Synthesis, characterization, and antioxidant and bleomycin-dependent DNA damage evaluation of curcumin analogs.

In an attempt to find a new class of antioxidant agents, a series of pyrazole, pyridopyrazoltriazine, pyrazolotriazine, isoxazole, and pyridine-containing products were prepared, starting with curcumin and appropriate chemical reagents. Thus, curcumin 1 undergoes coupling reaction with diazonium salts 2-5 to afford the corresponding 4-arylazo derivatives 6-9. Heating of 6 and/or 7 in acetic acid furnished the corresponding pyrazolotriazines 10 and 11.

Synthesis, characterization and in vitro antimicrobial activity of novel 2-thioxo-4-thiazolidinones and 4,4'-bis(2-thioxo-4-thiazolidinone-3-yl)diphenylsulfones.

2-Thioxo-4-thiazolidinones (3a,b) were achieved by cyclocondensation of isothiocyanatosulfonamides (1a,b) with sulfanylacetic acid at reflux temperature in dioxane in the presence of triethylamine. Compound (3a) was exploited to synthesize the versatile hitherto unknown 2-thioxo-4-thiazolidinones (5-10) via its reaction with some electrophiles. Cyclization of 4,4'-diisothiocyanate diphenylsulfone (11) with sulfanylacetic acid furnished 4,4'-bis(2-thioxo-4-thiazolidinone-3-yl)diphenylsulfone (12) which on treatment with excess 4-methoxybenzaldehyde in refluxing dioxane in the presence of piperidine yielded the bisbenzylidene derivative (13).