Planta Med. 2003 Feb; 69(2): 148-52.

Two new protopines argemexicaines A and B and the anti-HIV alkaloid 6-acetonyldihydrochelerythrine from formosan Argemone mexicana.

Chang YC, Hsieh PW, Chang FR, Wu RR, Liaw CC, Lee KH, Wu YC.

Department of Chemical Engineering, Kao Yuan Institute of Technology, Kaohsiung, Taiwan, ROC.

Two new protopine-type alkaloids, argemexicaine A (1) and argemexicaine B (2), along with thirteen known alkaloids, were isolated from MeOH extracts of Formosan Argemone mexicana L. (Papaveraceae). Physical and spectral analyses, particularly IR and thermo-modulated 1D and 2D NMR, were used to determine the transannular conformations of the isolated protopine-type alkaloids. The known benzo[ c]phenanthridine (+/-)-6-acetonyldihydrochelerythrine (5) exhibited significant anti-HIV activity in H9 lymphocytes with EC50 and TI (Therapeutic Index) values of 1.77 microg/mL and 14.6, respectively.