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

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.