Design and Synthesis of 3-Triazolo-coumarins and Their Applications in Scavenging Radicals and Protecting DNA

In this study, we synthesized a series of 3-triazolo-coumarins and evaluated their antioxidant activities respectively by two methods: trapping 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical(ABTS+·) and oxidation of DNA which was induced by Cu2+/glutathione(GSH), ·OH and 2,2′-azobis(2-amidinopropane hydrochloride)(AAPH). Among the nine 3-triazolo-coumarins, compounds 6c and 6f-6i were synthesized for the first time, which exhibited the capability of terminating radical propagation-chains in oxidation of DNA induced by AAPH. In this study, we found that phenethylamine moiety, hydroxyl and ortho-methoxy are the key groups to enhance the antioxidant activities of compounds.