New aporphine alkaloids with antitumor activities from the roots of Thalictrum omeiense .

Two new aporphine alkaloids, 6a R -2'-(3-oxobutenyl)-thaliadin ( 1 ) and N -methylthalisopynine ( 2 ), along with ten known analogs ( 3 - 12 ), were isolated from the roots of Thalictrum omeiense W. T. Wang et S. H. Wang. Their structures were determined by extensive spectroscopic and X-ray crystallographic analyses. Compounds 1 - 7 and 9 - 12 were tested for their antiproliferative effects in vitro against two human cancer cell lines (A549 and MCF-7). Among them, compounds 1 , 3, and 7 exhibited moderate inhibitory activity against the tested cell lines with IC 50 values ranging from 23.73 to 34.97 μM.