A new pyranoxanthone from the stems of Calophyllum membranaceum

Abstract

A new pyranoxanthone, membraxanthone A (1) has been isolated from the ethanol extract of the stem of Calophyllum membranaceum, together with three known pyranoxanthones, nigrolineaxanthone W (2), calophinone (3) and caloxanthone I (4), and three known triterpenoids, friedelin (5), canophyllol (6) and canophyllic acid (7). Their structures were elucidated on the basis of chemical evidence and intensive spectroscopic analysis including HRESI-MS, 1D- and 2D-NMR. All of the compounds were isolated from this plant for the first time. These xanthones showed no activities towards human cancer cell lines KB, BC-1 and NCI-4460. © ARKAT USA, Inc.