title: Structures and antiproliferative activity of saponins from Sechium pittieri and S. talamancense.
abstract: Six bisdesmosidic bayogenin saponins, named tacacosides A1, A2, B1, B2, B3 and C, were isolated from the fruit and aerial parts of Sechium pittieri (COGN.) C. Jeffrey and S. talamancense (WUNDERLIN) C. Jeffrey, Costa Rican cucurbitaceae plants. Their structures were elucidated on spectral and chemical evidence as follows. Tacacoside A1: 3-O[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-beta-D-apiofuranosyl-(1-->3)] - alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) ester, tacacoside A2: 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta-D-xylopyranosyl-(1-->3)]-a lph a-L- rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) ester, tacacoside B1: 3-O-[beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl- (1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1- ->2)-alpha- arabinopyranosyl) ester, tacacoside B2: 3-O-[beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl-(1-->3)- beta-D-xylpyranosyl-(1-->4)-[beta-D-xylopyranosyl- (1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) ester, tacacoside B3: 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl] bayogenin 28-O-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl- (1-->4)-alpha-L-rhamnopyranosyl- (1-->2)-alpha-L-arabinopyranosyl] ester, and tacacoside C: 3-O-[beta-D-glucopyranosyl]bayogenin 28-O-[alpha-L-rhamnopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)- alpha-L-arabinopyranosyl] ester. These saponins showed moderate antiproliferative activity (ED50:10-74 micrograms/ml) against MK-1, HeLa and B16F10 cells.
authors.affiliation: Centro de Investigaciones en Productos Naturales, Universidad de Costa Rica, San Jose, Costa Rica.
authors.forename: V H
authors.initials: VH
authors.lastname: Castro
authors.forename: E
authors.initials: E
authors.lastname: Ramirez
authors.forename: G A
authors.initials: GA
authors.lastname: Mora
authors.forename: Y
authors.initials: Y
authors.lastname: Iwase
authors.forename: T
authors.initials: T
authors.lastname: Nagao
authors.forename: H
authors.initials: H
authors.lastname: Okabe
authors.forename: H
authors.initials: H
authors.lastname: Matsunaga
authors.forename: M
authors.initials: M
authors.lastname: Katano
authors.forename: M
authors.initials: M
authors.lastname: Mori
mesh_terms: D002240:Carbohydrate Sequence; D002455:Cell Division / Q000187:drug effects; D003364:Costa Rica; D005638:Fruit; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010936:Plant Extracts / Q000737:chemistry*; D012503:Saponins / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D012503:Saponins