Phenolics and Phenolic Glycosides from Wrightia pubescens and Their Hepatoprotective Activities

Thirty compounds including 13 new phenolic glycosides (1-6, 9-15) and 17 known aromatic compounds and aromatic glycosides (7-8, 16-30) were isolated from the roots of Wrightia pubescens. The structures of the new phenolic glycosides were established by extensive NMR spectroscopic data analysis as well as chemical derivatization method. The isolated compounds were evaluated for their hepatoprotective activities using cell model of acetaminophen (APAP)-induced HepG2 cells. The results indicated that phenolic glycosides (2, 4, 5, 7, 8, 11, 13) pretreatment enhanced the cells viability and reduced the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT). The hepatoprotective mechanism of a representative new compound, wrightioside D (4), was further investigated. Compound 4 exhibited hepatoprotective effects via reducing oxidative stress by attenuating ROS formation and inhibiting apoptosis in APAP-treated HepG2 cells.