Two New Cyototoxic Cardenolides from the Whole Plants of Adonis multiflora Nishikawa & Koki Ito.

A phytochemical investigation of the whole plants of Adonis multiflora Nishikawa & Koki Ito. resulted in the isolation and identification of two new cardenolides--adonioside A (1) and adonioside B (6)--as well as four known cardenolides: tupichinolide (2) oleandrine (3), cryptostigmin II (4), and cymarin (5). Their structures were elucidated on the basis of NMR, MS, and IR spectroscopic analyses. Compounds 1, 2, 5, and 6 showed significant cytotoxicity against six human cancer cell lines (HCT-116, HepG2, HeLa, SK-OV-3, and SK-MEL-5, and SK-BR-3).