Triterpenoid saponins from the stems of Clematis parviloba

Abstract

Sixteen triterpenoid saponins (1–16) were isolated from the stems of Clematis parviloba, including a new compound, parvilobaside A (1), which was established as 23-O-acetyl-hederagenin-3-O-β-d-ribopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranoside on the basis of various spectroscopic techniques and chemical evidences. Among the isolated compounds, clematoside S (2) and α-hederin (4) showed moderate cytotoxic activities against four human tumor cell lines (HCT-8, Bel-7402, BGC-823, and A-2780) with IC₅₀ values in the range of 1.44–6.86 μg/ml.

Keywords:

• Clematis parviloba
• triterpenoid saponins
• cytotoxic activity
• parvilobaside A

Acknowledgements

The authors are grateful to Prof. Puzhu Cong for his valuable advice on MS analysis, and also to Prof. Zailin Li and Yulin Lin for collecting and authenticating the plant material. Thanks are also due to Shanghai Zhongchuang Pharmaceutical Science and Technology Co. Ltd for affording the prep-HPLC apparatus.