RESUMEN
A new class of potential pyrazoline derivatives had been synthesized and evaluated for their anti oxidant activities. The obtained five new 1,3,5-triphenyl-2-pyrazolines and another ten 3-[2"-hydroxynapthalen- 1"-yl]-1,5-diphenyl-2-pyrazolines were evaluated for antioxidative activities by using different reactive oxygen species [ROS] assays containing superoxide anion, hydroxyl radical, ABTS cation radical scavenging assays and inhibition of lipid peroxidation assay. The compounds exhibited more prominent effects in scavenging the free radical assays and also inhibited the lipid peroxidation. Compounds 10,13 possessing trimethoxy substitution on phenyl ring at position 5 of the 2-pyrazolines exhibited maximum activity, infact more than that of the standard drug ascorbic acid. Compounds11, 3, 4, 2 and 1 having dimethyl amino groups at position 4 of the phenyl ring at position 5 of the 2-pyrazolines also showed good activity. The present study revealed that an electron releasing group at position 4 of the phenyl ring is very much essential for all these 2-pyrazolines to show significant activity