[Two new taraxerane triterpenoids from mastic]

Three taraxerane nortriterpenoids were isolated from mastic by using various modern chromatographic separation techniques. They were identified as(5R,8R,9R,10S,11S,12R,13S,17R,18R)-28-norlupa-11,12-epoxy-14-taraxerene-3,16-dione(1),(5R,8R,9R,10S,11S,12R,13S,17S,18S)-17-hydroxy-28-norlupa-11,12-epoxy-14-taraxerene-3-one(2), and(5R,8R,9R,10R,11S,12R,13R,14S,17S,18S)-14,17-epoxy-28-norlupa-11,12-oxidotaraxerone(3) through the high-resolution electrospray ionization mass spectrometry(HR-ESI-MS), infrared(IR), ultraviolet(UV), nuclear magnetic resonance(NMR), and single-crystal X-ray diffraction techniques as well as comparison with literature data. Compounds 1-3 were C-28 nortriterpenoids and isolated from mastic for the first time, and compounds 1-2 were new ones. In the model for RAW264.7 cell anti-inflammation induced by lipopolysaccharide(LPS), compound 1 demonstrates an inhibitory effect on nitric oxide(NO) [IC_(50)=(13.38±0.68) μmol·L~(-1)], comparable to the activity of the positive control dexamethasone [IC_(50)=(14.59±1.49) μmol·L~(-1)]. Compounds 2 and 3 exhibit weaker inhibitory effects, with IC_(50) values of(24.17±2.56) and(22.25±2.84) μmol·L~(-1), respectively.