Immunosuppressive terpenoids from extracts of Tripterygium wilfordii

Abstract The clinically used extract (T Π ) of Tripterygium wilfordii Hook f. give 19 new compounds, including five kaurane diterpenes ( 1 – 5 ), one manoyl oxide diterpene ( 6 ), and one abietane diterpene ( 7 ), three ursene triterpenes ( 8 , 9 and 15 ), six oleanane triterpenes ( 10 – 13 , 16 and 19 ), and three friedelane triterpenes ( 14 , 17 and 18 ), as well as 15 known compounds ( 20 – 34 ). Their structures were elucidated by spectroscopy and X-ray analysis. Based on the screening of isolated compounds and other compounds reported in previous papers [J. Nat. Prod. 62 (1999) 1522; J. Nat. Prod. (2001) in press; Phytochemistry 53 (2000) 805], we identified the main components that are responsible for the therapeutic effect of T Π .