THE STRUCTURE OF GARCINONE-E

As part of a survey of anti-tumorpromotive chemicals, garcinone E (1) and nine known xanthones, 8-deoxygartanin, gartanin, xanthone I, beta- mangostin, garcinone B, 6-deoxy-gamma-mangostin, ihydroxy-3-methoxy-2- (3-methyl-2-butenyl)xanthone, gamma-mangostin and alpha-mangostin, tog ether with egonol, were isolated from the fruit hulls of Garcinia mang ostana L. collected in Thailand. The structure of garcinone E was eluc idated as etrahydroxy-2,5,8-tri-(3-methyl-2-butenyl)xanthone by spectr oscopic methods, including the application of a number of two dimensio nal (2D) NMR techniques (H-1-H-1, C-13-H-1 correlation spectroscopy (C OSY), nuclear Overhauser effect spectroscopy (NOESY) and correlation v ia long-range coupling (COLOC).