Synthesis, characterization and evaluation of benzylidene analogues as a new class of potential antioxidant agents.

Seventeen analogues of benzylidene were synthesized and evaluated for in vitro hydrogen peroxide scavenging activity. The structure of the newly synthesized compounds were confirmed by elemental and spectral (IR, 1H-NMR, 13C-NMR) studies. The antioxidant activity of the titled compounds was evaluated. Compounds: 4h--N'-[2-amino-3-(morpholinomethyl)benzylidene]isonicotinohydrazide, 4p 7-(4-(2-amino-3-[(2-isonicotinoylhydrazono)methyl]benzyl}piperazin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquino- line-3-carboxylic acid and 4q 7-(4-{2-amino-3-[(2 isonicotinoylhydrazono)methyl]benzyl} piperazin-1-yl)-1-ethyl-6,8-difluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid were the most active compounds with significant hydrogen peroxide scavenging activity.