Bioactive triterpenoids from Callistemon lanceolatus

A new triterpenoid, 30-hydroxyalphitolic acid 1, and eight known triterpenoids, alphitolic acid 2, lupenol 3, 3-acetoxy-olean-18-en-28-oic acid 4, betulinic acid 5, ursolic acid 6, betulinic acid 3-O-caffeate 7, morolic acid 3-O-caffeate 8, and ursolic acid 3-O-caffeate 9, were isolated from Callistemon lanceolatus. Their structures were determined using spectroscopic techniques, which included 1D- and 2D-NMR. All compounds were evaluated for the inhibition of LPS-induced nitric oxide production in murine macrophage RAW264.7 cells. Betulinic acid 3-O-caffeate 7 showed a moderate inhibitory effect on nitric oxide production with IC(50) value of 15.4 microM.