Clinopodium genus species are popular traditional Chinese medicinal herbs used to treat bruises and swelling and are also purported to improve blood circulation 1,2 . In recent years, several papers have described phytochemistry investigations of various species of clinopodium and it was found to be rich in saponins 3, 4 , flavones 5,6 , polyphenols 7,8 , terpenes 9,10 , etc. Clinopodium urticifolium belongs to the Clinopodium genus, which widely distributed in Gansu, shaanxi, ningxia, in

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... est China. In previous work, some bioactive compounds were isolated from this plant 8, 11, 12 . Motivated by a search for bioactive metabolites from this plant, a reinvestigation for the chemical constituents of the whole plant of C. urticifolium were carried out. As a result, a new pterocarpan (1), together with four known pterocarpan derivatives (2-5), were isolated from this plant. In addition, the cytotoxicity of compound 1 was evaluated. This work deals with the isolation, structural elucidation and biological activities of the new compound. EXPERIMENTAL Optical rotations were measured with a Horiba SEPA-300 polarimeter. UV spectra were obtained using a Shimadzu UV-2401A spectrophotometer. CD spectra were measured on a JASCO J-810 spectropolarimeter. A Tenor 27 spectrophotometer was used for scanning IR spectroscopy with KBr pellets. 1D