Cytotoxic polyisoprenes and glycosides of long-chain fatty alcohols from Dimocarpus fumatus

The ethanolic extract from the stem bark of Dimocarpus fumatus, showed in v itro cytotoxic activity against KB cells. Fractionation of the extract gave compounds belonging to different classes. The two major components have be en identified as a benzoquinone, sargaquinone, and a chromene, sargaol. One sphingolipid, soyacerebroside I, two glycosides of sitosterol, and fatty a cids were also identified. Besides these known compounds, two new glycoside s of long-chain fatty alcohols have been identified as 1-O-[alpha-L-rhamnop yranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl- (1 --> 6)-beta-D-glucopyranosyl]hexadecanol and 1-O-[[alpha-L-arabinopyrano syl-(1 --> 3)]-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 - -> 3)-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] hexadecanol, and a mixture of three new diacylglycerylglucosides has been isolated. The se structures were elucidated by analysis of 2D-NMR and mass spectra. (C) 1 998 Published by Elsevier Science Ltd. All rights reserved.