Development of diarylpentadienone analogues as alpha-glucosidase inhibitor: Synthesis, in vitro biological and in vivo toxicity evaluations, and molecular docking analysis

B i o o r g an i c C h e m i s tr y 1 0 4 (2 020 )1 04277

Contents lists available at ScienceDirect

Bioorganic Chemistry

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

Development of diarylpentadienone analogues as alpha-glucosidase

inhibitor: Synthesis, in vitro biological and in vivo toxicity evaluations, and

molecular docking analysis

Maryam Aisyah Abdullah^a,1, Yu-Ri Lee^b,1, Siti Nurulhuda Mastuki^c, Sze Wei Leong^c,

Wan Norhamidah Wan Ibrahim^c,d, Muhammad Alif Mohammad Latif^e, Aizi Nor Mazila Ramli^f,

⁎

Mohd Fadhlizil Fasihi Mohd Aluwi^f, Siti Munirah Mohd Faudzi^a,c,, Cheol-Hee Kim^b,

^aDepartment of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

^bDepartment of Biology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, South Korea

^cLaboratory of Natural Products, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

^dDepartment of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

^eDepartment of Chemistry, Centre of Foundation Studies for Agricultural Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

^fFaculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, Gambang, Kuantan, 26300 Pahang, Malaysia

A R T I C L E I N F O

A B S T R A C T

Keywords:

A series of aminated- (1–9) and sulfonamide-containing diarylpentadienones (10–18) were synthesized, struc-

turally characterized, and evaluated for their in vitro anti-diabetic potential on α-glucosidase and DPP-4 en-

zymes. It was found that all the new molecules were non-associated PAINS compounds. The sulfonamide-con-

taining series (compounds 10–18) selectively inhibited α-glucosidase over DPP-4, in which compound 18

Diarylpentadienones

Sulfonamide

α-glucosidase inhibitor

Zebraﬁsh

demonstrated the highest activity with an IC₅₀value of 5.69

0.5 µM through a competitive inhibition me-

Molecular docking

chanism. Structure-activity relationship (SAR) studies concluded that the introduction of the tri-

ﬂuoromethylbenzene sulfonamide moiety was essential for the suppression of α-glucosidase. The most active

compound 18, was then further tested for in vivo toxicities using the zebraﬁsh animal model, with no toxic eﬀects

detected in the normal embryonic development, blood vessel formation, and apoptosis of zebraﬁsh. Docking

simulation studies were also carried out to better understand the binding interactions of compound 18 towards

the homology modeled α -glucosidase and the human lysosomal α -glucosidase enzymes. The overall results

suggest that the new sulfonamide-containing diarylpentadienones, compound 18, could be a promising candi-

date in the search for a new α-glucosidase inhibitor, and can serve as a basis for further studies involving hit-to-

lead optimization, in vivo eﬃcacy and safety assessment in an animal model and mechanism of action for the

treatment of T2DM patients.

1. Introduction

source of fuel, glucose [2]. As reported by the International Diabetes

Federation (IDF), T2DM comprises approximately 90% of all cases of

Diabetes mellitus or diabetes has become an increasing problem

worldwide, both in rich and poor countries. It is a chronic and pro-

gressive disease associated with elevated glucose levels in the blood and

is known as hyperglycaemia if the condition persists over a prolonged

period. Over time, diabetes may lead to complications such as heart

attack, stroke, kidney failure, leg amputation, vision loss, and nerve

damage [1]. Most diabetes patients are aﬀected by type 2 diabetes

mellitus (T2DM), a metabolic disorder that is often coupled with insulin

resistance that aﬀects the way the body metabolises its important

diabetes, and to date, it is estimated that 15 million people are aﬀected

globally [3]. Previously, T2DM had only been diagnosed in older adults,

but surprisingly, the current statistics show that T2DM is becoming

more prevalent among children and adolescents due to escalating

obesity and overweight incidences among the youth [1]. While current

T2DM therapies involving the increase of insulin secretion have shown

therapeutically beneﬁcial eﬀects, these are often accompanied by un-

desirable side eﬀects such as hypoglycaemia and weight gain. Due to

the reported adverse side eﬀects, most of these treatments are

^⁎Corresponding authors at: Laboratory of Natural Products, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

E-mail addresses: sitimunirah@upm.edu.my (S.M. Mohd Faudzi), zebrakim@cnu.ac.kr (C.-H. Kim).

¹These authors contributed equally.

https://doi.org/10.1016/j.bioorg.2020.104277

Received 2 March 2020; Received in revised form 31 July 2020; Accepted 10 September 2020

A v a i l a b l e o n l i n e 1 4 S ep t e m b e r 2 020

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

unsatisfactory with regards to the prevention of complications and

preservation of quality of life [4]. Thus, there is a signiﬁcant medical

need for the discovery of new and eﬀective anti-diabetic agents for the

treatment of T2DM.

bioactivities of diarylpentadienone derivatives, to the best of our

knowledge, there is very little scientiﬁc information with regards to

their potential as an anti-diabetic drug.

Thus, in continuation of our endeavors toward exploration of the

therapeutic potential and clinical implication of diarylpentadienones

particularly as α-glucosidase and DPP-4 inhibitors, we herein report the

design, synthesis, in vitro biological evaluation, toxicity proﬁling using

zebraﬁsh in vivo animal model, and molecular docking of a new series of

integrated sulfonamide-containing diarylpentadienones as potential

anti-diabetic agents for the treatment of T2DM.

α-Glucosidase is an enzyme that catalyses the ﬁnal steps in the di-

gestion of carbohydrate; hence, α-glucosidase inhibitors could retard

the catabolism of dietary carbohydrates to suppress postprandial hy-

perglycaemia. There are arguments that α-glucosidase inhibitors such

as acarbose (Glucobay) and miglitol (Glyset), although eﬀective in

decreasing the absorption of glucose by interfering with the action of α-

glucosidases in the small intestinal mucosa, are often associated with

abdominal bloating, diarrhoea, and ﬂatulence [5]. α-Glucosidase in-

hibitors also raise post-meal levels of glucagon-like peptide-1 (GLP-1),

an incretin hormone secreted by the intestine following the ingestion of

various nutrients to stimulate insulin secretion and inhibit glucagon

release, which slows the gastric emptying process and suppresses ap-

petite [6]. This means that they do not increase the likelihood of weight

gain, unlike sulfonylureas and thiazolidinediones [7].

2. Results and discussions

2.1. Pan-assay interference compounds (PAINS) and aggregator

identiﬁcation

PAINS is deﬁned as a substance with reactive structural cores that

may give false-positive results in biological assays due to several me-

chanisms, including protein binding interactions [40] and the forma-

tion of colloidal aggregates [41]. Scientiﬁc manuscripts primarily re-

porting on the activity and therapeutic utility of curcuminoids and

chalconoids-related compounds are regularly published and has caught

the attention of the scientiﬁc community. Chalconoids, a derivative of

curcumin has been previously reported as a PAINS-associated class of

compounds due to its reactive α,β-unsaturated ketone linker moiety. In

order to avoid any misleading information, the identiﬁcation of any

PAINS-containing molecules in the newly designed bioactive candidates

prior to the synthesis work has become a crucial step to validate that

the function of a compound is as expected. In view of this, we input all

18 newly designed diarylpentadienones and its derivatives into publicly

available ﬁlter servers, FAF-Drugs4 [42] and Aggregator Advisor [43]

for PAINS and aggregator identiﬁcation, respectively.

Since 2006, dipeptidyl peptidase-4 (DPP-4) inhibitors have become

a new class of agents that are proven to be an eﬀective treatment of

diabetes by improving glycaemic control [8]. DPP-4 inhibitors target

DPP-4, a serine protease enzyme which deactivates two potent stimu-

lators of insulin secretion, GLP-1, and glucose-dependent insulinotropic

polypeptide (gastric inhibitory polypeptide or GIP) [9]. Like GLP-1, GIP

also helps to delay digestion and decrease appetite. However, both

hormones are rapidly cleaved to their inactive forms by the enzyme

DPP-4, thus, reducing their potency in preventing diabetes-related

complications. Therefore, it is important to note that inhibition of DPP-

4 is compulsory to increase levels of endogenous incretin hormones

GLP-1 and GIP for the treatment of diabetes [10].

Chalcone is a small bioactive molecule composing of 1,3-diarylprop-

2-en-1-one framework and is one of the abundant secondary metabo-

lites of terrestrial plants and precursors of ﬂavonoid biosynthesis

[11–13,33]. These molecules have been receiving great attention by the

scientiﬁc community due to its simple chemistry, ease of synthesis,

diversity of substituents, safety, and a vast number of recognized bio-

logical activities, including anti-obesity, anti-hypertensive and anti-

diabetic activities [13–15]. Several reports even indicate that chalcones

may inhibit the enzymes α-amylase [16–19] and α-glucosidase

[16,20–24]. Seo et al. (2005) reported aminated series of chalcone

exhibited greater inhibition of three glycosidase enzymes (α-glucosi-

dase from baker’s yeast, α-amylase from Bacillus licheniformis and β-

amylase from barley) over other chalcone derivatives. The α-glucosi-

dase inhibitory was then improved progressively when the aminated

series were chemically modiﬁed into sulfonamide chalcones, which

shown 150-fold stronger suppression than acarbose [25].

Based on the PAINS identiﬁcation analysis, none of the newly syn-

thesized molecules were PAINS-associated compounds (see Supporting

Information). Likewise, through the in-silico aggregator prediction

analysis, none of the compounds were similar to any known aggregator.

However, all molecules (compounds 1–18) were predicted with a

highly calculated LogP (3.4 to 6.7) and may be potential aggregates.

The respective LogP range (> 3) was previously reported in many other

aggregators [44].

To test this prediction, we intended to investigate aggregation in the

identiﬁed prominent α-glucosidase inhibitor 18 (as discussed in Section

2.3) via centrifugation counter-screen technique [45]. However, due to

sample availability and a complex puriﬁcation of 18 , we, therefore, use

its ortho-analogue 16 as the tested compound. Theoretically, this

method induces the formation of pellets originating from aggregates,

leaving only the monomeric compound in the post-centrifugation su-

pernatants as illustrated in Fig. 1, and thus lowering the bioactivity

when compared to pre-centrifugation tested sample [46,45].

Sulfonamide, too, has received a lot of attention and is used as an

intermediate functional group in many therapeutic drugs [26]. Several

synthetic pharmacological agents that consist of a sulfonamide group

possess anti-bacterial [27], antimalarial [28], diuretic [29], anti-rheu-

matic [30], and anti-retroviral properties [31]. Previous studies also

reported that sulfonamide-containing compounds are essential for DPP-

4 inhibitory activity [32].

As depicted in Fig. 2, the recorded α-glucosidase inhibitory activ-

ities of pre- and post-centrifuged supernatants of 16 was almost com-

parable with IC₅₀of 8.56

2.3 µM and 9.92

2.3 µM, respectively.

Moreover, Rocha et al. (2019) investigated the eﬀect of an extra

double bond on the enone linker chain of the synthesized chalcone

derivative, the diarylpentadienone against α-glucosidase [33]. Results

revealed a slight improvement in the inhibitory activity of dia-

rylpentadienones when compared to its chalcone derivative and the

standard α-glucosidase inhibitor (AGI), acarbose. Recently, researchers

have discovered diarylpentadienone analogues along with their various

pharmacological activities, including promising anti-inﬂammatory

property, signiﬁcant anti-cancer eﬀect towards leukaemia and breast

cancer, excellent anti-microbial, anti-fungal, and anti-rhinovirus prop-

erties, and as an eﬀective antioxidant [34–39]. Despite the numerous

These results herein verify that the inhibitory property of 16 did not

attribute to the formation of the aggregates, which indirectly gave a

hint of the non-aggregate characteristic of 18.

In this study, we particularly would like to reinforce the importance

of identifying artifactual aggregates as a fundamental step in experi-

mental validation to avoid promiscuous inhibition that may lead to

false-positive bioactivity [44,47–49]. This can be achieved by per-

forming the computational predictions and accurate experimental

procedures to control for aggregation in minimizing the impact of this

important issue in drug design. Regrettably, only a few studies have

directly addressed this issue in the published literature.

2

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

Fig. 1. Aggregates (top panel) can be removed via centrifugation of samples. If the post-centrifugation supernatant aliquots show reduced inhibitory activity

compared to the pre-centrifugation sample, the compound is suspected to be an aggregator. In contrast, non-aggregators (bottom panel) recorded similar bioactivity

on pre- and post-centrifugation tested samples [45].

100

Transform Infra-Red (FTIR), and Direct Infusion-Mass Spectrometry

IC₅₀un-centrifuged : 8.56 2.3 µM

(DIMS).

IC₅₀centrifuged : 9.92 2.0 µM

The ¹H NMR spectra of all aminated-diarylpentadienone analogues

80

exhibited a moderate and broad singlet at 5–7 ppm, indicative of pri-

mary amine groups. The signal becomes weaker after the introduction

60

of sulfonamide moiety. DIMS and FT-IR results further verify that all the

compounds were successfully synthesized. The molecular ion peak de-

tected in each DIMS spectrum was compatible with their respective

40

molecular formula. For instance, the IR spectra of compounds 1–9 show

a

weak band at 3100–3300 cm⁻¹and

a

strong band at

1500–1600 cm⁻¹due to the NeH and C]O stretching vibrations, re-

spectively. Meanwhile, compounds 10–18 shows a weak band around

3100–3300 cm⁻¹due to the NeH stretching of a secondary amine and

1500–1600 cm⁻¹due to the C]O stretching vibrations. Two strong

absorption bands were observed around 1200 and 1000 cm⁻¹, in-

dicating the asymmetric and symmetric stretching peak of the SO₂

group.

20

0

pre-centrifugation

post-centrifugation

0.0

0.5

1.0

1.5

log [16]

Fig. 2. Dose-response curves of 16 to determine aggregate formation using

centrifugation counter-screen technique.

It was observed, with the use of the Claisen-Schmidt condensation

reaction carried out at room temperature overnight, that low amounts

of crude aminated-diarypentadienones (1–9) were produced at ap-

proximately 7% − 40% yield. Under these conditions, the possibility of

the Cannizaro reaction taking place simultaneously was considered,

thereby decreasing the yield of the desired product [50].

2.2. Chemistry

The aminated-diarylpentadienones (1–9) were synthesized via

Claisen-Schmidt condensation of the appropriate cinnamaldehydes and

aminoacetophenones in the presence of a catalytic amount of NaOH.

Further sulfonylation reaction between compounds 1–9 and p-tri-

ﬂuoromethylbenzenesulfonyl chloride to aﬀorded sulfonamide-con-

taining diarylpentadienones (10–18) is described in Scheme 1. All the

synthesized compounds were puriﬁed by ﬂash chromatography and

recrystallization techniques and were structurally characterized by

spectroscopic analyses, including the ¹H and ¹³C NMR, Fourier

2.3. In vitro α-glucosidase and DPP-4 inhibition activities

Eighteen puriﬁed diarylpentadienone derivatives (1–18) were

ﬁrstly screened in vitro against α-glucosidase and DPP-4 enzymes at

50 µM and 100 µM test concentrations, respectively. Based on the

preliminary evaluation, nine compounds (10–18) were signiﬁcantly

O

S Cl

O

H

O

S

O

R

F₃C

CH₃

F₃C

HN

R

H₂N

R

H₂N

a

b

1-9

10-18

Scheme 1. General synthetic step for compounds 1–18. Reagents and conditions: (a) amino-acetophenone, 6 M NaOH, EtOH, RT (overnight), (b) p-tri-

ﬂuoromethylbenzenesulfonyl chloride, pyridine, MeOH, RT (overnight).

3

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

Table 1

α-Glucosidase and DPP-4 suppression of the tested diarylpentadienone derivatives 1–18. Data are presented as mean

SEM, and n = 3

.

Compound

R₁(Ring A)

R₂(Ring B)

α-Glucosidase^#

DPP-4^#

Inhibition at 50 µM (%)

^aIC₅₀(µM)

SEM

Inhibition at 100 µM (%)

^bIC₅₀(µM)

SEM

1

2

3

4

5

6

7

8

9

2-NH₂

3-NH₂

4-NH₂

2-NH₂

3-NH₂

4-NH₂

2-NH₂

3-NH₂

4-NH₂

H

4.27

0.2

0.1

ND

70.20

26.85

68.78

68.40

31.11

44.48

37.75

46.10

70.02

2.0

0.7

4.2

5.9

10.0

3.6

3.2

3.0

1.6

26.91

ND

2.3

H

59.60

36.65

37.21

24.07

24.10

20.61

54.02

59.85

H

0.1

0.2

0.1

0.2

0.1

ND

OMe

Cl

ND

Cl

ND

Cl

79.02

2.9

4.4

10

11

12

13

14

15

16

17

18

H

95.56

83.10

92.61

94.35

96.91

93.99

98.80

97.17

99.16

97.79

–

5.1

1.6

2.6

3.7

1.7

9.1

1.2

3.5

7.5

0.1*

6.29

7.16

8.63

14.04

11.69

12.16

8.56

7.21

5.69

0.22

–

0.9

72.76

47.96

48.33

62.38

71.52

75.49

66.68

58.59

53.46

0.5

3.9

3.7

5.0

0.9

2.9

2.8

2.2

3.2

54.08

ND

H

0.5

4.4

H

ND

OMe

Cl

1.2

ND

0.9

2.1

33.67

17.81

ND

0.8

0.3

2.3

Cl

0.4

ND

Cl

0.5

ND

Acarbose*

0.1*

Sitagliptin^**

88.48

3.1

0.07

0.1

ND = Compound is not determined

* Standard drug used for α-glucosidase inhibitory assay, screened at initial concentration of 3.91 µM

** Standard drug used for DPP-4 inhibitory assay

a

b

#

IC₅₀determination was conducted for compounds of > 80% α-glucosidase inhibition

IC₅₀determination was conducted for compounds of > 70% DPP-4 inhibition

The IC₅₀graph of the respective compounds can be found in the Supporting Information

inhibited at > 80% α-glucosidase, whereas ﬁve analogues (1, 9, 10,

14, and 15) were shown to exhibit good suppression at > 70% on

DPP-4 enzyme, indicating that these new diarylpentadienones may

potentially possess anti-diabetic properties. The IC₅₀values of fourteen

bioactive compounds were further determined and were compared to

the standard anti-diabetic drugs, acarbose and sitagliptin, respectively.

The overall inhibitory eﬀects of α-glucosidase and DPP-4 towards the

aminated- and sulfonylated-diarylpentanoids (1–18) are tabulated in

Table 1.

(IC₅₀= 8.63

(IC₅₀= 11.69

(IC₅₀= 8.56

4.4 µM), 13 (IC₅₀= 14.04

0.9 µM), 15 (IC₅₀= 12.16

2.3 µM) and 17 (IC₅₀= 7.21

1.2 µM), 14

2.1 µM), 16

0.4 µM) have pro-

gressively improved the α-glucosidase inhibitory activity compared to

their parent aminated-diarylpentadienones (compounds 1–9), which is

further verifying the importance of the sulfonamide. The O]S = O of

the triﬂuoromethylbenzene sulfonamide (p-CF₃C₆H₄SO₂) group might

contribute to the increase in the hydrogen bonding capabilities of the

bioactive molecules towards α-glucosidase enzyme, coupled with the

reducing basicity of the sulfonamide moiety, which has ultimately im-

proved the targeted bioactivity (the interactions will be discussed in

detail in Section 2.5).

The α-glucosidase bioassay was conducted using α-glucosidase from

Bacillus stearothermophilus as the target enzyme according to the pro-

tocol in optimal conditions [51,52]. Acarbose was used as a standard

positive control in this in vitro assay for activity comparison. From the

results obtained, the aminated-diarylpentadienones (1–9) showed

lower percentages of α-glucosidase inhibition compared to the sulfo-

namide-containing series (10–18) and were too inactive than acarbose.

This observation might have been due to the higher basicity of the

primary amino group of compounds 1–9, which may have reduced the

inhibitory activity, regardless of the position of the amino moiety on

phenyl Ring A (ortho/meta/para).

Following that, we investigated the impacts of substituents with

diﬀerent electronic properties on Ring B of the sulfonamide-containing

diarylpentadienone series, which was responsible for the varying de-

grees of anti-diabetic potency. Interestingly, the lower electron density,

p-chloro-substituted and unsubstituted phenyl on ring B compounds

(10–12 and 16–18) demonstrated slightly higher α-glucosidase in-

hibition than the p-methoxy-substituted (13, 14, and 15) analogues. It

is therefore suggested, through this preliminary works, that the pre-

sence of electron-withdrawing groups or a lower electron density

moiety (e.g., halogens) on Ring B accompanied with the sulfonamide

group on Ring A of diarylpentadienone scaﬀold are the features that

were responsible towards signiﬁcant α-glucosidase inhibition.

On the other hand, it is interesting to note that the α-glucosidase

suppression ability was enhanced signiﬁcantly with the IC₅₀values

ranging from 5.69 to 12.16 µM when the sulfonamide moiety was in-

troduced on Ring A, regardless of the ortho, meta, and para positioning.

The result of the α-glucosidase suppression screening showed that

compound 18 displayed signiﬁcant α-glucosidase inhibitory activity

In addition, we compared the eﬀects of ortho-, meta-, and para-

substitution of sulfonamide on the Ring A feature towards α-glucosi-

dase suppression. It was apparent that the para-sulfonamide substituted

compound 18, together with the para-chloro group on Ring B, showed

higher inhibitory activity, whereas the ortho- and meta-sulfonamide

substituted analogues exhibited a slightly lower yet comparable α-

with IC₅₀values of 5.69

0.5 µM in a dose-dependent manner

(Fig. 3), however, the potency was 27-folds lower to acarbose (IC₅₀

value of 0.21

(IC₅₀= 6.29

0.1 µM). Whereas, compounds 10

0.9 µM) , 11 (IC₅₀= 7.16 1.6 µM), 12

4

M.A. Abdullah, et al.

150

BioorganicChemistry104(2020)104277

150

IC₅₀: 5.69 0.5 µM

R²: 0.985

IC₅₀: 0.21 0.1 µM

R²

: 0.9922

100

50

100

50

0

-3

-2

-1

0

1

0.0

0.5

1.0

log [18]

1.5

2.0

log [Acarbose]

Fig. 3. Dose-response curve of compound 18 and acarbose on α-glucosidase inhibition.

glucosidase inhibition activity when Ring B was replaced with free

phenyl and para-methoxyphenyl, respectively. These ﬁndings further

conﬁrmed the enhancing eﬀect of para-substitution and the critical role

of sulfonamide moiety in α-glucosidase inhibitory activity.

The analysis was carried out by investigating the eﬀects of inhibitors’

concentration (0, 2.5, 5.0, 7.5, 10.0, 12.5, 15.0 and 20.0 µM) on en-

zyme activity at diﬀerent concentrations of substrate (1.25, 2, 4, 10, 20

and 30 mM). As depicted in Fig. 4, analogue 18 behaved as a compe-

titive inhibitor, as the K_mvalue increase and V_maxremained constant

with increasing concentrations of the compound.

In summary, these results revealed that the nature of substituents on

the phenyl ring B with diﬀerent sulfonamide locations on ring A of the

newly synthesized diarylpentadienones are closely associated with the

biological activities of α-glucosidase inhibitors. This information

gathered through structure–activity relationships (SAR) studies could

potentially guide future structural modiﬁcations of these sulfonylated-

diarylpentadienones for the improvement of α-glucosidase inhibitory

activity, as well as to identify new leads with desirable inhibitory

properties. In this regard, para-sulfonamide (Ring A) and para-chloro

were identiﬁed as the most important feature for α-glucosidase in-

hibitory activity.

2.5. In vivo toxicity test in zebraﬁsh embryos

In the last two decades, the zebraﬁsh has become extensively used

as a toxicological model, in part due to their small size, rapid external

development, short life cycle, high reproductive rate, and simple hus-

bandry requirements [53]. This in vivo model has been routinely used to

perform rapid risk assessments and regulations in addition to the

measurements of therapeutic activities of compounds through in vivo

approaches as it exhibits a diverse repertoire of biological processes and

possesses a fully integrated vertebrate organ system [54,55].

In order to proﬁle the toxic eﬀects of compound 18 that showed

promising potential as an α-glucosidase inhibitor, we treated zebraﬁsh

embryos with various dosages of the compound (1, 2, 5, 10, 20, and

40 µM) starting from 6 hpf via bath immersion. At 24 and 48 hpf,

morphological comparisons were made between exposed embryos

versus the control (Fig. 5) to observe any morphological deformities via

an embryo acute toxicity test.

Following the α-glucosidase in vitro assay, all the synthesized

compounds were also assayed for DPP-4 inhibition activity to explore

the potential of diarylpentadienones towards diﬀerent target enzymes

responsible for diabetes or T2DM. The standard drug, sitagliptin was

used as a positive control in the respective assays. Among all the de-

rivatives, compound 15 exhibited the highest activity in this series with

IC₅₀values of 17.81

0.3 µM. However, this compound showed

weaker activity by > 100 folds compared to the standard sitagliptin

(IC₅₀= 0.071

0.005 µM). In brief, no SAR can be summarized

throughout this ﬁnding, it is therefore suggested, further chemical

modiﬁcations on the structural core is needed to establish this class of

compound as new anti-DPP-4 agents.

As shown in Fig. 5, the treated embryos were alive after exposure to

compound 18 at 24 hpf and 48 hpf with no signs of morphological

deformities. Results showed that embryos treated with compound 18

displayed similar body length, yolk extension, curve trunks, somite

boundary, blood circulation, and pigment cell development compared

to the control, reﬂecting the non-toxic properties of compound 18 up to

40 µM.

2.4. Kinetic studies of 18 against α-glucosidase

The inhibition mechanism of the most active sulfonamide analogue

18 against α-glucosidase was deduced from the Lineweaver-Burk plot.

To further determine whether compound 18 may cause apoptosis or

cell death at 10, 20, and 40 uM concentrations, the treated embryos

were assessed using a vital ﬂuorescent dye, acridine orange (AO) at 108

hpf to mark apoptotic cells. Apoptosis is a critical component of the

normal developmental process in multiple tissues and organ systems.

The process of apoptotic cell death is highly conserved and follows a

morphologically distinctive pattern. Apoptosis can be described with

speciﬁc cellular shrinkage, membrane blebbing, nuclear condensation

and nuclear fragmentation that commonly recognized as hallmarks of

this type of cell death [56]. The vital dye AO staining technique has

been commonly applied for cell death monitoring in live animals, in-

cluding zebraﬁsh. Based on the results as depicted in Fig. 6, AO-positive

cells were clearly and broadly detected throughout the bodies of the

DMSO vehicle- and compound 18-treated transgenic zebraﬁsh at all

tested concentrations. The results indicate that compound 18 has no

negative interferences towards apoptosis in the developing zebraﬁsh

embryos as compared to the control.

120

Competitive inhibition

100

80

10 μM

60

7.5 μM

5 μM

40

20

0

2.5 μM

0 μM

-0.1

0

0.1

0.2

0.3

-20

1/[S] (mM^-1)

Fig. 4. Lineweaver-Burk plot analysis of the inhibition kinetics of α-glucosidase

suppression eﬀects by compound 18.

5

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

A

B

0.1% DMSO

24 hpf

48 hpf

0.1% DMSO

1 μM

2 μM

5 μM

1 μM

10 μM

20 μM

40 μM

10 μM

2 μM

5 μM

20 μM

40 μM

Fig. 5. Morphological features of zebraﬁsh larvae at diﬀerent developmental stages of (A) 24 hpf and (B) 48 hpf after exposure to compound 18 at various

concentrations, 1, 2, 5, 10, 20, and 40 µM, respectively. Scale bars, 200 µm.

development in the vertebrate model system. Since blood vessel func-

tion is critical for vertebrate embryonic development [58], we further

our investigations on the toxic eﬀects of compound 18 by using a

transgenic line of zebraﬁsh that speciﬁcally expresses green ﬂuorescent

protein (GFP) in their vascular endothelial cells, Tg(kdrl:egfp) to de-

lineate the normal development of the blood vessel. The late gastrula 10

hpf Tg(kdrl:egfp) zebraﬁsh embryos were incubated with compound 18

in diﬀerent concentrations of 10, 20, and 40 µM for a day and examined

at 30 hpf under a ﬂuorescent microscope. Compound 18 treatment up

to 40 µM revealed no adverse eﬀects on the normal development of

vasculature, including intersegmental vessels (ISVs), as shown in Fig. 7.

2.6. Molecular docking studies

In order to gain functional and structural insights into the binding

mode of the most active analogues into their respective protein, mo-

lecular docking was performed using AutoDockVina. Compound 18 was

selected for the docking studies into the homology modeled α-gluco-

sidase protein (PDB ID: 2ZE0) and human lysosomal acid α-glucosidase

(GAA, PDB ID: 5NN8), whereas compound 15 was selected for the

molecular interaction with DPP-4.

Fig. 6. (A) Eﬀects of long-term exposure (4.5 days) of compound 18 on zeb-

raﬁsh larvae at diﬀerent concentrations, 10, 20 and 40 μM, respectively. (B)

Acridine orange staining for cell death. Signals in yolk and lens are auto-

ﬂuorescence. Scale bars, 200 µm. (For interpretation of the references to colour

in this ﬁgure legend, the reader is referred to the web version of this article.)

Since the crystal structure of the α-glucosidase from Bacillus stear-

othermophilus was unavailable at the time of writing, a homology model

of the α-glucosidase was built according to a previously reported

method for the molecular docking analysis. α-Glucosidase of Bacillus

subtilis (PDB ID: 2ZE0) was chosen as the template for the respective

homology model since it shared 98.7% identity and possesses a se-

quence similarity score of 0.62 with α-glucosidase of Bacillus stear-

othermophilus (Swissprot code P53341/P38158). The homologous

Considering the conservation of the basic vascular pattern in dif-

ferent vertebrates, the signaling molecules and cellular mechanisms by

which blood vessels form have been evolutionarily conserved [57].

Consequently, it is possible to gain signiﬁcant insights into pathological

blood vessel formation through the study of embryonic vascular

10 uM

20 uM

40 uM

Control

ISV

Fig. 7. Eﬀects of compound 18 with diﬀerent concentrations (10, 20, and 40 µM) on the blood vessel development in transgenic zebraﬁsh, Tg(kdrl:egfp) at 30 hpf.

Vasculogenesis and angiogenesis, including intersegmental vessels (arrows), in the trunk region were normal in both the untreated control and compound 18-treated

zebraﬁsh. Scale bars, 200 µm.

6

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

Fig. 8. 3D and 2D diagram of the binding interactions of (A) compound 18 and (B) acarbose with the active site residues of the α-glucosidase receptor. (Green line: H

bond; orange line: π-cation/anion; purple line: π - π stacked/T-shaped; light purple: Alkyl/π-Alkyl). (For interpretation of the references to colour in this ﬁgure

legend, the reader is referred to the web version of this article.)

Table 2

Data of interactions resulting from the molecular docking of compounds 18 and acarbose into α-glucosidase.

Compound 18

Acarbose

Active site

Interactions

With

Bonding distance (Å)

Active site

Interactions

With

Bonding distance (Å)

Tyr15

Asn58

Trp434

H bond

S]O

2.88

2.84

4.59

5.20

Ala200

Asn324

Arg415

Asp199

H bond

OeH

O

2.98

2.296

2.26

2.21

H bond

S]O

π-alkyl/ Alkyl

π-π T-shaped

π-π stacked

π-π T-shaped

π-alkyl/ Alkyl

π-cation/anion

CF₃

Benzene (Phenyl sulfonamide)

OeH

Tyr63

Benzene (Ring B)

4.50

5.14

4.60

3.45

5.02

3.58

4.18

Asp326

Asp382

H bond

OeH

CeO

OeH

CeO

CH₃

2.86

2.38

2.88

2.27

3.42

3.74

3.45

3.97

4.95

4.40

Tyr63

Cl

H bond

His103

Ala200

Arg381

Asp382

Arg415

Cl

Carbon H bond

H bond

Cl

Ala59

Benzene (Phenyl sulfonamide)

Benzene (Ring A)

Glu256

Asn258

Asp60

Carbon H bond

π-sigma

Tyr63

Phe144

Phe163

π-alkyl

CH₃

protein was generated by the MODELER protocol and the optimized

structure was further validated by the Ramachandran plot (see

Supporting Information) obtained from RAMPAGE server. According to

the Ramachandran plot, 95.3% of residues were found in the favored

regions while 4.7% of residues were in the allowed regions. In addition,

with no detection of outlier residues, the generated homology model

was therefore deemed acceptable.

enhancing the α-glucosidase inhibition property. On the other hand, the

p-chloro group of the Ring B fragment displayed hydrophobic contact

(light purple dashed line) with Tyr63, His103, and Ala200 residues on

the active site. This observation could be used to explain the better

performance of chlorinated compounds compared to their respective

non-chlorinated analogues. Meanwhile, interaction mode of acarbose

with the homology modeled bacterial α-glucosidase protein revealed

several hydrogen-bonding interactions with the protein residues

(Ala200, Asn324, Arg415, Asp199, Asp326, Asp382 and Ala59) in the

active site of α-glucosidase (Fig. 8B), thereby justifying the higher α-

glucosidase inhibitory potency than 18. All the binding interactions

involved were tabulated in Table 2.

Based on the molecular docking analysis (Fig. 8A), the sulfonamide

moiety of compound 18 forms two strong hydrogen bonding (green

dashed line) interactions with Tyr15 and Asn58 residues. Meanwhile,

the phenyl moiety of Ring A was found to bond with Asp382 and

Arg415 residues, through the additional π-cation/anion (orange dashed

line) interactions, respectively. These ﬁndings, therefore, justify the

important role of the extended sulfonamide-containing Ring A in

Compound 1 – 17 were also docked individually into the same ac-

tive pocket site of homology bacterial α-glucosidase model to rationally

7

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

Table 3

domain is linked to a domain composed of β-sheet, catalytic (β/α)8

barrel made of two inserts β3 (insert I) and β4 (insert II), as well as the

proximal and distal β-sheet domains located at the C-terminus. The

substrate-binding pocket is narrow and positioned near the C-terminal

ends of β-strands of the catalytic (β/α)8 domain and was shaped by a

loop from the N-terminal β-sheet domain and both inserts I and II. The

Asp518 and Asp616 residues were determined to act as the catalytic

nucleophile and catalytic acid/base, respectively [59].

Data of selected interactions resulting from the molecular docking of com-

pounds 1–17 into α-glucosidase.

Compounds IC₅₀(µM)

Protein-ligand interactions

Ligand

Receptors Interaction

Bonding

distance

(Å)

Results showed that 18 binds with His674 and Asp616 via H-bonds

and the acidic residues (Asp404, Asp518 and Asp616) on the active site

by halogen (ﬂuorine) and π-anion interactions. Moreover, Trp481,

Trp516, Phe649 and His674 interacts hydrophobically to the tri-

ﬂuoromethylbenzene sulfonamide moiety, in which further conﬁrming

the critical role of the extended sulfonamide-containing Ring A frag-

ment in eliciting the α-glucosidase inhibitor potency of 18. For com-

parison, the standard drug acarbose was docked into the same active

site of this crystal. The multiple numbers of H-bonds formed between

acarbose with the Asp518, Asp616 and Arg600 residues of the GAA

active site, thus suggested a higher α-glucosidase inhibition activity

compared to 18. The binding interaction of compounds 18 and acar-

bose in the active site of human GAA are shown in Table 4.

1

2

3

4

5

ND

C]O

–

Arg415

–

H bond

–

2.45

2.46

–

–NH

C of

Asp382

Glu256

H bond

2.00

Carbon H bond 3.34

–OCH₃

C]O

NeH

S]O

6

ND

His103

Gln167

Glu256

Asp382

Asn58

H bond

2.70

2.04

2.07

2.04

2.00

2.65

2.34

2.66

1.98

3.06

4.90

2.65

2.69

2.49

2.73

5.19

2.20

3.18

3.16

2.49

2.80

2.35

3.43

4.91

2.92

2.52

H bond

7

8

ND

H bond

Asn58

H bond

9

ND

Asp382

Arg415

Asn61

H bond

10

6.29

0.9

H bond

Considering a multiple interactions between 18 and important re-

sidues in the active sites of human α-glucosidase, this bioactive ana-

logue 18 deserved further biological investigation with regards of its

potency on the expression of multiple human α-glucosidases including

lysosomal GAA, ER-localised GANAB and intestinal maltase-glucoa-

mylase (MGAM) towards the development of promising drug candi-

dates for the treatment of T2DM.

F of -CF₃Trp434

F of -CF₃Gln167

π-alkyl/ Alkyl

H bond

11

12

7.16

8.63

0.5

4.4

NeH

S]O

Asn258

Arg415

H bond

F of -CF₃Trp434

π-alkyl/ Alkyl

H bond

13

14

14.04

11.69

1.2 NeH

Asn258

F of -CF₃Gln167

Halogen (F)

H bond

Our study also focused on understanding the binding mode of dia-

rylpentadienone moiety, and to investigate the necessary interactions

required for DPP-4 inhibition. With the collected in vitro results in hand,

the most active compound 15 was further subjected to a molecular

docking study to explicate key molecular interactions. To begin, the

protein structure of DPP-4 (PDB ID: 5T4B) was retrieved from the

Brookhaven Protein Data Bank (PDB).

0.9 F of -CF₃Gln167

S]O

NeH

Arg197

Asp326

H bond

F of -CF₃Asp60

F of -CF₃Glu256

Halogen (F)

π-anion

15

12.16

2.1 S]O

Tyr15

H bond

S]O

C of

Arg415

Glu256

H bond

Carbon H bond 3.61

The DPP-4 enzyme consists of two domains, an eight-stranded β-

propeller domain at the N-terminus and an α/β-hydrolase domain at

the C-terminus. The X-ray crystal study of various inhibitors in complex

with DPP-4 revealed that the binding site of DPP-4 mainly comprises of

three parts: an S1 pocket, the N-terminal recognition region, and an S2

pocket. The S1 hydrophobic pocket consisted of residues Tyr631,

Val656, Trp659, Tyr662, Tyr666, and Val711 adjacent to the catalytic

triad of the active site. The active site is positioned in the hydrolase

domain and comprised of catalytic triad residues Ser630, Asp708, and

His740. The N-terminal recognition region is formed by Glu205,

Glu206, and Tyr662, while the hydrophobic S2 pocket, which is larger

compared with S1, is surrounded by residues Phe357, Arg358, Ser209,

and Tyr666.

–OCH₃

NeH

16

17

8.56

7.21

2.3

0.4

Asn258

H bond

2.07

3.16

3.19

2.49

2.80

2.46

3.23

F of -CF₃Gln167

Halogen (F)

H bond

S]O

NeH

Arg197

Asp326

H bond

F of -CF₃Asp60

Halogen (F)

explore their chemical space in the active sites and thus establish the

SAR. Based on the results, it is conceivable that the multiple H-bonds

generated through the N, O and/or F atoms of triﬂuoromethylbenzene

sulfonamide moiety in coupled with the halogen (ﬂuorine) bonds to the

active site residues as observed in the sulfonamide-containing analo-

gues (10–17) might contribute to the enhanced α-glucosidase in-

hibitory properties. On the contrary, the H-bonds formed through –NH

and C]O groups are less signiﬁcant to inﬂuence the α-glucosidase in-

hibition potency as exerted by 1–9, thus verifying the importance of the

triﬂuoromethylbenzene sulfonamide sub-structure of the molecules.

The selected binding interactions of 1 – 17 were summarized in Table 3,

while the docking illustrations were compiled in Supporting

Information.

Fig. 10 illustrates the molecular interactions of compound 15 with

DPP-4. It has been found that the oxygen of the carbonyl group present

on the bridge of the diarypentadienone forms a carbon-hydrogen bond

with Ser630, a vital residue for the N-terminal recognition site. The

secondary amino group present on Ring A protrudes towards the Ser630

and Tyr631 of the S1 pocket by creating a hydrogen bond with the

neighboring Tyr547. All other interactions are tabulated in Table 5.

2.7. Conclusion

Additionally, compound 18 was docked on the human lysosomal

acid α-glucosidase (GAA, PDB ID: 5NN8) active site to predict its

binding mechanism on the human α-glucosidase enzyme (Fig. 9A). The

catalytic site of human GAA is mainly composed of acidic (Asp404.

Asp518, Glu521 and Asp616) and basic residues (Arg600 and His674)

[59]. The structure of human α-glucosidase is resembling the structures

of human glucoside hydrolase family, GH311 homologues, maltase

glucoamylase and sucrase-isomaltase. The N-terminal trefoil type-P

In conclusion, a new series of non-PAINS associated diarylpenta-

dienone derivatives (1–18) were successfully synthesized and have

shown their potential as eﬀective and selective anti-diabetic promising

molecules against α-glucosidase through in vitro experimental evidence.

The signiﬁcance of p-sulfonamide-diarylpentadienones with haloge-

nated (-Cl) phenyl (Ring B) of compound 18 was demonstrated to

possess remarkable α-glucosidase inhibition activities with an IC₅₀

value of 5.69

0.7 µM through competitive mode. Furthermore,

8

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

Fig. 9. 3D and 2D diagram of the binding interactions of (A) compound 18 and (B) acarbose on the human lysosomal α-glucosidase receptor. (Green line: H bond;

orange line: π-cation/anion; purple line: π- π stacked/T-shaped; light purple: Alkyl/π-Alkyl; cyan line: Halogen (Fluorine); yellow line: π-Sulfur). (For interpretation

of the references to colour in this ﬁgure legend, the reader is referred to the web version of this article.)

compound 18 recorded no signs of toxicity, particularly on the normal

embryonic development, blood vessel formation and apoptosis of zeb-

raﬁsh in vivo model. Overall, these results suggest that compound 18

could be a promising candidate towards the discovery of a new anti-

diabetic agent and can serve as a basis for further studies involving the

in vivo eﬃcacy and safety assessment in the animal models.

converted to SMILES (Simpliﬁed Molecular Input Line Entry System)

format. The SMILES formulas were then converted into Symyx SDF

(Spatial Data File) ﬁle format as recommended by the FAF-Drugs4 Bank

Formatter

(http://mobyle.rpbs.univ-paris-diderot.fr/cgi-bin/portal.

py#forms::Bank-Formatter ), before automatically redirected as the

input ﬁle into the FAF-Drugs4 server (http://mobyle.rpbs.univ-paris-

diderot.fr/cgi-bin/portal.py#forms::FAF-Drugs4 ) for the ﬁltration of

PAINS using PAINS ﬁlter A, B, and C [42]. The generated results are

available at the following address (http://mobyle.rpbs.univ-paris-

diderot.fr/cgi-bin/portal.py?form=admetox#jobs::FAF-Drugs4.

T05472492539883 ).

3. Experimental section

3.1. PAINS and aggregator ﬁltration

3.1.1. In-silico PAINS identiﬁcation

All chemical structures of the diarylpentadienones series and its

derivatives were drawn using ChemDraw Ultra 12.0 and subsequently

3.1.2. In-silico aggregator identiﬁcation

The SMILES ﬁle containing the synthesized molecules generated

Table 4

Data of interactions resulting from the molecular docking of compounds 18 and acarbose into human lysosomal α-glucosidase.

Compound 18

Acarbose

Active site

Interactions

With

Bonding distance (Å)

Active site

Interactions

With

Bonding distance (Å)

His674

Asp616

Asp404

Asp518

Asp616

Trp481

Trp516

Phe649

His674

Ala284

Leu650

Leu678

H bond

F

2.11

2.07

3.70

3.54

3.82

5.40

5.53

5.10

5.25

5.37

5.08

5.50

5.28

Arg600

Met519

Asp282

H Bond

OeH

CeH

OeH

CeH

CH₃

1.92

2.26

2.25

2.61

2.71

1.94

3.10

2.62

2.70

2.29

4.40

H bond

NeH

H Bond

Halogen (ﬂuorine)

π-anion

F

H Bond

F

Carbon H Bond

H Bond

Benzene (Phenyl sulfonamide)

π-sulfur

S

Asp616

π-π T-shaped

π-alkyl

Benzene (Phenyl sulfonamide)

Carbon H Bond

π-alkyl

CF₃

π-alkyl

CF₃

Asp518

Asp616

Trp481

π-alkyl

CF₃

π-alkyl

Benzene (Ring A)

Benzene (Ring B)

π-alkyl

9

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

Fig. 10. 3D and 2D diagram of the binding interactions of compound 15 with the active site residues of the DPP-4 receptor. (Green line: H bond; light blue line:

Carbon/ π-donor H bond; purple line: π-π stacked/T-shaped; light purple: Alkyl/π-Alkyl).

homogenous, before the addition of 2.2 mmol cinnamaldehyde into the

resultant mixture and was left to stir overnight. The general reaction is

depicted in a synthetic pathway in Scheme 1. After the reaction was

completed and veriﬁed by TLC, crushed ice was added into the reaction

ﬂask and was slowly stirred to quench the reaction. Following that, the

resultant reaction mixture was extracted with ethyl acetate (10 ml × 3

times) before further washing with brine. The organic layer was col-

lected, ﬁltered over anhydrous magnesium sulphate (MgSO₄), and dried

by rotary evaporator to yield the crude products (1–9).

Table 5

Data of interactions resulting from the molecular docking of compounds 15

with DPP-4 active sites.

Active site

Interactions

With

Bonding distance

(Å)

Ser630

Trp629

Tyr666

H bond

carbonyl

Benzene (Phenyl

sulfonamide)

CF₃

3.55

3.57

3.91

4.03

π donor H bond

Carbon H bond

Tyr547

π-π stacked

H bond

Benzene (Ring A)

Amine

5.40

2.63

2.92

4.80

4.03

5.38

5.28

3.3.1. 1-(2-Aminophenyl)-5-phenylpenta-2,4-dien-1-one (1)

Orange solid; 7% crude; mp 79-80˚C; IR (UATR) 3448, 3352 (NH),

H bond

S]O

1562 (C]O), 1448 (C]C) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆):

Val656

Tyr662

Tyr631

Trp659

π-alkyl / Alkyl

CF₃

δ = 6.62 (ddd, J = 8.3, 6.8, 1.5 Hz, 1H, Ar-CH), 6.83 (d, J = 8.3 Hz,

1H, Ar-CH), 7.12 (d, J = 15.8 Hz, 1H, CH = CH-Ar), 7.24 (d,

J = 10.7 Hz, 1H, Ar-CH), 7.27 (dd, J = 15.8, 7.7 Hz, 1H, CH = CH-Ar),

7.34 (t, J = 7.3 Hz, 1H, Ar-CH), 7.40 (d, J = 7.0, 2H, 2 × Ar-CH), 7.43

(d, J = 14.6 Hz, 1H, COCH = CH), 7.53 (dd, J = 14.6, 10.7 Hz, 1H,

COCH = CH), 7.61 (d, J = 7.5 Hz, 2H, 2 × Ar-CH), 7.90 (dd, J = 8.0,

1.1 Hz, 1H, Ar-CH). ¹³C NMR (126 MHz, acetone‑d₆): δ = 114.8, 116.9,

117.07, 126.8, 127.1 (2 × Ar-CH), 127.5, 128.7 (2 × Ar-CH), 130.7,

133.9, 136.6, 140.1, 142.36, 190.65; HRMS (ESI): m/z calcd for

CF₃

from the in-silico PAINS analysis was input into the Aggregator Advisor

server (http://advisor.bkslab.org/) for the identiﬁcation of potential

aggregators [51].

3.2. Material and equipment

C

₁₇H₁₅ON-H^-: 248.0790 [M−H]^-; found: 248.0788.

All chemicals and reagents were purchased from Merck and Sigma

Aldrich. The solvents used in the spectroscopic measurements were of

spectroscopic grade. The reaction mixtures were extracted with suitable

organic solvents, dried over anhydrous magnesium sulphate, and con-

centrated by a rotatory evaporator. The progress of the reaction was

monitored via thin layer chromatography using aluminium TLC sheets

of silica gel 60 f254 (layer thickness 0.2 mm) from Merck.

Subsequently, the puriﬁcation was performed via gravitational column

chromatography using Merck silica gel 60 PF₂₅₄No. 7734 (mesh

70–230) and Merck silica gel 60 PF₂₅₄No. 9835 (mesh 230–400). Mass

spectra were recorded using a GCMS-QP5050A (Shimadzu, Kyoto,

Japan) Mass Spectrometer. ¹H and ¹³C NMR spectra were measured in

CDCl₃(unless otherwise indicated) on a Varian 500 MHz NMR

Spectrometer (Varian Inc., California, USA). Chemical shifts were re-

ported in δ (ppm) values relative to the standard tetramethylsilane

(TMS), while the melting points were determined using a Fisher-Johns

melting point apparatus.

3.3.2. 1-(3-Aminophenyl)-5-phenylpenta-2,4-dien-1-one (2)

Yellow solid; 40% crude; mp 142-143˚C; IR (UATR) 3358 (NH),

1572 (C]O), 1275 (C]C) cm⁻¹

,

¹H NMR (500 MHz, acetone‑d₆):

δ = 4.93 (s, 2H, NH₂), 6.92 (d, J = 7.4 Hz, 1H, Ar-CH), 7.17 (app. t,

J = 15.9 Hz, 1H, CH = CH-Ar), 7.21 (d, J = 7.0 Hz, 1H, Ar-CH), 7.22

(d, J = 8.6 Hz, 1H, Ar-CH), 7.25 (d, J = 14.6 Hz, 1H, COCH = CH),

7.26 (d, J = 15.9 Hz, 1H, CH = CH-Ar), 7.32 (s,1H), 7.35 (d,

J = 7.1 Hz, 1H, Ar-CH), 7.40 (d, J = 7.4 Hz, 1H, Ar-CH), 7.41 (t,

J = 7.4 Hz, 1H, Ar-CH), 7.54 (dd, J = 14.8, 1H, COCH = CH), 7.61 (d,

J = 7.5 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz, acetone‑d₆):

δ = 113.1, 116.8, 118.7, 125.9 (2 × Ar-CH), 127.3, 127.4, 128.9

(2 × Ar-CH), 129.1, 129.2, 136.6, 139.2, 141.1, 143.7; HRMS (ESI): m/

z calcd for C₁₇H₁₅ON-H^-: 248.0790 [M−H]^-; found: 248.0786.

3.3.3. 1-(4-Aminophenyl)-5-phenylpenta-2,4-dien-1-one (3)

Yellow solid; 57% crude; mp 194-195˚C; IR (UATR) 3331, 3206

(NH), 1561 (C]O), 1256 (C]C) cm⁻¹

;

¹H NMR (500 MHz, acet-

3.3. General procedure for the synthesis of aminated-diarylpentadienone

one‑d₆): δ = 5.56 (s, 2H, NH₂), 6.74 (d, J = 7.5 Hz, 2H, 2 × Ar-CH),

7.09 (d, J = 15.6 Hz, 1H, CH = CH-Ar), 7.22 (dd, J = 15.6, 10.9 Hz,

1H, CH = CH-Ar), 7.33 (d, J = 14.7 Hz, 1H, COCH = CH), 7.34 (d,

J = 7.4 Hz, 1H, Ar-CH), 7.40 (t, J = 7.5 Hz, 2H, 2 × Ar-CH), 7.50 (dd,

J = 14.7, 10.9 Hz, 1H, COCH = CH), 7.59 (d, J = 7.5 Hz, 2H, 2 × Ar-

CH), 7.88 (d, J = 5.6 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz,

(1–9)

In cold conditions, 2 mmol of aminoacetophenones were ﬁrst dis-

solved in 10 ml of ethanol prior to the drop-wise addition of 1 ml 6 M

NaOH aqueous solution. The mixed solution was stirred until

10

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

acetone‑d₆): δ = 113.0, 113.1, 125.9, 126.9, 127.0 (2 × Ar-CH), 127.6,

128.7, 128.8 (2 × Ar-CH), 130.6 (2 × Ar-CH), 136.6, 139.8, 141.8,

153.3, 186.2; HRMS (ESI): m/z calcd for C₁₇H₁₅ON-H^-: 248.0790

[M−H]^-; found: 248.0788.

CH), 7.18 (d, J = 15.8 Hz, 1H, CH = CH-Ar), 7.23 (d, 15.0, 1H,

COCH = CH), 7.23 (app. d, 1H), 7.24 (dd, 15.8, 10.8, CH = CH-Ar),

7.25 (d, J = 5.5, 1H, Ar-CH), 7.31 (s, 1H, Ar-CH), 7.44 (d, J = 8.5 Hz,

2H, 2 × Ar-CH), 7.54 (dd, J = 15.0, 10.8 Hz, 1H, COCH = CH), 7.63

(d, J = 8.5 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz, acetone‑d₆):

δ = 113.3, 116.7, 118.6, 126.4, 128.1, 128.7 (2 × Ar-CH), 128.9

(2 × Ar-CH), 129.1, 134.0, 135.3, 139.1, 139.4, 143.2, 148.9, 189.4;

HRMS (ESI): m/z calcd for C₁₇H₁₄ClNO-H^-: 282.0610 [M−H]^-; found:

282.0613.

3.3.4. 1-(2-Aminophenyl)-5-(4-methoxyphenyl)penta-2,4-dien-1-one (4)

Yellow solid; 10% crude; mp 95-96˚C; IR (UATR) 3297 (NH, str.),

2918 (sp³CH, str.) 1538 (C]O, str.), 1349 (C]C, str.) cm⁻¹; ¹H NMR

(500 MHz, CDCl₃): δ = 3.84 (s, 3H, CH₃), 6.30 (s, 2H, NH₂), 6.67 (d,

J = 7.1 Hz, 1H, Ar-CH), 6.68 (d, J = 8.4 Hz, 1H, Ar-CH), 6.91 (td,

J = 9.2, 1.7 Hz, 1H, Ar-CH), 6.91 (d, J = 15.3 Hz, 1H, CH = CH-Ar),

6.92 (d, J = 8.9 Hz, 1H, Ar-CH), 6.93 (app. t, J = 15.3 Hz, 1H,

CH = CH-Ar), 7.14 (d, J = 14.7 Hz, 1H, COCH = CH), 7.28 (d,

J = 7.4 Hz, 1H, Ar-CH), 7.44 (d, J = 8.6 Hz, 2H, 2 × Ar-CH), 7.53 (dd,

J = 14.7, 9.4 Hz, 1H, COCH = CH), 7.79 (d, J = 8.0 Hz, 1H, Ar-

CH);¹³C NMR (126 MHz, CDCl₃): δ = 55.2, 114.2 (2 × Ar-CH), 115.8,

117.2, 119.2, 125.1, 125.3, 128.6 (2 × Ar-CH), 129.1, 130.8, 134.0,

140.6, 143.6, 150.8, 160.3, 191.8; HRMS (ESI): m/z calcd for

3.3.9. 1-(4-Aminophenyl)-5-(4-chlorophenyl)penta-2,4-dien-1-one (9)

Yellow solid; 12% crude; mp 145-146˚C; IR (UATR) 3352 (NH, str.),

1571 (C]O, str.), 1260 (C]C, str.) cm⁻¹

;

¹H NMR (500 MHz, acet-

one‑d₆): δ = 5.53 (d, J = 7.2 Hz, 2H, NH₂), 6.73 (d, J = 8.4 Hz, 2H,

2 × Ar-H), 7.15 (d, J = 15.6 Hz, 1H, CH = CH-Ar), 7.30 (dd, J = 15.6,

11.0 Hz, 1H, CH = CH-Ar), 7.40 (d, J = 14.8 Hz, 1H, COCH = CH),

7.49 (d, J = 8.3 Hz, 2H, 2 × Ar-H), 7.54 (dd, J = 14.8, 11.0 Hz, 1H,

COCH = CH), 7.68 (d, J = 8.3 Hz, 2H, 2 × Ar-H), 7.92 (d, J = 8.4 Hz,

2H, 2 × Ar-H); ¹³C NMR (126 MHz, acetone‑d₆): δ = 113.1, 113.2,

126.5, 128.3, 128.5, 128.6 (2 × Ar-CH), 128.9 (2 × Ar-CH), 130.7

(2 × Ar-CH), 133.8, 135.6, 138.2, 141.5, 145.7, 186.2; HRMS (ESI): m/

z calcd for C₁₇H₁₄ClNO-H^-: 282.0610 [M−H]^-; found: 282.0606.

C

₁₈H₁₇NO₂-H^-: 278.0800 [M−H]^-; found: 278.0788.

3.3.5. 1-(3-Aminophenyl)-5-(4-methoxyphenyl)penta-2,4-dien-1-one (5)

Orange solid; 23% crude; mp 151-152˚C; IR (UATR) 3448, 3352

(NH, str.), 2925 (sp³CH, str.) 1562 (C]O, str.), 1448 (C]C, str.) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆): δ = 3.91 (s, 3H, CH₃), 4.98 (s, 2H,

NH₂), 6.98 (d, J = 7.8 Hz, 1H, Ar-CH), 7.04 (d, J = 8.6 Hz, 2H, 2 × Ar-

CH), 7.17 (d, J = 6.6 Hz, 1H, Ar-CH), 7.24 (d, J = 14.8 Hz, 1H,

COCH = CH), 7.28 (d, J = 16.5 Hz, 1H, CH = CH-Ar), 7.31 (dd,

J = 16.5, 10.3 Hz, 1H, CH = CH-Ar), 7.38 (s, 1H, Ar-CH), 7.59 (dd,

J = 14.8, 10.3, 1H, COCH = CH), 7.64 (d, J = 8.6 Hz, 2H, 2 × Ar-CH);

¹³C NMR (126 MHz, acetone‑d₆): δ = 55.0, 113.5, 114.5 (2 × Ar-CH),

116.8, 118.6, 124.8, 125.3 (2 × Ar-CH), 128.9, 129.3, 129.4, 139.6,

141.2, 144.3, 148.9, 160.9, 189.5; HRMS (ESI): m/z calcd for

C₁₈H₁₇NO₂-H^-: 278.0800 [M−H]^-; found: 278.0808.

3.4. General procedure for the synthesis of sulfonylated-diarylpentadienone

(10–18)

The sulfonamide-containing diarylpentadienones (10–18) were

synthesized via condensation of equimolar quantity of 4-tri-

ﬂuoromethylbenzenesulfonyl chloride and aminated-diarypentadie-

none (1–9) in methanol (5 ml) prior to the addition of pyridine as a

catalyst (3–5 drops) once the homogenous mixture was obtained. The

reaction mixture was left to stir for 24 h at room temperature and

monitored with TLC to complete reaction. Ten mL of water was then

poured to the reaction mixture to quench the reaction and the solid

products were collected, while extraction with ethyl acetate was carried

out for the non-precipitated mixture. The obtained products were

combined and subjected to column chromatography before further re-

crystallization to yield a puriﬁed end-product.

3.3.6. 1-(4-Aminophenyl)-5-(4-methoxyphenyl)penta-2,4-dien-1-one (6)

Yellow solid; 40% crude; mp 98-99˚C; IR (UATR) 3331, 3206 (NH,

str.), 2921 (sp³CH, str.) 1561 (C]O, str.), 1256 (C]C, str.) cm⁻¹; ¹H

NMR (500 MHz, acetone‑d₆): δ = 3.83 (s, 3H, CH₃), 5.53 (s, 2H, NH₂),

6.73 (d, J = 8.4 Hz, 2H, 2 × Ar-CH), 6.96 (d, J = 8.5 Hz, 2H, 2 × Ar-

CH), 7.06 (d, J = 14.6 Hz, 1H, COCH = CH), 7.07 (dd, J = 15.6,

9.5 Hz, 1H, CH = CH-Ar), 7.26 (d, J = 15.6 Hz, 1H, CH = CH-Ar), 7.49

(dd, J = 14.6, 9.5 Hz, 1H, COCH = CH), 7.54 (d, J = 8.5 Hz, 2H,

2 × Ar-CH), 7.86 (d, J = 8.4 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz,

acetone‑d₆): δ = 54.7, 113.1 (2 × Ar-CH), 114.2 (2 × Ar-CH), 124.6,

125.3, 127.0, 128.5 (2 × Ar-CH), 129.3, 130.5 (2 × Ar-CH), 139.8,

142.4, 153.2, 160.4, 186.2; HRMS (ESI): m/z calcd for C₁₈H₁₇NO₂-H^-:

278.0800 [M−H]^-; found: 278.0785.

3.4.1. N-[2-(5-phenylpenta-2,4-dienoyl)phenyl]-4-

triﬂuoromethylbenzenesulfonamide (10)

Pale yellow solid; 8% crude; mp 105-106˚C; IR (UATR) 1622 (C]O,

str.), 1560 (C]C, str.), 1230 (S]O, assym.), 1144 (S]O, symm.)

cm⁻¹

;

¹H NMR (500 MHz, CDCl₃): δ = 6.90 (d, J = 15.0 Hz, 1H,

COCH = CH), 6.96 (dd, J = 15.5, 10.6 Hz, 1H, CH = CH-Ar), 7.06 (d,

J = 15.5 Hz, 1H, CH = CH-Ar), 7.17 (t, J = 7.6 Hz, 1H, Ar-CH), 7.38

(dd, J = 15.0, 10.6 Hz, 1H, COCH = CH), 7.39 (d, J = 7.4 Hz, 2H,

2 × Ar-CH), 7.50 (t, J = 7.4 Hz, 1H), 7.52 (app. m, 3H), 7.66 (d,

J = 8.1 Hz, 2H, 2 × Ar-CH), 7.74 (d, J = 8.2 Hz, 1H, Ar-CH), 7.80 (d,

J = 7.8 Hz, 1H, Ar-CH), 7.92 (d, J = 8.1 Hz, 2H, 2 × Ar-CH), 11.38 (s,

1H, NH); ¹³C NMR (126 MHz, acetone‑d₆): δ = 118.6, 120.3, 123.4,

123.9, 124.8, 125.3, 126.8, 127.4 (2 × Ar-CH), 128.0 (2 × Ar-CH),

128.1, 128.9 (2 × Ar-CH), 129.4 , 131.1, 132.8, 134.5, 135.0, 136.2,

139.2, 143.1, 146.4, 192.9; HRMS (ESI): m/z calcd for C₂₄H₁₈F₃NO₃S-

H^-: 456.0190 [M−H]^-; found: 456.0188.

3.3.7. 1-(2-Aminophenyl)-5-(4-chlorophenyl)penta-2,4-dien-1-one (7)

Yellow solid; 28% crude; mp 109-110˚C; IR (UATR) 3302 (NH, str.),

1617 (C]C, str.) 1564 (C]O, str.), cm⁻¹

;

¹H NMR (500 MHz, acet-

one‑d₆): δ = 6.61 (t, 1H, Ar-CH), 6.83 (d, J = 8.3 Hz, 1H, Ar-CH), 7.11

(s, 2H, NH₂), 7.11 (d, J = 15.6 Hz, 1H, CH = CH-Ar), 7.27 (app. t,

J = 6.8 1H, Ar-CH), 7.27 (dd, J = 15.6, 10.5 Hz, 1H, CH = CH-Ar),

7.43 (d, J = 8.5 Hz, 2H, 2 × Ar-CH), 7.47 (d, J = 14.7 Hz, 1H,

COCH = CH), 7.50 (dd, J = 14.7, 10.5 Hz, 1H, COCH = CH), 7.63 (dd,

J = 1.00 Hz, 2H, 2 × Ar-CH), 7.88 (d, J = 8.1 Hz, 1H, Ar-CH); ¹³C

NMR (126 MHz, acetone‑d₆): δ = 114.7, 117.0, 118.2, 127.3, 128.3,

128.5 (2 × Ar-CH), 128.9 (2 × Ar-CH), 130.7, 133.8, 134.0, 135.5,

138.4, 141.9, 152.1, 190.6; HRMS (ESI): m/z calcd for C₁₇H₁₄ClNO-H^-:

282.0610 [M−H]^-; found: 282.0607.

3.4.2. N-[3-(5-phenylpenta-2,4-dienoyl)phenyl]-4-

triﬂuoromethylbenzenesulfonamide (11)

Pale yellow solid; 22% crude; mp 145-146˚C; IR (UATR) 3358 (NH,

str.), 1572 (C]O, str.), 1275 (C]C, str.), 1145 (S]O, assym.), 998

(S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆): δ = 7.19 (d,

J = 15.5 Hz, 1H, CH = CH-Ar), 7.22 (d, J = 14.5 Hz, 1H,

COCH = CH), 7.25 (dd, J = 15.5, 10.2 Hz, 1H, CH = CH-Ar), 7.36 (t,

J = 7.3 Hz, 1H, Ar-CH), 7.41 (d, J = 7.7 Hz, 1H, Ar-CH), 7.42 (d,

J = 7.1 Hz, 1H, Ar-CH), 7.47 (d, J = 6.9 Hz, 1H, Ar-CH), 7.48 (app. t,

J = 8.0, 1H, Ar-CH), 7.56 (dd, J = 14.9, 10.2 Hz, 1H, COCH = CH),

3.3.8. 1-(3-Aminophenyl)-5-(4-chlorophenyl)penta-2,4-dien-1-one (8)

Yellow solid; 31% crude; mp 132-133˚C; IR (UATR) 3350 (NH, str.),

1564 (C]O, str.), 1488 (C]C, str.) cm⁻¹

;

¹H NMR (500 MHz, acet-

one‑d₆): δ = 4.92 (s, 2H, NH₂), 6.92 (ddd, J = 7.8, 2.3, 1.0 Hz, 1H, Ar-

11

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

7.62 (d, J = 7.4 Hz, 2H, 2 × Ar-CH), 7.79 (dt, J = 6.5, 1.8 Hz, 1H, Ar-

CH), 7.88 (d, J = 2.0 Hz, 1H, Ar-CH), 7.93 (d, J = 8.4 Hz, 2H, 2 × Ar-

CH), 8.06 (d, J = 8.3 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz, acet-

one‑d₆): δ = 120.4, 124.7, 124.9, 125.0, 126.3, 126.4, 127.1, 127.3

(2 × Ar-CH), 127.9 (2 × Ar-CH), 128.8 (2 × Ar-CH), 129.2, 129.7,

133.5, 133.8, 136.3, 137.8, 139.3, 141.9, 143.5, 144.7, 188.3; HRMS

(ESI): m/z calcd for C₂₄H₁₈F₃NO₃S-H^-: 456.1020 [M−H]^-; found:

456.1022.

(S]O, assym.), 1153 (S]O, symm.)cm⁻¹

;

¹H NMR (500 MHz, acet-

one‑d₆): δ = 3.84 (s, 3H, CH₃), 6.97 (d, J = 8.7 Hz, 2H, 2 × Ar-CH),

7.01 (d, J = 15.5 Hz, 1H, CH = CH-Ar), 7.11 (dd, J = 15.5, 10.0 Hz,

1H, CH = CH-Ar), 7.22 (d, J = 14.8 Hz, 1H, COCH = CH), 7.39 (d,

J = 8.6 Hz, 2H, 2 × Ar-CH), 7.40 (dd, J = 8.7, 3.2 Hz, 1H, Ar-H), 7.54

(dd, J = 14.8, 10.0 Hz, 1H, COCH = CH), 7.56 (d, J = 8.7 Hz, 2H,

2 × Ar-CH), 7.94 (s, 1H, Ar-CH), 7.97 (d, J = 8.7 Hz, 2H, 2 × Ar-CH),

8.12 (d, J = 8.4 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz, acetone‑d₆):

δ = 54.95, 114.4 (2 × Ar-CH), 118.9 (2 × Ar-CH), 126.3, 126.4,

126.4, 126.5, 126.5, 127.0 (2 × Ar-CH), 127.9, 129.7 (2 × Ar-CH),

130.4 (2 × Ar-CH), 133.2, 141.6, 143.5, 152.4, 162.2, 193.0; HRMS

(ESI): m/z calcd for C₂₅H₂₀F₃NO₄S-H^-: 486.1720 [M−H]^-; found:

486.1716.

3.4.3. N-[4-(5-phenylpenta-2,4-dienoyl)phenyl]-4-

triﬂuoromethylbenzenesulfonamide (12)

Pale yellow solid; 27% crude; mp 178-179˚C; IR (UATR) 3041 (NH,

str.), 1578 (C]O, str.), 1306 (C]C, str.), 1136 (S]O, assym.), 1010

(S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆): δ = 7.17 (d,

J = 15.6 Hz, 1H, CH = CH-Ar), 7.22 (app. dd, J = 10.2 Hz 1H), 7.30

(d, J = 14.8 Hz, 1H, COCH = CH), 7.36 (d, J = 7.2 Hz, 1H, Ar-CH),

7.40 (d, J = 6.6 Hz, 2H, 2 × Ar-CH), 7.41 (dd, J = 15.6, 10.2 Hz, 1H,

CH = CH-Ar), 7.55 (dd, J = 14.8, 10.2 Hz, 1H, COCH = CH), 7.61 (d,

J = 7.4 Hz, 2H, 2 × Ar-CH), 7.95 (d, J = 8.4 Hz, 2H, 2 × Ar-CH), 7.99

(d, J = 8.7 Hz, 2H, 2 × Ar-CH), 8.12 (d, J = 8.3 Hz, 2H, 2 × Ar-CH);

¹³C NMR (126 MHz, acetone‑d₆): δ = 119.3, 125.2, 126.5, 126.6,

127.2, 127.3 (2 × Ar-CH), 128.1 (2 × Ar-CH), 128.9 (2 × Ar-CH),

129.2, 129.9 (2 × Ar-CH), 132.6, 134.3, 136.5, 141.5, 141.6, 144.1,

187.5; HRMS (ESI): m/z calcd for C₂₄H₁₈F₃NO₃S-H^-: 456.0550 [M−H]^-;

found: 456.0555.

3.4.7. N-(2-[5-(4-chlorophenyl)penta-2,4-dienoyl]phenyl)-4-

triﬂuoromethylbenzenesulfonamide (16)

Pale yellow solid; 38% crude; mp 178-179˚C; IR (UATR) 3093 (NH,

str.), 1567 (C]O, str.), 1489 (C]C, str.), 1319 (S]O, assym.), 1157

(S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆): δ = 7.22 (dd,

J = 15.5, 7.4 Hz, 1H, CH = CH-Ar), 7.25 (app. m, 2H) 7.26 (d,

J = 15.2 Hz, 1H, CH = CH-Ar), 7.27 (d, J = 15.5 Hz, 1H, CH = CH-

Ar), 7.27 (d, J = 14.7 Hz, 1H, COCH = CH), 7.46 (d, J = 8.5 Hz, 2H,

2 × Ar-CH), 7.56 (dd, J = 14.7, 7.4, Hz, 1H, COCH = CH), 7.61 (d,

J = 8.3 Hz, 1H, Ar-CH), 7.65 (d, J = 8.5 Hz, 2H, 2 × Ar-CH), 7.72 (d,

J = 8.3 Hz, 1H, Ar-CH), 7.90 (d, J = 8.3 Hz, 2H, 2 × Ar-CH), 8.04 (d,

J = 8.0 Hz, 1H, Ar-CH), 8.05 (d, J = 8.1 Hz, 2H, 2 × Ar-CH), 11.58 (s,

1H, NH); ¹³C NMR (126 MHz, acetone‑d₆): δ = 120.3, 120.5, 123.9,

124.1, 124.8, 125.9, 125.9, 126.4, 126.5, 127.6, 128.1, 128.8, 128.9

(2 × Ar-CH), 129.0 (2 × Ar-CH), 131.1, 134.5, 134.5, 135.1, 139.2,

141.4, 145.9, 192.8; HRMS (ESI): m/z calcd for C₂₄H₁₇ClF₃NO₃S-H^-:

490.0540 [M−H]^-; found: 490.0544.

3.4.4. N-(2-[5-(4-methoxyphenyl)penta-2,4-dienoyl]phenyl)-4-

triﬂuoromethylbenzenesulfonamide (13)

Pale yellow solid; 11% crude; mp 178-179˚C; IR (UATR) 3325 (NH,

str.), 2932 (CH alkane, str.), 1543 (C]O, str.), 1309 (C]C, str.), 1270

(S]O, assym.), 1144 (S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acet-

one‑d₆): δ = 3.83 (s, 3H, CH₃), 6.99 (d, J = 8.8 Hz, 2H, 2 × Ar-CH),

7.08 (dd, J = 15.5, 11.0 Hz, 1H, CH = CH-Ar), 7.17 (d, J = 14.7 Hz,

1H, COCH = CH), 7.21 (d, J = 15.5 Hz, 1H, CH = CH-Ar), 7.59 (d,

J = 8.8 Hz, 1H, 2 × Ar-CH), 7.60 (dd, J = 14.7, 11.0 Hz, 1H,

COCH = CH), 7.60 (app. t, J = 8.1 Hz, 1H, Ar-CH), 7.72 (d,

J = 7.7 Hz, 1H, Ar-CH), 7.89 (d, J = 8.4 Hz, 2H, 2 × Ar-CH), 8.03 (d,

J = 7.7 Hz, 1H, Ar-CH), 8.04 (d, J = 8.1 Hz, 2H, 2 × Ar-CH), 11.67 (s,

1H, NH); ¹³C NMR (126 MHz, acetone‑d₆): δ = 54.8, 114.3 (2 × Ar-

CH), 120.3, 123.9, 124.0, 124.6, 126.4, 128.1 (2 × Ar-CH), 128.9,

129.1 (2 × Ar-CH), 131.0, 134.4, 143.3, 147.1, 161.1, 192.8, 205.6;

HRMS (ESI): m/z calcd for C₂₅H₂₀F₃NO₄S-H^-: 486.0880 [M−H]^-; found:

486.0878.

3.4.8. N-(3-[5-(4-chlorophenyl)penta-2,4-dienoyl]phenyl)-4-

triﬂuoromethylbenzenesulfonamide (17)

Pale yellow solid; 16% crude; mp 178-179˚C; IR (UATR) 3358 (NH,

str.), 1572 (C]O, str.), 1275 (C]C, str.), 1145 (S]O, assym.), 998

(S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆): δ = 7.18 (d,

J = 15.6 Hz, 1H, CH = CH-Ar), 7.23 (d, J = 15.0 Hz, 1H,

COCH = CH), 7.24 (dd, J = 15.6, 10.7 Hz, 1H, CH = CH-Ar), 7.44 (d,

J = 8.5 Hz, 2H, 2 × Ar-CH), 7.47 (d, J = 8.5 Hz, 1H, Ar-CH), 7.48 (dd,

J = 7.6, 4.2 Hz, 1H, Ar-CH), 7.54 (dd, J = 15.0, 10.7 Hz, 1H,

COCH = CH), 7.64 (d, J = 8.5 Hz, 2H, 2 × Ar-CH), 7.78 (d, 1H,

J = 8.5 Hz), 7.87 (s, 1H, Ar-CH), 7.92 (d, J = 8.4 Hz, 2H, 2 × Ar-CH),

8.06 (d, J = 8.4 Hz, 2H, 2 × Ar-CH); ¹³C NMR (126 MHz, acetone‑d₆):

δ = 120.4, 124.7, 124.9, 125.5, 126.4 (2 × Ar-CH), 127.9, 127.9

(2 × Ar-CH), 128.8 (2 × Ar-CH), 128.9 (2 × Ar-CH), 129.7, 133.5,

134.2, 135.2, 137.9, 139.2, 140.3, 143.5, 144.4, 155.7, 188.4; HRMS

(ESI): m/z calcd for C₂₄H₁₇ClF₃NO₃S-H^-: 490.1100 [M−H]^-; found:

490.1113.

3.4.5. N-(3-[5-(4-methoxyphenyl)penta-2,4-dienoyl]phenyl)-4-

triﬂuoromethylbenzenesulfonamide (14)

Pale yellow solid; 23% crude; mp 178-179˚C; IR (UATR) 3300 (NH,

str.), 2924 (CH alkane, str.), 1561 (C]O, str.), 1319 (C]C, str.), 1239

(S]O, assym.), 1152 (S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acet-

one‑d₆): δ = 3.84 (s, 3H, CH₃), 6.98 (d, J = 8.7 Hz, 2H, 2 × Ar-CH),

7.09 (dd, J = 15.7, 10.0 Hz, 1H, CH = CH-Ar), 7.13 (d, J = 14.6,

10.0 Hz, 1H, COCH = CH), 7.15 (d, J = 15.7 Hz, 1H, CH = CH-Ar),

7.45 (app. d, J = 8.0 Hz, 1H, Ar-CH), 7.46 (d, J = 5.5 Hz, Ar-CH), 7.55

(dd, J = 14.6, 10.0 Hz, 1H, COCH = CH), 7.58 (d, J = 8.7 Hz, 1H,

2 × Ar-CH), 7.78 (dd, J = 8.0, 2.0 Hz, 1H, Ar-CH), 7.86 (s, 1H, Ar-CH),

7.93 (d, J = 8.3 Hz, 2H, 2 × Ar-CH), 8.05 (d, J = 8.3 Hz, 2H, 2 × Ar-

CH), 9.50 (s, 1H, NH); ¹³C NMR (126, MHz, acetone‑d₆): δ = 54.9,

114.4 (2 × Ar-CH), 120.5, 123.8, 124.8, 124.9, 125.0, 126.5, 126.5,

128.1 (2 × Ar-CH), 129.0 (2 × Ar-CH), 129.1, 129.8, 131.0, 131.1,

133.4, 135.8, 139.6, 142.1, 145.5, 160.9, 188.3; HRMS (ESI): m/z calcd

for C₂₅H₂₀F₃NO₄S-H^-: 486.1590 [M−H]^-; found: 486.1588.

3.4.9. N-(4-[5-(4-chlorophenyl)penta-2,4-dienoyl]phenyl)-4-

triﬂuoromethylbenzenesulfonamide (18)

Pale yellow solid; 19% crude; mp 178-179˚C; IR (UATR) 3158 (NH,

str.), 1562 (C]O, str.), 1401 (C]C, str.), 1315 (S]O, assym.), 1155

(S]O, symm.) cm⁻¹

;

¹H NMR (500 MHz, acetone‑d₆): δ = 7.16 (d,

J = 15.6 Hz, 1H, CH = CH-Ar), 7.21 (dd, J = 15.6, 10.5 Hz, 1H,

CH = CH-Ar), 7.31 (d, J = 14.8 Hz, 1H, COCH = CH), 7.40 (d,

J = 8.7 Hz, 1H, 2 × Ar-CH), 7.41 (d, J = 8.7 Hz, 1H, 2 × Ar-CH), 7.44

(d, J = 8.5 Hz, 1H, 2 × Ar-CH), 7.53 (dd, J = 14.8, 10.5 Hz, 1H,

COCH = CH), 7.95 (d, J = 8.4 Hz, 2H, 2 × Ar-CH), 7.98 (d,

J = 8.8 Hz, 2H, 2 × Ar-CH), 8.12 (d, J = 8.3 Hz, 2H, 2 × Ar-CH); ¹³

C

NMR (126 MHz, acetone‑d₆): δ = 119.8 (2 × Ar-CH), 125.2 (2 × Ar-

CH), 126.5, 127.4, 127.5 (2 × Ar-CH), 128.4, 128.5, 128.8, 128.9

(2 × Ar-CH), 129.0, 129.5 (2 × Ar-CH), 132.1, 133.7, 135.5, 138.1,

140.2, 141.4, 186.5, 192.9; HRMS (ESI): m/z calcd for

3.4.6. N-(4-[5-(4-methoxyphenyl)penta-2,4-dienoyl]phenyl)-4-

triﬂuoromethylbenzenesulfonamide (15)

Pale yellow solid; 34% crude; mp 178-179˚C; IR (UATR) 3148 (NH,

str.), 2925 (CH alkane, str.), 1587 (C]O, str.), 1508 (C]C, str.), 1316

C

₂₄H₁₇ClF₃NO₃S-H^-: 490.0885 [M−H]^-; found: 490.0887.

12

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

3.5. In vitro biological evaluation

405 nm using a spectrophotometer (Tecan Saﬁre, Grödig, Austria) in

interval 5 to 30 min. The type of inhibition was determined via the

Lineweaver-Burk plot (the inverse of velocity (1/v) against the inverse

of the substrate concentration (1/[S])) were derived from the resulting

data.

The puriﬁed diarylpentadienone analogues tested for both in vitro α-

glucosidase and DPP-4 inhibitory evaluations were of 95–99% purity

based on their respective high-performance liquid chromatography

(HPLC) proﬁles.

3.6. In vivo toxicity in zebraﬁsh embryos

3.5.1. α-Glucosidase inhibitory assay

α-Glucosidase inhibition assay was performed following a pre-

viously described method with slight modiﬁcations [51,52]. α-Gluco-

sidase extracted from Bacillus stearothermophilus was used as the source

of enzyme, while p-nitrophenyl-α-^D-glucopyranoside (PNPG) and acar-

bose were used as a substrate and standard, respectively. A mixture of

10 µl sample, 130 µl phosphate buﬀer (pH 6.5, 30 mM), and 10 µl

enzyme in a 96 well plate was pre-incubated at room temperature for

5 min before 50 µl of PNPG substrate solution (10 mM) was added and

the reaction mixture was further incubated at room temperature for

15 min. The reaction was quenched by the addition of 50 µl of 2 M

glycine (pH 10) into the mixture. The absorbance of the liberated p-

nitrophenol was measured at 405 nm using a spectrophotometer (Te-

can Saﬁre, Grödig, Austria). All reactions were carried out in triplicates

and the IC₅₀measurements (> 50% inhibition) were performed in the

presence of serial dilutions of tested compounds (50 to 1.53 µM), cal-

culated by the non-linear regression analysis using GraphPad Prism

3.6.1. Zebraﬁsh husbandry and embryo collection

We obtained embryos through natural mating of either wild-type

(WT) or transgenic Tg(kdrl:egfp) adult zebraﬁsh obtained from the

Laboratory of Natural Products, Universiti Putra Malaysia, and the

Zebraﬁsh Center for Disease Modeling, Korea. They were kept in a

mixed male and female enclosure with a ratio of 2:3 with 14 h of light:

10 h of darkness-controlled photoperiod with ambient temperature at

28.5 °C. They were fed four times a day, alternately with brine shrimp

(Artemia salina, San Francisco Bay Brand, San Francisco, CA) and with

commercial dry ﬂake food (Sera Vipan). The embryos were collected

30 min after the onset of light, washed with distilled water, rinsed with

embryo media (15 mM NaCl, 0.5 mM KCl, 1 mM MgSO₄, 0.15 mM

KH₂PO₄, 0.05 mM Na₂HPO₄, 1 mM CaCl₂, 0.7 mM NaHCO₃, pH 7.0),

and then incubated at 28 °C. To eliminate fungal growth, the un-

fertilized embryos were discarded. The fertilized embryos were ex-

amined and chosen under a standard dissection microscope (SZX-12,

Olympus, Tokyo, Japan). Animal experiments were conducted ac-

cording to approved guidelines and regulations of the Institutional

Animal Care and Use Committee (IACUC) at the Animal Ethics

Committee of Universiti Putra Malaysia (IACUC/AUP-R079) and

Chungnam National University.

(version 8.0; GraphPad software) and expressed as mean

SEM. The

tested samples can be in two forms of supernatants: pre- and post-

centrifugation and were prepared as described by Auld et al., 2017 for

the aggregation assay [45], while the pre-centrifugation supernatant of

all compounds were used in in vitro α-glucosidase and DPP-4 inhibition

assays.

3.6.2. Acute toxicity testing on zebraﬁsh embryos

3.5.2. DPP-4 enzyme assay

To test acute toxicity on early embryonic development, ten zebra-

ﬁsh embryos at 6 hpf were placed in each well of a 24 well plate,

containing 1 ml of embryo medium. Compound 18 was dissolved in

dimethyl sulfoxide (DMSO) to make a 40 mM stock solution and diluted

into the embryonic water at 1, 2, 5, 10, 20, and 40 uM concentrations.

The compound solution was changed every day to maintain freshness of

solutions. To acquire microscopic images, zebraﬁsh embryos were de-

chorionated using forceps, anesthetized in Tricaine (Sigma-Aldrich),

and mounted in 3% methylcellulose. Embryos were visualized using a

Nikon AZ100 microscope (Nikon, Tokyo, Japan). Digital images were

captured using a Nikon Digital Sight DS-Fil1 digital camera (Nikon) and

processed with NIS-Elements F 3.0 (Nikon)

The DPP-4 inhibition activity was determined using a DPP-4

Inhibitor Screening Assay Kit (Cayman Chemical Inc., Michigan, USA),

pre-stored at −80˚C. A standard DPP-4 inhibitor, sitagliptin, was uti-

lized as a positive control, while the Gly-Pro-Aminocoumarin (AMC)

was used as a substrate. Stock solution of inhibitors were made by re-

suspending each of the weighed pure solid diarylpentadienones in

DMSO and diluted in an assay buﬀer to a ﬁnal concentration of 100 µM

in each well. The ﬁnal concentration of DMSO adjusted in the assay was

1%. Thirty µl of diluted buﬀer (20 mM Tris-HCl, 100 mM NaCl, 1 mM

EDTA, pH 8.0) and 10 µl of compounds 1–18 (100 µM) were mixed with

10 µl DPP-4 (human recombinant) in a half volume 96-well white mi-

croplate. Fifty µl of substrate was then added to the well, and the

mixture was incubated for 30 min at 37 °C. After incubation, the

ﬂuorescence emitted by each compound was measured at excitation

wavelength of 350–360 nm and emission wavelength of 450–465 nm in

a multimode microplate reader (Biotek PLUS, California, USA). All re-

actions were carried out in triplicates and the IC₅₀measurements

(> 70% inhibition) were performed in the presence of serial dilutions

of tested compounds (100 to 6.13 µM), calculated by the non-linear

regression analysis using GraphPad Prism (version 8.0; GraphPad

3.6.3. Evaluation of apoptosis

Evaluation of cell death in the wild-type (WT) zebraﬁsh larvae after

treatment with compound 18 was determined via a vital ﬂuorescent

dye acridine orange method that often used as a marker of apoptotic

cells in zebraﬁsh. Acridine orange staining is a rapid method and has

been shown to be highly selective for apoptotic cells where determi-

nation of apoptosis was made by measuring relative acridine orange -

ﬂuorescence in zebraﬁsh embryos. Zebraﬁsh larvae were placed in the

egg water containing 4 µg/ml of acridine orange (Sigma) for 20 min.

Afterwards, the live zebraﬁsh larvae were washed with the egg water 5

times for 5 min each, anesthetized with tricaine and mounted in 3%

methylcellulose, prior examined by stereomicroscopy and ﬂuorescent

microscopy, as previously described [60,61].

software) and expressed as mean

SEM.

3.5.3. Kinetic studies against α-glucosidase

The kinetic studies were performed on the most active 18 as pre-

viously described method [51,52] using diﬀerent concentrations of

substrate and compounds to determine the mode of α-glucosidase in-

hibition. Compound 18 with concentrations of 20.0, 15.0, 12.5, 10.0,

7.5, 5.0, 2.5 and 0 µM was used for this kinetic analysis. Meanwhile, the

concentrations of substrate were varied at 30, 20, 10, 4, 2 and 1.25 mM.

A mixture of 10 µl sample, 130 µl phosphate buﬀer (pH 6.5, 30 mM),

and 10 µl enzyme in a 96 well plate was pre-incubated at room tem-

perature for 5 min before 50 µl of PNPG substrate solution of diﬀerent

concentrations was added. The absorbance was directly measured at

3.6.4. Evaluation of adverse eﬀect on the formation of blood vessel

Zebraﬁsh embryos obtained from the blood vessel-speciﬁc EGFP

ﬂuorescent transgenic zebraﬁsh line, Tg(kdrl:egfp), were treated with

0.1% dimethyl sulfoxide (DMSO) as a control or treated with various

concentrations of compound 18. Treatment with compound 18 com-

menced from the late gastrula stage at 10 hpf and examined at 30 hpf

when normal blood vessel formation was prominent in the control

13

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

zebraﬁsh. For bioimaging, embryos were mounted in 3% methylcellu-

lose on a glass slide and live animal images were captured using a stereo

microscope (LEICA MZ16FA) and digital camera (LEICA DFC450C).

9480700 and grant from the Korean Ministry of Trade, Industry and

Energy (10063396 to C.H.K.)

Appendix A. Supplementary data

3.6.5. Statistical analysis

Supplementary data to this article can be found online at https://

doi.org/10.1016/j.bioorg.2020.104277.

Statistical analyses were performed using SPSS (SPSS v. 25.0). One-

way analysis of variance (ANOVA) was used to determine the eﬀects of

each treatment groups to the control. Data were represented as

References

mean

standard error mean (SEM) using GraphPad Prism (Graphpad

Software, USA). The data were signiﬁcantly diﬀerent when p ≤ 0.05.

To assure these values were independent, the data analyzed were based

on a per well basis in order to avoid any interaction biases among the

embryos.

[1] G. Roglic, Int. J. Noncomm. Diseases. 1 (2016) 3–8 .

[2] K.G.M.M. Alberti, P.F. Zimmet, Diabetic Med. 15 (1998) 539–553 .

[3] D. Atlas, International diabetes federation. IDF Diabetes Atlas, 7th edition.,

International Diabetes Federation, Brussels, Belgium, 2015 .

[4] S.H. Havale, M. Pal, Bioorg. Med. Chem. 17 (2009) 1783–1802 .

[5] S. Matthaei, R. Bierwirth, A. Fritsche, B. Gallwitz, H.U. Häring, H.G. Joost,

M. Kellerer, C. Kloos, T. Kunt, M. Nauck, G. Schernthaner, Exp. Clin. Endocrinol.

Diabetes. 117 (2009) 522–557 .

3.7. Molecular docking studies

[6] E.Y. Lee, S. Kaneko, P. Jutabha, X. Zhang, S. Seino, T. Jomori, N. Anzai, T. Miki, J.

Endocrinol. 224 (2015) 205–214 .

3.7.1. Homology modelling and model veriﬁcation

A three-dimensional model of B. stearothermophilus α-glucosidase

was built by comparative modeling using the SWISS-MODEL program

(automated protein structure homology-modeling server; http://

swissmodel.expasy.org). The crystallographic structure of the related

GH-13 α-glycosidase from the Geobacillus sp. strain HTA-462 (PDB:

2ZE0) was selected as the template due to its highest sequence identity

(94%) with respect to the B. stearothermophilus α-glucosidase [62]. The

amino acid sequence of B. stearothermophilus α-glycosidase (EC

3.2.1.20), which comprised of 555 amino acid residues was retrieved

(GenBank accession: D84648.1; NCBI http://www.ncbi.nlm.nih.gov).

The modeled protein was checked using the PROCHECK (stereo-

chemical quality analysis software) program [63].

[7] Alpha Glucosidase Inhibitors (2020, June 2). Retrieve from https://www.diabetes.

co.uk/diabetes-medication/alpha-glucosidase-inhibitors.html.

[8] C.H. McIntosh, Can. J. Diabetes. 32 (2008) 131–139 .

[9] K. Makrilakis, Int. J. Environ. Res. Public Health. 16 (2019) 2720–2739 .

[10] A.K. Singh, Indian J. Endocrinology Metab. 18 (2014) 753–760 .

[11] S.L. Gaonkar, U.N. Vignesh, Res. Chem. Intermed. 43 (2017) 6043–6077 .

[12] C. Zhuang, W. Zhang, C. Sheng, W. Zhang, C. Xing, Z. Miao, Chem. Rev. 117 (2017)

7762–7810 .

[13] Z. Rozmer, P. Perjési, Phytochem. Rev. 15 (2016) 87–120 .

[14] D.I. Batovska, I.T. Todorova, Curr. Clin. Pharmacol. 5 (2010) 1–29 .

[15] B. Orlikova, D. Tasdemir, F. Golais, M. Dicato, M. Diederich, Genes Nutr. 6 (2011)

125–147 .

[16] H. Sun, D. Wang, X. Song, Y. Zhang, W. Ding, X. Peng, X. Zhang, Y. Li, Y. Ma,

R. Wang, P. Yu, J. Agric. Food Chem. 65 (2017) 1574–1581 .

[17] Y.C. Hu, Y.D. Luo, L. Li, M.K. Joshi, Y.H. Lu, J. Agric. Food Chem. 60 (2012)

10683–10688 .

[18] X.W. Yang, M.Z. Huang, Y.S. Jin, L.N. Sun, Y. Song, H.S. Chen, Fitoterapia. 83

(2012) 1169–1175 .

3.7.2. Ligand preparation, energy minimization and geometrical

optimization

[19] A.T. Bale, K.M. Khan, U. Salar, S. Chigurupati, T. Fasina, F. Ali, A. Kanwal,

M. Wadood, S.S. Taha, M. Nanda, S.P. Ghufran, Bioorg. Chem. 79 (2018) 179–189 .

[20] F. Jabeen, P.V. Oliferenko, A.A. Oliferenko, G.G. Pillai, F.L. Ansari, C.D. Hall,

A.R. Katritzky, Eur. J. Med. Chem. 80 (2014) 228–242 .

The theoretical 3D structure ligand of the most active inhibitor

(compounds 15 and 18) was ﬁrstly drawn in Chemdraw Ultra 12.0 as a

2D structure before being saved as MDL mol ﬁle. The ligand structure

ﬁle was imported to Avogadro (version 1.2.0) as a 3D model and was

optimized by means of energy minimization carried out with General

AMBER Force Field (GAFF) force ﬁeld. These ligands were prepared by

assigning nonpolar hydrogens using AutoDockTools 1.5.4.

[21] C.Y. Cai, L. Rao, Y. Rao, J.X. Guo, Z.Z. Xiao, J.Y. Cao, Z.S. Huang, B. Wang, Eur. J.

Med. Chem. 130 (2017) 51–59 .

[22] F.L. Ansari, S. Umbreen, L. Hussain, T. Makhmoor, S.A. Nawaz, M.A. Lodhi,

S.N. Khan, F. Shaheen, M.I. Choudhary, Chem. Biodivers. 2 (2005) 487–496 .

[23] H. Sun, Y. Li, X. Zhang, Y. Lei, W. Ding, X. Zhao, H. Wang, X. Song, Q. Yao,

Y. Zhang, Y. Ma, R. Wang, T. Zhu, P.Y. Bioorg, Med. Chem. Lett. 25 (2015)

4567–4571 .

[24] H.W. Ryu, B.W. Lee, M.J. Curtis-Long, S. Jung, Y.B. Ryu, W.S. Lee, K.H. Park, J.

Agric. Food Chem. 58 (2010) 202–208 .

3.7.3. Docking studies and results visualization

[25] W.D. Seo, J.H. Kim, J.E. Kang, H.W. Ryu, M.J. Curtis-Long, H.S. Lee, M.S. Yang,

K.H. Park, Bioorg. Med. Chem. Lett. 15 (2005) 5514–5516 .

[26] A.S. Kalgutkar, R. Jones, A. Sawant, Chapter 5: Sulfonamide as an essential func-

tional group in drug design, in: D.A. Smith (Ed.), Metabolism, Pharmacokinetics

and toxicity of Functional Groups: Impact of Chemical Building Blocks on ADMET,

Cambridge, RSC Publishing, 2010, pp. 210–273 .

Docking calculations were performed with the software

AutodockVina. The Vina program was employed to generate the

docking input ﬁles and to analyze the docking results. The proteins

were considered rigid. The ﬁnal output of the docking procedure was a

set of solutions ranked according to their corresponding scoring func-

tion values, each deﬁned by the 3D coordinates of its atoms. The

Discovery studio visualizer 4.0 (Accelrys, San Diego, USA) was used to

visualize and analyze the results. For Homo sapiens-sourced of α-glu-

cosidase, the X-ray coordinates of human lysosomal acid-alpha-gluco-

sidase, GAA, in complex with acarbose (PDB code: 5NN8,

resolution = 2.45 Å) was retrieved and treated as discussed above for

ﬁle preparation.

[27] I.M. Prlina, C.P. Dahlen, A.J. Bischoﬀ, Antibiot. Med. Clin. Ther. (New York, NY). 5

(1958) 242–250 .

[28] B.P. Ryan, M. J. Australia. 1 (1975) 101–103 .

[29] W.W. Douglas, R.P. Rubin, J. Physiol. 159 (1961) 40–57 .

[30] A. Markham, Drugs. 77 (2017) 697–704 .

[31] J.C. Adkins, D. Faulds, Drugs. 55 (1998) 837–842 .

[32] P. Chen, D. Feng, X. Qian, J. Apgar, R. Wilkening, J.T. Kuethe, Y.D. Gao, G. Scapin,

J. Cox, G. Doss, G. Eiermann, Bioorg. Med. Chem. Lett. 25 (2015) 5767–5771 .

[33] S. Rocha, A. Sousa, D. Ribeiro, C.M. Correia, V.L.M. Silva, C.M.M. Santos,

A.M.S. Silva, A.N. Araujo, E. Fernandes, M. Freitas, Food Funct. 10 (2019)

5510–5520 .

[34] Z. Wang, Sen, L.Z. Cheng, H.P. Zhou, X.H. Liu, F.H. Chen, Bioorg. Med. Chem. Lett.

27 (2017) 1803–1807 .

Declaration of Competing Interest

[35] J.A.Q. Suarez, D.G. Rando, R.P. Santos, C.P. Gonçalves, E. Ferreira, J.E. de

Carvalho, L. Kohn, D.A. Maria, F. Faião-Flores, D. Michalik, M.C. Marcucci, Bioorg.

Med. Chem. 18 (2010) 6275–6281 .

The authors declare that they have no known competing ﬁnancial

interests or personal relationships that could have appeared to inﬂu-

ence the work reported in this paper.

[36] D.J. Weldon, M.D. Saulsbury, J. Goh, L. Rowland, L. Robinson, C. Miller,

J. Christian, L. Amis, N. Taylor, C. Dill, Bioorg. Med. Chem. Lett. 24 (2014)

3381–3384 .

[37] D. Batovska, S. Parushev, B. Stamboliyska, I. Tsvetkova, Eur. J. Med. Chem. 44

(2009) 2211–2218 .

Acknowledgement

[38] C. Conti, P. Mastromarino, P. Goldoni, G. Portalone, N. Desideri, Antiviral Chem.

Chemother. 16 (2005) 267–276 .

The authors would like to acknowledge Universiti Putra Malaysia

for their ﬁnancial support under the Putra grant – Putra Young

Initiative (IPM) with sponsorship reference number GP-IPM/2016/

[39] S. Das, I. Mitra, S. Batuta, M.N. Alam, K. Roy, N.A. Begum, Bioorg. Med. Chem. Lett.

24 (2014) 5050–5054 .

[40] G.M. Rishton, Drug Disc. Today. 8 (2003) 86–96 .

14

M.A. Abdullah, et al.

BioorganicChemistry104(2020)104277

[41] K.E. Coan, B.K. Shoichet, J. Am. Chem. Soc. 130 (2008) 9606–9612 .

[42] D. Lagorce, L. Bouslama, J. Becot, M.A. Miteva, B.O. Villoutreix, Bioinform. 33

(2017) 3658–3660 .

Chem. 134 (2012) 905–911 .

[53] C.R. Garcia, P.D. Noyes, R.L. Tanguay, Pharmacol. Ther. 16 (2016) 11–21 .

[54] C.A. MacRae, R.T. Peterson, Nat. Rev. Drug Discov. 14 (2015) 721–731 .

[55] R.L. Tanguay, Toxicol. Sci. 163 (2018) 3–4 .

[43] J.J. Irwin, D. Duan, H. Torosyan, A.K. Doak, K.T. Ziebart, T. Sterling, G. Tumanian,

B.K. Shoichet, J. Med. Chem. 58 (2015) 7076–7087 .

[56] L.K. Cole, L.S. Ross, Dev. Biol. 240 (2001) 123–142 .

[57] B.M. Weinstein, N.D. Lawson, Cold Spring Harb Symp Quant Biol. 67 (2002)

155–162 .

[44] L.G. Viviani, E. Piccirillo, A. Cheﬀer, L. de Rezende, H. Ulrich, A.M. Carmona-

Ribeiro, A.T. Amaral, Molecules. 23 (2018) 876–1890 .

[45] D. S. Auld, J. Inglese, J. L. Dahlin, Assay Interference by Aggregation. 2017 Jul 26.

In: G. S. Sittampalam, A. Grossman, K. Brimacombe, Assay Guidance Manual

[Internet]. Bethesda (MD): Eli Lilly & Company and the National Center for

Advancing Translational Sciences; 2004. Available from: https://www.ncbi.nlm.

nih.gov/books/NBK442297/.

[58] O. Cleaver, P.A. Krieg, Molecular mechanisms of vascular development, in:

R.P. Harvey, N. Rosenthal (Eds.), Heart Development, San Diego, Academic Press,

1999, pp. 221–252 .

[59] N.U. Rehman, K. Raﬁq, A. Khan, S.A. Halim, L. Ali, N. Al-Saady, A.H. Al-Balushi,

H.K. Al-Busaidi, A. Al-Harrasi, Mar. Drugs. 17 (2019) 666–680 .

[60] Y.M. Jeong, T.E. Jin, J.H. Choi, M.S. Lee, H.T. Kim, K.S. Hwang, D.S. Park, H.W. Oh,

J.K. Choi, V. Korzh, M. Schachner, K.H. You, C.H. Kim, J. Genet. Genomics. 41

(2014) 583–589 .

[46] S.L. McGovern, B.T. Helfand, B. Feng, B.K. Shoichet, J. Med. Chem. 46 (2003)

4265–4272 .

[47] J.B. Baell, J.W.M. Nissink, ACS Chem. Biol. 13 (2018) 36–44 .

[48] C. Aldrich, C. BErtozzi, G.I. Georg, L. Kiessling, C. Lindsley, D. Liotta, K.M. Merz Jr,

A. Schepartz, S. Wang, ACS Chem. Neurosci. 8 (2017) 420–423 .

[49] J.B. Baell, G.A. Holloway, J. Med. Chem. 53 (2010) 2719–2740 .

[50] D.N. Dhar, J.B. Lal, J. Org. Chem. 23 (1958) 1159–1161 .

[51] J.S. Kim, C.S. Kwon, K.H. Son, Biosci. Biotechnol. Biochem. 64 (2000) 2458–2461 .

[52] B. Sarmadi, F. Aminuddin, M. Hamid, N. Saari, A. Abdul-Hamid, A. Ismail, Food

[61] H.T. Kim, J.H. So, S.H. Jung, D.G. Ahn, W. Koh, N.S. Kim, S.H. Kim, S. Lee,

C.H. Kim, BMC Dev. Biol. 11 (2011) 49–56 .

[62] T. Shirai, V.S. Hung, K. Morinaka, T. Kobayashi, S. Ito. Proteins: Struct. Funct. Bioinf.

73 (2008) 126–133 .

[63] R.A. Laskowski, J.A.C. Rullmann, M.W. MacArthur, R. Kaptein, J.M. Thornton, J.

Biomol. NMR. 8 (1996) 477–486 .

15

Article Doi

Development of diarylpentadienone analogues as alpha-glucosidase inhibitor: Synthesis, in vitro biological and in vivo toxicity evaluations, and molecular docking analysis

DOI: 10.1016/j.bioorg.2020.104277

Source and publish data:

Authors:

Article abstract of DOI:10.1016/j.bioorg.2020.104277

Full text of DOI:10.1016/j.bioorg.2020.104277

Products guided by the article

R&D Labs maybe for 82784-35-8

Relevant to this article

Hot Product