Medicinal Foodstuffs. XIX. Absolute Stereostructures of Canavalioside, a New Ent-Kaurane-Type Diterpene Glycoside, and Gladiatosides A₁, A₂, A₃, B₁, B₂, B₃, C₁, and C₂, New Acylated Flavonol Glycosides, from Sword Bean, the Seeds of Canavalia gladiata

Abstract

A new ent-kaurane-type glycoside, canavalioside, and eight new acylated flavonol glycosides, gladiatosides A₁, A₂, A₃, B₁, B₂, B₃, C₁ and C₂, were isolated from the seed of Canavalia gladiata together with robinin, kaempferol 3-O-β-D-galactopyranosyl-7-O-α-L-rhamnopyranoside, and kaikasaponin III. The absolute stereostructures of canavalioside and gladiatosides A₁, A₂, A₃, B₁, B₂, B₃, C₁ and C₂ were elucidated on the basis of chemical and physicochemical evidence.