D. tangutica (Thymelaeaceae) has been used in the traditional Chinese medicine for treatment of various diseases. From the EtOH extract of its stem and root bark, a new bioactive diterpene, tanguticacine (I), was isolated in 0.011% yield. Also gniditrin (II), excoecariatoxin (III), daphnetoxin (IV), and palmitic acid were identified. The structures of these compounds were elucidated by UV, IR, MS, 1H-NMR spectra and chem. evidence. The min. abortifacient dose of I was 300 mg/monkey.

Key words: BIOLOGICAL ACTIVITY, ANTICARCINOGEN, MASS SPECTROGRAPHY, PROTON MAGNETIC RESONANCE SPECTROMETRY, STRUCTURAL ANALYSIS, STRUCTURE AND PROPERTY CORRELATION, DITERPENES, CONTRACEPTIVE, THYMELAEEACEAE