Pregnane glycosides and steroid saponins from Smilax bockii Warb. and their NGF-potentiating activity

Abstract

The chemical constituents of the roots of Smilax bockii Warb. were investigated and two pregnane glycosides and three steroid saponins were isolated. Their structures were established as 3β-hydroxypregna-5,16-dien-20-one-3-O-α-L-rhamnopyranosyl(1 → 4)-α-L-rhamnopyranosyl(1 → 4)-[α-L-rhamnopyranosyl(1 → 2)]-β-D-glucopyranoside (1), 3β-hydroxypregna-5,16-dien-20-one-3-O-α-L-rhamnopyranosyl(1 → 2)-[α-L-rhamnopyranosyl(1 → 4)]-β-D-glucopyranoside (2), dioscin (3), methyl protodioscin (4), 26-O-β-D-glucopyranosyl-22α-methoxyl-(25R)-furost-5-en-3β, 26-diol 3-O-α-L-rhamnopyranosyl(1 → 4)-α-L-rhamnopyranosyl(1 → 4)-[α-L-rhamnopyranosyl(1 → 2)]-β-D-glucopyranoside (5) on the basis of spectral analysis and chemical methods. Compound 1 is a new natural product and compounds 2, 5 were first isolated from the genus Smilax. Compound 5 showed enhancing activity of nerve growth factor (NGF)-induced neurite outgrowth in PC 12D cells.

Keywords:

• Smilax bockii Warb
• Pregnane glycosides
• Steroid saponins
• NGF-potentiating activity

Acknowledgement

Special thanks are due to the Analytical Detective Center, Shenyang Pharmaceutical University, for recording HRMS and NMR spectra.