Synthesis and biological evaluation of some novel pyrazolines

Chalcones (2a and 2b) were prepared from 2-acetyl benzofuran (1) and condensed with different aromatic acid hydrazides (3a-o) to get the corresponding pyrazolines (4a-o and 5a-o). The structures of all these compounds have been established on the basis of analytical and spectral data. Compounds have been screened for antiinflammatory, antioxidant and antibacterial studies. Among the 7 compounds that were screened for antiinflammatory activity, compounds 4g and 5m showed 83.4% and 80.5% inhibition of oedema volume, while the standard drug (ibuprofen) showed inhibition of 91.9%. Compounds 4k and 5h showed moderate activity of 72.8% and 59.6% respectively. All the 30 compounds were tested for antioxidant activity at 1000, 500, 250, 100, 50, 25 and 10 mg/ml concentrations against standard drug ascorbic acid. Compounds 4g, 4h, 4k, 4m, 5g, 5h, 5k and 5m showed excellent antioxidant activity as compared with ascorbic acid. Among the 30 compounds that were screened against two Gram +ve ( Staphylococcus aureus and Bacillus subtilis ) and two gram -ve ( Escherichia coli and Pseudomonas aeruginosa ) organisms, compounds possessing p-chloro, p-fluoro, 2-amino-5-bromo, 2-hydroxy-5-nitro and 3,5-dichloro substitutions on the phenyl ring showed good activity against Escherichia coli and Bacillus subtilis. The activity is comparable with that of the standard drug ciprofloxacin.