Company (Milwaukee, WI), were used without further puri-

ﬁcation. Compounds 1a [27], 1b [28], 2a [37], 8a, [38] and 9a [37]

were prepared according to a reported procedures.

(Kcal/

mol)

○

(A )

SC-558

4b

ꢀ 11.9919

ꢀ 14.7129

ꢀ 11.3604

His90

SO₂NH₂

H-bond

(2.95)

Tyr355

(3.10)

His90

N-2 pyrazole

SO₂

H-bond

(3.27)

Ser353

(3.75)

His90

Pyrazole ring

π-H

7a

SH

H-bond

(4.05)

Gln192

(3.12)

Ser353

(3.56)

His90

SH

Triazole ring

π-H

10e

ꢀ 17.9317

C-3

H-bond

(3,72)

Arg120

(2.85)

Leu531

(3.90)

Arg120

(2.89)

Ser353

(4.18)

Ser530

(3.64)

Ala516

(3.16)

Ser353

(3.90)

methylsulfonylphenyl

N-1 triazole

Triazole ring

π-H

–

11c

11e

ꢀ 18.7027

ꢀ 17.0581

C

–

O

H-bond

-H

Triazole ring

π

Procedure for the synthesis of pyrazole-4-carbohydrazide 2b: A

mixture of the pyrazole ester 1b (0.005 mol, 1.54 g) and hydrazine

hydrate 99% (15 mL) was heated under reﬂux for 16 h then cooled at

room temperature. The formed solid was ﬁltered, dried, and crystallized

from aqueous ethanol 95% to give 2b. Yield of (87%); white crystals; m.

p. 175–177 ^◦C; R_f= 0.15 (chloroform: methanol = 9.7 : 0.3); (IR (KBr):

S-triazolothiadiazine

SO₂

H-bond

Pyrazole ring

π-H

–

3432 (NH), 3296, 3265 (forked, NH ), 1625 (C O), 1412, 1146 (SO ).

–

2

¹H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.62 (s, 3H, CH₃-pyrazole); 3.32

(s, 3H, SO₂CH₃); 4.41 (s, 2H, D₂O exchangeable, NH₂); 7.86 (d, J = 8.4

Hz, 2H, methylsulfonylphenyl H-3, H-5); 8.10 (d, J = 8.4 Hz, 2H,

methylsulfonylphenyl H-2, H-6); 8.14 (s, 1H, pyrazole H-3), 9.47 (s, 1H,

D₂O exchangeable, NH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.05

3. Conclusion

Novel series of pyrazole/ triazole thione hybrids(4a,b, 5a,b, 7a,b,

9a,b, and 10a-f) and fused triazoles (11a-f) were synthesized and

evaluated against both COX-1 and COX-2 enzymes as selective COX-2

inhibitors. The in-vivo anti-inﬂammatory biological results of the most

selective compounds 4b, 7a, 10e, 11c, and 11d showed that all the

tested compounds revealed higher anti-inﬂammatory activity with

lower ulcerogenicity than celecoxib. Regarding the cardiovascular sys-

tem, the evaluation result conﬁrmed that 7a is a perfect cardio-

protective agent in contrast to the reference drug celecoxib. This was

proved via decreasing the cardiac diagnostic biomarkers of myocardial

damage, including ALP, AST, CK-MB, and LDH levels, and decreasing

(CH₃-pyrazole), 43.90 (SO₂CH₃), 115.48 (C-4 pyrazole), 125.86,

+

–

128.79, 140.06, 140.34, 142.26, 143.06, 163.12 (C O). MS m/z (ES ):

295.19 (M⁺+1, 9.82), 294.11 (M^+., 41.83). Anal. Calcd. for:

C

₁₂H₁₄N₄O₃S: C, 48.97; H, 4.79; N, 19.04; Found; C, 48.78; H, 4.98; N,

19.25.

General procedure for the synthesis of N-phenylhydrazine-1-

carbothioamide derivatives 3a,b: A mixture of appropriate acid hy-

drazide 2a or 2b (0.01 mol) and phenyl isothiocyanate (0.012 mol, 1.62

g) in absolute ethanol (15 mL) was heated under reﬂux for 15 h in the

presence of triethylamine (5 drops). The formed precipitate was

collected by ﬁltration while hot and crystallized from aqueous ethanol

the inﬂammatory markers TNF-α and IL6.

Table 6

The calculated parameters for ADME studies of celecoxib and the newly synthesized compounds 4b, 7a, 10e, 11c, and 11e using the SwissADME server.

Cmpound no

MW^a

HBD^b

HBA^c

MlogP^d

ROTB^e

TPSA^f

violations

BS^g

4b

411.5

1

4

3

6

3

6

7

2.80

2.01

2.29

6.46

4.55

2.65

4

2

6

5

7

4

126.04

98.19

0

2

0

0.55

0.17

0.55

7a

257.31

468.55

589.94

663.61

381.73

10e

147.63

85.86

11c

11e

137.61

86.36

Celecoxib

a

Molecular weight.

b

Number of hydrogen bond donors.

Number of hydrogen bond acceptors.

Partition coefﬁcient (lipophilicity)

Number of rotatable bonds.

c

d

e

f

Topological polar surface area.

Bioavailability score.

g

14

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

95% to give the target compound 3a,b.

mol) and sodium metal (0.012 mol, 0.027 g) in absolute ethanol (15 mL)

were stirred at room temperature for 30 min, then methyl iodide (0.015

mol, 2.13 g) was added. The reaction mixture was stirred at room

temperature for 3 h, then the formed salt was ﬁltered off and the ﬁltrate

was evaporated under the vaccum. The residue was crystalized from

methanol to afford the target compounds 5a,b.

2-(5-Methyl-1-phenyl-1H-pyrazole-4-carbonyl)-N-phenyl-

hydrazine-1-carbothioamide (3a): Yield (78%); white solid; m.p.

◦

220–222 C; R_f= 0.31 (chloroform : methanol = 9.7 : 0.3); IR (KBr):

1

–

3261, 3192 (3 NH), 1659 (C O), 1280 (C S). H NMR (DMSO‑d , 400

–

6

MHz, δ ppm): 2.55 (s, 3H, CH₃); 7.17 (t, J = 7.6 Hz, 1H, phenyl-

isothiocyanate H-4); 7.34 (t, J = 7.6 Hz, 2H, phenylisothiocyanate H-3,

H-5); 7.47–7.60 (m, 7H, phenylisothiocyanate H-2, H-6, and phenyl H-2,

H-3, H-4, H-5, H-6); 8.22 (s, 1H, pyrazole H-3); 9.70 (s, 1H, D₂O

exchangeable, NH); 9.81 (s, 1H, D₂O exchangeable, NH); 10.22 (s, 1H,

D₂O exchangeable, NH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.06

(CH₃), 113.98 (pyrazole C-4), 125.49, 125.70, 126.42, 128.41, 128.95,

3-(5-Methyl-1-phenyl-1H-pyrazol-4-yl)-5-(methylthio)-4-

phenyl-4H-1,2,4-triazole (5a): Yield (49%); white cystals; m.p.

197–199 ^◦C; R_f= 0.72 (chloroform: methanol = 9.7 : 0.3);IR (KBr):

1

–

3067, 3047 (CH aromatic), 2925 (CH aliphatic), 1594 (C N). H NMR

–

(DMSO‑d₆, 400 MHz, δ ppm): δ 2.62 (s, 3H, CH₃); 3.37 (s, 3H, SCH₃);

6.88 (s, 1H, pyrazole H-3); 7.46–7.64 (m, 10H, phenyl and phenyl-

isothiocyanate H-2, H-3, H-4, H-5, H-6). ¹³C NMR (DMSO‑d₆, 100 MHz, δ

ppm): 12.34 (CH₃), 39.16 (SCH₃), 108.04 (pyrazole C-4), 125.35,

128.33, 128.81, 129.80, 130.57, 130.85, 134.03, 138.16, 139.09,

139.98, 149.87 (triazole C-3), 152.05 (triazole C-5). Anal. Calcd. for:

–

129.83, 139.03, 139.72, 140.16, 142.91, 163.12 (C O), 181.71 (C S).

Anal. Calcd. for: C₁₈H₁₇N₅OS: C, 61.52; H, 4.88; N, 19.93; Found; C,

61.73; H, 5.02; N, 19.86.

2-(5-Methyl-1-(4-(methylsulfonyl)phenyl)-1H-pyrazole-4-

carbonyl)-N-phenylhydrazine-1-carbothioamide (3b): Yield (70%);

white solid; m.p. 125–127 ^◦C; R_f= 0.25 (chloroform : methanol = 9.7 :

C

₁₉H₁₇N₅S: C, 65.68; H, 4.93; N, 20.16; Found; C, 65.88; H, 5.11; N,

19.95.

–

0.3); IR (KBr): 3280, 3254, 3196 (3 NH), 1678 (C O), 1405, 1147 (SO )

3-(5-Methyl-1-(4-(methylsulfonyl)phenyl)-1H-pyrazol-4-yl)-5-

2

1

–

1294 (C S). H NMR (DMSO‑d , 400 MHz, δ ppm): 2.65 (s, 3H, CH );

(methylthio)-4-phenyl-4H-1,2,4-triazole (5b): Yield (65%); white

–

3.33 (s, 3H, SO₂CH₃); 7.17 (t, J⁶= 7.2 Hz, 1H, phenylisothiocyanate ³H-

4); 7.35 (t, J = 7.2 Hz, 2H, phenylisothiocyanate H-3, H-5); 7.42–7.61

(m, 2H, phenylisothiocyanate H-2, H-6); 7.88 (d, J = 8.4 Hz, 2H,

methylsulfonylphenyl H-3, H-5); 8.13 (d, J = 8.4 Hz, 2H, methyl-

sulfonylphenyl H-2, H-6); 8.30 (s, 1H, pyrazole H-3), 9.73 (s, 1H, D₂O

exchangeable, NH); 9.83 (s, 1H, D₂O exchangeable, NH); 10.29 (s, 1H,

D₂O exchangeable, NH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.20

(CH₃-pyrazole), 43.92 (SO₂CH₃), 114.86 (pyrazole C-4), 125.97,

crystals; m.p. ^◦C; R_f= 0.59 (chloroform: methanol = 9.7 : 0.3);IR (KBr):

–

3098 (CH aromatic), 2997, 2917 (CH aliphatic), 1592 (C N), 1402,

1

1147 (SO₂). H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.62 (s, 3H, CH₃);

3.33 (s, 3H, SCH₃); 3.54 (s, 3H, SO₂CH₃); 7.22 (t, J = 8 Hz, 1H, phenyl H-

4); 7.44 (t, J = 8 Hz, 2H, phenyl H-2, H-6); 7.54–7.56 (d, J = 7.6 Hz, 2H,

phenyl H-3, H-5); 7.91 (d, J = 8 Hz, 2H, methylsulfonylphenyl H-3, H-5);

8.12 (d, J = 8 Hz, 2H, methylsulfonylphenyl H-2, H-6); 8.13 (s, 1H,

pyrazole H-3). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.29 (CH₃),

38.70 (SCH₃), 43.88 (SO₂CH₃), 107.64 (pyrazole C-4), 122.77, 125.45,

125.78, 128.89, 129.60, 139.71, 139.93, 140.46, 142.79, 143.04,

154.39 (triazole C-5), 162.27 (triazole C-3). MS m/z (ES⁺): 425.02 (M^+.,

9.77). Anal. Calcd. for: C₂₀H₁₉N₅O₂S₂: C, 56.45; H, 4.50; N, 16.46;

Found; C, 56.60; H, 4.27; N, 16.79.

126.45, 128.45, 128.88, 129.17, 139.70, 140.45, 141.10, 142.89,

143.51, 162.89 (C O), 181.76 (C S). MS m/z (ES ): 430.25 (M^+.+ 1,

+

–

5.51), 429.53 (M^+., 18.66). Anal. Calcd. for: C₁₉H₁₉N₅O₃S₂: C, 53.13; H,

4.46; N, 16.31; Found; C, 53.50; H, 4.24; N, 15.98.

General procedure for the synthesis of 4-phenyl-1,2,4-triazole-

3-thiol derivatives 4a,b: A stirring mixture of the carbothioamide de-

rivative 3a or 3b (0.01 mol) and potassium hydroxide (0.01 mol, 0.56 g)

in methanol (30 mL) was heated under reﬂux for 24 h. After cooling, the

solution was acidiﬁed with hydrochloric acid and the precipitate was

ﬁltered, dried, and crystallized from aqueous ethanol 95% to obtain

pure triazole-3-thiol derivatives 4a,b.

General procedure for the synthesis of 2-(5-methyl-1-phenyl-

1H-pyrazole-4-carbonyl)hydrazine-1-carbothioamide derivatives

6a,b: A mixture of pyrazole hydrazide 2a or 2b (0.01 mol), ammonium

thiocyanate (0.03 mol, 2.3 g), and hydrochloric acid (2 mL) in iso-

propanol (30 mL) was heated under reﬂux for 10 h. The solvent was

evaporated under vacuum; the residue obtained was stirred with

crushed ice. The resulted precipitate was ﬁltered off, dried, and crys-

tallized from aqueous ethanol 95% to obtain compounds 6a,b.

2-(5-Methyl-1-phenyl-1H-pyrazole-4-carbonyl)hydrazine-1-car-

bothioamide (6a): Yield (68%); white solid; m.p. 285–287 ^◦C; R_f= 0.41

5-(5-Methyl-1-phenyl-1H-pyrazol-4-yl)-4-phenyl-4H-1,2,4-tri-

azole-3-thiol (4a): Yield (72%); white crystals; m.p. 246–248 ^◦C; R_f=

1

0.55 (chloroform: methanol = 9.7:0.3); IR (KBr): 2730 (SH). H NMR

(DMSO‑d₆, 400 MHz, δ ppm): 2.48 (s, 3H, CH₃); 6.79(s, 1H, pyrazole H-

3); 7.49–7.65 (m, 10H, phenyl and phenylisothiocyanate H-2, H-3, H-4,

H-5, H-6); 14.08 (s, 1H, D₂O exchangeable, SH). ¹³C NMR (DMSO‑d₆,

100 MHz, δ ppm): 12.39 (CH₃), 107.37 (pyrazole C-4), 125.47, 128.94,

129.43, 129.57, 129.86, 130.06, 135.03, 138.36, 138.92, 140.44,

146.15 (triazole C-5), 168.14 (triazole C-3). Anal. Calcd. for: C₁₈H₁₅N₅S:

C, 64.84; H, 4.53; N, 21.01; Found; C, 65.03; H, 4.78; N, 21.23.

5-(5-Methyl-1-(4-(methylsulfonyl)phenyl)-1H-pyrazol-4-yl)-4-

phenyl-4H-1,2,4-triazole-3-thiol (4b): Yield (70%); white crystals; m.

p. 170–172 ^◦C; R_f= 0.42 (chloroform: methanol = 9.7 : 0.3); IR (KBr):

(chloroform: methanol = 9.3 : 0.7); IR (KBr): 3481, 3390, 3263 (NH₂, 2

1

–

NH), 1685 (C O), 1276 (C S). H NMR (DMSO‑d , 400 MHz, δ ppm):

–

6

2.52 (s, 3H, CH₃); 7.48–7.61 (m, 5H, phenyl H-2, H-3, H-4, H-5, H-6);

7.89 (s, 2H, D₂O exchangeable, NH₂); 8.16 (s, 1H, pyrazole H-3); 9.33 (s,

1H, D₂O exchangeable, NH); 10.08 (s, 1H, D₂O exchangeable, NH). ¹³

C

NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.01 (CH₃), 113.89 (pyrazole C-4),

–

125.68, 128.91, 129.81, 139.05, 140.03, 142.79, 162.82 (C O), 182.73

(C S). MS m/z (ES ): 276.82 (M + 1, 5.85), 275.35 (M^+., 10.98).

+

+.

–

Anal. Calcd. for: C₁₂H₁₃N₅OS: C, 52.35; H, 4.76; N, 25.44; Found; C,

1

2862 (SH), 1425, 1147 (SO₂). H NMR (DMSO‑d₆, 400 MHz, δ ppm):

52.50; H, 4.98; N, 25.69.

2.71 (s, 3H, CH₃); 3.33 (s, 3H, SO₂CH₃); 7.00 (t, J = 7.6 Hz, 1H, phenyl

H-4); 7.36 (t, J = 7.6 Hz, 2H, phenylisothiocyanate H-3, H-5); 7.62 (d, J

= 7.6 Hz, 2H, phenylisothiocyanate H-2, H-6); 7.94 (d, J = 8.4 Hz, 2H,

methylsulfonylphenyl H-3, H-5); 8.13 (d, J = 8.4 Hz, 2H, methyl-

sulfonylphenyl H-2, H-6); 8.16 (s, 1H, pyrazole H-3), not detected (SH).

¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.47 (CH₃), 43.87 (SO₂CH₃),

107.58 (pyrazole C-4), 117.44, 122.09, 125.83, 128.91, 129.55, 139.43,

139.66, 140.19 (pyrazole C-5), 140.59 (pyrazole C-3), 142.86, 155.57

(triazole C-5), 159.57 (triazole C-3). MS m/z (ES⁺): 411.05 (M^+., 3.71).

Anal. Calcd. for: C₁₉H₁₇N₅O₂S₂: C, 55.46; H, 4.16; N, 17.02; Found; C,

55.21; H, 3.99; N, 17.08.

2-(5-Methyl-1-(4-(methylsulfonyl)phenyl)-1H-pyrazole-4-

carbonyl)hydrazine-1-carbothioamide (6b): Yield (57%); white

solid; m.p. 275–277 ^◦C; R_f= 0.36 (chloroform: methanol = 9.3 : 0.7); IR

–

(KBr): 3375, 3347 (forked, NH ), 3262, 3176 (2 NH), 1683 (C O), 1293

2

1

–

(C S), 1402, 1146 (SO ). H NMR (DMSO‑d , 400 MHz, δ ppm): 2.62 (s,

3H, CH₃); 3.32 (s, 3H, ²SO₂CH₃); 7.64 (s, 2H, D₂O exchangeable NH₂);

7.87 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl H-3, H-5); 8.11 (d, J =

8.4 Hz, 2H, methylsulfonylphenyl H-2, H-6); 8.23 (s, 1H, pyrazole H-3),

9.35 (s, 1H, D₂O exchangeable, NH); 10.14 (s, 1H, D₂O exchangeable,

NH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.13 (CH₃), 43.90

(SO₂CH₃), 114.76 (pyrazole C-4), 125.93, 128.87, 140.50, 141.10,

6

–

General procedure for the synthesis of 5-(methylthio)-4-phenyl-

1,2,4-triazole derivatives 5a,b: A triazole derivatives 4a or 4b (0.01

142.89, 143.39, 162.58 (C O), 182.68 (C S). Anal. Calcd. for:

–

C

₁₃H₁₅N₅O₃S₂: C, 44.18; H, 4.28; N, 19.82; Found; C, 44.05; H, 4.53; N,

15

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

19.96.

128.86, 140.46, 141.02, 143.02, 145.63 (triazole C-5), 166.37 (triazole

C-3). MS m/z (ES⁺): 351.18 (M^+.+ 1, 20.52), 350.16 (M^+., 67.10). Anal.

Calcd. for: C₁₃H₁₄N₆O₂S₂: C, 44.56; H, 4.03; N, 23.98; Found; C, 44.70;

H, 3.84; N, 24.05.

General method for the synthesis of 4H-1,2,4-triazole-3-thiol

derivatives 7a,b: A mixture of the appropriate thiosemicarbazides 6a

or 6b (0.005 mol) and potassium hydroxide (0.01 mol, 0.56 g) in

aqueous ethanol 95% (40 mL) was heated under reﬂux for 36 h. Then

after completion of the reaction, the resulting solution was poured into

ice water, HCl (37%) was added drop by drop to the mixture, the formed

white crude product was ﬁltered, dried, and crystallized from acetic acid

to give compounds 7a,b.

General procedure for the preparation of (E,Z)-4-(benzylidene

amino)-1,2,4-triazole-3-thiol derivatives 10a-h: A mixture of com-

pound 9a or 9b (0.01 mol), appropriate aromatic aldehydes (0.01 mol)

and glacial acetic acid (0.5 mL) in absolute ethanol (25 mL) was heated

under reﬂux for 12–24 h. The resulting solid was ﬁltered while hot, and

puriﬁed by washing with hot aqueous ethanol 95% to get the target

compounds 10a-f.

5-(5-Methyl-1-phenyl-1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-

thiol (7a): Yield (65%); white cystals; m.p. 190–192 ^◦C; R_f= 0.75

(chloroform: methanol = 9.3 : 0.7); IR (KBr): 3433 (NH), 2661 (SH). ¹H

NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.52 (s, 3H, CH₃); 7.50–7.57 (m, 5H,

H-2, phenyl H-3, H-4, H-5, H-6); 8.17 (s, 1H, pyrazole H-3); 13.58 (s, 1H,

D₂O exchangeable, NH); 13.66 (s, 1H, D₂O exchangeable, SH). ¹³C NMR

(DMSO‑d₆, 100 MHz, δ ppm): 12.40 (CH₃), 107.68 (pyrazole C-4),

125.57, 128.92, 129.79, 138.95, 139.07, 139.10, 146.14 (triazole C-5),

166.14 (triazole C-3). MS m/z (ES⁺): 258.32 (M^+.+ 1, 8.77), 257.13

(M^+., 28.29). Anal. Calcd. for: C₁₂H₁₁N₅S: C, 56.01; H, 4.31; N, 27.22;

Found; C, 55.87; H, 4.60; N, 27.40.

(E,Z)-4-(Benzylideneamino)-5-(5-methyl-1-phenyl-1H-pyrazol-

4-yl)-4H-1,2,4-triazole-3-thiol (10a): Yield (87%); white cystals; m.p.

◦

272–274 C; R_f= 0.59 (chloroform: methanol = 9.5 : 0.5); IR (KBr):

1

2763 (SH). H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.53 (s, 3H, CH₃);

7.51–7.67 (m, 8H, phenyl H-2, H-3, H-4, H-5, H-6, benzaldehyde H-3, H-

4, H-5); 7.97 (d, J = 7.2 Hz, 2H, benzaldehyde H-2, H-6); 8.10 (s, 1H,

pyrazole H-3); 9.85 (s, 1H, CH = N); 14.17 (s, 1H, D₂O exchangeable,

SH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.58 (CH₃), 106.87 (pyr-

azole C-4), 125.65, 128.98, 129.23, 129.79, 129.82, 132.50, 133.36,

139.09, 139.99, 140.39, 144.84 (triazole C-5), 161.58 (CH = N), 166.35

(triazole C-3). Anal. Calcd. for: C₁₉H₁₆N₆S: C, 63.31; H, 4.47; N, 23.32;

Found; C, 63.07; H, 4.45; N, 23.38.

5-(5-Methyl-1-(4-(methylsulfonyl)phenyl)-1H-pyrazol-4-yl)-4H-

1,2,4-triazole-3-thiol (7b): Yield (68%); white solid; m.p. 217–219 ^◦C;

R_f= 0.62 (chloroform: methanol = 9.3 : 0.7); IR (KBr): 2675 (SH), 1409,

1

1151 (SO₂). H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.62 (s, 3H, CH₃);

(E,Z)-4-((4-Methoxybenzylidene)amino)-5-(5-methyl-1-phenyl-

1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-thiol (10b): Yield (94%); yel-

low cystals; m.p. 254–256 ^◦C; R_f= 0.57 (chloroform: methanol = 9.5 :

0.5); IR (KBr): 2753 (SH). ¹H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.53 (s,

3H, CH₃); 3.88 (s, 3H, OCH₃); 7.16 (d, J = 8.4 Hz, 2H, methoxyphenyl H-

3, H-5); 7.50–7.59 (m, 5H, phenyl H-2, H-3, H-4, H-5, H-6); 7.93 (d, J =

8.4 Hz, 2H, methoxyphenyl H-2, H-6); 8.08 (s, 1H, pyrazole H-3); 9.61

(s, 1H, CH = N); 14.11 (s, 1H, D₂O exchangeable, SH). ¹³C NMR

(DMSO‑d₆, 100 MHz, δ ppm): 12.57 (CH₃), 56.06 (OCH₃), 106.94

(pyrazole C-4), 115.29, 124. 87, 125.66, 128.99, 129.83, 131.28,

139.07, 139.90, 140.33, 144.69 (triazole C-5), 161.57 (CH = N), 163.52,

166.67 (triazole C-3). Anal. Calcd. for: C₂₀H₁₈N₆OS: C, 61.52; H, 4.65;

N, 21.52; Found; C, 61.36; H, 4.87; N, 21.78.

3.32 (s, 3H, SO₂CH₃); 7.90 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl H-

3, H-5); 8.12 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl H-2, H-6); 8.24 (s,

1H, pyrazole H-3), 13.62 (s, 1H, D₂O exchangeable, NH); 13.71 (s, 1H,

D₂O exchangeable, SH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.59

(CH₃), 43.89 (SO₂CH₃), 108.62 (pyrazole C-4), 125.83, 128.87, 139.70,

139.93, 140.54, 142.90, 145.83 (triazole C-5), 166.22 (triazole C-3).

Anal. Calcd. for: C₁₃H₁₃N₅O₂S₂: C, 46.55; H, 3.91; N, 20.88; Found; C,

46.57; H, 4.04; N, 20.67.

Procedure for the preparation of 5-(5-Methyl-1-(4-(methyl-

sulfonyl)phenyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole-2-thiol 8b: A

mixture of the carbohydrazide 2b (0.005 mol, 1.47 g), potassium hy-

droxide (0.015 mol, 0.84 g), and carbon disulﬁde (0.015 mol, 1.14 g) in

methanol (50 mL) was heated under reﬂux for 12 h. After completion of

the reaction, the mixture was ﬁltered while hot, the ﬁltrate mass was

poured onto crushed ice, and neutralized with hydrochloric acid. The

formed crude product was ﬁltered, dried, and crystallized from aqueous

ethanol 95% to give the target product 8b. Yield 72%; pale yellow

crystals; m.p. 231–233 ^◦C; R_f= 0.27 (chloroform: methanol = 9.7 : 0.3);

IR (KBr): 2738 (SH), 1409, 1150 (SO₂). ¹H NMR (DMSO‑d₆, 400 MHz, δ

ppm): 2.63 (s, 3H, CH₃); 3.33 (s, 3H, SO₂CH₃); 7.93 (d, J = 8.8 Hz, 2H,

methylsulfonylphenyl H-3, H-5); 8.13 (d, J = 8.8 Hz, 2H, methyl-

sulfonylphenyl H-2, H-6); 8.27 (s, 1H, pyrazole H-3), 14.69 (s, 1H, D₂O

exchangeable, SH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.46 (CH₃),

43.87 (SO₂CH₃), 106.35 (pyrazole C-4), 126.03, 128.94, 140.14,

140.88, 141.34, 142.55, 157.13 (oxadiazole C-5), 176.95 (oxadiazole C-

2). MS m/z (ES⁺): 337.10 (M^+.+ 1, 3.87), 336.11 (M^+., 15.09). Anal.

Calcd. for: C₁₃H₁₂N₄O₃S₂: C, 46.42; H, 3.60; N, 16.66; Found; C, 46.22;

H, 3.83; N, 16.95.

(E,Z)-4-((4-Chlorobenzylidene)amino)-5-(5-methyl-1-phenyl-

1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-thiol (10c): Yield (90%); white

cystals; m.p. 197–199 ^◦C; R_f= 0.56 (chloroform: methanol = 9.5 : 0.5);

IR (KBr): 2749 (SH). ¹H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.52 (s, 3H,

CH₃); 7.52–7.68 (m, 7H, chlorophenyl H-3, H-5, phenyl H-2, H-3, H-4,

H-5, H-6); 8.01–8.06 (m, 2H, chlorophenyl H-2, H-6); 8.10 (s, 1H, pyr-

azole H-3); 9.91 (s, 1H, CH = N); 14.19 (s, 1H, D₂O exchangeable, SH).

¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.56 (CH₃), 106.79 (pyrazole C-

4), 125.65, 129.00, 129.83, 129.97, 130.88, 131.41, 137.99, 139.07,

140.00, 140.43, 144.86 (triazole C-5), 161.56 (CH = N), 164.85 (tri-

azole C-3). Anal. Calcd. for: C₁₉H₁₅ClN₆S: C, 57.79; H, 3.83; N, 21.28;

Found; C, 58.04; H, 3.78; N, 21.36.

(E,Z)-4-(Benzylideneamino)-5-(5-methyl-1-(4-(methylsulfonyl)

phenyl)-1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-thiol (10d): Yield

(85%); white cystals; m.p. 240–242 ^◦C; R_f= 0.50 (chloroform: methanol

= 9.5 : 0.5); IR (KBr): 2760 (SH), 1396, 1153 (SO₂). ¹H NMR (DMSO‑d₆,

400 MHz, δ ppm): 2.63 (s, 3H, CH₃); 3.33 (s, 3H, SO₂CH₃); 7.59–7.67 (m,

3H, benzaldehyde H-3, H-4, H-5); 7.93 (d, J = 8.4 Hz, 2H, methyl-

sulfonylphenyl H-3, H-5); 7.97 (d, J = 7.2 Hz, 2H, benzaldehyde H-2, H-

6); 8.12 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl H-2, H-6); 8.19 (s, 1H,

pyrazole H-3); 9.87 (s, 1H, CH = N); 14.22 (s, 1H, D₂O exchangeable,

SH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.71 (CH₃), 43.89

(SO₂CH₃), 107.84 (pyrazole C-4), 125.92, 128.87, 129.24, 129.80,

132.47, 133.38, 140.46, 140.98, 141.00, 142.93, 144.55 (triazole C-5),

161.68 (CH = N), 166.30 (triazole C-3). Anal. Calcd. for: C₂₀H₁₈N₆O₂S₂:

C, 54.78; H, 4.14; N, 19.16; Found; C, 55.01; H, 4.03; N, 19.18.

(E,Z)-4-((4-Methoxybenzylidene)amino)-5-(5-methyl-1-(4-

Procedure for the synthesis of 4-Amino-5-(5-methyl-1-(4-

(methylsulfonyl)phenyl)-1H-pyrazol-4-yl)-

4H-1,2,4-triazole-3-

thiol (9b): A suspension of 8b (0.001 mol, 0.33 g) in hydrazine hydrate

(5 mL) was heated under reﬂux for 24 h. The reaction mixture was then

cooled, diluted with water (10 mL) and acidiﬁed with hydrochloric acid,

the formed precipitate was ﬁltered, dried, and crystallised from aqueous

ethanol 95%. Yield 95%; white solid; m.p. 198–200 ^◦C; R_f= 0.25

(chloroform: methanol = 9.7 : 0.3); IR (KBr): 3433, 3316 (forked, NH₂),

1

2776 (SH), 1390, 1149 (SO₂). H NMR (DMSO‑d₆, 400 MHz, δ ppm):

2.60 (s, 3H, CH₃); 3.33 (s, 3H, SO₂CH₃); 5.81 (s, 2H, D₂O exchangeable,

NH₂); 7.93 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl H-3, H-5); 8.12 (d,

J = 8.4 Hz, 2H, methylsulfonylphenyl H-2, H-6); 8.42 (s, 1H, pyrazole H-

3), 13.89 (s, 1H, D₂O exchangeable, SH). ¹³C NMR (DMSO‑d₆, 100 MHz,

δ ppm): 12.46 (CH₃), 43.91 (SO₂CH₃), 108.12 (pyrazole C-4), 125.85,

(methylsulfonyl)phenyl)-1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-

◦

thiol (10e): Yield (89%); yellow cystals; m.p. 227–229 C; R_f= 0.48

(chloroform: methanol = 9.5 : 0.5); IR (KBr): 2763 (SH), 1417, 1151

16

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

(SO₂). ¹H NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.62 (s, 3H, CH₃); 3.33 (s,

3H, SO₂CH₃); 3.88 (s, 3H, OCH₃); 7.15 (d, J = 8.4 Hz, 2H, methox-

yphenyl H-3, H-5); 7.91–7.94 (m, 4H, methylsulfonylphenyl H-2, H-3,

H-5, H-6); 8.12 (d, J = 8.4 Hz, 2H, methoxyphenyl H-2, H-6); 8.16 (s,

1H, pyrazole H-3); 9.64 (s, 1H, CH = N); 14.15 (s, 1H, D₂O exchange-

able, SH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.73 (CH₃), 43.89

(SO₂CH₃), 56.07 (OCH₃), 107.93 (pyrazole C-4), 115.28, 124,87,

125.91, 128.87, 131.29, 140.56, 140.90, 142.93, 144.41 (triazole C-5),

161.68 (CH = N), 163.52, 166.50 (triazole C-3). Anal. Calcd. for:

(4-Bromophenyl)(6-(4-chlorophenyl)-3-(5-methyl-1-phenyl-1H-

pyrazol-4-yl)-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadia-

zin-7-yl)methanone (11c): Yield (85%); white cystals; m.p.

◦

147–149 C; R_f= 0.46 (chloroform: methanol = 9.5 : 0.5); IR (KBr):

1

–

3433 (NH), 1686 (C O). H NMR (DMSO‑d , 400 MHz, δ ppm): 2.58 (s,

–

6

3H, CH₃); 5.21 (t, J = 5.6 Hz, 1H, triazolothiadiazine H-6); 5.84 (d, J =

5.6 Hz, 1H, triazolothiadiazine H-7); 7.34 (d, J = 5.6 Hz, 1H, D₂O

exchangeable NH); 7.44 (d, J = 8.4 Hz, 2H, chlorophenyl H-2, H-6);

7.49–7.62 (m, 7H, chlorophenyl H-3, H-5, phenyl H-2, H-3, H-4, H-5, H-

6); 7.84 (d, J = 8.4 Hz, 2H, bromophenyl H-3, H-5); 8.05 (d, J = 8.4 Hz,

2H, bromophenyl H-2, H-6); 8.35 (s, 1H, pyrazole H-3). ¹³C NMR

(DMSO‑d₆, 100 MHz, δ ppm): 12.59 (CH₃), 43.39 (triazolothiadiazine C-

6), 57.36 (triazolothiadiazine C-7), 107.65 (pyrazole C-4), 125.51,

128.73, 128.85, 129.04, 129.74, 129.79, 131.41, 132.62, 133.23,

C

₂₁H₂₀N₆O₃S₂: C, 53.83; H, 4.30; N, 17.94; Found; C, 54.10; H, 4.11; N,

18.02.

(E,Z)-4-((4-Chlorobenzylidene)amino)-5-(5-methyl-1-(4-(meth-

ylsulfonyl)phenyl)-1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-thiol

(10f): Yield (89%); white cystals; m.p. 187–189 ^◦C; R_f= 0.49 (chloro-

form: methanol = 9.5 : 0.5); IR (KBr): 2762 (SH), 1394, 1153 (SO₂). ¹H

NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.62 (s, 3H, CH₃); 3.33 (s, 3H,

SO₂CH₃); 7.68 (d, J = 8.4 Hz, 2H, chlorophenyl H-3, H-5); 7.93 (d, J =

8.4 Hz, 2H, methylsulfonylphenyl H-3, H-5); 7.99 (d, J = 8.4 Hz, 2H,

chlorophenyl H-2, H-6); 8.12 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl

H-2, H-6); 8.18 (s, 1H, pyrazole H-3); 9.93 (s, 1H, CH = N); 14.23 (s, 1H,

D₂O exchangeable, SH). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm): 12.70

(CH₃), 43.89 (SO₂CH₃), 107.77 (pyrazole C-4), 125.92, 128.88, 129.97,

130.89, 131.38, 138.01, 140.56, 141.02, 142.91, 144.57 (triazole C-5),

161.66 (CH = N), 164.81 (triazole C-3). Anal. Calcd. for: C₂₀H₁₇N₆O₂S₂:

C, 50.79; H, 3.62; N, 17.77; Found; C, 50.74; H, 3.83; N, 17.99.

General procedure for the synthesis of [1,2,4]triazolo[3,4-b]

[1,3,4]thiadiazin-7-yl)methanone derivatives 11a-f: A mixture of

appropriate Schiff base of 1,2,4-triazoles 10a-f (0.01 mol), 4-bromo-

133.92, 136.50, 139.23, 139.37, 140.79, 148.03 (triazolothiadiazine C-

+

8a), 194.66 (C O). MS m/z (ES ): 593.89 (M^+.+ 1, 8.99), 592.04 (M^+.,

–

43.29). Anal. Calcd. for: C₂₇H₂₀BrClN₆OS: C, 54.79; H, 3.41; N, 14.20;

Found; C, 54.84; H, 3.53; N, 14.17.

(4-Bromophenyl)(3-(5-methyl-1-(4-(methylsulfonyl)phenyl)-

1H-pyrazol-4-yl)-6-phenyl-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b]

[1,3,4]thiadiazin-7-yl)methanone (11d): Yield (82%); white cystals;

m.p. 182–184 ^◦C; R_f= 0.39 (chloroform: methanol = 9.5 : 0.5); IR (KBr):

1

–

3433 (NH), 1688 (C O), 1385, 1149 (SO ). H NMR (DMSO‑d , 400

MHz, δ ppm): 2.68 (s, 3H, CH₃-pyrazole); 3.33 (s, 3H, SO₂CH₃); 5⁶.15 (t,

J = 5.6 Hz, 1H, triazolothiadiazine H-6); 5.85 (d, J = 5.6 Hz, 1H, tri-

azolothiadiazine H-7); 7.27–7.37 (m, 4H, 1H D₂O exchangeable, NH,

phenyl H-3, H-4, H-5); 7.52 (d, J = 7.6 Hz, 2H, phenyl H-2, H-6); 7.83 (d,

J = 8.4 Hz, 2H, bromophenyl H-3, H-5); 7.94 (d, J = 8.4 Hz, 2H,

methylsulfonylphenyl H-3, H-5); 8.03 (d, J = 8.4 Hz, 2H, methyl-

sulfonylphenyl H-2, H-6); 8.12 (7.83 (d, J = 8.4 Hz, 2H, bromophenyl H-

2, H-6); 8.42 (s, 1H, pyrazole H-3). ¹³C NMR (DMSO‑d₆, 100 MHz, δ

ppm): 12.74 (CH₃), 43.85 (SO₂CH₃), 43.93 (triazolothiadiazine C-6),

58.35 (triazolothiadiazine C-7), 108.73 (pyrazole C-4), 125.67, 127.15,

127.76, 128.85, 129.03, 129.10, 131.35, 132.63, 133.96, 137.37,

2

α

-bromoacetophenones (0.01 mol, 2.63 g), and triethylamine (0.01 mol,

0.20 g) in absolute ethanol (10 mL) was heated under reﬂux for 2–3 h.

The formed precipitate was ﬁltered off while hot, dried, and crystallized

from aqueous ethanol 95% to afford the target compounds 11a-f.

(4-Bromophenyl)(3-(5-methyl-1-phenyl-1H-pyrazol-4-yl)-6-

phenyl-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-7-

yl)methanone (11a): Yield (90%); white cystals; m.p. 173–175 ^◦C; R_f

139.93, 140.29, 141.34, 143.19 (triazolothiadiazine C-3), 147.75 (tri-

–

= 0.47 (chloroform: methanol = 9.5 : 0.5); IR (KBr): 3434 (NH), 1680

azolothiadiazine C-8a), 194.74 (C O). Anal. Calcd. for:

–

1

–

(C O). H NMR (DMSO‑d , 400 MHz, δ ppm): 2.59 (s, 3H, CH ); 5.14 (t,

C

₂₈H₂₃BrN₆O₃S₂: C, 52.92; H, 3.65; N, 13.22; Found; C, 53.00; H, 3.57;

N, 13.26.

(4-Bromophenyl)(6-(4-methoxyphenyl)-3-(5-methyl-1-(4-

(methylsulfonyl)phenyl)-1H-pyrazol-4-yl)-6,7-dihydro-5H-[1,2,4]

J = 6 Hz, 1H, triazoloth⁶iadiazine H-6); 5.85 (d, J = 6 Hz, 1H, tri-

azolothiadiazine H-7); 7.30–7.62 (m, 11H, 1H D₂O exchangeable NH,

phenyl H-2, H-3, H-4, H-5, H-6, ph-triazolothiadiazine H-2, H-3, H-4, H-

5, H-6); 7.83 (d, J = 8.4 Hz, 2H, bromophenyl H-3, H-5); 8.03 (d, J = 8.4

Hz, 2H, bromophenyl H-2, H-6); 8.33 (s, 1H, pyrazole H-3). ¹³C NMR

(DMSO‑d₆, 100 MHz, δ ppm): 12.59 (CH₃), 56.50 (triazolothiadiazine C-

6), 58.41 (triazolothiadiazine C-7), 107.72 (pyrazole C-4), 125.51,

127.78, 128.58, 128.72, 129.01, 129.09, 129.78, 131.53, 132.62,

3

triazolo[3,4-b][1,3,4]thiadiazin-7-yl)methanone

(11e):

Yield

(85%); white cystals; m.p. 169–171 ^◦C; R_f= 0.37 (chloroform: methanol

1

–

= 9.5 : 0.5); IR (KBr): 3434 (NH), 1687 (C O), 1385, 1149 (SO ). H

2

NMR (DMSO‑d₆, 400 MHz, δ ppm): 2.68 (s, 3H, CH₃); 3.33 (s, 3H,

SO₂CH₃); 3.71 (s, 3H, OCH₃); 5.05 (t, J = 5.6 Hz, 1H, triazolothiadiazine

H-6); 5.83 (d, J = 5.6 Hz, 1H, triazolothiadiazine H-7); 6.90 (d, J = 8.4

Hz, 2H, methoxyphenyl H-3, H-5); 7.25 (d, J = 5.6 Hz, 1H, D₂O

exchangeable NH); 7.44 (d, J = 8.4 Hz, 2H, methoxyphenyl H-2, H-6);

7.83 (d, J = 8.4 Hz, 2H, bromophenyl H-3, H-5); 7.94 (d, J = 8.4 Hz, 2H,

methysulfonylphenyl H-3, H-5); 8.01 (d, J = 8.4 Hz, 2H, methyl-

sulfonylphenyl H-2, H-6); 8.12 (d, J = 8.4 Hz, 2H, bromophenyl H-2, H-

6); 8.40 (s, 1H, pyrazole H-3). ¹³C NMR (DMSO‑d₆, 100 MHz, δ ppm):

12.75 (CH₃), 43.94 (SO₂CH₃), 44.00 (triazolothiadiazine C-6), 55.57

(OCH₃), 58.12 (triazolothiadiazine C-7), 108.73 (pyrazole C-4), 114.45,

125.651, 128.85, 129.02, 129.11, 131.41, 132.64, 134.01, 139.90,

140.30, 141.43, 143.20 , 147.79 (triazolothiadiazole C-8a), 159.43,

133.97, 137.46, 139.22, 139.34, 141.09, 148.03 (triazolothiadiazine C-

–

8a), 194.72 (C O). Anal. Calcd. for: C₂₇H₂₁BrN₆OS: C, 58.17; H, 3.80;

N, 15.08; Found; C, 57.99; H, 3.88; N, 15.20.

(4-Bromophenyl)(6-(4-methoxyphenyl)-3-(5-methyl-1-phenyl-

1H-pyrazol-4-yl)-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thia-

diazin-7-yl)methanone (11b): Yield (89%); white cystals; m.p.

◦

196–198 C; R_f= 0.45 (chloroform: methanol = 9.5 : 0.5); IR (KBr):

1

–

3435 (NH), 1681 (C O). H NMR (DMSO‑d , 400 MHz, δ ppm): 2.59 (s,

6

3H, CH₃); 3.72 (s, 3H, OCH₃); 5.04 (t, J = 5.6 Hz, 1H, triazolothiadiazine

H-6); 5.83 (d, J = 5.6 Hz, 1H, triazolothiadiazine H-7); 6.90 (d, J = 7.6

Hz, 2H, methoxyphenyl H-3, H-5); 7.23 (d, J = 5.6 Hz, 1H, D₂O

exchangeable NH); 7.44 (d, J = 7.6 Hz, 2H, methoxyphenyl H-2, H-6);

7.50–7.52 (m, 1H, phenyl H-4); 7.56–7.60 (m, 4H, phenyl H-2, H-3, H-5,

H-6); 7.82 (d, J = 8.4 Hz, 2H, bromophenyl H-3, H-5); 8.01 (d, J = 8.4

Hz, 2H, bromophenyl H-2, H-6); 8.31 (s, 1H, pyrazole H-3). ¹³C NMR

(DMSO‑d₆, 100 MHz, δ ppm): 12.59 (CH₃), 55.56 (OCH₃), 56.51 (tri-

azolothiadiazine C-6), 58.24 (triazolothiadiazine C-7), 107.73 (pyrazole

C-4), 114.45, 125.50, 128.72, 129.01, 129.12, 129.20, 129.78, 131.30,

132.64, 134.02, 139.23, 139.33, 139.36, 141.21, 148.07, 159.43 (C-8a

+

+.

–

194.75 (C O). MS m/z (ES ): 665.92 (M , 1.75). Anal. Calcd. for:

–

C₂₉H₂₅BrN₆O₄S₂: C, 52.33; H, 3.79; N,12.63; Found; C, 52.39; H, 3.84;

N, 12.82.

(4-Bromophenyl)(6-(4-chlorophenyl)-3-(5-methyl-1-(4-(methyl-

sulfonyl)phenyl)-1H-pyrazol-4-yl)-6,7-dihydro-5H-[1,2,4]triazolo

[3,4-b][1,3,4]thiadiazin-7-yl)methanone (11f): Yield (82%); white

cystals; m.p. 156–158 ^◦C; R_f= 0.38 (chloroform: methanol = 9.5 : 0.5);

IR (KBr): 3433 (NH), 1687 (C O), 1385, 1149 (SO ). ¹H NMR

–

2

–

triazolothiadiazole), 194.73 (C O). Anal. Calcd. for: C₂₈H₂₃BrN₆O₂S: C,

(DMSO‑d₆, 400 MHz, δ ppm): 2.67 (s, 3H, CH₃); 3.35 (s, 3H, SO₂CH₃);

–

57.24; H, 3.59; N,14.31; Found; C, 57.26; H, 3.33; N, 14.52.

5.23 (t, J = 5.6 Hz, 1H, triazolothiadiazine H-6); 5.85 (d, J = 5.6 Hz, 1H,

17

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

triazolothiadiazine H-7); 7.36 (d, J = 5.6 Hz, 1H, D₂O exchangeable

NH); 7.43 (d, J = 8.4 Hz, 2H, chorophenyl H-3, H-5); 7.55 (d, J = 8.4 Hz,

2H, chlorophenyl H-2, H-6); 7.84 (d, J = 8.4 Hz, 2H, bromophenyl H-3,

H-5); 7.95 (d, J = 8.4 Hz, 2H, methylsulfonylphenyl H-3, H-5); 8.05 (d, J

= 8.4 Hz, 2H, methylsulfonylphenyl H-2, H-6); 8.13 (d, J = 8.4 Hz, 2H,

bromophenyl H-2, H-6); 8.43 (s, 1H, pyrazole H-3). ¹³C NMR (DMSO‑d₆,

using pins on a corkboard for examination. The gastric mucosa was

checked for the presence of ulcers through illuminated magnifying

lenses. Ulcer index was measured according to Cho and Ogle’s method

[40].

4.2.2.3. Stomach

histopathological

examination. Histopathological

100 MHz,

δ ppm): 12.73 (CH₃), 43.32 (SO₂CH₃), 43.94 (tri-

studies were done to determine the effect of compounds (4b, 7a, 10e,

11c, and 11e) on the stomach compared with that of the celecoxib and

indomethacin as a positive control. Brieﬂy, the stomach of the rats of

each group of animals was ﬁxed in 10% neutral buffered formalin for 48

h. Then dehydrated, cleared, embedded in parafﬁn, sectioned (5 µm),

and stained with H&E stain following previously described method

[41,42].

azolothiadiazine C-6), 57.34 (triazolothiadiazine C-7), 108.61 (pyrazole

C-4), 125.64, 128.86, 129.11, 129.72, 131.40, 132.64, 133.26, 133.88,

136.36, 139.99, 140.28, 140.32, 141.09, 143.18 (triazolothiadiazole C-

–

3), 147.77 (triazolothiadiazole C-8a), 194.67 (C O). Anal. Calcd. for:

–

C

₂₈H₂₂BrClN₆O₃S₂: C, 50.20; H, 3.31; N, 12.54; Found; C, 50.34; H,

3.15; N, 12.78.

4.2.3. Cardiovascular evaluation

4.2. Biological evaluation

Eighteen rats were randomly assigned into 3 groups (6 animals in

each group). The ﬁrst group revived a vehicle and served as normal

control. A suspension of the tested compound 7a and celecoxib in 1%

tween in saline was administered P.O (100 mg/kg) once daily for two

weeks. On the 15th day, animals were anesthetized by ketamine (100

mg/kg). Blood samples were collected from the retroorbital, allowed to

clot, separated by centrifugation at 1000 g for 15 min, and used for

assessment of heart function biomarkers (AST, ALP, LDH, CK-MB, TNF-

4.2.1. In-vitro cyclooxygenase (COX-1/2) inhibition assays

An enzyme immunoassay (EIA) kit (Cayman Chemical, Ann Arbor,

MI) was used to screen for isozyme-speciﬁc inhibition in vitro. The po-

tency of the tested compounds was determined by the concentration that

inhibited enzymes by 50% (IC₅₀). Also, the COX-2 S.I. was calculated

and compared with that of celecoxib (IC₅₀(COX-1)/IC₅₀(COX-2)) [23].

α

, IL-6, and IL-1β). Each rat’s abdomen was opened and the heart was

4.2.2. In-vivo anti-inﬂammatory studies

removed and rinsed in ice-cold physiological saline and used for the

histopathological examination.

Chemicals and kits: Carrageenan, celecoxib, and indomethacin

were purchased from Sigma-Aldrich (St. Louis, MO, USA). ALP and AST

kits were purchased from BioDiagnostics (Cairo, Egypt). CK-MB and

4.2.3.1. Assessment of the cardiac function biomarkers and inﬂammatory

cytokines. The effect of compound 7a on the heart function biomarkers

compared with that of the celecoxib was assessed in the rat sera. The

activities of AST, ALP, LDH, and CK-MB were assayed spectrophoto-

metrically in the rats’ sera according to manufacturers’ instructions

using commercial kits. Also, the serum levels of inﬂmmatroy cytokines;

LDH were purchased from Thermo Fisher Scientiﬁc (USA). Rat TNF-α,

IL-6, and IL-1β ELISA kits were purchased from Elabscience Company

(USA).

Animal and ethics statement: Adult male Wister albino rats

weighing 160–180 g were used in this study. Rats were allowed to have

14 days for acclimation before any experimental procedure. These rats

were housed in a controlled environment with access to food and water.

Following the guidelines for the care of laboratory animals, all tests were

performed. All experimental procedures were carried out following the

Animal Ethics Committee regulations of Beni-Suef University, Beni-Suef,

Egypt.

TNF-α and IL-6 were determined in serum using ELISA kits according to

the according to manufacturers’ instructions.

4.2.3.2. Histopathological examination of the heart. Histopathological

studies were done to determine the effect of compound 7a on the heart

compared to that of celecoxib. Brieﬂy, the heart of the rats of compound

7a and celecoxib as a standard were ﬁxed in 10% neutral buffered

formalin for 48 h. Then dehydrated, cleared, embedded in parafﬁn,

sectioned (5 µm), and stained with H&E stain following previously

described method [41,43].

4.2.2.1. In-vivo anti-inﬂammatory activity using carrageenan-induced rat

paw edema assay. The anti-inﬂammatory activity of 4b, 7a, 10e, 11c,

and 11e, the most selective synthesized candidates, was estimated in-

vivo using the paw edema method in rats [34]. Rats were classiﬁed into 8

groups, and each group has three animals. The ﬁrst rat group was

administered with the vehicle, ﬁve groups were administrated with

compounds (4b, 7a, 10e, 11c, and 11e) in which each compound was

administered in a dose of 50 mg/kg (one group per one compound), and

ﬁnally, the last group was administrated with celecoxib (50 mg/kg).

Paw edema was induced one hour after administration of vehicle, can-

didates, or celecoxib by injecting carrageenan (1% in saline) (0.05 mL/

rat) subcutaneously into the left hind paw of each rat. After 1, 3, and 5 h

of carrageenan injection, a Vernier Caliper was used to measure paw

thickness and estimate the difference between paw volumes. The per-

centage inhibition of edema thickness in treated animals compared to

the control group was used to determine anti-inﬂammatory activity.

4.3. Docking study

Docking studies were performed using the Molecular Operating

Environment (MOE) software. The crystal structure of SC-558 bound at

the murine COX-2 active site was obtained from the protein data bank

(PDB: 1CX2). Then, the crystallized ligand was docked using London DG

and force ﬁeld energy to detect the binding energy score, amino acid

interactions, and relative mean square deviation (rmsd = 1.7). A virtual

library of designed compounds and standard COX-2 inhibitors SC-558

was energy minimized, which was followed by the generation of 50

conformers. The entire energy-minimized library was docked with the

prepared catalytic domains of COX-2 (PDB code: 1CX2) using London

DG forces. For each docked compound, one conformer was chosen ac-

cording to superposition with the ligand, energy score of binding with

the active site, and the number of the binding interaction with amino

acid residues. The binding interactions of the docked compounds with

the receptor and docking score were studied using 2D and 3D pictures.

4.2.2.2. Ulcerogenic liability. Ulcerogenic liability was measured for the

most selective candidates (4b, 7a, 10e, 11c, and 11e) and celecoxib as a

standard and was compared to indomethacin. Rats were fasted for 18 h

and divided into 8 groups before drug administration. The vehicle was

given to the control group. Other groups received candidates and cele-

coxib and indomethacin according to reported procedures [4,39]. Rats

have received the required dose for three successive days. After the last

dose, each rat’s stomach was cut and opened through the greater cur-

vature and washed with saline. The separated stomach was stretched

4.4. ADME proﬁling

The most selective compounds 4b, 7a, 10e, 11c, and 11e had been

18

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

cytotoxic agents and COX-2/LOX inhibitors, Archiv der pharmazie, 351 (2018)

[1700311-1700322]. doi: 10.1002/ardp.201700311.

drawn by Chem Sketch (v.12) and then converted to the SMILE name

using the tool (Swiss ADME) that estimates the physicochemical pa-

rameters and pharmacokinetic characteristics.

[17] H.A.H. Elshemy, E.K.A. Abdelall, A.A. Azouz, A. Moawad, W.A.M. Ali, N.

M. Safwat, Synthesis, anti-inﬂammatory, cyclooxygenases inhibitions assays and

histopathological study of poly-substituted 1,3,5-triazines: Conﬁrmation of

regiospeciﬁc pyrazole cyclization by HMBC, Eur J Med Chem. 127 (2017) 10–21,

https://doi.org/10.1016/j.ejmech.2016.12.030.

Declaration of Competing Interest

[18] K.R.A. Abdellatif, E.K.A. Abdelall, H.A.H. Elshemy, E.-S. El-Nahass, M.M. Abdel-

Fattah, Y.Y.M. Abdelgawad, New indomethacin analogs as selective COX-2

inhibitors: Synthesis, COX-1/2 inhibitory activity, anti-inﬂammatory,

ulcerogenicity, histopathological, and docking studies, Arch Pharm. 354 (4) (2021)

2000328, https://doi.org/10.1002/ardp.v354.410.1002/ardp.202000328.

[19] E.K.A. Abdelall, P.F. Lamie, A.K.M. Ahmed, E.S. EL-Nahas, COX-1/COX-2

inhibition assays and histopathological study of the new designed anti-

inﬂammatory agent with a pyrazolopyrimidine core, Bioorg Chem. 86 (2019)

235–253, https://doi.org/10.1016/j.bioorg.2019.01.031.

The authors declare that they have no known competing ﬁnancial

interests or personal relationships that could have appeared to inﬂuence

the work reported in this paper.

Acknowledgments

[20] K.R.A. Abdellatif, E.K.A. Abdelall, M.B. Labib, W.A.A. Fadaly, T.H. Zidan, Design,

synthesis of celecoxib-tolmetin drug hybrids as selective and potent COX-2

inhibitors, Bioorg Chem. 90 (2019) 103029–103040, https://doi.org/10.1016/j.

bioorg.2019.103029.

The authors thank the conﬁrmatory diagnostic unit at the Egyptian

Company for Drugs and Veterinary Vaccines (VACSERA) for their help in

some of the in vitro biological tests.

[21] K.R.A. Abdellatif, E.K.A. Abdelall, P.F. Lamie, M.B. Labib, E.S. El-Nahaas, M.

M. Abdelhakeem, New pyrazole derivatives possessing amino/methanesulphonyl

pharmacophore with good gastric safety proﬁle: Design, synthesis, cyclooxygenase

inhibition, anti-inﬂammatory activity and histopathological studies, Bioorg Chem.

95 (2020) 103540–103552, https://doi.org/10.1016/j.bioorg.2019.103540.

[22] Eman K.A. Abdelall, Abdou O. Abdelhamid, Amany A. Azouz, Synthesis and

biological evaluations of new nitric oxide-anti-inﬂammatory drug hybrids,

Bioorganic Med Chem Lett. 27 (18) (2017) 4358–4369, https://doi.org/10.1016/j.

bmcl.2017.08.023.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.

org/10.1016/j.bioorg.2021.105122.

References

[23] W.A.A. Fadaly, Y.A.M.M. Elshaier, E.H.M. Hassanein, K.R.A. Abdellatif, New 1,2,4-

triazole/pyrazole hybrids linked to oxime moiety as nitric oxide donor celecoxib

analogs: Synthesis, cyclooxygenase inhibition anti-inﬂammatory, ulcerogenicity,

anti-proliferative activities, apoptosis, molecular modeling and nitric oxide release,

Bioorg Chem. 98 (2020) 103752–103837, https://doi.org/10.1016/j.

bioorg.2020.103752.

[1] L.M. Jackson, C.J. Hawkey, COX-2 selective nonsteroidal anti-inﬂammatory drugs:

Do they really offer any advantages? Drugs. 59 (6) (2000) 1207–1216, https://doi.

org/10.2165/00003495-200059060-00001.

[2] K.R.A. Abdellatif, H.A.H. Elshemy, A.A. Azoz, 1-(4-Methane(amino)

sulfonylphenyl)-3-(4-substituted-phenyl)-5-(4-triﬂuoromethylphenyl)-1H-2-

pyrazolines/pyrazoles as potential antiinﬂammatory agents, Bioorg. Chem. 63

(2015) 13–23, https://doi.org/10.1016/j.bioorg.2015.09.002.

[24] Rajeev Kharb, Prabodh Chander Sharma, Mohammed Shahar Yar, Pharmacological

signiﬁcance of triazole scaffold, J Enzyme Inhib Med Chem. 26 (1) (2011) 1–21,

https://doi.org/10.3109/14756360903524304.

[3] E.K.A. Abdelall, G.M. Kamel, Synthesis of new thiazolo-celecoxib analogues as dual

cyclooxygenase-2/15-lipoxygenase inhibitors: Determination of regio-speciﬁc

different pyrazole cyclization by 2D NMR, Eur J Med Chem. 118 (2016) 250–258,

https://doi.org/10.1016/j.ejmech.2016.04.049.

[25] Renata Paprocka, Malgorzata Wiese, Andrzej Eljaszewicz, Anna Helmin-Basa,

Andrzej Gzella, Bozena Modzelewska-Banachiewicz, Jacek Michalkiewicz,

Synthesis and anti-inﬂammatory activity of new 1,2,4-triazole derivatives,

Bioorganic Med Chem Lett. 25 (13) (2015) 2664–2667, https://doi.org/10.1016/j.

bmcl.2015.04.079.

[4] K.R.A. Abdellatif, W.A.A. Fadaly, W.A.M. Ali, G.M. Kamel, Synthesis,

cyclooxygenase inhibition, anti-inﬂammatory evaluation and ulcerogenic liability

of new 1,5-diarylpyrazole derivatives, J Enzyme Inhib Med Chem, 31(2016) [54-

60]. doi:10.1080/14756366.2016.1201815.

[26] Birsen Tozkoparan, Esra Küpeli, Erdem Yes¸ilada, Mevlüt Ertan, Preparation of 5-

aryl-3-alkylthio-l,2,4-triazoles and corresponding sulfones with antiinﬂammatory-

analgesic activity. Bioorganic, Med Chem. 15 (4) (2007) 1808–1814, https://doi.

org/10.1016/j.bmc.2006.11.029.

¨

[5] H. Süleyman, B. Demircan, Y. Karagoz, Anti-inﬂammatory and side effects of

cyclooxygenase inhibitors, Pharmacol Reports 59 (2007) 247–258, https://doi.

org/10.1016/j.etp.2006.06.004.

[27] Giulia Menozzi, Luisa Mosti, Pietro Schenone, Reaction of 2-dimethylamino-

methylene-1,3-diones with dinucleophiles. VI. Synthesis of ethyl or methyl 1,5-

disubstituted 1H-pyrazole-4-carboxylates, J Heterocycl Chem. 24 (6) (1987)

1669–1675, https://doi.org/10.1002/jhet.v24:610.1002/jhet.5570240634.

[28] E.S. Hamanaka, A. Guzman-Perez, R.B. Ruggeri, R.T. Webster, J. Christian,

Mularski, N-[(Substituted ﬁve-membered di or triaza diunsaturated ring) carbonyl]

guanidine derivative for the treatment of ischemia, United States Pat. 12 (2002) [1-

84]. doi:US006492401B1 (10).

[6] M.C. Allison, A.G. Howatson, C.J. Torrance, F.D. Lee, R.I. Russell, Gastrointestinal

damage associated with the use of nonsteroidal anti-inﬂammatory drugs, N Engl J

Med. 327 (11) (1992) 749–754, https://doi.org/10.1056/

NEJM199209103271101.

[7] N.H. Amin, M.T. El-Saadi, A.A. Hefny, A.H. Abdelazeem, H.AH. Elshemy, K.

RA. Abdellatif, Anti-inﬂammatory indomethacin analogs endowed with

preferential COX-2 inhibitory activity, Fut, Med Chem. 10 (21) (2018) 2521–2535,

https://doi.org/10.4155/fmc-2018-0224.

[29] S. Ahmad, B.P. Panda, M. Fahim, N. Dhyani, K. Dubey, Ameliorative effect of

beraprost sodium on celecoxib induced cardiotoxicity in rats, Iran, J Pharm Res. 17

(2018) 155–163, https://doi.org/10.22037/ijpr.2018.2183.

[8] D.L. Simmons, R.M. Botting, T. Hla, Cyclooxygenase isozymes: The biology of

prostaglandin synthesis and inhibition, Pharmacol Rev. 56 (3) (2004) 387–437,

https://doi.org/10.1124/pr.56.3.3.

[30] S. Atashbar, T. Sabzalipour, A. Salimi, Stabilization of mitochondrial function by

ellagic acid prevents celecoxib-induced toxicity in rat cardiomyocytes and isolated

mitochondria, Drug Res. 71 (2021) 219 –227, https://pubmed.ncbi.nlm.nih.gov/

33276407/.

[9] R.M. Garavito, A.M. Mulichak, The structure of mammalian cyclooxygenases, Annu

Rev Biophys Biomol Struct. 32 (1) (2003) 183–206, https://doi.org/10.1146/

annurev.biophys.32.110601.141906.

[31] Imene Amine Khodja, Houssem Boulebd, Chawki Bensouici, Ali Belfaitah, Design,

synthesis, biological evaluation, molecular docking, DFT calculations and in silico

ADME analysis of (benz)imidazole-hydrazone derivatives as promising

antioxidant, antifungal, and anti-acetylcholinesterase agents, J Mol Struct. 1218

(2020) 128527–128538, https://doi.org/10.1016/j.molstruc.2020.128527.

[32] P.F. Lamie, J.N. Philoppes, Thiopyrimidine/chalcone hybrids: design, synthesis,

ADMET prediction, and anticancer evaluation as STAT3/STAT5a inhibitors,

J Enzyme Inhib Med Chem 35 (2020) 864–879, https://doi.org/10.1080/

14756366.2020.1740922.

[10] R.G. Kurumbail, A.M. Stevens, J.K. Gierse, J.J. McDonald, R.A. Stegeman, J.Y. Pak,

D. Gildehaus, J.M. iyashiro, T.D. Penning, K. Seibert, P.C. Isakson, W.C. Stallings,

Structural basis for selective inhibition of cyclooxygenase-2 by anti-inﬂammatory

agents, Lett to Nat. 384 (6610) (1996) 644–648, https://doi.org/10.1038/

384644a0.

[11] R.N. DuBois, S.B. Abramson, L. Crofford, R.A. Gupta, L.S. Simon, L.B.A. Putte, P.

E. Lipsky, Cyclooxygenase in biology and disease, FASEB J. 12 (12) (1998)

1063–1073, https://doi.org/10.1096/fsb2.v12.1210.1096/fasebj.12.12.1063.

[12] H.-K. Heim, K. Broich, Selective COX-2 inhibitors and risk of thromboembolic

events – regulatory aspects, Thromb Haemost. 96 (2006) 423–432, https://doi.

org/10.1160/TH06.

[33] A. Daina, O. Michielin, V. Zoete, SwissADME: A free web tool to evaluate

pharmacokinetics, drug-likeness and medicinal chemistry friendliness of small

molecules, Sci Rep., 7 (2017) [42717-42730]. doi:10.1038/srep42717.

[34] Christopher A. Lipinski, Franco Lombardo, Beryl W. Dominy, Paul J. Feeney,

Experimental and computational approaches to estimate solubility and

permeability in drug discovery and development settings, Adv Drug Deliv Rev. 64

(2012) 4–17, https://doi.org/10.1016/j.addr.2012.09.019.

[13] P.F. Lamie, J.N. Philoppes, A.A. Azouz, N.M. Safwat, Novel tetrazole and

cyanamide derivatives as inhibitors of cyclooxygenase-2 enzyme: design, synthesis,

anti-inﬂammatory evaluation, ulcerogenic liability and docking study, J Enzyme

Inhib Med Chem. 32 (1) (2017) 805–820, https://doi.org/10.1080/

14756366.2017.1326110.

[35] Vishwanathan Balasubramanya Iyer, Bannimath Gurupadayya, Venkata

Sairam Koganti, Bharthkumar Inturi, Ravandur Shivanna Chandan, Design,

synthesis and biological evaluation of 1,3,4-oxadiazoles as promising anti-

inﬂammatory agents, Med Chem Res 26 (1) (2017) 190–204, https://doi.org/

10.1007/s00044-016-1740-6.

[14] G.S. Hassan, G.H. Hegazy, N.M. Ibrahim, S.H. Fahim, New ibuprofen derivatives as

H₂S and NO donors as safer anti-inﬂammatory agents, Future, Med Chem. 11 (23)

(2019) 3029–3045, https://doi.org/10.4155/fmc-2018-0467.

[15] E.K.A. Abdelall, Synthesis and biological evaluations of novel isoxazoles and

furoxan derivative as anti-inﬂammatory agent, Bioorg Chem. 94 (2020), https://

doi.org/10.1016/j.bioorg.2019.103441.

[36] H. M. Faidallah, S.A.F. Rostom S.A.F. Synthesis, anti-Inﬂammatory activity, and

COX-1/2 inhibition proﬁle of some novel non-acidic polysubstituted pyrazoles and

´

[16] P.F. Lamie, J.N. Philoppes, L. Rarova, Design, synthesis, and biological evaluation

of novel 1,2-diaryl-4-substituted-benzylidene-5(4H)-imidazolone derivatives as

19

K.R.A. Abdellatif et al.

Bioorganic Chemistry 114 (2021) 105122

pyrano[2,3-c]pyrazoles, Arch Pharm (Weinheim), 350 (2017) [1-17]. doi:10.1002/

rats, Eur J Pharmacol 55 (1) (1979) 23–33, https://doi.org/10.1016/0014-2999

(79)90144-4.

ardp.201700025.

[37] Cherkupally Sanjeeva Reddy, Lade Sanjeeva Rao, Gaddam Rajesh Kumar,

Adki Nagaraj, Synthesis of new 1,2,4-triazole[3,4-b][1,3,4]thiadiazoles bearing

pyrazole as potent antimicrobial agents, Chem Pharm Bull. 58 (10) (2010)

1328–1331, https://doi.org/10.1248/cpb.58.1328.

[41] J.D. Bancroft, M. Gamble, Theory and Practice of Histological Techniques, (2008):

Elsevier Health Sciences (2008).

[42] M.A. Abdelgawad, M.B. Labib, W.A.M. Ali, G. Kamel, A.A. Azouz, E.S. EL-Nahass,

Design, synthesis, analgesic, anti-inﬂammatory activity of novel pyrazolones

possessing aminosulfonyl pharmacophore as inhibitors of COX-2/5-LOX enzymes:

Histopathological and docking studies, Bioorg Chem. 78 (2018) 103–114, https://

doi.org/10.1016/j.bioorg.2018.03.011.

[38] C.A. Winter, E.A. Risley, G.W. Nuss, Carrageenin-induced edema in hind paw of the

rat as an assay for anti-inﬂammatory drugs, Proc Soc Exp Biol Med. 111 (3) (1962)

544–547, https://doi.org/10.3181/00379727-111-27849.

[39] Khaled R.A. Abdellatif, Mohamed A. Abdelgawad, Heba A.H. Elshemy, Shahinda S.

R. Alsayed, Design, synthesis and biological screening of new 4-thiazolidinone

derivatives with promising COX-2 selectivity, anti-inﬂammatory activity and

gastric safety proﬁle, Bioorg Chem 64 (2016) 1–12, https://doi.org/10.1016/j.

bioorg.2015.11.001.

[43] E.H. Hassanein, O.A. Abd Elghafar, M.A. Ahmed, W.M. Gad-Elrab, J.S. Ajarem, A.

A. Allam, A.M. Mahmoud, Edaravone and acetovanillone upregulate NRF2 and

PI3k/AKT/mtor signaling and prevent cyclophosphamide cardiotoxicity in Rats,

Drug Des Devel Ther. 14 (2020) 5275–5288, https://doi.org/10.2147/DDDT.

S281854.

[40] Chi H. Cho, Clive W. Ogle, Cholinergic-mediated gastric mast cell degranulation

with subsequent histamine H1- and H2-receptor activation in stress ulceration in

20

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