Isolation and structure elucidation of four new triterpenoid estersaponins from fruits of Pittosporum tobira ait

Four new triterpenoid estersaponins, tentatively designated as IIIA2 ( 1 ), IIIA3 ( 2 ), IIIB2 ( 3 ), and IIIC4 ( 4 ) have been isolated from fruits of Pittosporum tobira ait . and their structures elucidated by spectroscopic and chemical analyses. All the four compounds consist of an acylated pentacyclic triterpenoid aglycone which bears the same oligosaccharide portion. The crude saponin mixture (CIDI) was found to show significant in vitro and in vivo cytotoxicity in different human cancer cell lines.