Cardiac Glycosides from the Seeds of Thevetia peruviana.
Tian DM, Cheng HY, Jiang MM, Shen WZ, Tang JS, Yao XS.
Investigation of the seeds of Thevetia peruviana resulted in the isolation of 15 new (2-16) and 18 known (1 and 17-33) cardiac glycosides. Eight 19-nor-cardenolides (1-8), including two rare 19-nor-10-hydroperoxycardenolides, were obtained from T. peruviana for the first time. All the structures were characterized by NMR spectroscopy and chemical derivatization. The inhibitory effects of cardiac glycosides 1-33 against three cancer cell lines (human lung cancer cells, P15; human gastric cancer cells, MGC-803; and human pancreatic cancer cells, SW1990) and one normal hepatocyte cell line, LO2, were evaluated, and a preliminary structure-activity relationship is discussed. In addition, cardiac glycosides 1, 22, 26, and 28 were evaluated for their apoptosis-inducing activities in MGC-803 cells, showing IC50 values in the range 0.02-0.53 μM.