Isolation and Structural Determination of Steroidal Glycosides from the Bulbs of Easter Lily (Lilium longiflorum Thunb.)

摘要

The bulbs of the Easter lily (Lilium longiflorum Thunb.) are used as a food and medicine in several Asian cultures, and they are cultivated as an ornamental plant throughout the world. A new steroidal glycoalkaloid and two new furostanol saponins, along with two known steroidal glycosides, were isolated from the bulbs of L longiflorum. The new steroidal glycoalkaloid was identified as (22R,25R)-spirosol-5-en-3β-yl O-α-L-rhamnopyranosyl-(1→ 2)-[6-O-acetyl-β-D-glucopyranosyl-(1→ 4)]-β-D-gluco-pyranoside. The new furostanol saponins were identified as (25H)-26-O-(β-D-glucopyranosyl)-furost-5-en-3β,22α,26-triol 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→ 3)-β-D-glucopyrano-side and (25R)-26-O-(β-D-glucopyranosyl)-furost-5-en-3β22α,26-triol 3-O-α-L-rhamnopyranosyl-(1→ 2)-α-L-xylopyranosyl-(1→ 3)-β-D-glucopyranoside. The previously known steroidal glycosides, (22R,25R)-spirosol-5-en-3/S-yl O-α-L-rhamnopyranosyl-(1→ 2)-β-D-glucopyranosyl-(1→ 4)-β-D-glucopyranoside and (25R)-26-O-(βD-glucopyranosyl)-furost-5-en-3β,22α,26-triol 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→ 4)-β-D-glucopyranoside were identified in L longiflorum for the first time. These new compounds from L longiflorum and the isolation methodologies employed can be used for studies on the biological role of steroidal glycosides in plant development and plant-pathogen interactions, as well as for studies in food and human health, for which little is known.