STUDY ON GLYCOSIDAL CONSTITUENTS FROM EPIGYNUM AURITUM

A known compound and a new glycoside, epigeoside, were isolated from the rhizomes of Epigynum auritum (Schneid.) Tsiang et P. T. Li (Apocynaceae). The structure of known compound was identified as daucosterol (β-sitosterol-β- D- glucopyranoside). The structure of epigeoside has been deduced on the basis of spectral analysis and chemical reactions as catechin-3-O-α-L-rhamnopyranosyl-( 1→4 ) -β- D-glucopyranosyl-( 1 →6 )-β-D-glucopyranoside. Partial hydrolysis of Ⅱ with 0.2 mol/L HC1 afforded compound Ⅱa and rhamnose. Acid hydrolysis of Ⅱa with 2 mol/L HC1 afforded an aglycone which was identified by comparison with catechin, and glucose.