A phytochemical investigation of the barks of Eucommia ulmoides Oliv. resulted in the isolation of 18 flavonoids (1-18). The new compound, eucommiaflavone (1) was structurally elucidated by various spectroscopic analyses. In particular, Mo2(OAc)4-induced circular dichroism (ICD) analysis was applied to determine the absolute configuration of 1. Furthermore, five flavonoids (4, 9, 11, 13, and 15) revealed significant in vitro hepatoprotective activity against D-galactosamine-induced cytotoxicity in human hepatoma HepG2 cells.
Keywords: Eucommia ulmoides; flavonoids; hepatoprotective activity; phytochemistry.