Antimicrobial triterpenoids from licania heteromorpha

Six triterpenoids having a lupane and oleane skeleton were isolated from the leaves and young branches of Licania heteromorpha Bentham var. heteromorpha and were identified as: Betulinic acid 1, alphitolic acid 2, 3β-O-trans-p-coumaroyl alphitolic acid 3, 3β-O-cis-p-coumaroyl alphitolic acid 4, 3β-O-trans-p-coumaroyl maslinic acid 5, 3β-O-cis-p-coumaroyl maslinic acid 6. The antimicrobial activity of these compounds was evaluated in vitro on clinically isolated microorganisms employing a microdilution method. Compounds 2, 3, 5, and 6 showed antimicrobial activity on Gram-positive bacteria and yeasts, whereas none of the six triterpenoids were active against Gram-negative organisms.