Indian Journal of Pharmaceutical Sciences

Published by Indian Pharmaceutical Association
Online ISSN: 0250-474X
D-003, a mixture of high molecular weight acids, inhibits cholesterol synthesis prior to mevalonate and prevents osteoporosis induced by ovariectomy in rats, and both osteoporosis and osteonecrosis induced by corticoids in rats. The aim of this study was to investigate effects of D-003 on lipopolysaccharides-induced osteonecrosis in rabbits. Animals were randomized into 5 groups: a sham and four groups injected with lipopolysaccharides: one treated orally with vehicle and three with D-003 (5, 25 and 200 mg/kg, respectively) during four weeks. We assessed the effects of treatments on the incidence of osteonecrosis (number of animals with osteonecrosis lesions/animals per group), the mean numbers and areas of osteonecrosis per animal and on the mean sizes of the bone marrow fat cells. The incidence of osteonecrosis in the groups of D-003 25 and 200 mg/kg was significantly lower than in the positive controls. The reduction of osteonecrosis increased with the doses, but significant dose-dependence relationship was not achieved. D-003 significantly and dose-dependently decreased the number of osteonecrosis lesions per animal as compared to the positive controls. Likewise, the mean osteonecrosis areas in the proximal femoral and humeral bones were significantly decreased by D-003. The injection of lipopolysaccharides significantly increased the average size of bone marrow fat cells as compared to the negative controls, and such increase was significantly and markedly reduced with D-003. It is concluded that D-003 reduced the incidence, number and percent areas of osteonecrosis lesions, and the size of bone marrow fat cells, a marker of adipogenesis, in rabbits with lipopolysaccharides-induced ostenonecrosis.
Based on principles of pharmacophore delineation and drug designing, compounds containing diketofunctionallity namely 1,2-bis[5-thiazolyl]ethane-1,2-diones were designed and synthesized as antiinflammatory agents. The compounds were evaluated in carrageenan-induced rat-paw edema method. G-3, G-6, G-17, G-20, G-23, G-22, L-708 and 906 showed good antiinflammatory activity. In addition as diketo functionality containing compounds are reported to have HIV-1 integrase inhibitory property, and these compounds contains diketo functionality, so these compounds were screened in assay for HIV-1 integrase inhibition. Few compounds showed weak HIV-1 integrase Inhibitory activity.
CRCs of histamine-induced contraction of guinea pig tracheal chains in the presence of saline (control) (-□-), aminophylline (standard) (-Δ-), test compound (4) at two doses of 200 µg/ml (-О-) and 400 µg/ml (-◊-), respectively. Graph a is for 4a; graph b is for 4b; graph c is for 4c; graph d is for 4d. d c 
CRCs of histamine-induced contraction of guinea pig ileum in presence of saline control (-□-), chlorpheniramine maleate (standard) (-Δ-), test compound (4) at two doses of 200 µg/ml (-О-) and 400 µg/ml (-◊-) respectively. Graph a is for 4a; graph b is for 4b; graph c is for 4c; graph d is for 4d. 
A series of new 10-(alkylamino)-8-methyl-2, 6-dihydroimidazo[1, 2-c]pyrimido[5, 4-e]pyrimidine-5(3H)-thiones (4a-g) were subjected to molecular property prediction (drug-likeness, lipophilicity and solubility parameters) using Osiris Property Explorer, ALOGPS 2.1, Molinspiration and ACD/Chemsketch 12.0 software programmes. The calculated drug-related properties of the designed molecules were similar to those found in most marketed drugs. Amongst the proposed analogues, four promising candidates were chosen (4a-d) for synthesis on the basis of Lipinski's 'Rule of Five' and drug-likeness scores. The significant biological activity of the test compounds in two in vitro modes (isolated guinea pig tracheal chain preparation, isolated guinea pig ileum) supports the promise and accuracy of the prediction. Among them, 4a was the most potent antihistaminic (IC50 value of 30.2 μM; standard, chlorpheniramine maleate showed an IC50 of 14.1 μM).
Structures of I, II and lonafarnib Molecules from benzocycloheptapyridine class of farnesyl protein transferase inhibitors which are currently under investigation  
Flexible alignment of lonafarnib with compound I and test compounds (6e). Alignment of I with lonafarnib (2a) and with one of the test compounds (6e) is given in fi g. 2b. From 2b, it is clear that alignment of 6e is highly signifi cant compared to that of lonafarnib  
Scheme 1: Synthesis of test compounds 6a-h Reagents and conditions (a) concentrated H 2 SO 4 , KNO 3 , -5º, 30 min; (b) SnCl 2 .2H 2 O, RT, 1 h; (c) Br 2 , AcOH, 15º, 2 h; (d) i) NaNO 2 , concentrated HCl, 0º, 1 h ii) hypophosphorus acid, 5º, 2 h  
Eight novel 1-(substituted acetyl)-4-(10-bromo-8-chloro-5,6-dihydro-11H-benzo[5,6] cyclohepta [1,2-b] pyridine-11-ylidene)piperidines were designed by incorporating zinc binding groups to enhance activity. The designed molecules were synthesized and were evaluated for antitumor activity in vitro in five cell lines and for farnesyl protein transferase inhibition. Test compounds (6a-h) exhibited antitumor activity in most of the cell lines but were less potent than adriamycin. Compound 6e was most active with IC(50) values of <15 μM in two cell lines tested. Test compounds also exhibited potent FPT inhibitory activity and 6c was most potent with IC(50) value of <30 μM.
A series of 1,2,4-dithiazole were synthesized from 1,2,4-thiadiazoles in the presence of CS(2) and evaluated for their antimicrobial, anticonvulsant, analgesic and neurotoxicity potential. The compounds provided significant protection against maximal electroshock-induced seizures and seizures induced by 300 mg/kg of subcutaneous pentylenetetrazole administration. The designed compounds (3a-g) were screened in vitro for antibacterial activity against Staphylococcus aureus Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa and antifungal activity in fungal strains of Candida albicans and Aspergillus niger. Synthesized compounds exhibited moderate antibacterial and antifungal activity. N,N -Di-naphthalen-1-yl-N -(thioxo-5H -[1,2,4]dithiazol-3-yl)-guanidine and N,N -Bis-(4-fluoro-phenyl)-N -(5-thioxo-5H -[1,2,4]dithiazol-3-yl)-guanidine showed analgesic activity by tail flick method.
Two new series of 3-[2-(3,4-disubstituted-2,3-dihydrothiazol-2-ylidene)hydrazonopropylidenyl]-2-(methylthio)-3H-[1,2,4]triazolo[1,5-a]benzimidazole (6-29) and 3-[2-(3-substituted-4-oxothiazolidin-2-ylidene)hydrazonopropylidenyl]-2-(methylthio)-3H-[1,2,4]triazolo[1,5-a]benzimidazole (30-33) were synthesised starting from 1-[2-(methylthio)-3H-[1,2,4]triazolo[1,5-a]benzimidazol-3-yl] acetone N(4)-alkyl (aryl) thiosemicarbazones (2-5). Chemical structures of the compounds have been elucidated by different spectral data as well as elemental microanalysis. The newly synthesised compounds were tested for their in vitro antimicrobial activity using the standard agar cup diffusion method. Results revealed that most of the test compounds showed promising broad spectrum antibacterial and antifungal profiles against tested microorganisms, relative to references.
In a wide search program towards new and efficient antibacterial agents, we assessed the extent to which physicochemical properties can be exploited to promote antibacterial activity associated with a series of substituted s-triazine. The synthesized compounds (1a-12b) were subsequently screened for their in vitro antibacterial activity against three gram positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus) and three Gram-negative microorganism (Salmonella typhi, Escherichia coli, Klebsiella aerogenes) by the broth dilution technique, recommended by European Committee for antimicrobial susceptibility testing with reference to streptomycin.
Antimicrobial activity of newly synthesized compounds ■ A. niger ■ S. aureus ■ E. coli and ■ B. subtilis  
Synthesis of title compounds (4a-j) was carried out by following aminomethylation Mannich reaction. Test compounds were effective in inhibiting edema induced by carrageenan. The percent inhibition obseved was in the range of 25-83.3%. Compound (4c, e, h and j) were also tested for analgesic effect and showed percent protection ranging between 57-65%. All the synthesized compounds were active against E. coli and S. aureus but only compounds (4 b, c, e, i and j) were active against B. subtilis. All these compound were also found active against A. niger. Compound 4j was the most active compound with 83.3% inhibition of edema, 65.35% percent protection and inhibited all the three bacterial strains.
Scheme 2. The mechanistic equations for formation of pyrano[2,3-d] thiazolocarbonitriles.
The synthesis benzimidazolylpyrano [2,3-d] [1,3] thiazolocarbonitriles (5a-j) were achieved by cyclocondensation of arylidene amino-benzo[d]imidazole-2-thiols (3a-j) with mercaptoacetic acid followed by cyclization with 2-(phenylmethylene)malononitrile. Further more, the present study aimed at the evaluation of in vitro antiinflammatory activity and antioxidant activity of synthetic compounds. All tested compounds showed appreciable activity against the standard drugs.
In the present investigation, two new series, 1-(4-benzylphenyl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)-1-propanone and 1-(4-ethylphenyl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)-1-propanone from beta-(4-benzylbenzoyl)propionic acid and beta-(4-ethylbenzoyl)propionic acid, respectively, were synthesized and tested for antiinflammatory, analgesic, lipid peroxidation, ulcerogenic and antibacterial actions. A fair number of compounds were found to have good antiinflammatory activity in carrageenan-induced rat paw edema test, while a few compounds showed significant antibacterial activity. The newly synthesized compounds showed very low ulcerogenic action.
Design of new enoyl-ACP reductase inhibitor.  
Synthetic route of titled derivatives (Fa-Fe). Reaction conditions are (a) NH 2 NHCONH 2 , H 2 O, CH 3 COONa, C 2 H 5 OH, stirring, 20 min; (b) CH 3 COONa, CH 3 COOH, Br 2 +CH 3 COOH, stirring, 2h; (c) DMF, furfural, 2-3 drops concentrated H 2 SO 4 , 6-7h reflux. Fa: phenyl, Fb: 4-chloro phenyl, Fc: 4-methoxy phenyl, Fd: 4-nitro phenyl, Fe: 3-nitro phenyl.  
Docking pose of Fb The oxadiazole ring stacks with the nicotinamide ring of the NAD + with an interplanar distance of 3.7Å.  
Formation of a ternary complex between Fb and NAD + Pharmacophore modelling created by LigandScout 3.1 version.  
A series of novel N-(furan-2-yl)-1-(5-substituted) phenyl-1,3,4-oxadiazol-2-yl) methanimines (Fa-e) were synthesized and evaluated for antitubercular activity against Mycobacterium tuberculosis (H37Rv) strain by using alamar blue assay. The synthesized compounds were characterized based on IR, (1)HMR and mass spectral analysis. The toxicity profile was predicted by organic chemistry portal, a web based application for predicting in silico absorption, distribution, metabolism, excretion and toxicity, and the novel derivatives under study did not show any toxicity issues. The mechanism of action of the titled derivatives was predicted by docking on the Mycobacterium tuberculosis Enoyl-ACP reductase enzyme. The docking study concluded that Fb and Fa possessed good binding energy indicating more prominent interaction towards the active sites NAD and TYR 158. The antitubercular studies showed that the both Fa and Fb possessed significant activity with the MIC as low as 3.125 μg/ml.
In this study, various 5-β-[(N-benzenesulphony/tosyl)-4-(un) substituted anilino]ethyl-2-mercapto-1,3,4-oxadiazole (4a-f), with sulphonamide moiety at the side chain have been synthesised. The structures of the newly synthesised compounds have been established on the basis of their spectral data and elemental analysis. All the compounds were screened for antimicrobial activities against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger. Colletotrichum capsici and antituberclosis activity against Mycobacterium tuberculosis H37Rv strain. Only two compounds 4b (73%) and 4e (54%), have shown moderate antituberculosis activity. All the compounds have shown moderate antiinflamatory activity and least ulcerogenecity. Most of the compounds have shown significant analgesic activity (64.20-120.72%) in comparison with the standard, Aspirin (49.39%) In the MES method, however only compound 4a, exhibited a protection of 33.33%, and others failed to protect.
Scheme of synthesis.  
Plot of mean paw volume (ml) after administration of compounds 3a-3e and 6a-6e.  
Plot of number of writhes after i. p. administration of 1% acetic acid solution to animal treated with compounds 3a-3e, 6a-6e and standards.  
Plot of mean ulcer sore of animal after the administration of test compounds.  
Synthesis of 1,3,4-oxadiazole derivatives of diclofenac and mefenamic acid are described. The target compounds 5-[2-(2,6-dichloroanilino)benzyl]-2-aryl-1,3,4-oxadiazole (3a-3e) and 5-[2-(2,3-dimethylanilino)phenyl]-2-(aryl)-1,3,4-oxadiazole (6a-6e) were obtained by treating 2 and 5 with various aromatic acids using POCl(3) as dehydrating agent. They were purified and characterized by IR, (1)H-NMR and elemental analysis. These compounds were further subjected to antiinflammatory, analgesic and acute ulcerogenic activity. Compound 3c and 6d exhibited good antiinflammatory activity and compounds 3c, 3e, 6c, 6d, 6e were found to be non ulcerogenic.
Scheme 1: Synthetic route for the preparation of novel 2,5- disubstituted-1,3,4-oxadiazoles 3a-o.  
In the present study, 2,5-disubstituted-1,3,4-oxadiazoles (3a-o) have been synthesized by the condensation of 4-methoxybenzohydrazide (1) with different aromatic acids (2a-o) in presence of phosphoryl chloride. The structural assignment of this compound (3a-o) has been made on the basis of elemental analysis, UV, IR, (1)H NMR and mass spectral data. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria and fungi viz., Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium, Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteriae, Candida albicans, Aspergillus niger and Aspergillus flavus were compared with the standard antibiotics such as chloramphenicol (50 mug/ml) and griseofulvin (50 mug/ml) using well agar diffusion technique. Compounds 3e, 3g, 3h and 3m exhibits highest antibacterial activity and compounds 3d, 3g and 3h showed better antifungal activity. The synthesized compounds (3a-o) were screened for their in vitro antiinflammatory activity against carrageenan-induced rat paw oedema. Compounds 3f and 3i were found to be most active compound of this series, which shows 46.42% and 50% inflammation inhibitory activity, whereas standard drug phenylbutazone exhibit 53.57% antiinflammatory activity at a dose of 50 mg/kg po.
Structures of 2-(5-alkyl-1,3,4-oxadiazol-2-yl)-3H-benzo[f] chromen-3-ones (4a-e)  
A novel series of 2-(5-alkyl-1,3,4-oxadiazol-2-yl)-3H-benzo[f]chromen-3-ones (4a-e) have been evaluated for analgesic, antibacterial and antiviral activities. Analgesic activity was carried out using acetic acid-induced writhing method in Swiss albino male mice. The antibacterial activity was performed against Gram-positive and Gram-negative clinical strains by agar well diffusion method. The in vitro antiviral activity was carried out against camelpox and buffalopox viruses. The analgesic activity exhibited by the compounds 4a, 4c and 4d were found to be more significant compared to the standard. The bacterial activity was determined by the inhibition of growth of the organism by the drugs at different concentrations. All the compounds showed significant activity when compared with the drug ciprofloxacin. The in vitro antiviral activity of the compound 4b tested against camelpox and buffalopox viruses revealed no activity when tested at concentrations of 250 μg. The compound 4b did not alter the titres of both the viruses and the titres remain, respectively, 10(6.5) TCID50 and 10(6.74) TCID50 per ml for camelpox vaccine virus and buffalopox vaccine virus. However, the compounds 4a-e showed significant analgesic and antibacterial activities.
Synthetic route for the preparation of 5-substituted-2-amino-1,3,4-oxadiazoles 4a-k
Mechanistic proposal for the electrooxidation of semicarbazone 3a-k
An efficient electrochemical method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (4a-k) at platinum anode through the electrooxidation of semicarbazone (3a-k) at controlled potential electrolysis has been reported in the present study. The electrolysis was carried out in the acetic acid solvent and lithium perchlorate was used as supporting electrolyte. The products were characterized by IR,(1)H-NMR,(13)C-NMR, mass spectra and elemental analysis. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria viz., Klebsilla penumoniae, Escherichia coli, Bassilus subtilis and Streptococcus aureus and antifungal activity against Aspergillus niger and Crysosporium pannical and results have been compared with the standard antibacterial streptomycin and antifungal griseofulvin. Compounds exhibits significant antibacterial activity and antifungal activity. Compounds 4a and g exhibited equal while 4c, d, i and j slightly less antibacterial activity than standard streptomycin. Compounds 4a and g exhibited equal while 4b, c, d, f and i displayed slightly less antifungal activity than standard griseofulvins.
Scheme 1: Synthesis of {[(4,6-disubstitutedpyrimidine-2-yl)thio] methyl}-N-phenyl-1,3,4-thiadiazol-2-amine R= -C 6 H 5 , 2-OH.C 6 H 4 and 4-NO 2. C 6 H 4 , R'= -C 6 H 5 , 4-OCH 3 .C 6 H 4 , 2-OH. C 6 H 4 , -CH=CH.C 6 H 5 and 3-furyl  
A number of substituted-α,β-unsaturated carbonyl compounds (1a-i) were prepared by Claisen-Schmidt condensation of substituted acetophenone with selected araldehydes, which on cycloaddition with thiourea furnished 4,6-disubstituted pyrimidine-2-thiols (2a-i). Reaction of (2a-i) with ethyl chloroacetate followed by condensation with hydrazine hydrate yielded 2-[(4,6-disubstituted pyrimidine-2-yl) thio] acetohydrazides (4a-c). Condensation of compounds (4a-c) with phenyl isothiocyanate gave 2-{[(4,6-disubstituted pyrimidine-2-yl) thio] acetyl}-N-phenylhydrazinecarbothioamides (5a-c) which on treatment with concentrated sulphuric acid afforded titled compounds 5-{(4,6-disubstituted pyrimidine-2-yl) thio] methyl}-N-phenyl-1,3,4-thiadiazole-2-amines (6a-c). These compounds have been characterized on the basis of elemental analysis, IR, (1)H NMR and MS. Compounds have been evaluated for their anticancer and antioxidant activities. Compounds 2b, 2c and 6b exhibited significant antitumor activity against human breast cancer MCF 7 cell line. However, moderate antioxidant activity was observed with compounds 2c, 2d, 2g and 6b.
A series of novel 3, 4-methylenedioxybenzene scaffold incorporated 1,3,5-trisubstituted-2-pyrazoline derivatives was synthesised as potent antitubercular agents via chalcone intermediates by reaction with hydrazines. The structures of the compounds were confirmed by IR, 1HNMR, 13CNMR and mass spectral data. The novel pyrazolines were screened for in vitro antitubercular activity by almar blue dye method against M. tuberculosis H37Rv. All the compounds exhibited excellent activity that could be due to the presence of 3,4-methylenedioxybenzene frame work in the molecules. Some of the compounds also showed in vitro cytotoxicity on EAC cell lines in tryphan blue exclusion assay suggesting their safety.
Synthesis of new series of 1,4-dihydropyridine derivatives (1a-g) and (2a-g)
Mass spectral fragmentation of compound (2a)
Comparison of duration of convulsion with test compounds. Compound (2a-g) was used two does at 50 (
) and 100 (■) (mg/kg), whereas, phenytoin was used as a standard.
A series of 1,4-dihydropyridine derivatives (1a-g) were prepared from three compounds condensation of Hantzsch synthesis. A new series of 2,2'-{[4-(aryl)-2,6-dimethyl-1,4-dihydropyridine-3,5-diyl]dicarbonyl}dihydrazinecarbothioamide (2a-g) were prepared from compounds diethyl 4-(aryl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (1a-g) reacted with thiosemicarbazide to give the corresponding compounds (2a-g) by hydrazinolysis method. The synthesized compounds were confirmed by IR, (1)HNMR, (13)CNMR, mass spectral and elemental analyses. The newly synthesized compounds (2a-g) were screened for anticonvulsant activity against in swiss albino rat. The test was evaluated by maximal electrode induced convulsion method. Synthesized compounds were used two (50 and 100 mg/kg) concentrations. Compounds (1a-g) were inactive while compounds (2a-g) have moderate anti-convulsant activity compared with standard phenytoin drug. The compound 2,2'-{[4-(furan-2-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-diyl]dicarbonyl} dihydrazinecarbothioamide (2a) has highly active compared with other compound (2b-2g).
A spectrophotometric method of assay of mefenamic acid in tablets involving, dissolving the tablet powder in 1,4-dioxane and measuring the absorbance at 353.2 nm. The concentration of mefenamic acid is determined using the previously prepared calibration curve using standard solution of mefenamic acid in dioxane. The method was tested by assay of six different commercial tablets containing mefenamic acid.
Thiazolidin-4-one fused pyrimidines, [1,5]-benzodiazepines and their oxygen substituted hydroxylamine derivatives have been screened for antibacterial, antifungal and antimalarial activity. Bacillus subtilis, Escherichia coli, Proteus mirabilis and Salmonella typhi were used for antibacterial screening. Aspergillus fumigatus and Candida albicans were used for antifungal screening and Plasmodium species were used for antimalarial screening. The antibacterial and antifungal activities are expressed in terms of zone of inhibition and antimalarial activity is expressed in IC(50) value. Fifteen compounds 2Xa, 2Xb, 2Xc, 2Xs, 3IV, 3Va, 3Vc, 3VIIIa, 3VIIIh, 3IXa, 3IXb, 3IXc, 3Xa, 4IXa and 4Xa were tested for antibacterial as well as antifungal activity and seven compounds 2IXb, 2Xb, 3VIIIc, 3Xc, 4IXa, 4Xa and 4IXw were tested for antimalarial activity. Streptomycin, griseofulvin and chloroquine were taken as standard drugs in antibacterial, antifungal and antimalarial activity, respectively. The compound 2Xs was found significant antimicrobial against Bacillus subtilis, E. coli, Aspergillus fumigatus and Candida albicans as well as compound 3Xa was significant antimicrobial against Bacillus subtilis, E. coli, Salmonella typhi, Aspergillus fumigatus and Candida albicans. The compound 2Xb showed significant antimalarial activity.
A reversed-phase liquid chromatographic method for the determination of 1,7,7-trimethyl-bicyclo(2,2,1)heptan-2-one in a cream formulation is developed and validated. The separation was achieved using an isocratic mobile phase, on a Lichrosorb C8 column. The calibration curve is linear (r(2)= 0.9999) from 25-175% of the analytical concentration of 1.0 mg/ml. The mean percent standard deviation values for intra-day and inter-day precision studies were <1%. The recovery ranges 99.80-100.06% from a cream formulation. The method can be used reliably in quality control for the analysis of bulk cream samples and final product release.
Chemical structure of amoxicillin
Representative chromatograms of amoxicillin. Panel (a) Blank plasma sample. Panel (b) Blank plasma spiked with amoxicillin (20 µg/ml) and internal standard (I.S.). Panel (c) Plasma sample of volunteer #14R obtained after 1.5 hr from administration. Internal Standard: closed arrow. Amoxicillin: empty arrow.
Mean plasma concentration versus time plots of amoxicillin after oral administration. Oral administration was performed on 24 volunteers using Amoxil® (closed circles) as test formulation or Amoxicare® (open circles) as reference.
The aim of the study was to evaluate if two capsules (Amoxil(®) capsules, 500 mg/capsule) and one tablet (Amoxicare(®) tablets, 1000 mg/tablet) of amoxicillin have similar bioequivalence parameters. For this purpose a randomized, two-way, crossover, bioequivalence study was performed in 24 healthy, male volunteers, divided into two groups of 12 subjects each. One group was treated with the reference standard (Amoxil(®)) and the other one with the generic tablet Amoxicare(®), with a crossover after a wash-out period of 7 days. Blood samples were collected at fixed time intervals and amoxicillin was determined by a validated HPLC method. The pharmacokinetic parameters AUC(0-8), AUC(0-∞), C(max), T(max), K(e) and T(1/2) were determined for both formulations and statistically compared to evaluate the bioequivalence between the two brands of amoxicillin, using the statistical model recommended by the FDA. C(max) and AUC(0-∞) were statistically analyzed using analysis of variance (ANOVA); no statistically significant difference was observed between the two formulations. The 90% confidence intervals between the mean values of C(max) and AUC(0-∞) fall within the FDA specified bioequivalent limits (80-125%) suggesting that the two products are bioequivalent and the two formulations are interchangeable. Based on these findings it was concluded that the practice of interchangeability between the above formulations to achieve better patient compliance could be followed without compromising the extent of amoxicillin absorption.
Chemical structures of WCK 1152 and WCK 1153.
Chiral center is denoted by an asterisk in A) WCK 1152 and B) WCK 1153.
Reaction Scheme for Preparation of Derivative of WCK 1152.
RT: Room temperature, EEDQ: N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, h: hour, TEA: triethylamine, DCM: dichloromethane.
HPLC Chromatogram of WCK 1152 and WCK 1153.
Chromatograms with peak of N-Boc-proline derivative of WCK 1152 (RT = 25.1 min) and N-Boc-proline derivative of WCK 1153 (RT = 28.6 min)
A sensitive, simple, specific, precise, accurate and rugged method for determination of enantiomeric purity of S-(-)-1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-{4-amino-3,3-dimethylpiperidin-1-yl}-4-oxo-quinoline-3-carboxylic acid hydrochloride monohydrate, WCK 1152, a new drug substance has been developed. The method is based on prederivatization of analyte to diastereomer followed by RP-HPLC using endcapped C-18 stationary phase. Column was maintained at 30 degrees C. The UV/Vis detector was operated at 290 nm. Flow rate of the mobile phase was 1.25 ml/min. The method offers excellent separation of two enantiomers with resolution more than 4 and tailing factor less than 1.5. The method was validated for the quantification of R-(+)-enantiomer impurity, WCK 1153 in the bulk drug. Calibration curves showed excellent linearity over the concentration range of 0.1 to 1.5 mg/ml for WCK 1152 and 0.01 to 0.15 mg/ml for WCK 1153. Precision of the method was 1.13%. Limit of detection and limit of quantitation of the method for WCK 1152 were 0.0006 mg/ml and 0.0018 mg/ml and for WCK 1153 were 0.0007 mg/ml and 0.0021 mg/ml, respectively. Average recovery of the WCK 1153 in WCK 1152 was 94.4%. This method was employed in determining enantiomeric purity of clinical trial batches of WCK 1152.
A sensitive and specific high performance thin layer chromatographic method has been developed for estimation of a novel antihyperlipidemic agent LM 13765 in rabbit plasma and its use for pharmacokinetic study has been evaluated. The proposed method was employed to study pharmacokinetics of LM 13765 in rabbits. It was observed that LM 13765 metabolized immediately after oral administration. The metabolite of LM 13765 was identified and characterized as LM 13765-C. A sensitive and specific HPTLC method was developed for estimation of LM 13765-C in plasma after oral administration of LM 13765 and pharmacokinetic parameters were determined. Biological screening of LM 13765-C on hyperlipidemic rats indicated that it is less potent than the parent compound which is indicative of biotransformation of LM 13765 to active form LM 13765-C.
This article describes gas chromatography-flame ionization detection method for determination of 17 β-estradiol in rabbit plasma. 17 β-estradiol and internal standard progesterone were extracted from plasma using liquid-liquid extraction method. Linearity was found between 0.25 and 20 μg/ml (r(2)=0.994) for plasma samples. Intra-day and inter-day precision, expressed as the relative standard deviation were less than 5.5%, and accuracy (relative error) was less than 3.5%. The mean recovery of 17 β-estradiol samples was 94.4%. The limits of detection and quantification of method for plasma samples were 0.10 μg/ml and 0.15 μg/ml, respectively. Also, clinically used other 10 drugs were investigated to check for potential interferences and the method was successfully applied to the determination of 17 β-estradiol in New Zealand white rabbits.
A combination of fusion and surface adsorption techniques was used to enhance the dissolution rate of cefuroxime axetil. Solid dispersions of cefuroxime axetil were prepared by two methods, namely fusion method using poloxamer 188 alone and combination of poloxamer 188 and Neusilin US2 by fusion and surface adsorption method. Solid dispersions were evaluated for solubility, phase solubility, flowability, compressibility, Kawakita analysis, Fourier transform-infrared spectra, differential scanning calorimetry, powder X-ray diffraction study, in vitro drug release, and stability study. Solubility studies showed 12- and 14-fold increase in solubility for solid dispersions by fusion method, and fusion and surface adsorption method, respectively. Phase solubility studies showed negative ΔG (0) tr values for poloxamer 188 at various concentrations (0, 0.25, 0.5, 0.75 and 1%) indicating spontaneous nature of solubilisation. Fourier transform-infrared spectra and differential scanning calorimetry spectra showed that drug and excipients are compatible with each other. Powder X-ray diffraction study studies indicated that presence of Neusilin US2 is less likely to promote the reversion of the amorphous cefuroxime axetil to crystalline state. in vitro dissolution studies, T50% and mean dissolution time have shown better dissolution rate for solid dispersions by fusion and surface adsorption method. Cefuroxime axetil release at 15 min (Q15) and DE15 exhibited 23- and 20-fold improvement in dissolution rate. The optimized solid dispersion formulation was stable for 6 months of stability study as per ICH guidelines. The stability was ascertained from drug content, in vitro dissolution, Fourier transform-infrared spectra and differential scanning calorimetry study. Hence, this combined approach of fusion and surface adsorption can be used successfully to improve the dissolution rate of poorly soluble biopharmaceutical classification system class II drug cefuroxime axetil.
Synthetic route for the synthesis of 3 a-Reaction carried out with ethyl chloroacetate in presence of K2CO3 and acetone; b- reaction carried out with hydrazine hydrate in ethanol.
Synthetic route for the synthesis of 6a-o a- Reaction carried out in ethanol solution of sodium hydroxide at 25°
Synthetic route for the synthesis of 7a-o a- Reaction carried out in acetic acid and dioxane at reflux temperature.
Ethyl naphtho[2,1-b]furan-2-carboxylate (2) on reaction with hydrazine hydrate in presence of acid catalyst in ethanol medium affords naphtho[2,1-b]furan-2-carbohydrazide (3). The reaction of substituted acetophenones (4a-c) with aromatic aldehydes (5a-e) produces chalcones (6a-o) via the Claisen condensation. The reaction of naphtho[2,1-b]furan-2-carbohydrazide (3) with chalcones (6a-6o) in presence of acetic acid as catalyst in dioxane produces 1-(naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles (7a-o). The structures of newly synthesized compounds have been established by elemental analysis and spectral studies. The compounds 7a-o have been evaluated for their antimicrobial activity and some selected compounds evaluated for antiinflammatory, analgesic, anthelmintic, diuretic and antipyretic activities.
Scheme 1: Synthetic Scheme for the formation of title compounds Ar: Phenyl (a); 4-methylphenyl (b); 4-methoxyphenyl (c); 4-fluorophenyl (d); 4-chlorophenyl (e); 4-bromophenyl (f); 4-nitrophenyl (g)  
Seven new 2-(3-(4-aryl)-1-phenyl-1H-pyrazol-4-yl) chroman-4-ones (4a-4g) have been synthesized by cyclization of 2-hydroxychalcone analogues of pyrazole 3a-3g using conc. HCl in acetic acid. The structures of the compounds 4a-4g were established by the combined use of (1)HNMR, IR and mass spectra. All the seven compounds were tested in vitro for their antibacterial activity against two Gram positive bacteria namely Staphylococcus aureus and Bacillus subtilis and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The compounds 4b, 4c, 4e, 4f, 4g have displayed good antibacterial activity when compared with commercially available antibiotic, ciprofloxacin. These compounds also were screened for their antifungal activity against two ear pathogenic fungi, namely Aspergillus Niger and A. flavus. The compounds 4a, 4c, 4d, 4g exhibited good antifungal activity when compared with commercially available antifungal, fluconazole.
A number of mono and bicyclic nitroimidazoles were screened for in vitro antileishmanial activity. Among these, compounds belonging to the class of nitroimidazo[2,1-b]oxazoles showed moderate to good activity. This class of compounds had been reported previously to have pronounced antitubercular activity, particularly CGI17341 (5a). In the present study (5a) and (5d) and (7) were found to be more potent antileishmanials in vitro than the standard and less toxic in relation to a reference compound. (7) Was earlier formulated to have the phenyl group located on C-2(5b).
The chemical structures of the compounds used in the study  
The chemical structures of the compounds used in the study  
A molecular docking study was carried out on 28 compounds belonging to 2,4-diaminoquinazoline and 2,4-diaminopteridine analogs using Glide, FlexX and GOLD programs and the X-ray crystallographic structures of the quadruple mutant (1J3K:pdb) and wild type (1J3I:pdb) Plasmodium falciparum dihydrofolate reductase enzyme. The experimental conformation the bound ligand WR99210 was precisely reproduced by the docking procedures as demonstrated by low (<2.00 Å) root-mean-square deviations. The results indicated that most of the compounds dock into the active sites of both the wild type and quadruple mutant P. falciparum dihydrofolate reductase enzymes. Visual inspection of the binding modes also demonstrated that most of the compounds could form H-bond interactions with the key amino acid residues (Asp54, Ile14 and Leu/Ile164) and with better docking scores than the bound compound (5). Their long side chains orient in the hydrophobic portion of the active site which is occupied by trichloro aryloxy side chain of WR99210 (5). Thus, avoid potential steric clashes with Asn108 (mutated from Ser108). Such a clash is known to be responsible for the resistance of the P. falciparum to pyrimethamine and cycloguanil.
A pyrimidne nucleobase, 5-phenylthio-2,4-bisbenzyloxypyrimidine and its analogs were synthesized and scanned for in vitro antifungal activity using cup-plate and macrobroth dilution method against Candida albicans, Aspergillus niger, Aspergillus flavus and Aspergllus fumigatus. In the cup-plate method, 5-phenylthio-2,4-bisbenzyloxypyrimidine showed very good antifungal activity compared to clotrimazole at the concentrations of 100 and 1000 μg/ml and in the macrobroth dilution method, it showed comparable activity with respect to standard drugs fluconazole and itraconaole. In vivo antifungal activity of 5-phenylthio-2,4-bisbenzyloxypyrimidine at the dose levels of 10 and 30 mg/kg was carried by causing systemic infection of mice using the same fungi used in in vitro testing. The results from in vivo studies with 5-phenylthio-2,4-bisbenzyloxypyrimidine and fluconazole indicated that 5-phenylthio-2,4-bisbenzyloxypyrimidine had similar potency as fluconazole at both dose levels.
Scheme 1: Synthesis of {[(4,6-disubstitutedpyrimidine-2-yl)thio] methyl}-N-phenyl-1,3,4-thiadiazol-2-amine R=-C 6 H 5 , 2-OH.C 6 H 4 and 4-NO 2. C 6 H 4 , R'=-C 6 H 5 , 4-OCH 3 .C 6 H 4 , 2-OH. C 6 H 4 ,-CH=CH.C 6 H 5 and 3-furyl 
A set of seventy four molecules belonging to the class of thioglitazones were subjected to the QSAR analysis for their antihyperglycemic activity. All the molecules were subjected to energy minimization to get 3D structures, followed by conformational analysis to get the conformation of the molecule associated with the least energy and highest stability. Various physico-chemical parameters were then calculated using ALCHEMY 2000 software, namely, thermodynamic parameters, structure-dependant parameters, topological parameters and charge-dependant parameters. Multiple linear regression analysis was carried out on all the molecules. The final equation was developed by choosing optimal combination of descriptors after removing the outliers. Cross validation was performed by leave one out method to arrive at the final QSAR model for the chosen set of molecules to exhibit antihyperglycemic activity.
A series of 4-(2,5-dimethylpyrrol-1-yl)/4-pyrrol-1-yl benzoic acid hydrazide analogs, some derived triazoles, azetidinones, thiazolidinones, and pyrroles have been synthesized in good yields and structures of these compounds were established by IR, (1)H NMR, (13)C NMR, mass spectral, and elemental analysis. These compounds were evaluated for their preliminary in vitro antibacterial, antifungal, and antitubercular activity against Mycobacterium tuberculosis H37 Rv strain by the broth dilution assay method. Twenty one of these compounds displayed good antimicrobial activity, with a MIC value of 1-4 μg/ml. Several compounds 4c, 8-10, 15b-15h, and 16b-16d exhibited good in vitro antitubercular activity with MIC value 1-2 μg/ml. Further, some title compounds were also assessed for their cytotoxic activity (IC50) against mammalian Vero cell lines and A549 (lung adenocarcinoma) cell lines using the MTT assay method. The results revealed that these compounds exhibit antitubercular activity at non-cytotoxic concentrations.
The aim of the present study was the development and validation of a simple, precise and specific reversed phase HPLC method for the simultaneous determination of 22 components present in different essential oils namely cinnamon bark oil, caraway oil and cardamom fruit oil. The chromatographic separation of all the components was achieved on Wakosil-II C18 column with mixture of 30 mM ammonium acetate buffer (pH 4.7), methanol and acetonitrile in different ratio as mobile phase in a ternary linear gradient mode. The calibration graphs plotted with five different concentrations of each component were linear with a regression coefficient R(2) >0.999. The limit of detection and limit of quantitation were estimated for all the components. Effect on analytical responses by small and deliberate variation of critical factors was examined by robustness testing with Design of Experiment employing Central Composite Design and established that this method was robust. The method was then validated for linearity, precision, accuracy, specificity and demonstrated to be applicable to the determination of the ingredients in commercial sample of essential oil.
Mechanism-based inhibition of cytochrome P450 involves the bioactivation of the drug to a reactive metabolite, which leads to cytochrome inhibition via various mechanisms. This is generally seen in the Phase I of drug metabolism. However, gemfibrozil (hypolipidemic drug) leads to mechanism-based inhibition after generating glucuronide conjugate (gemfibrozil acyl-β-glucuronide) in the Phase II metabolism reaction. The mechanism involves the covalent binding of the benzyl radical (generated from the oxidation of aromatic methyl group in conjugate) to the heme of CYP2C8. This article deals with the development of a 2D QSAR model based on the inhibitory potential of gemfibrozil, its analogues and corresponding glucuronide conjugates in inhibiting the CYP2C8-catalysed amodiaquine N-deethylation. The 2D QSAR model was developed using multiple linear regression analysis in Accelrys Discovery Studio 2.5 and helps in identifying the descriptors, which are actually contributing to the inhibitory potency of the molecules studied. The built model was further validated using leave one out method. The best quantitative structure activity relationship model was selected having a correlation coefficient (r) of 0.814 and cross-validated correlation coefficient (q(2)) of 0.799. 2D QSAR revealed the importance of volume descriptor (Mor15v), shape descriptor (SP09) and 3D matrix-based descriptor (SpMax_RG) in defining the activity for this series of molecules. It was observed that volume and 3D matrix-based descriptors were crucial in imparting higher potency to gemfibrozil glucuronide conjugate, as compared with other molecules. The results obtained from the present study may be useful in predicting the inhibitory potential (IC50 for CYP2C8 inhibition) of the glucuronide conjugates of new molecules and compare with the standard gemfibrozil acyl-β-glucuronide (in terms of pIC50 values) in early stages of drug discovery and development.
The correlation graph using Model 3 The correlation graph between experimental and predicted Log IC 50 , for (a) training compounds and (b) test compounds.  
The c-Jan N-terminal kinases are members of the mitogen activated protein kinase family of signaling proteins. Amino pyridine based compounds, 4-anilino pyrimidine derivatives, and 2-pyridine carboxamide derivatives have been identified as potent JNK inhibitors with good cellular activity. In this study we calculated molecular topological and quantum chemical descriptors of 15 training compounds and three quantitative structure activity relationships models have been constructed. The significance of three models is judged on the basis of correlation, Fischer F test and quality factor (Q). This study is helpful for screening potent inhibitors of protein kinases.
In this paper we report the synthesis of a new family of 4-alkyl isocoumarin derivatives having bromo carbonyl and amino carbonyl group at 3(rd) position of the heterocyclic ring. Synthesis, spectral analysis and bioactivity of new isocoumarin derivatives are discussed in this paper. Some of the synthesized compounds displayed comparable antibacterial activity and some of the new compounds showed an interesting inhibitory effect on the growth of four pathogen fungi involved in plant diseases. A fair number of compounds were found to have good analgesic property on comparing with standard drug analgin.
Heteroaryl pyrroles used for CoMFA study. General structure of compounds used for CoMFA study. Rotatable bonds selected for conformational analysis are shown in bold face.  
A three dimensional quantitative structure-activity relationship study using the comparative molecular field analysis method was performed on a series of 3-aryl-4-[alpha-(1H-imidazol-1-yl) aryl methyl] pyrroles for their anticandida activity. This study was performed using 40 compounds, for which comparative molecular field analysis models were developed using a training set of 33 compounds. Database alignment of all 33 compounds was carried out by root-mean-square fit of atoms and field fit of the steric and electrostatic molecular fields. The resulting database was analyzed by partial least squares analysis with cross-validation; leave one out and no validation to extract optimum number of components. The analysis was then repeated with bootstrapping to generate the quantitative structure-activity relationship models. The predictive ability of comparative molecular field analysis model was evaluated by using a test set of 7 compounds. The 3D- quantitative structure-activity relationship model demonstrated a good fit, having r(2) value of 0.964 and a cross validated coefficient r(2) value as 0.598. Further comparison of the coefficient contour maps with the steric and electrostatic properties of the receptor has shown a high level of compatibility and good predictive capability.
Phosphoinositide-dependent kinase-1 plays a vital role in the PI3-kinase signaling pathway that regulates gene expression, cell cycle growth and proliferation. The common human cancers include lung, breast, blood and prostate possess over stimulation of the phosphoinositide-dependent kinase-1 signaling and making phosphoinositide-dependent kinase-1 an interesting therapeutic target in oncology. A ligand-based pharmacophore and atom-based 3D-QSAR studies were carried out on a set of 82 inhibitors of PDK1. A six point pharmacophore with two hydrogen bond acceptors (A), three hydrogen bond donors (D) and one hydrophobic group (H) was obtained. The pharmacophore hypothesis yielded a 3D-QSAR model with good partial least square statistics results. The training set correlation is characterized by partial least square factors (R(2) = 0.9557, SD = 0.2334, F = 215.5, P = 1.407e-32). The test set correlation is characterized by partial least square factors (Q(2) ext = 0.7510, RMSE = 0.5225, Pearson-R =0.8676). The external validation indicated that our QSAR model possess high predictive power with good value of 0.99 and value of 0.88. The docking results show the binding orientations of these inhibitors at active site amino acid residues (Ala162, Thr222, Glu209 and Glu166) of phosphoinositide-dependent kinase-1 protein. The binding free energy interactions of protein-ligand complex have been calculated, which plays an important role in molecular recognition and drug design approach.
In the present investigation, a series of 12 Mannich bases (QP1-12) and 5 Schiff bases (QSP1-5) of pyrazol-5(4H)-one moiety containing 3-(hydrazinyl)-2-phenylquinazolin-4(3H)-one has been synthesized and characterized by physicochemical as well as spectral means. The synthesized Mannich and Schiff bases were screened for their preliminary antimicrobial activity against Gram-positive and Gram-negative bacterial as well as fungal strains by the determination of zone of inhibition. Mannich bases (QP1-12) were found to be more potent antibacterial agents against Gram-positive bacteria, whereas Schiff bases (QSP1-5) were more potent against Gram-negative bacteria and fungi. Minimum inhibitory concentration result demonstrated that Mannich base compound (QP7) having ortho -OH and para -COOH group showed some improvement in antibacterial activity (minimum inhibitory concentration of 48.88×10(-3) μM/ml) among the tested Gram-positive organisms and it also exhibit minimum inhibitory concentration of value of 12.22×10(-3) μM/ml for Klebsiella pneumoniae. The antitubercular activity of synthesized compounds against Mycobacterium tuberculosis (H37Rv) was determined using microplate alamar blue assay. Compound QP11 showed appreciable antitubercular activity (minimum inhibitory concentration of 6.49×10(-3) μM/ml) which was more active than the standard drugs, ethambutol (minimum inhibitory concentration of 7.60×10(-3) μM/ml) and ciprofloxacin (9.4×10(-3) μM/ml). Compounds QP11, QP9, QSP1, QSP2, and QSP5 have good selective index and may be selected as a lead compound for the development of novel antitubercular agents.
New quinazolin-4-one derivatives, 6-bromo-2-methyl-3-(substituted phenyl)-(3H)-quinazolin-4-one, were synthesized and evaluated for antimicrobial and antiinflammatory activities. The structures attributed to synthesized compounds 1-8 were supported by the results of elemental analysis as well as by the UV, IR and (1)H NMR spectral data. Investigation of antimicrobial activity was performed using cup-plate agar diffusion method against Bacillus subtilis, Staphylococcus aureus and Pseudomonas aeruginosa and Candida albicans, Aspergillus niger and Curvularia lunata. Antiinflammatory activity was evaluated using the carrageenan-induced paw oedema test in rats. The results showed that compounds 2b, 2c, 2d, 2g and 2h exhibited significant antibacterial and antifungal activity comparable to standard drugs and compounds 2b and 2c showed good antiinflammatory activity comparable to ibuprofen.
Some of potent anticonvulsant compounds. 1 is methaqualone, 2 is rilozole, 3 is 2-(chloromethyl)-1-(4- methoxyphenyl)-quinazolin-4(1H)-one (3) and 4 is 2-methyl-3-(5- phenyl-4,5-dihydroisoxazoli-3-ylamino)quinazolin-4(3H)-one  
Synthesis of Schiff bases of 3-amino-6,8-dibromo-2-phenyl quinazolin-4(3H)-ones 9(a-l) Synthesis of Schiff bases of 3-amino-6,8-dibromo-2-phenyl quinazolin-4(3H)-ones 9a-l from reaction of 8 with different aldehydes a-l, (a) R= Ph-, (b) R= p-MeO-Ph-, (c) R= o-OH-Ph-, (d) R= p-N(CH 3 ) 2 -Ph-, (e) R= m-NO 2 -Ph-, (f) R= p-Me-Ph-, (g) R= p-OH-Ph-, (h) R= p-Cl-Ph-, (i) R= p-NO 2 -Ph-, (j) R= m,m,p-(OCH 3 ) 3 -Ph-, (k) R= p-OH,m-OMe-Ph-, (l) R=-CH=CH-Ph  
Quinazolone schiff base  
Schiff bases (9a-l) of 3-amino-6,8-dibromo-2-phenyl-quinazolin-4-(3H)-ones (8) with various substituted aldehydes were obtained by refluxing 1:1 molar equivalents of the reactants in dry ethanol for 6 h. The aminoquinazoline (8) was inturn obtained from 3,5-dibromoantharlinic acid via intermediate (7). All the synthesized compounds (9a-l) were evaluated for their anticonvulsant activity on albino mice by maximal electroshock method using phenytoin as a standard. The compound (9l) bearing a cinnamyl function displays a very high activity (82.74 %) at dose level of 100 mg/kg b.w.
Scheme 1: Synthesis of 2-phenyl-3-substituted quinazolin-4(3H)-ones For QAA1, R 1 is H, R 2 is H, Ar is -phenyl carboxylic acid; for QAA2, R 1 is Br, R 2 is H, Ar is -4-bromo-2-phenyl carboxylic acid; for QAA3, R 1 is Br, R 2 is Br, Ar is -4,6-dibromo-2-phenyl carboxylic acid; for MBR1, R 1 is Br, R 2 is H, Ar is -2-phenyl carboxylic acid; for MBR2, R 1 is Br, R 2 is H, Ar is -4-bromo-2-phenyl carboxylic acid; for DBR1, R 1 is Br, R 2 is Br, Ar is -2-phenyl carboxylic acid; for DBR2, R 1 is Br, R 2 is Br, Ar is -4-bromo-2 phenyl carboxylic acid; for DBR3, R 1 is Br, R 2 is Br, Ar is -4,6-dibromo-2-phenyl carboxylic acid.  
A series of novel 2,3-disubstitutedquinazolin-4(3H)-ones have been synthesized by condensation of 2-substituted benzo[1,3]oxazine-4-ones and anthranilic acid. Synthesized compounds were evaluated for in vitro antiviral activity against HIV, HSV and vaccinia viruses. 5-Bromo-2-(6-bromo-4-oxo-2-phenyl-4H-quinazolin-3-yl)-benzoic acid (MBR2) exhibited distinct antiviral activity against Herpes simplex and vaccinia viruses.
Benzoyl chloride was added to the solution of anthranilic acid in pyridine to afford crude 2-phenyl-benzo[d][1, 3] oxazin-4-one (1). To the solution of compound 1 in dry toluene, various substituted anilines were added and the mixture refluxed for 8 h to afford 2-phenyl-3-(substituted phenyl)-3H-quinazolin-4-ones (2a-2f). All the compounds were obtained in solid state in yields varying between 40 to 70%. Spectral characterization included FTIR, (1)H NMR and Electrospray MS. The synthesized compounds were screened for 5-HT(2) antagonist activity. Some of the title compounds have been found to show significant 5-HT(2) antagonist activity. The compound 2b, 3-(2-chlorophenyl)-2-phenyl-3H-quinazolin-4-one was the most potent derivative in the series of compound synthesized.
Scheme 1: Synthetic route for synthesis of Quinazolin-4(3H)One derivatives  
2-thio-3-aryl quinazolin-4(3H)one (1) was synthesized by reacting anthranilic acid with thiocarbamate salts of substituted aniline and carbon disulphide, which on reflux with excess of hydrazine hydrate to form 2-hydrazino quinazolin-4(3H)one derivatives (2). The reaction of (2) with variously substituted aryl aldehydes gave the corresponding hydrazones (3). Further, the cyclization of compound (3) in acetic anhydride gave tricyclic pyrazoloquinazolinones (4). All newly synthesized compounds have been tested for their antibacterial activity against gram +ve bacteria B. substilis, S. aureus and gram -ve bacteria E. coli, P. vulgaris. The species used for antifungal activity are Aspergillus niger and Phytophora. Introduction of -OCH3, -OH and -Cl groups to the heterocyclic frame work enhanced antibacterial and antifungal activities.
Scheme 1: Synthesis of the title compounds -NR1R2 in which R1 is H and R2 is 2-pyridyl or morpholino or 4-methylpiperazino or 4-ethylpiperazino or piperidino  
A series of the title compounds were synthesized and characterized by spectral data. All the compounds were evaluated for in vitro antihistaminic activity by inhibition of isotonic contractions induced by histamine on isolated guinea pig ileum and the compound 6-k showed significant activity. A few compounds have also been screened for in vivo bronchodilatory activity. These compounds exhibited significant protection against histamine-induced convulsions in guinea pig at the dose of 50 mumol.
The preclinical studies for drug screening involve the use of animals which is very time consuming and expensive and at times leads to suffering of the used organism. Animal right activists around the world are increasingly opposing the use of animals. This has forced the researchers to find ways to not only decrease the time involved in drug screening procedures but also decrease the number of animals used and also increase the humane care of animals. To fulfill this goal a number of new in vitro techniques have been devised which are called 'Alternatives' or 'Substitutes' for use of animals in research involving drugs. These 'Alternatives' are defined as the adjuncts which help to decrease the use as well as the number of animals in biomedical research. Russell and Burch have defined these alternatives by three R's - Reduction, Refinement and Replacement. These alternative strategies include physico-chemical methods and techniques utilizing tissue culture, microbiological system, stem cells, DNA chips, micro fluidics, computer analysis models, epidemiological surveys and plant-tissue based materials. The advantages of these alternatives include the decrease in the number of animals used, ability to obtain the results quickly, reduction in the costs and flexibility to control the variables of the experiment. However these techniques are not glittering gold and have their own shortcomings. The disadvantages include the lack of an appropriate alternative to study the whole animal's metabolic response, inability to study transplant models and idiosyncratic responses and inability to study the body's handling of drugs and its subsequent metabolites. None-the-less these aalternative methods to certain extent help to reduce the number of animals required for research. But such alternatives cannot eliminate the need for animals in research completely. Even though no animal model is a complete set of replica for a process within a human body, the intact animal does provide a better model of the complex interaction of the physiological processes.
Examples of lead compounds containing pyrazole and thiazolone rings with antimicrobial activity and designing of the pyrazolothiazol- 4(5H)-one derivatives.  
Antimicrobial screening of several novel pyrazolothiazol-4(5H)-one derivatives (3a-3j) has been performed. Reaction of aromatic aldehydes with aromatic ketones yielded starting chalcones (1a-1j) which have been subsequently reacted with thiosemicarbazide for obtaining N-thiocarbamoylpyrazole derivatives (2a-2j). These were further cyclized to pyrazolothiazol-4(5H)-one derivatives (3a-3j) in the presence of ethylbromoacetate. The structures of newly synthesized compounds were confirmed by FTIR and (1)H NMR and/or MS. The in vitro antimicrobial activity of these compounds was evaluated against Gram positive bacteria, Gram negative bacteria and fungi. Their minimum inhibitory concentration was determined by tube dilution method. The results showed that most of the compounds have promising antimicrobial activity as compared to standard drugs. Among the test compounds, 2-[5(4-chlorophenyl)-3-phenyl-4,5-dihydropyrazol-1-yl]-thiazol-4(5H)-one (3e) was found to show the most potent antimicrobial activity.
The present work aims at developing mucoahesive tablets of ondansetron hydrochloride using bioadhesive polymers like carbopol-934, sodium alginate and gelatin. Tablets prepared by direct compression using different polymer with varying ratio were evaluated for hardness, friability, uniformity of weight, disintegration time, microenvironmental pH, bioadhesion and in vitro release. Hardness, friability disintegration time and drug release were found within pharmacopoeial limit. Microenvironmental pH decreased whereas bioadhesive strength, water uptake, and in vitro release increased with increase in carbopol-934. Increasing sodium alginate and gelatin increased the microenviromental pH and decreased bioadhesive strength, water uptake and in vitro release. With a view to investigate the modulation of drug release from formulation by addition of pH modifiers viz. citric acid and sodium bicarbonate, the tablets with carbopol-934 (2.0), sodium alginate (0.5) and gelatin (6.5) were used and the effect of pH modifiers on microenvironmental pH, bioadhesion, water uptake, in vitro permeation and in vitro release was studied. Microenvironmental pH, bioadhesive strength, water uptake, in vitro release and permeation decreased with increasing concentration of citric acid whereas microenvironmental pH, water uptake and release were enhanced and bioadhesive strength was lowered with increase in sodium bicarbonate. Present study demonstrates carbopol-934, sodium alginate, gelatin polymer system with added pH modifier can be successfully formulated for buccal delivery of ondansetron with desired release profile.
Top-cited authors
Nayanabhirama Udupa
  • Manipal Academy of Higher Education
Bhanubhai Suhagia
  • Dharmsinh Desai University
Veerchamy Alagarsamy
  • MNR Group of Institution
Alex Joseph
  • Manipal Academy of Higher Education
  • PES College of Pharmacy