Hepatoprotective phenolic glycosides from Gymnema tingens.

Six new phenolic diglycosides, named gymnetinosides A-F (1-6), were isolated from the ethanolic extract of Gymnema tingens, together with three known diglycosides, sequinoside K (7), khaephuoside B (8), and albibrissinoside A (9). The structures of the new compounds were determined by spectroscopic techniques including 1D-, 2D NMR, mass spectroscopy, and circular dichroism. Compounds 1, 5, and 6 showed hepatoprotective activities against D-galactosamine-induced HL-7702 cell damage.