Abstract
A new triterpenoid saponin named clematichinenoside AR2, along with the six known compounds, was isolated and characterized from Clematis chinensis Osbeck (Ranunculaceae), a commonly used traditional Chinese medicine with anti-inflammatory and anti-rheumatoid activities. The structure of the new saponin was elucidated as 3-O-β-[(O-α-l-rhamnopyranosyl-(1 → 6)-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-ribopyranosyl-(1 → 3)-O-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranosyl)oxy]olean-12-en-21α-hydroxy-28-oic acid-O-α-l-rhamnopyranosyl-(1 → 4)-O-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl ester (1) by spectral analysis and chemical methods. The effects of two major saponins (clematichinenosides AR and AR2) on the secretion of TNF-α in murine peritoneal macrophages induced by lipopolysaccharides were further investigated. The result indicated that a majority of triterpenoid saponins of this herb may be useful in the exploration of lead compounds for the treatment of some autoimmune diseases.
Acknowledgements
Financial supports from the National Natural Science Foundation of China (Project No. 30772770) and High Technology Foundation Program of Jiangsu Province (No. BG2007613) are gratefully acknowledged.