Asymmetrical mono-carbonyl ferrocenylidene curcumin and their dihydropyrazole derivatives: Which possesses the highest activity to protect DNA or scavenge radical?

Abstract

A series of asymmetrical mono-carbonyl ferrocenylidene curcumin and their dihydropyrazole derivatives were synthesized. Their antioxidant abilities in protecting DNA against 2,2′-azobis(2-amidinopropane hydrochloride)-induced oxidation and scavenging 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS) radical were evaluated. In synthesis, the Michael addition reactions between phenylhydrazine and asymmetrical ferrocenylidene curcumin derivatives exhibit evident regioselectivity. The direction of addition depends on whether the benzene ring is substituted or not. The antioxidant abilities of compounds will increase when the ferrocenyl group is introduced. Moreover, such improvement derived from ferrocenyl group is also related to other substituent groups in molecule, not independent. Interestingly, p-dimethylamino group which is never considered as an active group, however, exhibits the best activity in protecting DNA and scavenging ABTS radical.