Six new triterpenoids and other triterpenoids and steroids from three Quercus species of Hong Kong

Abstract

Six new triterpenoids have been isolated from three local Quercus species, and identified as taraxera-1,14-dien-3-one (1) and taraxer-14-ene-3β,16α-diol (7)(from Q. bambusaefolia), 21αH-hopane-3β,22-diol (14)(from Q. championi), and 24,25-dimethyl-lanosta-9(11),23-dien-3β-ol (30), its acetate (29), and the corresponding ketone (31)(from Q. myrsinaefolia). The isolation of two steroids and seventeen other triterpenoids, including olean-12-ene-3,16-dione (3), taraxer-14-ene-3,16-dione (6), hop-17(21)-en-3-one (13), 3β-hydroxylup-20(29)-en-30-al (23), and lup-20(29)-ene-3β,30-diol (24), is also reported.