Four new cytotoxic tetrahydrofuranoid lignans from Sinopodophyllum emodi

Four new tetrahydrofuranoid lignans, (-)-tanegool-7'-methyl ether ( 1), (+)-7'-methoxylariciresinol (2), sinolignan C (3), and epipinoresinol-4,4'-di- O- β- D-glucopyranoside (4), were isolated from the roots and rhizomes of SINOPODOPHYLLUM EMODI together with one known lignan (5). Their structures and stereochemistry were elucidated on the basis of spectroscopic and mass spectrometric evidence. The isolation of compounds 1- 5 represents the first report of tetrahydrofuran lignans from the genus SINOPODOPHYLLUM. The cytotoxic activities of all isolated compounds were evaluated against HeLa and KB cell lines, and compound 1 showed the most potent cytotoxicity with IC₅₀ values of 9.7 µM and 4.7 µM, respectively.