Chemical constituents and absolute configuration of megastigmanes' isolated from Bunge.

Phytochemical investigation of a methanolic extract of collected from Vietnam resulted in the isolation of a new megastigmane glucoside, named sedumoside K (), together with 17 previously reported compounds (). Structural elucidation of the new compound was achieved by HRFABMS, NMR spectroscopic analysis, acid hydrolysis and quantum ECD calculations. The absolute configuration of compounds has been revised. The major isolates were tested for cytotoxic activity against HeLa human cervical cancer cells, and all showed moderate activities.