Ferrocenyl-Appended Aurone and Flavone: Which Possesses Higher Inhibitory Effects on DNA Oxidation and Radicals?

Abstract

The aim of the present work was to compare the antioxidative effect of the ferrocenyl-appended aurone with that of ferrocenyl-appended flavone; therefore, nine aurones together with the flavone-type analogues were synthesized by using chalcone as the reactant. The radical-scavenging property was evaluated by reacting with the 2,2′-azinobis­(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS^<b>+·</b>), 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. The cytotoxicity was estimated by inhibiting 2,2′-azobis­(2-amidinopropane hydrochloride) (AAPH)-induced oxidation of DNA. It was found that the introduction of the ferrocenyl group remarkably increased the radical-scavenging activities of aurone and flavone. Especially, the ferrocenyl group in flavones can quench radicals even in the absence of the phenolic hydroxyl group, while ferrocenyl-appended aurones can efficiently protect DNA against AAPH-induced oxidation. Therefore, the antioxidative effect was generated by the ferrocenyl group and enhanced by the electron-donating group attaching to the <i>para</i>-position of the ferrocenyl group. Introducing the ferrocenyl group into natural compounds may be a useful strategy for increasing the antioxidative effectiveness