Antioxidant and antiproliferative activities of hydroxyl-substituted Schiff bases

Eight hydroxyl-substituted Schiff bases were synthesized and bio-evaluated for their antioxidant and antiproliferative activities. Structure–activity relationship analysis indicates that o-diphenolic groups and 4-hydroxyl group attached to the aromatic B ring contribute critically to the activities. Eight hydroxyl-substituted Schiff bases with the different number and position of hydroxyl group on the two asymmetric aromatic rings (A and B rings) were prepared by the reaction between the corresponding aromatic aldehyde and aniline. Their antioxidant effects against the stable galvinoxyl radical (GO ) in ethyl acetate and methanol, and 2,2′-azobis(2-amidinopropane hydrochloride) (AAPH)-induced DNA strand breakage, and their antiproliferative effects on human hepatoma HepG2 cells, were investigated. Structure–activity relationship analysis demonstrates that o-dihydroxyl groups on the aromatic A ring and 4-hydroxyl group attached to the aromatic B ring contribute critically to the antioxidant and antiproliferative activities.