Characterization of acylmono‐, mono‐, di‐, tri‐ and tetraglycosylsterol and saponin in Adzuki bean ( Vigna angularis ) seeds

Five sterylglycosides (acylmono‐, mono‐, di tri‐ and tetraglycosylsterol) and a saponin were isolated from Adzuki beans and characterized. In the glycosylsterols, the principal component sterols were sitosterol and stigmasterol; the major sugar component was glucose. The glucose units were shown to be linked by β1,6‐bonds. The three oligoglycosylsterols were shown to be gentiobiosylsterol, gentiotriosylsterol and gentiotetraosylsterol; the latter two are novel sterylglycosides. The saponin was identified as glucopyranosyl‐(β1→2)‐glucopyranurosyl‐(β1→3′)‐soyasapogenol B (Azukisaponin I) which had previously been found in Adzuki beans.