Bioactive Triterpenoids from the Leaves and Twigs of Lithocarpus litseifolius and L corneus

Phytochemical investigation of the leaves and twigs of Lithocarpus litseifolius and Lithocarpus corneus resulted in the isolation of four new triterpenoids (1 - 4), three triterpenoids (5 - 7) isolated from a natural source for the first time, and six known compounds (8 - 13). In addition, four known triterpenoids (14 - 17) were isolated from L. corneus. Compound 1 is a 3,4- seco -lupane-type triterpenoid, and compounds 2 - 4 are lupane-type triterpenoids in different oxidation states. The structures of all isolated compounds were identified by spectroscopic methods, especially NMR and mass spectrometry data. The absolute configuration of 2 and 3 was confirmed by X-ray single crystallographic analysis. The anti-inflammatory activities of 1 - 17 and anti-HIV activities of 2 - 17 were evaluated. Among them, 3- epi -betulinic acid (8) showed a strong anti-HIV activity comparable to abacavir, a drug used for treating HIV/AIDS. 3,4- seco -4(23),20(29)-lupadiene-3,28-dioic acid (5) exhibited potent inhibition of superoxide-anion generation with 86.9 ± 2.8% inhibition at 1 μM.