Three New Triterpenes from the Seeds of Combretum quadrangulare and Their Hepatoprotective Activity

Three new triterpenes of the lupane type, 2α,6β-dihydroxybetulinic acid (1) and 6β-hydroxyhovenic acid (2), and an oleanane type, 6β-hydroxyarjunic acid (3), together with several known compounds, have been isolated from the MeOH extract of the seeds of Combretum quadrangulare. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and their hepatoprotective activities were tested for d-GalN/TNF-α-induced cell death in primary cultured mouse hepatocytes.