HIGHLY OXYGENATED QUASSINOIDS FROM EURYCOMA-LONGIFOLIA

Two novel C19-skeleton quassinoids, one with a lactonic linkage at C-7 and another with a lactonic linkage at C-12, and seven novel highly o xygenated quassinoids with a C20-skeleton were isolated from the leave s of Eurycoma longifolia. Their structures and stereochemistry were es tablished by spectroscopic data, including two-dimensional NMR techniq ues, and X-ray analysis. The relationships between their structures an d cytotoxicities are also discussed.