Synthesis, analgesic, anti-inflammatory, ulcerogenic index and antibacterial activities of novel 2-methylthio-3-substituted-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-4(3H)-ones

Article abstract of DOI:10.1016/j.ejmech.2006.06.005

A variety of novel 2-methylthio-3-substituted-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-4(3H)-ones have been synthesized by reacting (2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)dithiocarbamic acid methyl ester (5) with a variety of amines. The starting material dithiocarbamate (5) was synthesized from 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzo (b) thiophene (1) by a novel innovative route. The title compounds were investigated for analgesic, anti-inflammatory, ulcerogenicity index and antibacterial activities. While the test compounds exhibited significant activity, the compounds 1-methyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A1), 1-dimethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A2), 1-diethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A3) and 1-pyrrolidinyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A4) showed more potent analgesic activity and the compounds 1-dimethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A2), 1-diethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno-[2,3-d]pyrimidin-3-yl)thiourea (A3) and 1-pyrrolidinyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d] pyrimidin-3-yl)thiourea (A4) showed more potent anti-inflammatory activity than the reference standard diclofenac sodium.

Full text of DOI:10.1016/j.ejmech.2006.06.005

European Journal of Medicinal Chemistry 41 (2006) 1293–1300
http://france.elsevier.com/direct/ejmech
Original article
Synthesis, analgesic, anti-inflammatory, ulcerogenic index
and antibacterial activities of novel 2-methylthio-3-substituted-
5
,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-4(3H)-ones
a,
b
b
c
b
*
V. Alagarsamy , S. Meena , K.V. Ramseshu , V.R. Solomon , K. Thirumurugan
a
a
K. Dhanabal , M. Murugan
a
Medicinal Chemistry R&D Laboratory, Arulmigu Kalasalingam College of Pharmacy, Anand Nagar, Krishnankovil 626 190, India
b
Department of Pharmaceutical Chemistry, K.M. College of Pharmacy, Madurai 625 107, India
c
Medicinal Chemistry Laboratory, Central Drug Research Institute, Lucknow 226 001, India
Received 13 December 2005; received in revised form 12 June 2006; accepted 14 June 2006
Available online 22 August 2006
Abstract
A variety of novel 2-methylthio-3-substituted-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-4(3H)-ones have been synthesized by react-
ing (2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)dithiocarbamic acid methyl ester (5) with a variety of
amines. The starting material dithiocarbamate (5) was synthesized from 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzo (b) thiophene (1) by a
novel innovative route. The title compounds were investigated for analgesic, anti-inflammatory, ulcerogenicity index and antibacterial activities.
While the test compounds exhibited significant activity, the compounds 1-methyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno
[
(
2,3-d]pyrimidin-3-yl)thiourea (A1), 1-dimethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea
A2), 1-diethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A3) and 1-pyrrolidinyl-3-(2-
methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A4) showed more potent analgesic activity and the com-
pounds 1-dimethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A2), 1-diethyl-3-(2-methylthio-
4
-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno-[2,3-d]pyrimidin-3-yl)thiourea (A3) and 1-pyrrolidinyl-3-(2-
methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d] pyrimidin-3-yl)thiourea (A4) showed more potent anti-inflammatory activity than
the reference standard diclofenac sodium.
©
2006 Elsevier Masson SAS. All rights reserved.
Keywords: Thienopyrimidine; Thioureas; Pyrimidine; Analgesic; Anti-inflammatory
1
. Introduction
anti-inflammatory [2] activities. Recently reports have shown
that thienopyrimidines (bioisotere of quinazoline) possess
CNS and antibacterial activities [3–5]. Exploiting the bioisos-
terism concept, we have documented 2-phenyl-3-substituted
quinazolines [6], 2,3-disubstituted quinazolines [7], 2-methyl-
3-substituted quinazolin-4-(3H)-ones [8] and 2-methylthio-
3-substituted quinazolin-4-(3H)-ones [9] that exhibited good
analgesic and anti-inflammatory activities. The present work
is an extension of our ongoing efforts towards the development
and identification of new molecules by bioisotere concept, we
have aimed to synthesize some novel 2-methylthio-
Bacterial infections often produce pain and inflammation. In
normal practice, two groups of agents (chemotherapeutic,
analgesic and anti-inflammatory) are prescribed simulta-
neously. Unfortunately, none of drug possesses these three
activities in a single component. On our going medicinal chem-
istry research programme we have find that quinazolines and
condensed quinazolines exhibit potent antimicrobial [1] and
central nervous system (CNS) activities like analgesic and
3-substituted-5,6,7,8-tetrahydrobenzo
(b)
thieno[2,3-d]
*
pyrimidin-4(3H)-ones and screened for analgesic, anti-
Corresponding author.
E-mail address: samy_veera@yahoo.com (V. Alagarsamy).
inflammatory, ulcerogenicity index and antibacterial activities.
0223-5234/$ - see front matter © 2006 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2006.06.005

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V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
2
. Chemistry
confirmed the structures of the synthesized compounds, the
purity of these compounds was ascertained by microanalysis.
The title compounds were synthesized by nucleophilic sub-
stitution of (2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo
b) thieno[2,3-d]pyrimidin-3-yl) dithiocarbamic acid methyl
3. Results and discussion
(
ester (5) with different amines. The starting material (2-
methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-
d] pyrimidin-3-yl)dithiocarbamic acid methyl ester (5) was
synthesized by reacting the amino group of 3-amino-2-
3
.1. Analgesic activity
Test for analgesic activity was performed by tail-flick tech-
nique [10] using Wistar albino mice. The results of analgesic
activity indicate that all the test compounds exhibited signifi-
cant activity (Table 1). Compound A1 with methyl substitution
showed good activity; with increased lipophilicity (dimethyl
group), compound A2 showed an increase in activity. Further
increase in lipophilicity (diethyl group) compound A3 led to
even greater activity. Substitution with alicyclic amine (pyrro-
lidine) compound A4 showed moderate increase in activity.
Placement of alicyclic amines with additional heteroatoms
methylthio-5,6,7,8-tetrahydrobenzo
(b)
thieno[2,3-d]
pyrimidin-4(3H)-one (4) with carbon disulfide, sodium hydro-
xide and dimethyl sulfate. Compound 4 inturn was synthesized
from 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzo (b) thio-
phene (1) by a novel innovative route (Fig. 1). Thus 2-amino-
3
-carbethoxy-4,5,6,7-tetrahydrobenzo(b) thiophene (1), was
treated with carbon disulfide and sodium hydroxide to afford
sodium salt of dithiocarbamate, which upon methylation with
dimethyl sulfate afforded methyl ester of dithiocarbamic acid 2.
Compound 2 on treatment with hydrazine hydrate yielded the
thiosemicarbazide 3a which undergoes internal cyclization to
afford 3-amino-2-mercapto-5,6,7,8-tetrahydrobenzo (b) thieno
(compounds A5 and A6) led to a decrease in activity. Aromatic
substitution A7–A15 showed still lower activity. The com-
pounds with aliphatic substitution (compounds A1–A4)
showed better activity. Compound 1-pyrrolidinyl-3-(2-
methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-
d]pyrimidin-3-yl) thiourea (A4) was found to be the most
active analgesic agent and was more potent than diclofenac
sodium.
[
2,3-d]pyrimidin-4(3H)-one (3). Compound 3 upon methyla-
tion with dimethyl sulfate yielded the desired 3-amino-2-
methylthio-5,6,7,8-tetrahydrobenzo (b) thieno-[2,3-d]pyrimi-
din-4(3H)-one (4). Spectral data (IR, NMR, and mass spectra)
3.2. Anti-inflammatory activity
Anti-inflammatory activity was evaluated by carrageenan-
induced paw edema test in rats [11]. The anti-inflammatory
activity data (Table 2) indicated that all the test compounds
protected rats from carrageenan-induced inflammation and are
more potent than our earlier reported 2,3-disubtituted quinazo-
lin-4(3H)-ones. Compounds A2–A4 showed more anti-
inflammatory activity than diclofenac sodium.
3.3. Evaluation of ulcerogenicity index [12–14]
The ulcer index of the test compounds (Table 3) reveals that
the compounds 11–14 possessing electron withdrawing groups
exhibited higher ulcer index than the other test compounds.
The high ulcer index score for these compounds may be due
to the suppression of the prostaglandin synthesis.
3.4. Antibacterial activity
Evaluation of antibacterial activity was done by agar dilu-
tion method [15]. The results of antibacterial activity (Table 4)
indicate that all the test compounds exhibited moderate activity
against the tested bacteria. Compound A6 showed good activ-
ity against Pseudomonas aeruginosa, and Proteus vulgaris;
compound A8 exhibited good activity against P. aeruginosa,
Salmonella typhimurium and P. vulgaris; compound A13
exhibited good activity against Bacillus subtilis, Edwer-
siella tarda and S. typhimurium. While the compound A14
Fig. 1. Synthetic protocol of 2-methylthio-3-substituted-5,6,7,8-tetrahydroben-
zo (b) thieno[2,3-d]pyrimidin-4-(3H)-ones.

V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
1295
Table 1
PAA of test compounds (Tail-flick technique)
–
1
Compound code
Dose (mg kg
)
PAA
2 h
3
0 min
1 h
3 h
*
*
*
*
**
***
**
***
***
***
***
***
**
**
*
*
A1
10
46 ± 1.15
61 ± 1.92
52 ± 1.22
60 ± 1.51
46 ± 1.42
65 ± 1.31
55 ± 1.07
69 ± 1.56
57 ± 1.32
53 ± 1.31
69 ± 1.03
55 ± 1.36
74 ± 1.84
65 ± 1.36
75 ± 1.51
66 ± 1.42
77 ± 1.31
43 ± 1.05
59 ± 1.67
39 ± 1.16
55 ± 1.37
47 ± 1.12
56 ± 1.39
45 ± 1.34
53 ± 1.16
40 ± 1.41
48 ± 1.39
43 ± 1.23
51 ± 1.60
31 ± 1.17
46 ± 1.39
34 ± 1.39
49 ± 1.92
46 ± 1.63
49 ± 1.37
42 ± 1.21
45 ± 1.47
42 ± 1.31
49 ± 1.92
4 ± 0.59
36 ± 1.47
50 ± 1.73
43 ± 1.47
47 ± 1.72
46 ± 1.32
58 ± 1.17
47 ± 1.26
60 ± 1.39
32 ± 1.32
36 ± 1.09
35 ± 1.32
37 ± 1.49
30 ± 1.08
37 ± 1.23
31 ± 1.63
38 ± 1.81
31 ± 1.61
36 ± 1.74
32 ± 1.71
39 ± 1.83
26 ± 1.06
34 ± 1.15
27 ± 1.31
37 ± 1.39
27 ± 1.32
30 ± 1.61
23 ± 1.72
27 ± 1.43
25 ± 1.51
33 ± 1.32
4 ± 0.91
**
*
***
**
**
*
2
0
A2
10
*
**
***
*
2
0
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
**
*
A3
10
55 ± 1.09
69 ± 1.05
56 ± 1.21
73 ± 1.05
35 ± 1.16
46 ± 1.51
37 ± 1.09
50 ± 1.34
39 ± 1.12
46 ± 1.93
35 ± 1.16
43 ± 1.92
33 ± 1.12
41 ± 1.16
34 ± 1.21
43 ± 1.21
29 ± 1.17
43 ± 1.32
26 ± 1.37
41 ± 1.43
39 ± 1.93
49 ± 1.05
36 ± 1.31
45 ± 1.46
27 ± 1.39
41 ± 1.63
2 ± 0.35
**
*
***
**
*
2
0
74 ±1.93
62 ± 1.15
***
A4
10
**
***
***
*
2
0
76 ± 1.39
42 ± 0.95
53 ± 1.49
40 ± 1.18
52 ± 1.02
39 ± 1.12
54 ± 1.41
38 ± 1.04
49 ± 1.37
35 ± 1.26
47 ± 1.32
38 ± 1.90
48 ± 1.42
30 ± 1.19
45 ± 1.03
32 ± 1.41
52 ± 1.26
41 ± 1.71
50 ± 1.63
40 ± 1.46
47 ± 1.52
38 ± 1.69
45 ± 1.32
6 ± 0.49
43 ± 1.42
55 ± 1.16
*
A5
10
**
*
*
2
0
*
A6
10
*
**
*
**
*
*
2
0
*
A7
10
**
**
*
**
*
*
2
0
*
A8
10
**
*
*
2
0
*
*
A9
10
*
*
*
2
0
*
*
*
A10
A11
A12
A13
A14
A15
10
*
**
*
*
2
0
*
*
10
*
*
*
2
0
*
*
*
10
**
*
**
*
*
2
0
*
10
*
**
*
**
*
*
2
0
*
10
*
*
*
2
0
*
*
*
10
*
**
*
2
0
Control
Diclofenac
*
*
*
*
*
10
37 ± 1.69
46 ± 0.95
45 ± 0.92
62 ± 1.49
33 ± 0.96
39 ± 1.13
**
***
*
2
0
Each value represents the mean ± S.D. (n = 6). Significance levels *P < 0.5, **P < 0.01and ***P < 0.001 as compared with the respective control.
exhibited good activity against Salmonella paratyphi, E. tarda
and Klebsiella pneumoniae.
results of the analgesic and anti-inflammatory activities of the
present series showed that enhancement of activity (65%
analgesic and 45% anti-inflammatory activity) but there is no
increase in antibacterial activity. Interestingly these compounds
showed mild ulcer index unlike other Non Steroidal Anti
Inflammatory Drugs (NSAIDs). Hence this series could be
developed as a novel class of analgesic and anti-inflammatory
agents. However further structural modification is planned to
increase not only the analgesic and anti-inflammatory activities
also the antibacterial activity.
4
. Conclusions
In our earlier studies [6–9] we observed that the presence of
alkyl groups exhibited more analgesic and anti-inflammatory
activities over aryl groups at the N-3 position. Hence in the
C-2 position also we made a substitution in such a way as to
increase lipophilicity of the molecule. The placement of such a
group enhanced the analgesic and anti-inflammatory activities.
To compare the increase in activity we have taken the average
of all the readings of reaction time noted for each compound
for each pharmacological activity. The most active compound
of the C-2 phenyl series showed 43% analgesic and 36% anti-
inflammatory activity [6], whereas the C-2 methyl series lead
molecule showed 50% analgesic and 44% anti-inflammatory
activity [7]. Introduction of sulfur atom at C-2 position in the
above series i.e. by placing methyl thio group at C-2 position
showed 54% analgesic and 43% anti-inflammatory activity [9].
Replacement of benzene ring of the benzpyrimidine (quina-
zoline) series by its bioisostere along with the cyclohexyl ring
afforded the present series with the increased lipophilicity. The
5. Experimental protocols
5.1. Chemistry
Melting points were determined in open capillary tubes on a
Thomas Hoover apparatus and are uncorrected. IR spectra were
recorded in KBr on a Shimadzu FT-IR, 8300 spectrometer
−1
(cm ), mass spectra on a MASPEC msw 9629 mass spectro-
meter at 70 eV and NMR spectra on varian 300 MHz spectro-
meter, using tetramethylsilane as internal standard. Elemental
analyses were performed on Carlo erba 1108.

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V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
Table 2
Percent anti-inflammatory activity of test compounds (carrageenan-induced paw edema test in rats)
–
1
Compound code
Dose (mg kg
)
Percent protection
2 h
3
0 min
1 h
3 h
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
**
*
A1
10
33 ± 1.29
43 ± 1.15
36 ± 1.07
48 ± 1.47
39 ± 1.32
47 ± 1.16
35 ± 1.19
46 ± 1.32
29 ± 1.15
39 ± 1.26
29 ± 1.61
40 ± 1.34
27 ± 1.26
42 ± 1.47
25 ± 1.51
39 ± 1.54
22 ± 1.01
36 ± 1.23
25 ± 1.16
38 ± 1.32
26 ± 1.16
39 ± 1.28
23 ± 1.02
35 ± 1.19
31 ± 1.43
42 ± 1.22
27 ± 1.41
36 ± 1.56
29 ± 1.18
33 ± 1.53
37 ± 1.39
49 ± 1.27
38 ± 1.19
56 ± 1.37
42 ± 1.51
59 ± 1.06
41 ± 1.04
59 ± 1.41
30 ± 1.42
49 ± 2.41
35 ± 1.56
50 ± 1.51
39 ± 1.42
46 ± 1.53
35 ± 1.43
46 ± 2.38
32 ± 1.26
41 ± 1.38
34 ± 1.37
42 ± 1.63
29 ± 1.51
44 ± 1.83
27 ± 1.32
39 ± 1.42
35 ± 1.33
43 ± 1.62
30 ± 1.32
39 ± 1.39
29 ± 1.12
34 ± 1.36
40 ± 1.16
53 ± 1.32
43 ± 1.32
62 ± 1.76
46 ± 2.32
62 ± 2.03
45 ± 1.47
59 ± 1.32
36 ± 1.31
57 ± 1.63
32 ± 1.31
56 ± 1.64
40 ± 1.32
29 ± 1.09
41 ± 1.31
29 ± 1.51
40 ± 1.05
35 ± 1.32
46 ± 1.26
34 ± 1.03
42 ± 1.26
25 ± 1.25
34 ± 1.33
29 ± 1.51
32 ± 1.62
32 ± 1.21
38 ± 1.39
30 ± 1.62
39 ± 1.04
27 ± 1.23
31 ± 1.33
29 ± 1.23
32 ± 1.26
26 ± 1.14
30 ± 1.83
24 ± 1.21
25 ± 1.32
24 ± 1.74
42 ± 1.92
21 ± 1.04
37 ± 1.21
*
**
*
***
**
**
*
2
0
A2
10
*
*
*
***
**
***
**
***
*
***
**
**
*
2
0
A3
10
***
**
**
*
2
0
A4
10
*
*
*
*
*
**
**
*
2
0
*
A5
10
**
*
***
*
*
2
0
*
A6
10
***
**
**
*
***
**
*
2
0
*
A7
10
**
*
2
0
48±1.39
**
**
*
*
A8
10
39 ± 1.18
44 ± 1.83
35 ± 1.24
42 ± 1.46
37 ± 1.31
45 ± 1.47
33 ± 1.18
49 ± 1.14
30 ± 1.36
42 ± 1.42
33 ± 1.17
52 ± 1.95
31 ± 1.26
47 ± 1.45
31 ± 1.39
39 ± 1.46
**
**
**
*
**
*
2
0
A9
10
**
*
*
2
0
*
A10
A11
A12
A13
A14
A15
10
**
*
**
*
*
2
0
*
10
*
*
**
*
**
*
*
2
0
*
10
*
**
*
*
2
0
**
**
*
*
10
***
*
**
*
2
0
10
**
*
**
*
*
2
0
*
10
23 ± 1.86 36
36 ± 1.54
**
**
*
2
0
Control
Diclofenac
5.1 ± 0.29
6.1 ± 0.27
5.7 ± 0.32
3.2 ± 0.93
*
*
*
*
10
32 ± 0.63
45 ± 1.61
38 ± 1.58
52 ± 0.92
39 ± 1.97
60 ± 1.52
33 ± 0.93
*
*
**
***
*
2
0
42 ± 1.36
Each value represents the mean ± S.D. (n = 6). Significance levels *P < 0.5, **P < 0.01and ***P < 0.001 as compared with the respective control.
Table 3
5.1.1. Synthesis of methyl N-(3-carbethoxy-4,5,6,7-
tetrahydrobenzo (b) thienyl) dithiocarbamate (2)
Evaluation of ulcerogenicity index
Drug
A1
A2
A3
A4
A5
A6
A7
A8
Ulcer index
0.91 ± 0.21*
0.89 ± 0.27*
0.83 ± 0.24*
0.87 ± 0.27*
0.93 ± 0.24*
0.90 ± 0.29*
0.73 ± 0.16*
0.89 ± 0.36*
0.94 ± 0.13
0.79 ± 0.21*
1.09 ± 0.23**
1.13 ± 0.16**
1.06 ± 0.31**
1.17 ± 0.26**
0.97 ± 0.38*
1.05 ± 0.32
To
carbethoxy-4,5,6,7-tetrahydrobenzo (b) thiophene (1) (4.5 g,
.02 mol) in dimethyl sulfoxide (10 ml) at room temperature,
a
vigorously stirred solution of 2-amino-3-
0
carbon disulfide (1.98 g, 0.026 mol) and aqueous sodium
hydroxide (1.2 ml, 20 mol solution) were added simulta-
neously over 30 min, the stirring was continued for further
30 min. Dimethyl sulfate (2.5 g, 0.02 mol) was added drop
wise to the reaction mixture with stirring at 5–10 °C, it was
further stirred for 2 h and poured into ice-water, the solid
obtained was filtered, dried and recrystallized from ethanol.
Yield = 85%, m.p. 135–137 °C. IR: 3210 (NH), 1690 (C=O),
A9
A10
A11
A12
A13
A14
A15
Control
Aspirin
−1
1
1
060 (C=S) cm . H-NMR (CDCl ) δ 1.4–1.8 (m, 8H,
3
(
CH ) ), 2.0 (t, 3H, -COOCH CH ), 4.1 (q, 2H, -COOCH
2 4 2 3
CH ), 4.4 (s, 3H, -SCH ) and 7.3 (s, 1H, -NHCSSCH , D O
exchangeable).MS (m/z): 315 (M ). Anal. Calcd. for
2
3
3
3
2
+
1.73 ± 0.41**
–1
Dose 20 mg for test compounds and 200 mg kg for aspirin. Each value
represents the mean ± S.E.M. (n = 6). Significance levels *P < 0.05 and
C H NO S : C, 49.51; H, 5.44; N, 4.47. Found: C, 49.49; H,
1
3
17
2 3
5.42; N, 4.51.
**P < 0.01 as compared with the respective control.
5.1.2. Synthesis of 3-Amino-2-mercapto-5,6,7,8-
The 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzo (b) thio-
phene (1), was prepared as per the procedure described by
Gewald and Schinke [16].
tetrahydrobenzo (b) thieno[2,3-d] pyrimidin-4(3H)-one (3)
To a solution of 2 (3.15 g, 0.01 mol) in ethanol 30 ml was
treated with hydrazine hydrate (4.3 g, 0.01 mol, 99%) and

V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
1297
Table 4
Antibacterial activity of test compounds by agar-dilution method
a
Compound
Code
A1
A2
A3
A4
A5
A6
A7
B. subtilis
S. paratyphi
E. Tarda
P. aeruginosa
S .typhimurium
P. vulgaris
K. pneumoniae
39.06
78.12
78.12
156.25
78.12
39.06
78.12
78.12
156.25
78.12
78.12
39.06
9.76
39.06
156.25
78.12
39.06
39.06
39.06
156.25
78.12
78.12
39.06
39.06
78.12
156.25
9.76
39.06
156.25
78.12
78.12
78.12
39.06
78.12
39.06
39.06
78.12
78.12
39.06
9.76
156.25
39.06
156.25
39.06
39.06
9.76
78.12
39.06
78.12
156.25
39.06
78.12
156.25
9.76
78.12
156.25
78.12
78.12
9.76
78.12
39.06
39.06
78.12
78.12
9.76
78.12
78.12
78.12
156.25
78.12
156.25
39.06
39.06
156.25
156.25
39.06
78.12
78.12
9.76
78.12
9.76
78.12
9.76
A8
A9
78.12
78.12
39.06
39.06
78.12
39.06
39.06
0.018
78.12
156.25
39.06
78.12
39.06
78.12
39.06
1.22
A10
A11
A12
A13
A14
A15
Norflo-xacin
a
39.06
39.06
2.44
9.76
78.12
0.60
78.12
39.06
4.88
78.12
0.60
39.06
9.76
–1
MIC values (μg ml ).
refluxed on a water bath until the methylmercaptan evolution
ceases (8 h). After cooling, the solid obtained was filtered,
dried and recrystallized from ethanol/acetone mixture.
lized from ethanol. Yield = 71%, m.p. 119–121 °C. IR: 3290
−1 1
(NH), 1680 (C=O), 1160 (C=S) cm . H-NMR (CDCl ) δ
3
1.5–1.9 (m, 8H, (CH ) ), 3.4 (s, 3H, 2-SCH ), 3.6 (s, 3H,
2
4
3
Yield = 75%, m.p. 251–252 °C. IR: 3300, 3200 (NH ), 1680
3-SCH ) and 4.9 (s, 1H, NH, D O exchangeable). MS (m/z):
3 2
357 (M ). Anal. Calcd. for C H N OS : C, 43.67; H, 4.22;
13 15 3 4
N, 11.75. Found: C, 43.68; H, 4.19; N, 11.79.
2
−1
1
+
(
(
C=O) cm . H-NMR (CDCl ) δ 1.5–1.9 (m, 8H, (CH ) ), 3.2
3
2 4
s, 1H, -SH) and 5.4 (s, 2H, -NH , D O exchangeable). MS (m/
2
2
+
z): 253 (M ). Anal. Calcd. for C H N OS : C, 47.47; H,
1
0
11
3
2
4
.38; N, 16.68. Found: C, 47.40; H, 4.33; N, 16.66.
5.1.5. Synthesis of 1-methyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-
tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A1)
A mixture of 5 (3.57 g, 0.01 mol) and methylamine (0.62 g,
0.02 mol) in N,N-dimethyl formamide (20 ml) was refluxed for
29 h, cooled and poured into ice-water, the solid obtained was
filtered, dried and recrystallized from ethanol. Yield = 70%,
m.p. 193–195 °C. IR: 3300 (NH), 1680 (C=O), 1150 (C=S)
5
.1.3. Synthesis of 3-Amino-2-methylthio-5,6,7,8-
tetrahydrobenzo (b) thieno[2,3-d] pyrimidin-4(3H)-one (4)
To an ice cold solution of 3 (2.53 g, 0.01 mol) in dimethyl
formamide (50 ml), sodium hydroxide (0.4 g, 0.01 mol) was
added and the mixture was stirred for 1 h. To this dimethyl
sulfate (1.25 g, 0.01 mol) was added drop wise with constant
stirring. After the addition was completed, the reaction mixture
was further stirred for 3 h at room temperature. It was then
poured into ice-water and the solid obtained was filtered,
washed with water, dried and recrystallized from ethanol/acet-
one mixture. Yield = 79%, m.p. 216–219 °C. IR: 3350, 3330
−1 1
cm . H-NMR (CDCl
NCH ), 2.7 (s, 3H, SCH
and 4.9 (s, 1H, NH, D O exchangeable). MS (m/z): 340 (M ).
Anal. Calcd. for C13 OS : C, 45.92; H, 4.74; N, 16.47.
) δ 1.2–1.7 (m, 8H, (CH
) ), 2.3 (s, 3H,
2 4
3
), 4.6 (s, 1H, NH, D O exchangeable)
3
3
2
+
2
H
16
N
4
3
Found: C, 45.89; H, 4.76; N, 16.42.
−
1 1
(
(
NH ), 1690 (C=O) cm . H-NMR (CDCl ) δ 1.3–1.7 (m, 8H,
CH ) ), 3.9 (s, 3H, SCH ) and 6.5 (s, 2H, 3-NH , D O
5.1.6. Synthesis of 1-dimethyl-3-(2-methylthio-4-oxo-3H-
5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
thiourea (A2)
2
3
2
4
3
2
2
+
exchangeable); MS (m/z) 267 (M ). Anal. Calcd. for
C H N OS : C, 49.42; H, 4.90; N, 15.71. Found: C, 49.49;
H, 4.87; N, 15.73.
Compound A2 was prepared by adopting the same proce-
dure as for A1 and obtained in 72% yield, m.p. 161–162 °C.
1
1
13
3
2
−1
1
IR: 3350 (NH), 1690 (C=O), 1130 (C=S) cm . H-NMR
(CDCl ) δ 1.4–1.9 (m, 8H, (CH ), 2.3–2.5 (s, 6H,
N(CH ), 2.6–2.7 (s, 3H, SCH ), 4.9 (s, 1H, NH, D
exchangeable). MS (m/z): 354 (M ). Anal. Calcd. for
OS : C, 47.50; H, 5.12; N, 15.82. Found: C, 47.49;
5
.1.4. Synthesis of (2-methylthio-4-oxo-3H-5,6,7,8-
3
)
2 4
tetrahydrobenzo (b) thieno[2,3-d pyrimidin-3-yl)
dithiocarbamic acid methyl ester (5)
3
)
2
3
O
2
+
To a vigorously stirred solution of 4 (5.34 g, 0.02 mol) in
dimethyl sulfoxide (10 ml) at room temperature, carbon disul-
fide (1.6 ml, 0.026 mol) and sodium hydroxide (1.2 ml, 20 mol
solution) were added drop wise over 30 min, then the mixture
was allowed to stir for 30 min more. Dimethyl sulfate (2.5 g,
C
14
H
18
N
4
3
H, 5.09; N, 15.83.
5.1.7. Synthesis of 1-diethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-
tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A3)
Compound A3 was prepared by adopting the same proce-
dure as for A1 and obtained in 73% yield, m.p. 176–177 °C.
0
.02 mol) was added at 5–10 °C, stirring was continued for 3 h
and the reaction mixture was poured into ice-water, the solid
obtained was filtered, washed with water, dried and recrystal-
−1
1
IR: 3310 (NH), 1685 (C=O), 1120 (C=S) cm . H-NMR

1298
V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
(
CDCl ) δ 1.5–2.0 (m, 8H, (CH ) ), 2.3–2.5 (m, 4H, N(CH
5.1.12. Synthesis of 1-(4-methoxyphenyl)-3-(2-methylthio-4-
oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-
yl)thiourea (A8)
3
2 4
CH ) ), 2.8–3.0 (m, 6H, N(CH CH ) ), 3.1–3.3 (s, 3H,
2
3 2
2
3 2
SCH ), 4.8–4.9 (s,1H, NH, D O exchangeable). MS (m/z): 382
(
1
3
2
+
M ). Anal. Calcd. for C H N OS : C, 50.30; H, 5.80; N,
Compound A8 was prepared by adopting the same proce-
dure as for A1 and obtained in 69% yield, m.p. 239–242 °C.
1
6
22
4
3
4.66. Found: C, 50.29; H, 5.76; N, 14.65.
−1
1
IR: 3360 (NH), 1680 (C=O), 1150 (C=S) cm . H-NMR
(
3
CDCl ) δ 1.1–1.6 (m, 8H, (CH ) ), 3.3–3.4 (s, 3H, SCH ),
3 2 4 3
5
5
.1.8. Synthesis of 1-pyrrolidinyl-3-(2-methylthio-4-oxo-3H-
,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
.8–3.9 (s, 3H, OCH ), 4.4–4.5 (s, 1H, NH, D O exchange-
3 2
able), 4.6–4.7 (s, 1H, NH, D O exchangeable), 6.5–6.9 (m,
4
C H N O S : C, 52.82; H, 4.66; N, 12.96. Found: C,
5
2
thiourea (A4)
+
H, ArH) MS (m/z): 432 (M ). Anal. Calcd. for
Compound A4 was prepared by adopting the same proce-
dure as for A1 and obtained in 69% yield, m.p. 186–187 °C.
1
9 20 4 2 3
2.79; H, 4.69; N, 12.94.
−1
1
IR: 3360 (NH), 1670 (C=O), 1130 (C=S) cm . H-NMR
CDCl ) δ 1.1–1.6 (m, 8H, (CH ) ), 1.8–2.0 (m, 8H,
(
3
2 4
5
3
.1.13. Synthesis of 1-(3-methylphenyl)-3-(2-methylthio-4-oxo-
H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
N(CH –CH ) ) 2.9–3.0 (s, 3H, SCH ), 4.6–4.7 (s, 1H, NH,
D O exchangeable. MS (m/z): 380 (M ). Anal. Calcd. for
C H N OS : C, 50.57; H, 5.30; N, 14.74. Found: C, 50.53;
H, 5.32; N, 14.74.
2
2 2 ,
3
+
2
thiourea (A9)
1
6
20
4
3
Compound A9 was prepared by adopting the same proce-
dure as for A1 and obtained in 76% yield, m.p. 193–194 °C.
IR: 3290 (NH), 1685 (C=O), 1150 (C=S) cm . H-NMR
−1
1
5
5
.1.9. Synthesis of 1-morpholinyl-3-(2-methylthio-4-oxo-3H-
,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
(CDCl ) δ 1.1–1.7 (m, 8H, (CH ) ), 1.8–1.9 (s, 3H, CH ),
3
2 4
3
3.5–3.6 (s, 3H, SCH ), 4.5–4.6 (s, 1H, NH, D O exchange-
3
2
thiourea (A5)
able), 4.9–5.0 (s, 1H, NH, D O exchangeable), 6.6–7.1 (m,
4H, ArH). MS (m/z): 416 (M ). Anal. Calcd. for
C H N OS : C, 54.85; H, 4.84; N, 13.46. Found: C, 54.81;
19 20 4 3
H,4.88; N, 13.42.
2
+
Compound A5 was prepared by adopting the same proce-
dure as for A1 and obtained in 73% yield, m.p. 236–237 °C.
−1
1
IR: 3350 (NH), 1680 (C=O), 1140 (C=S) cm . H-NMR
CDCl ) δ 1.3–1.9 (m, 8H, (CH ) ), 2.3–2.5 (m, 4H,
(
3
2 4
N(CH –CH ) O), 2.8–3.0 (m, 4H, N(CH –CH ) O), 3.1–3.2
5.1.14. Synthesis of 1-(4-methylphenyl)-3-(2-methylthio-4-oxo-
3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
thiourea (A10)
2
2 2
2
2 2
(
s, 3H, SCH ), 4.7–4.8 (s, 1H, NH, D O exchangeable). MS
3 2
+
(
m/z): 396 (M ). Anal. Calcd. for C H N O S : C, 48.52; H,
16 20 4 2 3
5
.08; N, 14.12. Found: C, 48.49; H, 5.09; N, 14.14.
Compound A10 was prepared by adopting the same proce-
dure as for A1 and obtained in 71% yield, m.p. 211–213 °C.
IR: 3310 (NH), 1680 (C=O), 1145 (C=S) cm . H-NMR
−1
1
5
5
.1.10. Synthesis of 1-piperazinyl-3-(2-methylthio-4-oxo-3H-
,6,7,8-tetrahydrobenzo (b) thieno[2,3-d] pyrimidin-3-yl)
(
CDCl ) δ 1.3–1.8 (m, 8H, (CH ) ), 1.9–2.0 (s, 3H, CH ),
3 2 4 3
3
.5–3.6 (s, 3H, SCH ), 4.3–4.4 (s, 1H, NH, D O exchange-
3 2
thiourea (A6)
able), 4.8–4.9 (s, 1H, NH, D O exchangeable), 6.7–7.2 (m,
2
Compound A6 was prepared by adopting the same proce-
dure as for A1 and obtained in 72% yield, m.p. 209–211 °C.
+
4H, ArH). MS (m/z): 416 (M ). Anal. Calcd. for
C H N OS : C, 54.85; H, 4.84; N, 13.46. Found: C, 54.90;
−1
1
19 20
4
3
IR: 3310 (NH), 1690 (C=O), 1130 (C=S) cm . H-NMR
CDCl ) δ 1.1–1.6 (m, 8H, (CH ) ), 2.5–2.7 (m, 4H,
H, 4.85; N, 13.52.
(
3
2 4
N(CH –CH ) N), 3.0–3.2 (m, 4H, N(CH –CH ) N), 3.3–3.4
2
2 2
2
2 2
5
3
.1.15. Synthesis of 1-(4-nitrophenyl)-3-(2-methylthio-4-oxo-
H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
(
s, 3H, SCH ), 4.3–4.4 (s, 1H, NH, D O exchangeable),
3 2
4
.8–4.9 (s, 1H, NH, D O exchangeable). MS (m/z): 395
2
thiourea (A11)
+
(
M ). Anal. Calcd. for C H N OS : C, 48.65; H, 5.35; N,
16 21 5 3
Compound A11 was prepared by adopting the same proce-
dure as for A1 and obtained in 76% yield, m.p. 153–155 °C.
IR: 3350 (NH), 1685 (C=O), 1140 (C=S) cm . H-NMR
1
7.73. Found: C, 48.63; H, 5.37; N, 17.69.
−1
1
5
5
.1.11. Synthesis of 1-phenyl-3-(2-methylthio-4-oxo-3H-
,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
(CDCl ) δ 1.2–1.7 (m, 8H, (CH ) ), 3.5–3.6 (s, 3H, SCH ),
3
2 4
3
4
.5–4.6 (s, 1H, NH, D O exchangeable), 4.9–5.0 (s, 1H, NH,
2
thiourea (A7)
D O exchangeable), 6.7–7.1 (m, 4H, ArH). MS (m/z): 447
(M ). Anal. Calcd. for C18H N O S : C, 48.36; H, 3.83; N,
17 5 3 3
15.66. Found: C, 48.32; H, 3.81; N, 15.63.
2
+
Compound A1 was prepared by adopting the same proce-
dure as for A1 and obtained in 76% yield, m.p. 239–241 °C.
IR: 3310 (NH), 1670 (C=O), 1140 (C=S) cm . H-NMR
−1
1
(
4
CDCl ) δ 1.3–1.9 (m, 8H, (CH ) ), 3.1–3.2 (s, 3H, SCH ),
.5–4.6 (s, 1H, NH, D O exchangeable), 4.8–4.9(s, 1H, NH,
2
5.1.16. Synthesis of 1-(3-nitrolphenyl)-3-(2-methylthio-4-oxo-
3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
thiourea (A12)
Compound A12 was prepared by adopting the same proce-
dure as for A1 and obtained in 73% yield, m.p. 169–171 °C.
3
2 4
3
D O exchangeable), 6.9–7.3 (m, 5H, ArH). MS (m/z): 402
(
1
2
+
M ). Anal. Calcd. for C H N OS : C, 53.78; H, 4.51; N,
1
8
18
4
3
3.93. Found: C, 53.81; H, 4.50; N, 13.91.

V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
1299
−
1
1
IR: 3310 (NH), 1680 (C=O), 1130 (C=S) cm . H-NMR
(
4
and dark cycle; they were fed standard animal feed. All the
animals were acclimatized for a week before use. The Institu-
tional Animal Ethics committee approved the protocol adopted
for the experimentation of animals.
CDCl ) δ 1.2–1.8 (m, 8H, (CH ) ), 3.1–3.2 (s, 3H, SCH ),
3 2 4 3
.2–4.3 (s, 1H, NH, D O exchangeable), 4.6–4.7 (s, 1H, NH,
2
D O exchangeable), 6.9–7.3 (m, 4H, ArH). MS (m/z): 447
M ). Anal. Calcd. for C H N O S : C, 48.36; H, 3.83; N,
18 17 5 3 3
2
+
(
1
5.66. Found: C, 48.29; H, 3.76; N, 15.67.
5.2.1. Analgesic activity
Test for analgesic activity was performed by tail-flick tech-
nique [10] using Wistar albino mice (25–35 g) of either sex
selected by random sampling technique. Diclofenac sodium at
5
3
.1.17. Synthesis of 1-(4-chlorophenyl)-3-(2-methylthio-4-oxo-
H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
–
1
thiourea (A13)
a dose level of 10 and 20 mg kg was administered orally as
reference drug for comparison. The test compounds at two
Compound A13 was prepared by adopting the same proce-
dure as for A1 and obtained in 72% yield, m.p. 222–225 °C.
IR: 3310 (NH), 1690 (C=O), 1150 (C=S) cm . H-NMR
–
1
dose levels (10, 20 mg kg ) were administered orally. The
reaction time was recorded at 30 min, 1–3 h after the treatment,
and cut-off time was 10 s. The percent analgesic activity
(PAA) was calculated by the following formula,
−1
1
(
CDCl ) δ 1.2–1.8 (m, 8H, (CH ) ), 3.2–3.3 (s, 3H, SCH ),
3 2 4 3
4
.3–4.4 (s, 1H, NH, D O exchangeable), 4.7–4.8 (s, 1H, NH,
2
D O exchangeable), 6.5–7.0 (m, 4H, ArH). MS (m/z): 436
ꢀ
ꢁ
2
+
T2 ꢀ T1
(
M ). Anal. Calcd. for C H N OS Cl: C, 49.70; H, 3.93; N,
18 17 4 3
PAA ¼
ꢁ 100
1
0 ꢀ T1
1
2.88. Found: C, 49.53; H, 3.95; N, 13.79.
where T is the reaction time (s) before treatment, and T is the
reaction time (s) after treatment.
1
2
5
3
.1.18. Synthesis of 1-(4-bromophenyl)-3-(2-methylthio-4-oxo-
H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
thiourea (A14)
5
.2.2. Anti-inflammatory activity
Anti-inflammatory activity was evaluated by carrageenan-
induced paw edema test in rats [11]. Diclofenac sodium 10,
Compound A14 was prepared by adopting the same proce-
dure as for A1 and obtained in 76% yield, m.p. 242–243 °C.
IR: 3300 (NH), 1690 (C=O), 1150 (C=S) cm . H-NMR
−1
1
–
1
2
0 mg kg was administered as a standard drug for compari-
(
CDCl ) δ 1.2–1.8 (m, 8H, (CH ) ), 3.0–3.1 (s, 3H, SCH ),
3 2 4 3
son. The test compounds were administered at two dose levels
4
.2–4.3 (s, 1H, NH, D O exchangeable), 4.8–5.0 (s, 1H, NH,
2
–
1
(10 mg, 20 mg kg ). The paw volumes were measured using
D O exchangeable), 7.1–7.6 (m, 4H, ArH). MS (m/z): 481
2
+
the mercury displacement technique with the help of a plethys-
mograph immediately before and 30 min, 1–3 h after carragee-
nan injection. The percent inhibition of paw edema was calcu-
lated using the following formula
(
M ). Anal. Calcd. for C H N OS Br: C, 44.95; H, 3.56; N,
18 17 4 3
1
1.64. Found: C, 44.93; H, 3.52; N, 11.63.
5
5
.1.19. Synthesis of 1-(diphenyl)-3-(2-methylthio-4-oxo-3H-
,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)
Percent inhibition I ¼ 100½1 ꢀ ða ꢀ xÞ=ðb ꢀ yÞꢂ
thiourea (A15)
Compound A15 was prepared by adopting the same proce-
dure as for A1 and obtained in 70% yield. m.p 264-265 °C. IR:
Where x is the mean paw volume of rats before the admin-
istration of carrageenan and test compounds or reference com-
pound (test group), a is the mean paw volume of rats after the
administration of carrageenan in the test group (drug treated), b
is the mean paw volume of rats after the administration of car-
rageenan in the control group, y is the mean paw volume of
rats before the administration of carrageenan in the control
group.
−1
1
3
360 (NH), 1685 (C = O), 1130 (C = S) cm . H-NMR
(
CDCl ) δ 1.4–1.9 (m, 8H, (CH ) ), 3.0–3.1 (s, 3H, SCH ),
3
2 4
3
4
.8–4.9 (s, 1H, NH, D O exchangeable), 6.6–7.3 (m, 10H,
2
+
ArH). MS (m/z): 478 (M ). Anal. Calcd. for C H N OS : C,
2
4
22
4
3
6
0.30; H, 4.63; N, 11.72. Found: C, 60.29; H, 4.65; N, 12.69.
5
.2. Pharmacology
5.2.3. Evaluation of ulcerogenicity index
The synthesized compounds were evaluated for analgesic,
Ulceration in rats was induced as described by Goel et al.
anti-inflammatory, ulcerogenic index and antimicrobial activ-
ities. Student’s t-test was performed to ascertain the signifi-
cance of all the exhibited activities. The test compounds and
the standard drugs were administered in the form of a suspen-
sion (1% carboxy methyl cellulose as a vehicle) by oral route
of administration for analgesic and anti-inflammatory but for
ulcerogenicity studies by intra peritoneally as suspension in
[12]. Albino rats of wistar strain weighing 150–200 g of either
sex were divided into various groups each of six animals. Con-
trol group of animals were administered only with 10% v/v
Tween 80 suspension intraperitonially. One group was admi-
nistered with Aspirin (German Remedies) intraperitoneally in a
–
1
dose of 200 mg kg once daily for 3 days. The remaining
group of animals was administered with test compounds intra-
–
1
1
0% v/v Tween. Each group consisted of six animals. The ani-
peritoneally in a dose of 20 mg kg . On fourth day. Pylorus
was ligated as per the method of Shay et al. [13]. Animals were
fasted for 36 h before the pylorus ligation procedure. Four
hours after the ligation, animals were sacrificed. The stomach
mals were procured from the National Biological Center,
Madurai, India, and were maintained in colony cages at
2
5 ± 2 °C, relative humidity of 45–55%, under a 12 h light

1300
V. Alagarsamy et al. / European Journal of Medicinal Chemistry 41 (2006) 1293–1300
was removed and opened along with the greater curvature.
Ulcer index was determined by the method of Ganguly and
Bhatnagar [14] and recorded in Table 3.
[2] V. Alagarsamy, R. Revathi, S. Vijayakumar, K.V. Ramseshu, Pharmazie
8 (2003) 4–8.
3] A.E. Abdel-Rahman, E.A. Bakhite, E.A. Al-Taifi, J.Chin. Chem. Soc. 49
2002) 223.
5
[
(
[
[
4] R.V. Chambhare, B.G. Khadse, Eur. J. Med. Chem. 38 (2003) 89.
5] N.A. Santagati, A. Caruso, V.M.C. Cutuli, F. Caccamo, Farmaco 50
5
.2.4. Antibacterial activity
Evaluation of antibacterial activity by agar dilution method
(
1995) 689.
[
15]. The standard strains were procured from the American
[
6] V. Alagarsamy, V. Raja Solomon, G. Vanikavitha, V. Paluchamy, M.
Ravichandran, A. Arnald Sujin, A. Thangathirupathy, S. Amuthalakshmi,
R. Revathi, Biol. Pharm. Bull. 25 (2002) 1432–1435.
Type Culture Collection (ATCC), Rockville, USA, and the
pathological strains were procured from the Department of
Microbiology, Madurai Medical College and Research Insti-
tute, Madurai, India. The antibacterial activity of the synthe-
sized compounds was screened against the following bacterial
strains: P. vulgaris ATCC 9484, S. typhimurium ATCC 33068,
K. pneumoniae ATCC 13883, E. tarda, P. aeruginosa ATCC
[7] V. Alagarsamy, V. Muthukumar, N. Pavalarani, P. Vasanthanathan, R.
Revathi, Biol. Pharm. Bull. 26 (2003) 557–559.
[8] V. Alagarsamy, G. Murugananthan, R. Venkateshperumal, Biol. Pharm.
Bull. 26 (2003) 1711–1714.
[
9] V. Alagarsamy, R. Rajesh, R. Meena, S. Vijaykumar, K.V. Ramseshu, T.
Durai Anandakumar, Biol. Pharm. Bull. 27 (2004) 652–656.
2
853, B. subtilis ATCC 6051, and S. paratyphi. All bacteria
[
[
10] S.K. Kulkarni, Life Sci. 27 (1980) 185–188.
were grown on Muller–Hinton Agar (Hi-media) plates
11] C.A. Winter, E.A. Risely, G.N. Nu, Proc. Soc. Exp. Biol. 111 (1982)
(
(
37 °C, 24 h) and the minimum inhibitory concentration
MIC) was considered to be the lowest concentration that com-
5
44–547.
12] R.K. Goyal, A. Chakrabarthi, A.K. Sanyal, Planta Med. 29 (1985) 85–
8.
[
[
[
pletely inhibited the growth on agar plates, disregarding a sin-
gle colony or faint haze caused by the inoculums. The MIC of
the test compounds was compared with the reference drug nor-
floxacin.
8
13] H. Shay, S.A. Komarav, S.E. Fels, D. Meraza, M. Gruenstein, H. Siplet,
Gastroenterology 5 (1994) 43–61.
14] A.K. Ganguly, O.P. Bhatnagar, Can. J. Physilo. Pharmacol. 51 (1973)
7
48–750.
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