Abstract
The chemical structures of azukisaponins V (1) and VI (5), two of the six oligoglycosidic ingredients of total azukisaponin isolated from azuki beans, the seeds of Vigna angularis (WILLD.) OHWI et OHASHI (Leguminosae), were investigated. By means of photochemical degradation and chemical analyses, the structures of azukisaponins V and VI were elucidated to be 3-O-[α-L-rhamnopyranosyl (1→2)-β-D-glucopyranosyl (1→2)-β-D-glucuronopyranosyl]-soyasapogenol B (1) and 3-O-[β-D-glucopyranosyl (1→2)-β-D-glucuronopyranosyl]-29-O-[β-D-glucopyranosyl (1→6)-β-D-glucuronopyranosyl] azukisapogenol (5), respectively. Azukisaponin VI (5) is the first reported example of a 3, 29-bisdesmoside of an oleanene oligoglycoside.
