Hiroshi Yuasa

New triterpene saponins from Stenocereus eruca (Cactaceae)

Two new triterpene saponins, named stellatoside B (1) and erucasaponin A (2), were isolated from a cactaceous plant, Stenocereus eruca A. C. Gibson & K. E. Horak (Machaerocereus eruca Br. & R.). The structures of 1 and 2 were elucidated as 3-O-β-d-xylopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)-β-d-glucuronopyranosyl stellatogenin and 3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→3)]-β-d-glucuronopyranosyl betulinic acid 28-O-α-l-rhamnopyranosyl ester, respectively, on the basis of their spectroscopic data.

Triterpenoid saponins from Echinopsis macrogona (Cactaceae)

Triterpene saponins, pachanosides C1, E1, F1 and G1 (1-4), and bridgesides A1, C1, C2, D1, D2, E1 and E2 (5-11) were isolated from Echinopsis macrogona. Compounds 1-4 were saponins with pachanane type triterpene saponins, while the others (5-11) were oleanane type triterpene saponins. While the aglycones of 2-4 and 8-11 were hitherto unknown, the structure of pachanol C was revised in this paper. Their structures were elucidated on the basis of chemical and physicochemical evidence.