Synthesis of novel substituted 7-(benzylideneamino)-4-methyl-2H-chromen-2- one derivatives as anti-inflammatory and analgesic agents

Article abstract of DOI:10.1002/ardp.200800057

A series of novel Schiff' base-containing a 7-amino-4-methylcoumarin moiety have been synthesized III a-l, characterized by spectroscopic data and studied for their anti-inflammatory and analgesic activity. The results of the anti-inflammatory and analgesic activity evaluation of 7-(substituted benzylideneamino)-4-methyl-2H-chromen-2-one derivatives III a-l proved to be comparable or more potent with respect to the reference drugs. In particular, compounds 7-(4-chlorobenzylideneamino)-4-methyl-2H-chromen-2-one III f, 7-(2,4-dichlorobenzylideneamino)-4-methyl-2H-chromen-2-one III g and 7-(4-bromobenzylideneamino)-4-methyl-2H-chromen-2-one III h exhibited potent anti-inflammatory and analgesic activity.

Full text of DOI:10.1002/ardp.200800057

696
Arch. Pharm. Chem. Life Sci. 2008, 341, 696–700
Full Paper
Synthesis of Novel Substituted 7-(Benzylideneamino)-4-
Methyl-2H-Chromen-2-one Derivatives as Anti-inflammatory
and Analgesic Agents
Pradeepkumar Ronad1, Satyanarayana Dharbamalla2, Rajesh Hunshal3, and Veeresh Maddi1
1 Department of Pharmaceutical Chemistry, KLES College of Pharmacy, Vidyanagar, Hubli, Karnataka, India
2 Department of Pharmaceutical Chemistry, NGSM Institute of Pharmaceutical Sciences, Nanthoor,
Mangalore, Karnataka, India
3 Department of Pharmacology, Karnataka Institute of Medical Science, Hubli, Karnataka, India
A series of novel Schiff' base-containing a 7-amino-4-methylcoumarin moiety have been synthe-
sized III a–l, characterized by spectroscopic data and studied for their anti-inflammatory and
analgesic activity. The results of the anti-inflammatory and analgesic activity evaluation of 7-
(substituted benzylideneamino)-4-methyl-2H-chromen-2-one derivatives III a–l proved to be com-
parable or more potent with respect to the reference drugs. In particular, compounds 7-(4-
chlorobenzylideneamino)-4-methyl-2H-chromen-2-one III f, 7-(2,4-dichlorobenzylideneamino)-4-
methyl-2H-chromen-2-one III g and 7-(4-bromobenzylideneamino)-4-methyl-2H-chromen-2-one
III h exhibited potent anti-inflammatory and analgesic activity.
Keywords: 7-Amino-4-methylcoumarin / Analgesic activity / Anti-inflammatory activity / 2H-Chromen-2-ones / Schiff
base /
Received: March 11, 2008; accepted: May 15, 2008
DOI 10.1002/ardp.200800057
good antiphlogistic activities were found in copper com-
Introduction
plexes of Schiff' bases [8]. In search of novel anti-inflam-
matory drugs and continuation of our research [9, 10],
we have planned to report in this paper the synthesis of a
series of 7-(substituted benzylideneamino)-4-methyl-2H-
chromen-2-one derivatives III a–l and their anti-inflam-
matory and analgesic activity.
The synthesis of coumarin and its derivatives has
attracted considerable attention from organic and
medicinal chemists for many years, as a large number of
natural products contain this heterocyclic nucleus [1].
They have varied bioactivities, such as inhibition of plate-
let aggregation [2], antibacterial and antifungal [3], anti-
cancer [4], antitumor and antiviral [5], inhibition of HIV-1
protease [6]. A new trend in the development of non-ste-
roid anti-inflammatory drugs (NSAIDs) is the search for
compounds with simultaneous inhibitory effects on the
5-lipoxygenase and cycloxygenase enzymes [7]. Oxygena-
tion of arachidonic acid by lipoxygenase (LOX) to form
leukotriens proceeds through radical intermediates, and
thus, LOX participates in the production of free radicals.
Superoxide dismutase-like activity, radio-protective, and
Results and discussion
Chemistry
The sequence of the reactions employed for the construc-
tion of novel coumarin derivatives is outlined in
Scheme 1. The 7-amino-4-methylcoumarin I was pre-
pared by condensing meta-amino phenol with ethyl
chloroformate and ethyl acetoacetate in the presence of
sulphuric acid [11, 12]. Further, synthesis of the title com-
pounds III a–l were prepared by reacting them with 7-
amino-4-methylcoumarin I and substituted aromatic
aldehydes II. The purity of the compounds was confirmed
by TLC using silica gel G as stationary phase and suitable
solvent system as mobile phase as well as by melting
Correspondence: Pradeepkumar M. Ronad, Department of Pharma-
ceutical Chemistry, KLES' College of Pharmacy, Vidyanagar, Hubli-
580031, Karnataka, India.
E-Mail: ronad_p@rediffmail.com
Fax: +91-836-2371694
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Arch. Pharm. Chem. Life Sci. 2008, 341, 696–700
7-(Benzylideneamino)-4-methyl-2H-chromen-2-one
697
Table 1. Physical data of substituted 7-(benzylideneamino)-4-methyl-2H-chromen-2-one derivatives (III a–l).
Compound
G
Yield (%)
Melting Pointa)
Rf Valueb)
Mol. Formula
III a
III b
III c
III d
III e
III f
III g
III h
III i
III j
III k
III l
C6H5
82.6
79.2
73.1
94.6
83.5
62.7
68.8
55.2
56.3
38.4
69.2
44.0
176–178
162–164
215–216
192–194
212–213
160–161
150–152
154–156
208–209
202–204
170–172
180–182
0.53
0.81
0.83
0.43
0.33
0.69
0.51
0.61
0.79
0.61
0.67
0.47
C17H13NO2
C17H13NO3
C17H12NO4
C17H12NO4
C17H12NO4
C17H12ClNO2
C17H11Cl2NO2
C17H12ClNO2
C18H15NO2
C18H15NO3
C18H15NO3
C19H15NO2
2-C6H4OH
2-C6H4NO2
3-C6H4NO2
4-C6H4NO2
4-C6H4Cl
2,4-C6H4Cl2
3-C6H4Br
3-C6H4CH3
3-C6H4OCH3
4-C6H4OCH3
CH=CH-C6H5
a)
Recrystallization solvent: alcohol.
Ethyl acetate and cyclohexane (1 : 2)/iodine vapors as visualising agent.
b)
Scheme 1. Synthesis of substituted 7-(benzylideneamino)-4-
methyl-2H-chromen-2-one derivatives.
point determination. Structures of all the newly synthe-
sized compounds are well supported by the spectral data
such as IR, 1H-NMR, 13C-NMR, mass and elemental analysis
(Table 1).
Figure 1. Anti-inflammatory activity after three hours.
Acute toxicity
From preliminary toxicity studies, it was observed that drug used for the testing of the anti-inflammatory activ-
ity is diclofenac sodium. The test compounds were found
to be slow-acting anti-inflammatory agents. Compounds
animals were found to be safe up to a maximum dose of
2000 mg/kg body weight. But there were few changes in
the behavioral response like alertness, touch response, III f, g, h have shown inhibition after three hours, com-
parable with the standard drug, of 37.0%, 39.7%, and
33.7% inhibition, respectively. This is depicted in Fig. 1.
Hence, the compounds III f–h seem to be more effective
anti-inflammatory agents. The basic nucleus 7-amino-4-
methylcoumarin (7-AMC) has shown mild anti-inflamma-
tory activity. The results indicating the percentage inhib-
and restlessness. Therefore, 1/10th of the maximum tol-
erated dose, i.e. 200 mg/kg body weight (b.w.) was chosen
for the studies.
Anti-inflammatory activity
Inhibition of carrageenan-induced paw oedema in rats is
one of the most acceptable test procedures to evaluate ition of inflammation have been summarized in Table 2.
anti-inflammatory screening. Anti-inflammatory activity
Analgesic activity
Abdominal constriction response induced by acetic acid
exhibited by the compounds may be attributed to the
inhibition of cycloxygenase enzyme, which plays a vital
role in the inflammation process. Presently, the standard is a sensitive procedure to establish efficacy of peripher-
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

698
P. Ronad et al.
Arch. Pharm. Chem. Life Sci. 2008, 341, 696–700
Table 2. Anti-inflammatory activity of substituted 7-(benzylide-
neamino)-4-methyl-2H-chromen-2-one derivatives.
tuted with electron-withdrawing groups (halogen) at the
2-, or 4-, or both positions on the aromatic ring favors
analgesic and anti-inflammatory activity. Three com-
pounds, III f–h, were found to present a promising activ-
ity compared to standard. However, further studies are
required to establish their exact mechanism of action.
Compound
Paw mean volumea)
Edema inhibition
at 3 hr (%)
Control
III a
III b
III c
III d
III e
III f
III g
III h
III i
III j
III k
IIIl
7-AMC
Diclofenac
0.9900 l 0.0152
0.9530 l 0.0160
0.9367 l 0.01202
0.9500 l 0.01125
0.9300 l 0.01342
0.9867 l 0.0455
0.6233 l 0.01745a)
0.5967 l 0.01202c)
0.6567 l 0.01202b)
0.9700 l 0.0080
0.9400 l 0.01633
0.9533 l 0.00988
0.9200 l 0.0160
0.7355 l 0.0355
0.5600 l 0.01155c)
–
3.7
7.7
7.9
The authors have declared no conflict of interest.
7.7
0.3
37.0c)
39.7c)
33.7b)
2.0
Experimental
Chemistry
8.1
7.5
The melting points were determined by open capillaries on a
Thermonik melting point apparatus (Mumbai, India) and are
uncorrected. The IR spectra were recorded on a Thermo-Nicolet
FTIR-200 spectrometer (Nicolet, Madison, WI, USA), using KBr
pellets. 1H-NMR and 13C-NMR spectra were recorded on a Bruker
Avance II (400 MHz) spectrometer (Bruker Bioscience, Billerica,
MA, USA) in CDCl3 using TMS as an internal standard and the val-
ues are expressed in d ppm. The mass spectra were recorded
using GCMS-QP 2010 Shimaduzu (Cipla Laboratory, Mumbai,
India). Final compound have been analyzed for elemental com-
position results were found to be within l 0.4%. All the animal
experiments were approved by Institutional Animal Ethical
Committee (IAEC).
7.1
25.7b)
43.4c)
a)
Values are mean l SEM of six animals in each group.
p f 0.05.
p f 0.001.
b)
c)
Table 3. Analgesic activity of III f, III g, III h and 7-AMC.
Compound
No. of wriths in 15 min
% Protection
(mean l SEMa))
Control
III f
III g
III h
7-AMC
ASA
68.7 l 7.0
29.6 l 2.7
30.7 l 4.5
33.5 l 3.9
35.9 l 3.7
29.0 l 5.6
–
Synthesis of 7-amino-4-methyl-coumarin I
56.9b)
55.3b)
51.2b)
47.7b)
57.8b)
The condensation of meta-amino phenol with ethyl chlorofor-
mate and ethyl acetoacetate in the presence of sulphuric acid
gave 7-amino-4-methylcoumarin I It was recrystallized from
alcohol. The physical data and spectroscopic data were in accord-
ance with the literature [11, 12]. M.p.: 226–2278C. Yield 74.7%.
FAB-MS: 175 [M + 1]. IR (KBr) cm– 1: 3357.5 and 3250.0 (–NH2),
1697.1 (A C=O, a-pyrone). 1H-NMR (400 MHz, DMSO, d ppm): 7.3–
6.5 (m, 3H, Ar-H), 6.0 (s, 1H, a-pyrone 3-H), 4.1 (s, 1H, NH), 2.3 (s,
3H, 4-CH3 of a-pyrone). 13C-NMR (400 MHz, CDCl3, d ppm): 161.9
(2-C of a-pyrone), 153.5–100.3 (Ar-C), 111.7 (3-C of a-pyrone), 18.7
(4-CH3).
a)
l standard error of mean (n = 6); Dose of 200 mg/kg b.w., p.o.
Statistically significant (p f 0.05).
b)
ally-acting analgesics. Intraperitonial administration of
acetic acid causes an increase in the level of PGE2 and
PGF2a. Amongst the tested compounds, III f–h signifi-
cantly inhibited the acetic acid-induced writhing (up to
56.9%, 55.3%, and 51.2%, respectively). The basic nucleus
7-amino-4-methylcoumarin (7-AMC) has shown 47.7%
and other compounds, III a–l, in the range of 25–45% as
compared to the standard. The analgesic activity was
expressed as percentage of protection, the results are
summarized in Table 3.
General procedure for the synthesis of 7-
(benzylideneamino)-4-methyl-2H-chromen-2-one
derivatives [9] III a–l
A mixture of 7-amino-4-methylcoumarin (1.5 g, 0085 mmol) and
substituted aromatic aldehyde (0.017 mmol) in 25 mL of abso-
lute alcohol and 0.5 mL of acetic anhydride was refluxed for 6 h,
then, the solvent was removed under reduced pressure. The
resulting crude Schiff' base was washed with cold water and
recrystallized by using appropriate solvents. The purity of the
compounds was confirmed by TLC using silica gel G as stationary
phase, ethylacetate: cyclohexane (1 : 2) as mobile phase and
melting point. The structures of the compound were confirmed
by spectroscopic data.
Conclusion
The present study has shown that certain coumarin
Schiff' bases posses anti-inflammatory and analgesic
activity. Their synthesis was simple with satisfactory
yields. It was observed that the test compounds substi-
7-(Benzylideneamino)-4-methyl-2H-chromen-2-one III a
IR (KBr, cm– 1): 1717.4 (AC=O, a-pyrone), 1598.4 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.4 (s, 1H of -C=N), 7.9–7.1 (m, 8H, Ar-
H), 6.2 (s, 1H, C3-H of a-pyrone), 2.3 (s, 3H, 4-CH3 of a-pyrone). 13C-
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2008, 341, 696–700
7-(Benzylideneamino)-4-methyl-2H-chromen-2-one
699
NMR (400 MHz, CDCl3, d ppm): 160.5 (2C, C2 of a-pyrone and -
CH=N-), 153.5–115.1 (13C, Ar-C), 112.5 (1C, C3 of a-pyrone), 19.0
(1C, 4-CH3).
4-Methyl-7-(4-methylbenzylideneamino)-2H-chromen-2-
one III i
IR (KBr) cm– 1: 1727.8 (AC=O, a-pyrone), 1597.1 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.7 (s, 1H of -C=N), 7.9–7.2 (m, 7H, Ar-
H), 6.3 (s, 1H, C3-H of a-pyrone), 2.5 (s, 3H, 4-CH3 of a-pyrone), 2.4
(s, 3H, 39-Ar-CH3).
7-(2-Hydroxybenzylideneamino)-4-methyl-2H-chromen-
2-one III b
IR (KBr, cm– 1): 1719.9 (AC=O, a-pyrone), 1597.2 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 11.3 (s, 1H, -OH), 8.7 (s, 1H of -CH=N-),
7.7–7.0 (m, 7H, Ar-H), 6.3 (s, 1H, C3-H of a-pyrone), 2.5 (s, 3H, 4-
CH3 of a-pyrone). 13C-NMR (400 MHz, CDCl3, d ppm): 162.3 (1C, 29-
Ar-OH), 160.5 (2C, C2 of a-pyrone and -CH=N-), 153.5–115.5 (12C,
Ar-C), 112.5 (1C, C3 of a-pyrone), 19.0 (1C, 4-CH3).
7-(3-Methoxybenzylideneamino)-4-methyl-2H-chromen-
2-one III j
IR (KBr) cm– 1: 1735.4 (AC=O, a-pyrone), 1596.7 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.4 (3C, C2 of a-pyrone, 39-Ar-OCH3
and -CH=N-), 153.5–115.1 (12C, Ar-C), 112.5 (1C, C3 of a-pyrone),
55.9 (1C, 39-Ar-OCH3), 19.3 (1C, 4-CH3).
4-Methyl-7-(2-nitrobenzylideneamino)-2H-chromen-2-
one III c
7-(4-Methoxybenzylideneamino)-4-methyl-2H-chromen-
IR (KBr) cm– 1: 1727.8 (AC=O, a-pyrone), 1597.1 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.5 (2C, C2 of a-pyrone and -CH=N-),
153.5–115.4 (12C, Ar-C), 148.0 (1C, 2'-Ar-NO2), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
2-one III k
IR (KBr) cm– 1: 1723.3 (AC=O, a-pyrone), 1600.1 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.4 (s, 1H of -C=N), 7.9–7.0 (m, 7H, Ar-
H), 6.2 (s, 1H, C3-H of a-pyrone), 3.9 (s, 3H, 39-Ar-OCH3), 2.4 (s, 3H,
4-CH3 of a-pyrone).
4-Methyl-7-(3-nitrobenzylideneamino)-2H-chromen-2-
one III d
IR (KBr) cm– 1: 1728.7 (AC=O, a-pyrone), 1603.5 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.6 (2C, C2 of a-pyrone and -CH=N-),
153.5–115.4 (12C, Ar-C), 148.8 (1C, 2'-Ar-NO2), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
4-Methyl-7-(3-phenylallylideneamino)-2H-chromen-2-one
III l
IR (KBr) cm– 1: 1727.8 (AC=O, a-pyrone), 1602.6 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 7.8–7.2 (m, 8H, Ar-H), 7.5 (s, 1H of -
C=N), 7.2, 6.8 (s, 2H, -CH=CH-), 6.3 (s, 1H, C3-H of a-pyrone), 2.3 (s,
3H, 4-CH3 of a-pyrone).
4-Methyl-7-(4-nitrobenzylideneamino)-2H-chromen-2-
one III e
Biological assays
1
IR (KBr) cm– 1: 1730.8 (AC=O a-pyrone), 1602.6 (-CH=N-). H NMR
Albino mice of either sex weighing 20–25 g were used for acute
toxicity studies and analgesic activity. Healthy male albino adult
rats weighing 150–230 g were used for various pharmacological
screenings. Animal ethical clearance was obtained from Ethics
Committee of K. S. Hegde Medical Academy, Deralkatte, Manga-
lore, India (115/1999/CPCSEA). Animals were procured from
K. S. Hegde Medical Academy, Deralkatte, Mangalore, India, and
housed individually in polypropylene cages, maintained under
standard conditions of alternating 12-h light-and-dark cycles at
a constant temperature (25 l 28C and 35–60% relative humid-
ity). Animals were fed with standard rat pellet diet, (Hindustan
Lever Ltd., Mumbai, India) and water ad libitum.
(400 MHz, DMSO, d ppm): 8.6 (s, 1H of -C=N-), 8.4–7.2 (m, 7H, Ar-
H), 6.3 (s, 1H, C3-H of a-pyrone), 2.4 (s, 3H, 4-CH3 of a-pyrone).
7-(4-Chlorobenzylideneamino)-4-methyl-2H-chromen-2-
one III f
IR (KBr) cm– 1
:
1735.4 (AC=O, a-pyrone), 1596.7 13C-NMR
(400 MHz, CDCl3, d ppm): 160.6 (2C, C2 of a-pyrone and -CH=N-),
153.7–115.4 (12C, Ar-C), 136.8 (1C, 49-Ar-Cl), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
7-(2,4-Dichlorobenzylideneamino)-4-methyl-2H-
Acute toxicity
chromen-2-one III g
The acute toxicity test [13] was carried out according to the
Organization for Economic Co-operation and Development
(OECD)-guidelines to establish the effective dose of the test com-
pounds after obtaining ethical clearance from Ethics Committee
of K. S. Hegde Medical Academy, Deralkatte, Mangalore, India.
Albino mice of either sex weighing between 20–25 g were
grouped into six groups of six animals each, starved for 24 h
with water ad libitum prior to the test. On the day of the experi-
ment, animals were orally administered different compounds to
different groups with an increasing dose of 10, 20, 100, 200,
1000, and 2000 mg/kg body weight. Then, the animals were
observed continuously for 3 h concerning general behavioral,
neurological and autonomic profiles, then, every 30 min for the
next 3 h, and finally for the next 24 h or until death.
IR (KBr) cm– 1: 1723.8 (AC=O, a-pyrone), 1580.4 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.9 (s, 1H of -C=N-), 7.9–7.2 (m, 6H, Ar-
H), 6.3 (s, 1H, C3-H of a-pyrone), 2.4 (s, 3H, 4-CH3 of a-pyrone).
GCMS; m/z (M+): 331 (100%); 296 (60%); 268 (43%); 240 (20%); 131
(45%); 103 (55%); 77 (55%).
7-(4-Bromobenzylideneamino)-4-methyl-2H-chromen-2-
one III h
IR (KBr) cm– 1: 1723.3 (AC=O, a-pyrone), 1600.1 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.6 (2C, C2 of a-pyrone and -CH=N-),
153.6–115.4 (12C, Ar-C), 126.4 (1C, 29-Ar-NO2), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

700
P. Ronad et al.
Arch. Pharm. Chem. Life Sci. 2008, 341, 696–700
Anti-inflammatory activity
References
The anti-inflammatory activity [14] of the test compounds was
carried out using the carrageenan-induced rat paw oedema
inhibition method according to Winter et al. by employing 1.0%
carrageenan solution as the phlogistic agent. The test com-
pounds were administered orally as suspensions in 2% sodium
carboxy methylcellulose, 30 min before the injection of the
phlogestic agent, at dose level of 200 mg/kg body weight. Diclo-
fenac sodium was used as a standard at a dose level of 50 mg/kg
body weight. Groups of six albino rats of either sex were used in
each experiment. The sodium carboxy methyl cellulose (2%)
served as a control. The paw oedema volume was measured with
the help of plethysmograph by mercury displacement method
at 0 h (immediately after injection of carrageenan). Then, the
oedema volume was observed at 0.5, 1, 2, 3, 4, 5, and 6 h. The
results are depicted in Table 2. The percentage inhibition of
edema was calculated using the formula.
[1] A. Murakami, G. Gao, M. Omura, M. Yano, et al., Bioorg.
Med. Chem. Lett. 2000, 10, 59–63.
[2] A. K. Mitra, N. Karchaudhuri, S. K. Misra, A. K. Mukopad-
hyay, J. Ind. Chem. Soc. 1998, 75, 666–669.
[3] H. H. Sayed, A. H. Shamroukh, A. E. Rashad, Acta Pharm.
2006, 56, 231–244.
[4] C. J. Wang, Y. J. Hsieh, C. Y. Chu, Y. L. Lin, T. H. Tseng,
Cancer Lett. 2002, 183, 163–169.
[5] A. Najim, A. Iman Al–Masoudi, A. I. Ibrahim, et al., Acta
Pharm. 2006, 56, 175–188.
[6] S. Kirkiacharian, D. T. Thuy, S. Sicsic, R. Bakhchinian, et
al., II Farmaco. 2002, 57, 703–706.
[7] P. Silvester, J. Valentova, L. Bezakova, O. Marek, Neuro Endo-
crinol. Lett. 2006, 27(Suppl.2), 180–182.
[8] T. A. Lewis, L. Bayless, J. B. Eckman, J. L. Ellis, et al., Bioorg.
Med. Chem. Lett. 2004, 14, 2265–2273.
% Inhibition = 1 – Vt/Vc6100
[9] V. S. Maddi, K. S. Raghu, M. N. A. Rao, J. Pharm. Sci. 1992,
81(9), 964–966.
Vt and Vc is the edema volume in treated and control groups,
respectively.
[10] S. B. Girish, V. S. Maddi, S. N. Mamledesai, P. M. Ronad, et
al., Arzneim. Forsch. (Drug Res.) 2008; (In press).
Analgesic activity
[11] D. Robinson, Brackenwood and Great Britain inventors.
BioCarb AB, Sweden, assignee.”7–amino–4–methyl–cou-
marin–3–carboxyalkyl derivatives and fluorescent conju-
gates thereof” U.S. Patent No. 4956480. 1990 Sep.11.
The analgesic activity [15] of the test compounds was carried out
in vivo by acetic acid-induced writhing method. Albino mice of
either sex were divided into control, standard, and different test
groups of six mice each (20-25 g, b.w.). The control group
received 2 mg/kg of 2% aqueous gum acacia, p.o., standard was
treated with acetyl salicylic acid (ASA) at a dose level of 100 mg/
kg, and test compounds were administered p.o. at a dose level of
the groups received acetic acid i.p. (0.6% v/v in distilled water), at
a dose level of 1 mL/kg ten min after i.p.–injection of the acetic-
acid solution, the number of writhes per animal was recorded
for 20 min. The analgesic activity was expressed as percentage of
protection, the results are given in Table 3.
[12] J. E. Pretka, Wilmington and Del, inventors American
Cyanamid Company, New York, assignee. “4–substituted–
7–carboalkoxyaminocoumarin” U.S. Patent No. 3008969.
1961 Nov.14.
[13] OECD/OCDC, OECD “Guidelines for testing of chemicals”
Revised draft guidelines 423; acute oral toxicity class
method, Revised document, October 2000.
[14] C. A. Winter, E. A. Risley, G. W. Nuss, Proc. Soc. Exp. Biol.
Med. 1962, 111, 544–547.
Statistical analysis
[15] R. Koster, M. Anderson, E. J. De Beer, Fed. Proc. 1959, 18,
Data are presented as arithmetic mean l SEM. Statistical analysis
was performed by one way variance (ANOVA) followed by Dun-
nett's test, a ”p” value of less than 0.05 was considered as statisti-
cally significant using PARAMETRIC STASTICS, IBM PC version
1.01 by Londan software INC-1985.
412–413.
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com