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 ¹H‐NMR). All the title compounds were tested for their in‐vitro antimycobacterial activity against Mycobacterium tuberculosis H₃₇Rv using Alamar‐Blue susceptibility test, and the activity is expressed as the minimum inhibitory concentration (MIC) in μg/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 and pharmacological evaluation of a novel series of 5-(substituted)aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazolines as novel anti-inflammatory and analgesic agents

A novel series of 5-(substituted)aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazolines (3a-l) were synthesized by reacting various substituted 3-aryl-1-(3-coumarinyl)propan-1-ones (2a-l) with phenylhydrazine in the presence of hot pyridine. Structures of all new synthesized compounds were characterized on the basis of elemental analysis and spectral data (IR, (1)H NMR and (13)C NMR). The title compounds were screened for in vivo anti-inflammatory and analgesic activities at a dose of 200 mg/kg b.w. Among the 12 prepared compounds, Compounds 3d, e, i and j exhibited significant anti-inflammatory activity in model of acute inflammation such as carrageenan-induced rat edema paw while compounds 3d and e showed considerable activity in model of chronic inflammation such as adjuvant-induced arthritis and were compared with diclofenac (13.5 mg/kg b.w.) as a standard drug. These compounds were also found to have significant analgesic activity in the acetic acid induced writhing model and antipyretic activity in yeast-induced pyrexia model along with minimum ulcerogenic index.     

Synthesis and evaluation of anti-inflammatory and analgesic activity of 3-[(5-substituted-1,3,4-oxadiazol-2-yl-thio)acetyl]-2H-chromen-2-ones

A novel series of 3-[(5-substituted-1,3,4-oxadiazol-2-yl-thio)acetyl]-2H-chromen-2-one (7a–i) were synthesized by the condensation between the appropriately substituted 5-substituted-1,3,4-oxadiazolyl-2-thione (4a–i) derived from various existing NSAIDs and 3-(2-bromoacetyl)-2H-chromen-2-one (6) under reflux in the presence of sodium ethoxide. Structure of the synthesized compounds was established on the basis of physicochemical, elemental analysis, and spectral data. The title compounds were screened for in vivo acute anti-inflammatory and analgesic activities at a dose of 200 mg/kg bw. Among the series, four compounds 7c, 7e, 7f, and 7h were found to possess a significant anti-inflammatory and analgesic activity profile. In addition, these compounds were also found to possess a less degree of ulcerogenic potential as compared to standard NSAIDs.