Résumé
Phytochemical investigation of the aerial parts of Baeckea frutescens resulted in the isolation of three new mono- or sesquiterpene-based meroterpenoids, frutescones S-U (1-3), and one pair of new (±)-5,7-dihydroxy-8-isobutyryl-6-methyldihydroflavonol (4). Their structures and absolute configurations were established by HR-ESI-MS, 1D and 2D NMR, and quantum chemical ECD calculation. Compound 1 exhibited inhibitory effect on NO production in LPS-activated RAW 264.7 macrophages with an IC value being 0.81 μmol·L.
Résumé
In the present study, we carried out a phytochemical investigation of the ethanol extract of the aerial parts of Baeckea frutescens, which resulted in the isolation of two new flavonoid glycosides, myricetin 3-O-(5″-O-galloyl)-α-L-arabinofuranoside (1), 6-methylquercetin 7-O-β-D-glucopyranoside (2), one new methylchromone glycoside, 7-O-(4', 6'-digalloyl)-β-D-glucopyranosyl-5-hydroxy-2-methylchromone (3), together with three known compounds (4-6). The structures of these isolated compounds were established on the basis of 1D and 2D NMR techniques and chemical methods. The anti-inflammatory activities of the compounds 1-6 were evaluated for their inhibitory effects against cyclooxygenases-1 and -2 in vitro. Compounds 1-6 showed potent COX-1 and COX-2 inhibiting activities in vitro with IC values ranging from 1.95 to 5.54 μmol·L and ranging from 1.01 to 2.27 μmol·L, respectively.
Sujets)
Anti-inflammatoires , Chimie , Cyclooxygenase 1 , Chimie , Cyclooxygenase 2 , Chimie , Inhibiteurs des cyclooxygénases , Chimie , Flavonoïdes , Chimie , Structure moléculaire , Myrtaceae , Chimie , Parties aériennes de plante , Chimie , Extraits de plantes , ChimieRésumé
In the present study, we carried out a phytochemical investigation of the ethanol extract of the aerial parts of Baeckea frutescens, which resulted in the isolation of two new flavonoid glycosides, myricetin 3-O-(5″-O-galloyl)-α-L-arabinofuranoside (1), 6-methylquercetin 7-O-β-D-glucopyranoside (2), one new methylchromone glycoside, 7-O-(4', 6'-digalloyl)-β-D-glucopyranosyl-5-hydroxy-2-methylchromone (3), together with three known compounds (4-6). The structures of these isolated compounds were established on the basis of 1D and 2D NMR techniques and chemical methods. The anti-inflammatory activities of the compounds 1-6 were evaluated for their inhibitory effects against cyclooxygenases-1 and -2 in vitro. Compounds 1-6 showed potent COX-1 and COX-2 inhibiting activities in vitro with IC values ranging from 1.95 to 5.54 μmol·L and ranging from 1.01 to 2.27 μmol·L, respectively.
Sujets)
Anti-inflammatoires , Chimie , Cyclooxygenase 1 , Chimie , Cyclooxygenase 2 , Chimie , Inhibiteurs des cyclooxygénases , Chimie , Flavonoïdes , Chimie , Structure moléculaire , Myrtaceae , Chimie , Parties aériennes de plante , Chimie , Extraits de plantes , ChimieRésumé
The present study was designed to investigate the chemical constituents of the roots of Cyathula officinalis. Compounds were isolated by silica gel, Sephadex LH-20, ODS column chromatography, and preparative HPLC. Their structures were determined on the basis of 1D and 2D NMR techniques, mass spectrometry, and chemical methods. One new oleanane-type triterpenoid saponin, 28-O-[α-L-rhamnopyranosyl-(1→3)-β-D-glucuronopyranosyl-(1→3)-β-D-glucopyranosyl] hederagenin (1), was isolated from the roots of Cyathula officinalis. The anti-inflammatory activities of the isolates were evaluated for their inhibitory effects against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages cells. Compounds 2, 4, and 6 exhibited moderate anti-inflammatory activities.