Sulfated pregnane glycosides from Periploca graeca

Abstract

Six new pregnane glycosides, four of them sulfated derivatives, were isolated from small branches of Periploca graeca. The compounds were identified as 16α-[(6-O-sulfo-β-D-glucopyranosyl)oxy]pregn-5-en-20-ol-3β-yl O-(2-O-acetyl-β-D-digitalopyranosyl)-(1→4)-β-D-cymaropyranoside (1), 16α-[(6-O-sulfo-β-D-glucopyranosyl)oxy]pregn-5-en-20-ol-3β- yl O-β-D-oleandropyranosyl-(1→4)-β-D-oleandropyranoside (2), 16α-[(6-O-sulfo-β-D-glucopyranosyl)oxy]pregn-5-en-20-ol-3β-yl O-β-D-oleandropyranoside (3), 16α-[(6-O-sulfo-β-D- glucopyranosyl)oxy]pregn-5-ene-3β,20-diol (4), 20-O-[(β-D- glucopyranosyl-(1→6)-β-D-glucopyranosyl-(1→2)-β-D- digitalopyranosyl)oxy]pregn-5-en-16β-ol-β-yl O-β-D- digitalopyranosyl-(1→4)-β-D-cymaropyranoside (5), and calogenin 3-O-β-D-digitalopyranoside-20-O-β-D-canaropyranoside (6). Three pregnane glycosides, previously reported from the genus Periploca, were also isolated. Structures were established on the basis of spectroscopic analyses, including 1D and 2D NMR experiments, HRESIMS, elemental analysis, and chemical degradation. © 2005 American Chemical Society and American Society of Pharmacognosy.