Fimbricalyx A, a novel phenanthrenone derivative having a rare 2H-benz[e]inden-2-one substructure

Fimbricalyx A (1), a novel phenanthrenone derivative having a rare 2H-benz[e]inden-2-one substructure, was isolated from the root extract of Strophioblachia fimbricalyx. The structure of 1 was elucidated on the basis of NMR and MS data and confirmed by X-ray crystallography. The cytotoxicity of this compound against KB, MCF7 and NCI-H187 cancer cells is reported.