4 ACYLATED TRITERPENOID SAPONINS FROM ALBIZIA-PROCERA

Four new oleanane-type triterpene glycosides, proceraosides A-D (1-4), were isolated from the seeds of Albizia procera. Their structures wer e established by extensive NMR experiments and chemical methods. Compo unds 1-3 comprised acacic acid as the aglycon and a monoterpenic carbo xylic acid linked to a monoterpene quinovoside as the acyl moiety at C -21. The common oligosaccharide moiety linked to C-28 in 1-3 was deter mined as ha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester. The se compounds differed in the C-3-linked sugar unit or in the configura tion of C-6' of the inner monoterpene moiety in the C-21-linked acyl u nit. Compound 4 was established as the 16-deoxy analogue of 1.