Triterpenoid constituents in the bark of Balanops australiana

Two new triterpenoid natural products (friedelane-3 alpha ,21 alpha -diol a nd friedelane-3 alpha ,28,29-triol) have been isolated from the chloroform bark extract of Balanops australiana from Paluma, north Queensland, Austral ia. The known triterpenoids betulinic acid, friedelin, canophyllol, zeylano l and 21 alpha -hydroxyfriedelan-3-one were also isolated. The structures o f the compounds were elucidated on the basis of spectral analysis. A single -crystal X-ray structural analysis has been carried out on 21 alpha -hydrox yfriedelan-3-one.