Polyhydroxylated Steroidal Saponins from the Rhizomes of Convallaria majalis

Abstract

Six new polyhydroxylated spirostanol saponins (1–6) were isolated from the methanolic extract of the rhizomes of Convallaria majalis. On the basis of extensive spectroscopic analysis, including 2D NMR data, and a few chemical transformations, the structures of 1–6 were determined to be 1β,2β,3β-trihydroxy-5β-spirost-25(27)-en-5-yl β-D-galactopyranoside (1), (25S)-1β,2β,3β-trihydroxy-5β-spirostan-5-yl β-D-galactopyranoside (2), 1β,2β,3β,4β-tetrahydroxy-5β-spirost-25(27)-en-5-yl β-D-galactopyranoside (3), (25S)-1β,2β,3β,4β-tetrahydroxy-5β-spirostan-5-yl β-D-galactopyranoside (4), 1β,2β,3β,4β-tetrahydroxyspirost-25(27)-en-5-yl α-L-arabinopyranoside (5), and (25S)-1β,2β,3β,4β-tetrahydroxy-5β-spirostan-5-yl α-L-arabinopyranoside (6), respectively.