Synthesis, pharmacological screening and in silico studies of new class of Diclofenac analogues as a promising anti-inflammatory agents.

A novel series of 5-[2-(2,6-dichlorophenylamino)benzyl]-3-(substituted)-1,3,4-oxadiazol-2(3H)-thione (4a-k) derivatives have been synthesized by the Mannich reaction of 5-[2-(2,6-dichlorophenylamino)benzyl]-1,3,4-oxadiazol-2(3H)-thione (3) with an appropriately substituted primary/secondary amines, in the presence of formaldehyde and absolute ethanol. Structures of these novel compounds were characterized on the basis of physicochemical, spectral and elemental analysis. The title compounds (4a-k) were screened for in vivo acute anti-inflammatory and analgesic activities at a dose of 10mg/kg b.w. Compound 4k exhibited the most promising and significant anti-inflammatory profile while compounds 4a, 4d, 4e, 4i, and 4j showed moderate to good inhibitory activity at 2nd and 4thh, respectively. These compounds were also found to have considerable analgesic activity (acetic acid induced writhing model) and antipyretic activity (yeast induced pyrexia model). In addition, the tested compounds were also found to possess less degree of ulcerogenic potential as compared to the standard NSAIDs. Compounds that displayed promising anti-inflammatory profile were further evaluated for their inhibitory activity against cyclooxygenase enzyme (COX-1/COX-2), by colorimetric COX (ovine) inhibitor screening assay method. The results revealed that the compounds 4a, 4e, 4g and 4k exhibited effective inhibition against COX-2. In an attempt to understand the ligand-protein interactions in terms of the binding affinity, docking studies were performed using Molegro Virtual Docker (MVD-2013, 6.0) for those compounds, which showed good anti-inflammatory activity. It was observed that the binding affinities calculated were in agreement with the IC50 values.

Synthesis and antimicrobial activity of 7-(2-substituted phenylthiazolidinyl)-benzopyran-2-one derivatives.

A series of 7-(2-substituted phenylthiazolidinyl)-benzopyran-2-one derivatives have been synthesized by reaction of 7-amino-4-methyl-benzopyran-2-one (1) with an appropriate substituted aldehydes to obtain various Schiff bases (3a-k) which on treatment with thioglycolic acid afforded the title compounds (4a-k). Purity of the compounds has been confirmed by TLC. Structure of these compounds were established on the bases IR, 1H NMR, 13C NMR and Mass spectral data. Schiff bases and title compounds were evaluated for antibacterial and antifungal activities against various bacterial and fungal strains. The results showed that compounds 3d, 3f, 4d, 4f and 4i (100 microg/ml) exhibited good antibacterial and antifungal activity as that of standard antibiotics Ciprofloxacin and Griseofulvin.

Synthesis and antimycobacterial activity of a novel series of isonicotinylhydrazide derivatives.

A novel series of 14 new isonicotinyl hydrazide derivatives 2a-g, 3a-g containing a 4-thiazolidinone / 2-azetidinone nucleus were synthesized by reacting N'-substituted arylidene / heteroarylidene isonicotinyl hydrazide 1a-g with thioglycollic acid in the presence of dry benzene and with chloroacetyl chloride in the presence of triethylamine, respectively. Structures of all newly synthesized compounds were characterized on the basis of elemental analyses and spectral data (IR and (1)H-NMR). All the title compounds were tested for their in-vitro antimycobacterial activity against Mycobacterium tuberculosis H(37)Rv using Alamar-Blue susceptibility test, and the activity is expressed as the minimum inhibitory concentration (MIC) in microg/mL. Among the series, compounds 2b, 2g, 3b, and 3g displayed an encouraging antimycobacterial activity profile as compared to that of the reference drugs isoniazid / rifampicin.

Synthesis and antibacterial activity of a new series of 3-[3-(substituted phenyl)-1-isonicotinoyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives.

A novel series of 3-[3-(substituted phenyl)-1-isonicotinoyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives 4a-k have been synthesized by the reaction of 3-[2,3-dibromo-3-(substituted phenyl) propanoyl]-2H-chromen-2-one 3a-k and isonicotinic acid hydrazide in the presence of triethylamine in absolute ethanol, characterized by spectral data and screened for their in-vitro antibacterial activity against Gram-positive and Gram-negative bacteria. Among the series, compounds 4e, 4i, and 4k displayed an encouraging antibacterial activity profile as compared to the reference drug ampicillin against tested bacterial strains.

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

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.

Synthesis and evaluation of anti-inflammatory and analgesic activities of a novel series of substituted-N-(4-methyl-2-oxo-2H-chromen-7-yl) benzamides.

A novel series of coumarinyl amides (IVa-l) have been synthesized by reacting 7-amino-4-methylcoumarin (III) with various substituted aromatic acid chlorides. IR, 1H NMR, 13C NMR and HRMS spectral data characterized the structure of the synthesized compounds. The title compounds were screened for in vivo acute anti-inflammatory activity using the carrageenan-induced rat paw edema assay model. Among the compounds tested, 2-chloro-N-(4-methyl-2-oxo-2H-chromen-7-yl)benzamide (IVb) and 4-chloro-N-(4-methyl-2-oxo-2H-chromen-7-yl)benzamide (IVc) showed 60.5 and 62.3% edema protection, respectively, as compared to the standard drug diclofenac (CAS 15307-86-5) (63.5%) after third hour. Compounds N-(4-methyl-2-oxo-2H-chromen-7-yl)-4-nitrobenzamide (IVf) and N-(4-methyl-2-oxo-2H-chromen-7-yl)cinnamamide (IVg) showed moderate activity. The new compounds have been also tested for in vivo analgesic activity. Quantitative structure-activity relationship studies indicated that the chloro substitution at the aromatic ring enhanced the anti-inflammatory activity (IVb and IVc). These compounds were also found to provide significant protection in acetic acid induced writhing animal model, showing remarkable analgesic activity. Compounds IVb and IVc showed 55.1% and 56.3% protection, respectively, as compared to acetylsalicylic acid (CAS 50-78-2) (57.7%).