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.
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