New steroidal glycosides from Hosta plantaginea (Lam.) Aschers

Four new furostanol glycosides were isolated from the flowers of Hosta plantaginea (Lam.) Aschers. On the basis of spectroscopic methods including 1D and 2D NMR experiments, their structures were elucidated as 26-O-β-d-glucopyranosyl-(25R)-22-O-methyl-5α-furostan-2α,3β,22ξ,26-tetrol 3-O-α-l-rhamnopyranosyl-(1 → 4)-O-β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 2)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (hostaplantagineoside A, 1), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-20(22)-ene-2α,3β,26-triol-3-O-β-d-glucopyranosyl-(1 → 2)-O-β-d-xylopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (hostaplantagineoside B, 2), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-22(23)-ene-2α,3β,20α,26-tetraol-3-O-β-d-glucopyranosyl-(1 → 2)-O-β-d-xylopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-galactopyranoside (hostaplantagineoside C, 3), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-20(22)-ene-2α,3β,26-triol-3-O-α-l-rhamnopyranosyl-(1 → 4)-O-β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 2)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (hostaplantagineoside D, 4).