Convallasaponin A, a New 5β-Spirostanol Triglycoside from the Rhizomes of Convallaria majalis

The rhizomes of Convallaria majalis have been analyzed for their steroidal glycoside constituents, resulting in the isolation of a new 5β-spirostanol triglycoside, named convallasaponin A, along with two known cardenolide glycosides and a known cholestane glycoside. The structure of convallasaponin A was determined on the basis of extensive spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage. The cardenolide glycosides showed tumor specific cytotoxic activity.