Taccachatrones A-G, Highly Oxidized Steroids from the Rhizomes of Tacca chantrierii and Their Cytotoxicity Assessment.

Seven highly oxidized steroids, taccachatrones A-G ( 1 - 7 ), together with four known taccalonolides ( 8 - 11 ), were characterized from the rhizomes of Tacca chantrieri . The structures of 1 - 7 were established on the basis of spectroscopic data analysis, while the absolute configurations were determined by single-crystal X-ray diffraction. Compounds 1 - 4 may be derived from taccalonolide derivatives by the degradation of three carbon atoms. Compounds 7 , 8 , 10 , and 11 exhibited cytotoxicity to human cancer cell lines, indicating that the presence of a lactone moiety, as well as a double bond between C-22 and C-23, might play key roles in mediating their cytotoxicity.