[Study on anti-inflammatory components from Melicope pteleifolia]

Melicope pteleifolia is a plant belonging to the Melicope genus of the Rutaceae family. Known for a bitter taste and cold nature, its stems and tender branches with leaves possess properties of clearing heat, detoxifying, dispelling wind, and removing dampness and can be used to treat sore throat, malaria, jaundice hepatitis, rheumatic bone pain, eczema, dermatitis, and sores and ulcers. In this study, 19 compounds were isolated from the chloroform and n-butanol extracts of M. pteleifolia leaves by using liquid chromatography-mass spectrometry(LC-MS) and proton nuclear magnetic resonance(~1H-NMR)-guided separation techniques. The compounds were identified as isoleptonol(1), leptaones B-E(2-5), friedelin(6), evodionol(7), ethyl p-hydroxybenzoate(8), litseachromolaevane A(9), quercetin-7,3',4'-trimethyl ether(10), kokusaginin(11), 8-(1-hydroxyethyl)-5,6,7-trimethoxy-2,2-dimethyl-2H-1-benzopyran(12), ethyl p-hydroxycinnamate(13), 3-hydroxy-9-methyl-6H-benzo\[c\]chromen-6-one(14), agrimonolide(15), 7-hydroxycoumarin(16), scopoletin(17), isoscutellarein(18), and agrimonolide 6-O-glucoside(19). Among these, the new compounds included one chromene and four meroterpenoid(1-5). The anti-inflammatory activities of the newly identified compounds 1-5 were screened in vitro, showing that the five compounds(1-5) exhibited inhibitory effects on nitric oxide(NO) production in BV2 cells induced by lipopolysaccharide(LPS)/interferon(IFN)-γ, with IC_(50) values ranging from 12.25 to 36.48 μmol·L~(-1).