Two sesquiterpene pyridine alkaloids and a triterpenoid saponin from the root barks of Tripterygium hypoglaucum

Abstract

Two new sesquiterpene pyridine alkaloids hypoglaunines E (1) and F (2) and a new triterpenoid saponin hypoglaside A (3), together with a known diterpenoid glucoside 11-O-β-d-glucopyranosyl neotriptophenolide (4) and two known triterpenoids 23-nor-oxopristimerol (5) and 2,3-dihydroxy-6-oxo-D:A-froedo-24 nor-1,3,5(10),7-oleanatetraen-29-oic acid (6), have been isolated from the root barks of Tripterygium hypoglaucum. Their structures were elucidated by NMR spectroscopy and MS analysis. Compounds 1–3 were screened for their cytotoxic activities against five cancer cell lines, but all of them were inactive.

Keywords:

• Tripterygium hypoglaucum
• sesquiterpene pyridine alkaloids
• hypoglaunine
• triterpenoid saponin

Acknowledgements

We are grateful to the Department of Instrumental Analysis at the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College for all spectroscopic analyses. We also thank the Department of Pharmacology at the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College for the bioactivity tests. This work was financially supported by the National Key Technology R&D Program of China (Nos 2009BA173B03 and 2011BAI01B05) and the Science and Technology Major Project of Fujian Province (No. 2009YZ0001-1-6).