[A new nortriterpenoid from mastic].

Ten compounds were separated by various modern chromatographic methods from mastic. They were identified by HR-ESI-MS, IR, UV, NMR, quantum chemical calculation of NMR(qcc-NMR) and comparison with reported data in literature as 17β-hydroxy-28-norolean-18-en-3-one(1), 28-norolean-12,17-dien-3,11-dione(2), 28-norolean-16,18-dien-3-one(3),(24Z)-26-hydroxy-7,24-dientirucalla-3-one(4), masticadienonic acid(5)、masticadienolic acid(6)、erythrodiol(7), 3β,28-dihydroxyoleana-11,13(18)-diene(8), 3-oxo-olean-9(11),12-dien-28-oic acid(9), and 12-oleane-3,11-dione(10). Among them, compound 1 was a novel compound and compound 2 was a novel natural product. Compounds 1-2, 4, and 7-9 were isolated from mastic for the first time. Compound 1 significantly inhibited lipopolysaccharide-induced production of nitric oxide in mouse monocyte macrophage RAW264.7 cells with the IC_(50) of(7.44±0.49) μmol·L~(-1), which was more potent than the positive control, dexamethasone \[IC_(50)=(9.93±1.17) μmol·L~(-1)\]. Compounds 2-3, 5, and 9-10 also showed inhibitory effects, with the IC_(50) ranging from 14.82 to 28.82 μmol·L~(-1). Compounds 4-5, and 7 markedly inhibited the growth of human colon adenocarcinoma cells SW480, with the IC_(50) of(16.13±1.69),(27.40±1.81), and(10.01±0.10) μmol·L~(-1), respectively.