New cytotoxic tetrahydroprotoberberine-aporphine dimeric and aporphine alkaloids from Corydalis turtschaninovii.

Two new tetrahydroprotoberberine-aporphine dimeric alkaloids, corydaturtschines A (1) and B (2), and a new aporphine derivative, ethyl glausuccinate (3), together with 13 known protoberberine (4-16) and nine known aporphine alkaloids (17-25), were isolated from the tubers of Corydalis turtschaninovii. The structures of these new compounds were determined through spectral analyses, including extensive 2D-NMR data. The absolute configurations of the compounds were clarified by CD spectroscopic studies. The isolated compounds were tested for their cytotoxicity against four human cancer cell lines in vitro using a sulforhodamine B bioassay.