A new triterpenoid from Pittosporum glabratum Lindl.

The roots of Pittosporum glabratum Lindl. (Pittosporaceae) have been used as a folk medicine for the treatment of rheumatic arthritis, insomnia and hypertension.  Only a few chemical or biological studies on P. glabratum have been reported.  As part of our ongoing phytochemical research on this plant, four compounds were isolated.  Their structures were identified as 3β, 6β, 19α, 21α, 24-pentahydroxy-12-en-28-oleanolic acid (1), 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranosyl siaresinolic acid (2), 3, 4, 5-trimethoxyphenyl-1- O-β-D-(5-O-syringoyl)-apiofuranosyl-(1→6)-β-D-glucopyranoside (3) and 3, 4, 5-trimethoxyphenol-1-O-β-D- apiofuranosyl-(1→6)-β-D-glucopyranoside (4) on the basis of physical evidence and spectroscopic analysis.  Among them, compound 1 is a new triterpenoid, and compounds 2−4 are isolated from the genus Pittosporum for the first time.