An androstane bioside and 3'-thiazolidinone derivatives of doubly-linked cardenolide glycosides from the roots of Asclepias tuberosa

Abstract

Steroidal compounds in the roots of Asclepias tuberosa were investigated and 17α-hydroxyandrosta-4,6,15-trien-3-one 17-O-α- L-arabinopyranosyl-(1 → 6)-β-D-glucopyranoside, termed ascandroside, was isolated from the CHCl3-soluble fraction. Among five doubly-linked cardenolide glycosides, two were identified as 3'-spiro-linked thiazolidinone (4) and S- oxythiazolidinone derivatives (5) of Δ5-calotropin. The stereochemistry at the C-3' in these two cardenolides is discussed. 3'-O-β-D-Glucopyranosyl-Δ5-calotropin (3) was also isolated along with Δ5-calotropin and its 3'-acetate. Nine glycosides of uzarigenin, coroglaucigenin and corotoxigenin were identified.