Facile synthesis of dithiatetraaza-macrocycles of potential anti-inflammatory activity

Article abstract of DOI:10.1016/j.ejmech.2007.12.010

A facile synthetic approach towards dithiatetraaza-macrocycles 4a and b was achieved through reaction of 2,2′-[alkanediylbis(thio)]bisbenzenamines 1a and b with 1,4-phenylenediisocyanate. However, reaction of 1a and b with a variety of aryl-, alkylisocyanates or isothiocyanates 2a-f afforded the corresponding bisurea and their thio-analogues 3a-l. Anti-inflammatory activity of the prepared compounds (in a dose of 50 mg/kg body weight) using in vivo acute carrageenan-induced paw oedema in rats is studied. Compounds 3e and 4b reveal the best anti-inflammatory properties among all the tested compounds with potency (% oedema inhibition of the tested compounds regarding % oedema inhibition of indomethacin which was used as a reference standard in a dose of 10 mg/kg body weight ) 0.90 and 0.85, respectively.

Full text of DOI:10.1016/j.ejmech.2007.12.010

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European Journal of Medicinal Chemistry 43 (2008) 2116e2121
http://www.elsevier.com/locate/ejmech
Original article
Facile synthesis of dithiatetraaza-macrocycles
of potential anti-inflammatory activity
*
Adel S. Girgis
Pesticide Chemistry Department, National Research Centre, El-Behoos Street, Dokki, 12622 Cairo, Egypt
Received 28 June 2007; received in revised form 5 November 2007; accepted 6 December 2007
Available online 23 December 2007
Abstract
A facile synthetic approach towards dithiatetraaza-macrocycles 4a and b was achieved through reaction of 2,20-[alkanediylbis(thio)]bisben-
zenamines 1a and b with 1,4-phenylenediisocyanate. However, reaction of 1a and b with a variety of aryl-, alkylisocyanates or isothiocyanates
2aef afforded the corresponding bisurea and their thio-analogues 3ael. Anti-inflammatory activity of the prepared compounds (in a dose of
50 mg/kg body weight) using in vivo acute carrageenan-induced paw oedema in rats is studied. Compounds 3e and 4b reveal the best anti-
inflammatory properties among all the tested compounds with potency (% oedema inhibition of the tested compounds regarding % oedema
inhibition of indomethacin ‘‘which was used as a reference standard in a dose of 10 mg/kg body weight’’) 0.90 and 0.85, respectively.
Ó 2007 Elsevier Masson SAS. All rights reserved.
Keywords: Bisbenzenamines; Bisureas; Bisthioureas; Macrocycles; Anti-inflammatory
1. Introduction
antagonists (G-protein-coupled receptor bind to melanin
concentrating hormone) for treatment of obesity [13]. Other tri-
substituted analogues were reported as glucogen receptor antag-
onists which were efficacious in correcting hyperglycemia
conditions [14].
N,N0-Disubstituted ureas represent an important class of or-
ganic compounds attracting great attention of many researchers
due to their wide applications in various fields especially as bi-
ological and pharmacological active agents. Many N,N0-disub-
stituted urea derivatives were reported to possess anticancer
properties against human skin melanoma (M21), colon carci-
noma (HT-29), breast carcinoma (MCF-7), breast hormone-
independent adenocarcinoma (MDA-MB-231) and bladder
cancer (T-24) cell lines [1e5]. N-Aryl-N0-benzylureas were
reported to be transient receptor potential vanilloid 1 (TRPV1)
antagonists with good pharmacokinetic properties and great
potency in animal model of inflammatory pain [6]. On the other
hand, N,N0-disubstituted ureas as well as their thio-analogues
were reported to be nitric oxide production inhibitors in lipo-
polysaccharide-activited macrophages [7], antibacterial [8,9],
insecticidal and acaricidal [10e12] active agents. Many trisub-
stituted urea analogues were achieved to be MCH-R1
In the present work, it is intended to investigate synthesis of
bisurea containing-compounds as well as their thio-analogues
(i.e. compounds possessing two biologically active centers)
utilizing easily accessible starting chemicals and facile syn-
thetic approaches. The cyclic form structures will be also con-
sidered in an attempt to construct dithiatetraaza-macrocyclic
derivatives. The anti-inflammatory properties of the prepared
compounds will be screened not only to develop a promising
pharmacological active agent but also to determine the struc-
tureeactivity relationships of the adopted compounds. The re-
cent research reports concerning biological as well as
pharmacological properties of macrocyclic analogues also
prompted the present study. Many macrocyclic derivatives
have been achieved to be inhibitors of hepatitis C virus
(HCV) NS3 [15,16], FIV and HIV proteases [17], besides po-
tent activity against human cytomegalovirus (HCMV) [18].
Other analogues were reported to be inhibitors of b-secretase
* Tel.: þ202 2235 2405; fax: þ202 3337 0931.
E-mail address: girgisas10@yahoo.com
0223-5234/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2007.12.010

A.S. Girgis / European Journal of Medicinal Chemistry 43 (2008) 2116e2121
2117
(BACE-1, b-site amyloid precursor protein cleaving enzyme)
which is widely recognized as one of the most promising ther-
apeutic approaches for the treatment and prevention of Alz-
heimer’s disease [19]. Moreover, macrocyclic amides were
exhibited to be anti-inflammatory [20], antibacterial [21] and
inhibitors of malarial aspartic proteases plasmepsin I, II and
IV with considerable selectivity over the human aspartic pro-
tease cathepsin D [22].
COX-2 (inducible) and inhibition of COX-2 proving benefi-
cial in clinical situations had led to the introduction of
many potent anti-inflammatory agents called COX-2 inhibi-
tors [29e32].
2. Results and discussion
2.1. Chemistry
Non-steroidal anti-inflammatory drugs (NSAIDs) have
been recognized as important class of therapeutic agents for
the alleviation of pain and inflammation associated with
a number of pathological conditions especially for treatment
of rheumatoid disorders, osteoarthritis and also in many other
inflammatory diseases and injuries [23,24]. However, long
term use of NSAIDs has been associated with several side
effects such as gastrointestinal mucosal damage, bleeding, in-
tolerance and renal toxicity [25e28]. Consequently, extensive
research has been directed towards improving their pharmaco-
logical profiles.
Reaction of 2,20-[1,2-ethanediylbis(thio)]bisbenzenamine
1a and 2,20-[1,3-propanediylbis(thio)]bisbenzenamine dihy-
drochloride 1b with a variety of arylisocyanates (namely, phe-
nyl-, 3,4-dichlorophenyl-, 4-methoxyphenylisocyanate) 2aec
as 1:2 molar ratio in dry tetrahydrofuran ‘‘in presence of trie-
thylamine in case of 1b, where the dihydrochloride salt was
used’’ at room temperature, afforded the corresponding bi-
surea derivatives 3aef in good yields. The structure of 3aef
was inferred through spectroscopic (IR, 1H NMR) and elemen-
tal analyses data. The IR spectra of 3aef reveal the presence
of imino and carbonyl stretching vibration bands at
n ¼ 3336e3284, 1662e1638 cmꢀ1, respectively. 1H NMR
spectra exhibit the alkylsulfanyl function (singlet at
d ¼ 2.95e2.98 in case of 3a, c and e assignable to 2 SCH2
The most widely accepted mode of action of NSAIDs is the
inhibition of the cyclooxygenase enzyme involved in arachi-
donic acid conversion to prostaglandin. With the identifica-
tion of another isoform of constitutive COX-1, namely
RNCX
(2)
X
X
(CH2)n
N
H
S
S
N
H
THF, TEA "in case of 1b"
RHN
NHR
2a, R = C6H5, X = O
2b, R = 3,4-Cl2C6H3, X = O
2c, R = 4-H3COC6H4, X = O
2d, R = C2H5, X = O
2e, R = C6H5, X = S
2f, R = CH3, X = S
(3)
3a, R = C6H5, X = O, n = 2
3b, R = C6H5, X = O, n = 3
3c, R = 3,4-Cl2C6H3, X = O, n = 2
3d, R = 3,4-Cl2C6H3, X = O, n = 3
3e, R = 4-H3COC6H4, X = O, n = 2
3f, R = 4-H3COC6H4, X = O, n = 3
3g, R = C2H5, X = O, n = 2
3h, R = C2H5, X = O, n = 3
3i, R = C6H5, X = S, n = 2
(CH2)n
S
S
H2N
NH2
3j, R = C6H5, X = S, n = 3
(1)
3k, R = CH3, X = S, n = 2
3l, R = CH3, X = S, n = 3
1a, n = 2
1b, n = 3
(CH2)n
S
S
NCO
THF, TEA "in case of 1b"
OCN
HN
NH
O
O
N
H
N
H
(4)
4a, n = 2
4b, n = 3
Scheme 1.

2118
A.S. Girgis / European Journal of Medicinal Chemistry 43 (2008) 2116e2121
residue, quintet and triplet signals at d ¼ 1.72e1.74, 2.93e
2.94 in case of 3b, d and f corresponding to the SCH2CH2
and 2 SCH2, respectively), besides two sets of singlet signals
at d ¼ 8.17e8.37, 9.27e9.74 each integrated to 2 NH func-
tions (Scheme 1, Tables 1 and 2).
Similarly, reaction of 1a and b with ethylisocyanate 2d ‘‘as
a representative example of alkylisocyanate’’ afforded the cor-
responding bisurea analogues 3g and h. Moreover, bisthiourea
derivatives 3iel were obtained through reaction of 1a and
b with phenyl- and methylisothiocyanate (as representative
examples of aryl- and alkylisothiocyanate).
On the other hand, reaction of 1a and b with 1,4-phenyle-
nediisocyanate as 1:1 molar ratio under similar reaction condi-
tions gave dithiatetraaza-macrocycles 4a and b in 46e49%
yield. IR spectra of 4a and b reveal the imino and carbonyl
functions at n ¼ 3295e3293, 1642e1637 cmꢀ1, respectively.
In addition, 1H NMR spectra add good support for the deduced
structure exhibiting the alkylsulfanyl residues (singlet at
d ¼ 2.95 in case of 4a, quintet and triplet signals at d ¼ 1.70,
2.91 in case of 4b, respectively) besides the imino groups
(d ¼ 8.23e8.24, 9.36e9.38) and other expected aromatic pro-
tons (d ¼ 6.91e8.10). Mass spectra (CI) of 4a and b add sharp
evidence for the established structure which show the parent
ion peaks with considerable relative intensities (3e7%).
2.2. Anti-inflammatory activity
Anti-inflammatory activity of the synthesized compounds
3aej, 4a and b (in a dose of 50 mg/kg body weight) was
determined in vivo by the acute carrageenan-induced paw oe-
dema standard method in rats [33e35]. The anti-inflamma-
tory properties were compared with that of indomethacin
(in a dose of 10 mg/kg body weight) which was used as a ref-
erence standard. From the obtained results (Table 3), it has
been noticed that most of the tested compounds exhibit con-
siderable anti-inflammatory properties, especially compounds
3e and 4b which reveal remarkable activities with potency
(% oedema inhibition of the tested compounds regarding %
oedema inhibition of indomethacin) 0.90 and 0.85,
respectively.
Structureeactivity relationships based on the obtained re-
sults indicated that, substitution of the phenyl group in diary-
lurea analogues 3aef with an electron-donating moiety (e.g.
methoxy function) 3e and f is associated with enhancement
in pharmacological properties than the case of unsubstituted
phenyl derivatives 3a and b. However, attachment of the phe-
nyl group with a deactivating function (e.g. chlorine atom) 3c
and d led to decreasing pharmacological activity. This makes
the sequence of ruling anti-inflammatory properties regarding
Table 1
Physical data of the prepared compounds
Compd.
Mp (ꢁC)
Yield (%),
Reaction time (h)
Mol. formula
(Mol. wt.)
Analysis (%) Calcd/Found
C
H
N
3a
3b
3c
3d
3e
3f
3g
3h
3i
238e240a
211e213a
248e250b
228e230a
236e238b
202e204b
86, 10
80, 12
92, 2
C28H26N4O2S2
(514.64)
65.34
65.53
65.88
66.10
51.54
51.41
52.26
52.43
62.69
62.49
63.24
63.15
57.39
57.25
58.30
58.09
61.50
61.64
62.11
62.27
51.15
51.21
52.26
52.14
60.53
60.76
61.31
61.44
5.09
5.17
5.34
5.48
3.40
3.29
3.63
3.82
5.26
5.15
5.48
5.40
6.26
6.10
6.52
6.38
4.79
4.90
5.03
5.11
5.25
5.29
5.54
5.44
4.62
4.78
4.92
5.03
10.89
11.05
10.60
10.73
8.59
C29H28N4O2S2
(528.66)
C28H22Cl4N4O2S2
(652.44)
8.80
8.41
75, 10
80, 5
C29H24Cl4N4O2S2
(666.46)
8.59
9.75
C30H30N4O4S2
(574.69)
9.66
9.52
78, 10
72, 72
65, 72
77, 72
86, 72
76, 95
69, 95
46, 95
49, 95
C31H32N4O4S2
(588.72)
9.69
248e250
(Dioxane)
192e194c
C20H26N4O2S2
(418.56)
13.39
13.19
12.95
13.14
10.25
10.19
9.99
C21H28N4O2S2
(432.58)
176e177
(Dioxane)
165e167c
C28H26N4S4
(546.78)
3j
3k
3l
C29H28N4S4
(560.80)
9.75
148e150
(n-Butanol)
170e172c
C18H22N4S4
(422.65)
13.26
13.37
12.83
12.62
12.84
13.02
12.44
12.24
C19H24N4S4
(436.67)
4a
4b
a
>300d
>300d
C22H20N4O2S2
(436.53)
C23H22N4O2S2
(450.56)
Solvent: N,N-Dimethylformamideewater mixture as 5:1 v/v.
Solvent: N,N-Dimethylformamideewater mixture as 9:1 v/v.
Solvent: N,N-Dimethylformamideewater mixture as 1:1 v/v.
Solvent: Dimethyl sulfoxideewater mixture as 3:1 v/v.
b
c
d

A.S. Girgis / European Journal of Medicinal Chemistry 43 (2008) 2116e2121
2119
substitution of phenyl group in diarylurea derivatives as, me-
3. Experimental
thoxyphenyl > phenyl > dichlorophenyl as exhibited in com-
pounds 3e > 3a > 3c (potency, 0.90, 0.57, 0.12, respectively)
and compounds 3f > 3b > 3d (potency, 0.61, 0.51, 0.49,
respectively).
Moreover, substitution of the urea derivatives with an alkyl
function (e.g. ethyl group) may afford a better pharmacological
active agent comparable with the case of using phenyl moiety as
observed in pairs 3h and b (potency, 0.73, 0.51, respectively).
On the other hand, diarylthioureas seem to be more effective
anti-inflammatory active agents than the corresponding urea an-
alogues as observed in pairs 3i, a (potency, 0.75, 0.57, respec-
tively) and 3j, b (potency, 0.66, 0.51, respectively).
Table 4, demonstrates the anti-inflammatory properties of
compounds 3e and 4b ‘‘the most effective prepared ana-
logues’’ at successive time intervals (1, 2, 3 and 4 h). From
the observed data, it has been noticed that compound 4b re-
veals its anti-inflammatory behaviour more or less stable
among all the detected time intervals, in contrast to compound
3e, where its pharmacological effect increases with time.
Toxicological studies of the most promising prepared anti-
inflammatory active agents (3e and 4b) were performed using
LD50 standard method in mice [36] in 500, 750 and 1000 mg/kg
(body weight) ‘‘i.e. 10e20 folds of the used anti-inflammatory
effective dose’’. However, no toxic symptoms or mortality
rates were observed after 24 h postadministrations explaining
the safe behaviour of the used doses.
Melting points are uncorrected and recorded on an Electrother-
mal 9100 digital melting point apparatus. IR spectra (KBr) were
recorded ona Nexus 670FT-IR spectrophotometer. 1HNMR spec-
tra were recorded on a Varian MERCURY 300 MHz spectrometer
in DMSO-d6. Mass spectra (CI) were recorded on a Finnigan SSQ
7000 spectrometer. The starting compounds 1a and b [37,38]were
prepared according to the previously reported procedures.
3.1. Reaction of 1a and b with 2aef
A mixture of 1a and b (5 mmol) and the corresponding 2aef
(10 mmol) in dry tetrahydrofuran (25 ml) ‘‘containing triethyl-
amine (10 mmol) in case of 1b where the dihydrochloride salt
was used’’, was stirred at room temperature (20e25 ꢁC) for
the appropriate time. The separated solid was collected,
washed with water and crystallized from a suitable solvent af-
fording 3ael as colourless crystals. In case of 3d and k, the
reaction mixture was evaporated till dryness under reduced
pressure and the remaining residue was triturated with metha-
nol and diethyl ether giving 3d and k, respectively.
3.2. Synthesis of dithiatetraaza-macrocycles 4a and b
A solution of 1,4-phenylenediisocyanate (5 mmol) in dry
tetrahydrofuran (40 ml) was added dropwise to a solution of
Table 2
Spectroscopic data of the prepared compounds
Compd.
IR (nmax/cmꢀ1
)
1H NMR (DMSO-d6), d
3a
3300 (NH), 1651 (C]O),
1599, 1579 (C]C)
2.96 (s, 4H, 2 SCH2), 6.93e8.08 (m, 18H, arom. H), 8.28 (s, 2H, 2 NH), 9.43 (s, 2H, 2 NH)
3b
3c
3d
3e
3f
3303 (NH), 1638 (C]O),
1597, 1554 (C]C)
3336, 3284 (NH), 1662
(C]O), 1577, 1537 (C]C)
3291 (NH), 1647 (C]O),
1574, 1537 (C]C)
1.74 (quintet, 2H, SCH2CH2, J ¼ 7.5 Hz), 2.94 (t, 4H, 2 SCH2, J ¼ 7.2 Hz), 6.92e8.08 (m, 18H, arom. H),
8.26 (s, 2H, 2 NH), 9.44 (s, 2H, 2 NH)
2.98 (s, 4H, 2 SCH2), 6.98e8.10 (m, 14H, arom. H), 8.37 (s, 2H, 2 NH), 9.74 (s, 2H, 2 NH)
1.72 (quintet, 2H, SCH2CH2, J ¼ 7.2 Hz), 2.93 (t, 4H, 2 SCH2, J ¼ 7.2 Hz), 6.95e8.02 (m, 14H, arom. H), 8.30
(s, 2H, 2 NH), 9.72 (s, 2H, 2 NH)
3294 (NH), 1643 (C]O),
1581, 1552 (C]C)
2.95 (s, 4H, 2 SCH2), 3.73 (s, 6H, 2 OCH3), 6.86e8.11 (m, 16H, arom. H), 8.21 (s, 2H, 2 NH),
9.27 (s, 2H, 2 NH)
3311 (NH), 1652 (C]O),
1578, 1549 (C]C)
1.72 (quintet, 2H, SCH2CH2, J ¼ 7.5 Hz), 2.93 (t, 4H, 2 SCH2, J ¼ 7.5 Hz), 3.72 (s, 6H, 2 OCH3), 6.84e8.08
(m, 16H, arom. H), 8.17 (s, 2H, 2 NH), 9.27 (s, 2H, 2 NH)
3g
3h
3325 (NH), 1645 (C]O),
1561, 1526 (C]C)
1.06 (t, 6H, 2 CH3CH2, J ¼ 6.9 Hz), 2.87 (s, 4H, 2 SCH2), 3.09 (q, 2H, NCH2CH3, J ¼ 6.9 Hz), 3.11
(q, 2H, NCH2CH3, J ¼ 6.9 Hz), 6.87e8.06 (m, 12H, 8 arom. H þ 4 NH)
1.05 (t, 6H, 2 CH3CH2, J ¼ 7.2 Hz), 1.66 (quintet, 2H, SCH2CH2, J ¼ 7.2 Hz), 2.86
(t, 4H, 2 SCH2, J ¼ 7.2 Hz), 3.09 (q, 2H, NCH2CH3, J ¼ 7.2 Hz), 3.10 (q, 2H, NCH2CH3, J ¼ 7.2 Hz),
6.86e8.00 (m, 12H, 8 arom. H þ 4 NH)
3332, 3297 (NH), 1641
(C]O), 1578, 1560 (C]C)
3i
3238, 3160 (NH), 1533,
1498, 1473 (C]C, C]S)
3256, 3167 (NH), 1537,
1498, 1474 (C]C, C]S)
3240, 3163 (NH), 1541,
1510, 1468 (C]C, C]S)
3318, 3242, 3168 (NH), 1541,
1511, 1466 (C]C, C]S)
3295 (NH), 1642 (C]O),
1557, 1506 (C]C)
3.14 (s, 4H, 2 SCH2), 7.21e7.62 (m, 18H, arom. H), 9.32 (s, 2H, 2 NH), 10.00 (s, 2H, 2 NH)
3j
1.79 (quintet, 2H, SCH2CH2, J ¼ 6.9 Hz), 2.99 (t, 4H, 2 SCH2, J ¼ 7.2 Hz), 7.11e7.54
(m, 18H, arom. H), 9.14 (s, 2H, 2 NH), 9.87 (s, 2H, 2 NH)
3k
3l
2.98 (s, 6H, 2 NCH3), 3.11 (s, 4H, 2 SCH2), 7.23e7.54 (m, 8H, arom. H), 7.74 (br s, 2H, 2 NH), 9.01
(s, 2H, 2 NH)
1.80 (quintet, 2H, SCH2CH2, J ¼ 7.2 Hz), 2.91 (s, 6H, 2 NCH3), 2.98 (t, 4H, 2 SCH2, J ¼ 7.2 Hz),
7.18e7.43 (m, 8H, arom. H), 7.65 (br s, 2H, 2 NH), 8.89 (s, 2H, 2 NH)
2.95 (s, 4H, 2 SCH2), 6.91e8.10 (m, 12H, arom. H), 8.24 (s, 2H, 2 NH), 9.36 (s, 2H, 2 NH)
4aa
4bb
a
3293 (NH), 1637 (C]O),
1560, 1508 (C]C)
1.70 (quintet, 2H, SCH2CH2, J ¼ 6.9 Hz), 2.91 (t, 4H, 2 SCH2, J ¼ 6.9 Hz), 6.91e8.09
(m, 12H, arom. H), 8.23 (s, 2H, 2 NH), 9.38 (br s, 2H, 2 NH)
MS (CI): m/z (%) 436 (3).
MS (CI): m/z (%) 450 (7).
b

2120
A.S. Girgis / European Journal of Medicinal Chemistry 43 (2008) 2116e2121
Table 3
Anti-inflammatory activity of the tested compounds using acute carrageenan-
induced paw oedema in rats
indomethacin (reference standard in a dose of 10 mg/kg body
weight) and the tested compounds (3aej, 4a and b) dissolved
in DMSO, in a dose of 50 mg/kg (body weight) was given in-
traperitoneally 1 h before induction of inflammation. The con-
trol group was given DMSO only. Carrageenan paw oedema
was induced by subcutaneous injection of 1% solution of car-
rageenan in saline (0.1 ml/rat) into the right hind paw of rats.
Paw volumes were measured volumetrically after 4 h with ple-
thysmometer 7150 (UGO BASILE, Italy) and compared with
the initial hind paw volume of each rat for determining the oe-
dema volume. Data were collected, checked, revised and ana-
lyzed. Quantitative variables from normal distribution were
expressed as means ꢂ SE ‘‘standard error’’. The significant dif-
ference between groups was tested by using one-way ANOVA
followed by LSD test at p < 0.05.
Compound
Mean swelling
volume (ml)
% Inhibition
of oedema
Potencyc
Control
Indomethacin
0.665 ꢂ 0.038b
0.282 ꢂ 0.023a
0.447 ꢂ 0.035a
0.468 ꢂ 0.012a,b
0.618 ꢂ 0.053a,b
0.477 ꢂ 0.043a,b
0.320 ꢂ 0.017a
0.432 ꢂ 0.044a
0.445 ꢂ 0.024a
0.385 ꢂ 0.020a,b
0.377 ꢂ 0.036a
0.412 ꢂ 0.018a
0.433 ꢂ 0.032a,b
0.340 ꢂ 0.033a
00.0
57.6
32.8
29.6
7.1
e
1.00
0.57
0.51
0.12
0.49
0.90
0.61
0.57
0.73
0.75
0.66
0.61
0.85
3a
3b
3c
3d
3e
3f
3g
3h
3i
28.3
51.9
35.0
33.1
42.1
43.3
38.0
34.9
48.9
3j
4a
4b
a
The anti-inflammatory activity was expressed as percentage
inhibition of oedema volume in treated animals in comparison
with the control group (Tables 3 and 4).
Statistically significant from the control at p < 0.05.
Statistically significant from indomethacin at p < 0.05.
Potency was expressed as % oedema inhibition of the tested compounds
b
c
Vc ꢀ Vt
regarding % oedema inhibition of indomethacin ‘‘reference standard’’.
% Inhibition of oedema ¼
ꢃ 100
Vc
1a and b (5 mmol) in dry tetrahydrofuran (20 ml) ‘‘containing
triethylamine (10 mmol) in case of 1b, where the dihydro-
chloride salt was used’’, within a period of half an hour, while
stirring at room temperature (20e25 ꢁC). After complete addi-
tion, the reaction mixture was continued stirring at room tem-
perature for the appropriate time. Then, the separated solid
was collected, washed with water and crystallized from a suit-
able solvent giving 4a and b as colourless crystals.
where, Vc and Vt are the volumes of oedema for the control
and drug-treated animal groups, respectively, while potency
of the tested compounds was calculated regarding indometha-
cin ‘‘reference standard’’ treated group according to the fol-
lowing equation:
Potency
% Oedema inhibition of tested compound treated group
¼
% Oedema inhibition of indomethacin treated group
3.3. Anti-inflammatory activity screening
The anti-inflammatory activity screening for the prepared
compounds was determined in vivo by the acute carrageenan-
induced paw oedema standard method in rats [33e35]. Wister
albino rats of either sex (pregnant female animals were ex-
cluded) weighing 160e190 g were divided into 14 groups of
6 animals each ‘‘the animals had free access to standard com-
mercial diet and water adlibitum and were kept in rooms main-
tained at 22 ꢂ 1 ꢁC with 12 h light dark cycle, taking into
account international principles and local regulations concern-
ing the care and use of laboratory animals’’. Administration of
3.4. LD50 determination
The toxicological studies of the most promising prepared
anti-inflammatory active agents (3e and 4b) were determined
using standard known LD50 method in mice [36]. Albino
mice weighing 20e25 g were divided in 9 groups of 6 mice
each. Administrations of the tested compounds (3e and 4b)
dissolved in DMSO in 500, 750 and 1000 mg/kg (body
weight) were given intraperitoneally. The control groups
were given DMSO only. The toxic symptoms, mortality rates
Table 4
Anti-inflammatory activity of compounds 3e and 4b at successive time intervals using acute carrageenan-induced paw oedema in rats
Compd.
Mean swelling volume (ml) (% inhibition of oedema)
1 h
2 h
3 h
4 h
Control
0.293 ꢂ 0.013b
0.425 ꢂ 0.021b
0.515 ꢂ 0.027b
0.665 ꢂ 0.038b
(00.0)
0.145 ꢂ 0.009a
(50.5)
(00.0)
0.220 ꢂ 0.021a
(48.2)
(00.0)
0.257 ꢂ 0.028a
(50.1)
(00.0)
0.282 ꢂ 0.023a
(57.6)
Indomethacin
3e
4b
a
0.190 ꢂ 0.009a,b
0.262 ꢂ 0.018a
0.313 ꢂ 0.033a
0.320 ꢂ 0.017a
(35.2)
0.160 ꢂ 0.010a
(45.4)
(38.4)
0.238 ꢂ 0.024a
(44.0)
(39.2)
0.275 ꢂ 0.029a
(46.6)
(51.9)
0.340 ꢂ 0.033a
(48.9)
Statistically significant from the control at p < 0.05.
Statistically significant from indomethacin at p < 0.05.
b

A.S. Girgis / European Journal of Medicinal Chemistry 43 (2008) 2116e2121
2121
´
[13] S. Galiano, J. Ceras, N. Cirauqui, S. Perez, L. Juanenea, G. Rivera,
I. Aldana, A. Monge, Bioorg. Med. Chem. 15 (2007) 3896e3911.
[14] R. Liang, L. Abrardo, E.J. Brady, M.R. Candelore, V. Ding,
R. Saperstein, L.M. Tota, M. Wright, S. Mock, C. Tamvakopolous,
S. Tong, S. Zheng, B.B. Zhang, J.R. Tata, E.R. Parmee, Bioorg. Med.
Chem. Lett. 17 (2007) 587e592.
and postmortem findings in each group were recorded 24 h
postadministration.
LD50 of the tested compounds were calculated according to
the following formula:
P
[15] A. Arasappan, F.G. Njoroge, K.X. Chen, S. Venkatraman, T.N. Parekh,
H. Gu, J. Pichardo, N. Butkiewicz, A. Prongay, V. Madison,
V. Girijavallabhan, Bioorg. Med. Chem. Lett. 16 (2006) 3960e3965.
[16] K.X. Chen, F.G. Njoroge, A. Prongay, J. Pichardo, V. Madison,
V. Girijavallabhan, Bioorg. Med. Chem. Lett. 15 (2005) 4475e4478.
[17] C.C. Mak, A. Brik, D.L. Lerner, J.H. Elder, G.M. Morris, A.J. Olson, C.-
H. Wong, Bioorg. Med. Chem. 11 (2003) 2025e2040.
ðzxdÞ
LD50 ¼ Dm ꢀ
n
Where, Dm ¼ the largest dose which kill all animals, z ¼ mean
of dead animals between two successive groups, d ¼ the con-
stant factor between two successive doses, n ¼ number of
P
[18] G. Falardeau, H. Lachance, A. St-Pierre, C.G. Yannopoulos, M. Drouin,
´
J. Bedard, L. Chan, Bioorg. Med. Chem. Lett. 15 (2005) 1693e1695.
animals in each group,
¼ the sum of (z ꢃ d ).
[19] S.R. Lindsley, K.P. Moore, H.A. Rajapakse, H.G. Selnick, M.B. Young,
H. Zhu, S. Munshi, L. Kuo, G.B. McGaughey, D. Colussi, M.-
C. Crouthamel, M.-T. Lai, B. Pietrak, E.A. Price, S. Sankaranarayanan,
A.J. Simon, G.R. Seabrook, D.J. Hazuda, N.T. Pudvah, J.H. Hochman,
S.L. Graham, J.P. Vacca, P.G. Nantermet, Bioorg. Med. Chem. Lett. 17
(2007) 4057e4061.
Acknowledgment
The author is grateful to the (i) U.S.eEgypt Science and
Technology Joint Fund under Project No. MAN10-007-002,
(ii) Pharmacology Department, NRC, Cairo, Egypt, for allow-
ing performance of pharmacological activity screening.
[20] P. Rajakumar, A.M. Abdul Rasheed, A.I. Rabia, D. Chamundeeswari, Bi-
oorg. Med. Chem. Lett. 16 (2006) 6019e6023.
[21] E.A. Jefferson, E.E. Swayze, S.A. Osgood, A. Miyaji, L.M. Risen,
L.B. Blyn, Bioorg. Med. Chem. Lett. 13 (2003) 1635e1638.
References
´
´
[22] K. Ersmark, M. Nervall, H. Gutierrez-de-Teran, E. Hamelink,
L.K. Janka, J.C. Clemente, B.M. Dunn, A. Gogoll, B. Samuelsson,
J. Aqvist, A. Hallberg, Bioorg. Med. Chem. 14 (2006) 2197e2208.
[23] Y. Harrak, G. Rosell, G. Daidone, S. Plescia, D. Schillaci, M.D. Pujol,
Bioorg. Med. Chem. 15 (2007) 4876e4890.
´
[1] J.S. Fortin, J. Lacroix, M. Desjardins, A. Patenaude, E. Petitclerc, R. C.-
Gaudreault, Bioorg. Med. Chem. 15 (2007) 4456e4469.
[2] S. Fortin, E. Moreau, J. Lacroix, J.-C. Teulade, A. Patenaude, R. C.-Gau-
dreault, Bioorg. Med. Chem. Lett. 17 (2007) 2000e2004.
[3] S. Fortin, E. Moreau, A. Patenaude, M. Desjardins, J. Lacroix,
J.L.C. Rousseau, R. C.-Gaudreault, Bioorg. Med. Chem. 15 (2007)
1430e1438.
´
[24] A. Palomer, J.J. Perez, S. Naveo, O. Llorens, J. Pascual, M.L. Garcia,
´
D. Mauleon, J. Med. Chem. 43 (2000) 2280e2286.
[25] S.J. Sontag, Drugs 32 (1986) 445e447.
[26] M.C. Allison, A.G. Howatson, C.J. Torrance, F.D. Lee, R.I. Russell, N.
Engl. J. Med. 327 (1992) 749e754.
´
[4] E. Moreau, S. Fortin, M. Desjardins, J.L.C. Rousseau, E. Petitclerc,
[27] R.J. Flower, Nature Rev. Drug Discov. 2 (2003) 179e191.
[28] D.M. Clive, J.S. Stoff, N. Engl. J. Med. 310 (1984) 563e570.
[29] N. Futaki, K. Yoshikawa, Y. Hamasaka, I. Aria, S. Higuchi, Gen. Phar-
macol. 24 (1993) 105.
R. C.-Gaudreault, Bioorg. Med. Chem. 13 (2005) 6703e6712.
[5] C. Sanmartin, M. Echeverria, B. Mendivil, L. Cordeu, E. Cubedo,
J. Garcia-Foncillas, M. Font, J.A. Palop, Bioorg. Med. Chem. 13
(2005) 2031e2044.
[30] K. Seibert, Y. Zhang, K. Leahy, S. Hauser, J. Masferrer,
W. Perkins, L. Lee, P. Isakson, Proc. Natl. Acad. Sci. U.S.A. 91
(1994) 12013e12017.
[31] C.C. Chan, S. Boyce, C. Brideau, A.W. Ford-Hutchinson, R. Gordon,
D. Guay, R.G. Hill, C.S. Li, J. Mancini, M. Penneton, J. Pharmacol.
Exp. Ther. 274 (1995) 1531e1537.
[32] D.W. Gilroy, P.R. Colville-Nash, J. Mol. Med. (Berlin) 78 (2000) 121.
[33] A.S. Girgis, M. Ellithey, Bioorg. Med. Chem. 14 (2006) 8527e8532.
[34] A.S. Girgis, N. Mishriky, M. Ellithey, H.M. Hosni, H. Farag, Bioorg.
Med. Chem. 15 (2007) 2403e2413.
[35] C.A. Winter, E.A. Fisley, G.W. Nuss, Proc. Soc. Exp. Biol. Med. 111
(1962) 544.
[6] A. Gomtsyan, E.K. Bayburt, R. Keddy, S.C. Turner, T.K. Jinkerson,
S. Didomenico, R.J. Perner, J.R. Koenig, I. Drizin, H.A. McDonald,
C.S. Surowy, P. Honore, J. Mikusa, K.C. Marsh, J.M. Wetter,
C.R. Faltynek, C.-H. Lee, Bioorg. Med. Chem. Lett. 17 (2007) 3894e
3899.
[7] Y.J. Kim, J.-H. Ryu, Y.J. Cheon, H.J. Lim, R. Jeon, Bioorg. Med. Chem.
Lett. 17 (2007) 3317e3321.
[8] S. Nag, R. Pathak, M. Kumar, P.K. Shukla, S. Batra, Bioorg. Med. Chem.
Lett. 16 (2006) 3824e3828.
[9] P.P. Seth, R. Ranken, D.E. Robinson, S.A. Osgood, L.M. Risen,
E.L. Rodgers, M.T. Migawa, E.A. Jefferson, E.E. Swayze, Bioorg.
Med. Chem. Lett. 14 (2004) 5569e5572.
[36] C. Karber, Naunyn-Schmiedebergs Archiv fur experimentelle pathologie
¨
¨
und pharmakologie 162 (1931) 480.
[10] L. Chen, X.-M. Ou, C.-H. Mao, J. Shang, R.-Q. Huang, F.-C. Bi, Q.-
M. Wang, Bioorg. Med. Chem. 15 (2007) 3678e3683.
[11] M.S. Brouwer, A.C. Grosscurt, U.S. Patent 4609676, 1986.
[12] B. Daniele, M. Pietro, M. Giovanni, R. Franco, C. Vincenzo, EP
0211665, 1986.
[37] R.D. Cannon, B. Chiswell, L.M. Venanzi, J. Chem. Soc. A (1967)
1277e1281.
[38] A.A. Abbas, A.S. Girgis, Heteroat. Chem. 18 (2007) 249e254.