Muchimangins A-D: novel diphenylmethyl-substituted xanthones from Securidaca longepedunculata

Four new highly oxygenated xanthones, named muchimangins A-D (1-4), with a diphenylmethyl substituent have been isolated as extremely minor constituents from the root of Securidaca longepedunculata (Polygalaceae). Among them, muchimangin B (2) induced an apoptotic-like cell death of human pancreatic cancer PANC-1 cell line preferentially in nutrient deprived condition with PC50 of 38.9 μM.