Spectacular modification of Gambogic acid on microwave irradiation in methanol: isolation and structure identification of two products with potent anti-tumor activity

Abstract

Treatment of gambogic acid with methanol in acidic condition under microwave irradiation led to the formation of two new products bearing spectacular A ring systems which were different from reported Garcinia natural products. The chemical structures of these two compounds were elucidated by extensive NMR and MS spectroscopic analysis as well as crystallographic study. Both of the two products could significantly inhibit the growth of various tumor cell lines in vitro with IC(50) values at muM level through apoptotic pathway.