ABSTRACT
One new natural monoterpene, 5-O-ß-d-glucopyranosyl-2-hydroxy-p-cymene (1: ), and 11 known compounds were isolated through a biologically oriented approach from the aerial parts of Phagnalon sordidum L. The most active extract and fractions were selected using 3 complementary antioxidant activity assays. Results and the different methods were compared by relative antioxidant capacity index. In addition, the most active extract of P. sordidum was subjected to liquid chromatography coupled with electrospray ionization hybrid linear ion trap quadrupole Orbitrap mass spectrometry to quantify secondary metabolites. Antioxidant activities of ethyl acetate extract, and purified 3,4-dihydroxyacetophenone (3: ) and nebrodenside A (7: ) were demonstrated by in vitro cell free model assays, and their protective effect against H2O2-induced oxidative stress in a HepG2 (human hepatocellular carcinoma) cell line was established.
Subject(s)
Antioxidants/pharmacology , Asteraceae/chemistry , Plant Components, Aerial/chemistry , Plant Extracts/pharmacology , Antioxidants/isolation & purification , Hep G2 Cells/drug effects , Humans , Magnetic Resonance Spectroscopy , Oxidative Stress/drug effects , Plant Extracts/isolation & purificationABSTRACT
In this paper, the isolation of five new guaianolides (1: â-â5: ) and four (6: â-â9: ) known sesquiterpenes from Ormenis mixta aerial parts is reported. The structural determination of the guaianolides was obtained by NMR spectroscopic data, as well as MS experiments. Their relative configurations were assigned by a combined quantum mechanical/NMR approach, comparing the experimental 13C/1H NMR chemical shift data and 1 J H-H homonuclear coupling constants with the related predicted values. The isolates were assayed for their anti-inflammatory potential evaluating nitric oxide release and cyclooxygenase-2 expression in J774A.1 macrophages treated with lipopolysaccharide from Escherichia coli. Our results indicated that, among the tested compounds, 1: â-â3: , and 7: were able to inhibit nitric oxide release, while all were able to inhibit cyclooxygenase-2 expression with different potencies.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Chamomile/chemistry , Sesquiterpenes, Guaiane/pharmacology , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/isolation & purification , Cell Line , Cyclooxygenase 2/metabolism , Macrophages/drug effects , Macrophages/metabolism , Magnetic Resonance Spectroscopy , Mice , Nitric Oxide/metabolism , Plant Components, Aerial/chemistry , Sesquiterpenes, Guaiane/chemistry , Sesquiterpenes, Guaiane/isolation & purificationABSTRACT
In this paper, the isolation of one new iridoid glucoside, 6ß-acetoxyipolamiide (1: ), and thirteen (2: â-â14: ) known congeners from two Lamiaceae species, Stachys ocymastrum and Premna resinosa, leaf extracts is reported. The structural determination of the isolated compounds was performed by mono- and bidimensional NMR spectroscopic analysis as well as MS experiments. The isolates were assayed for their antiangiogenic activity by two in vivo models, zebrafish embryos and chick chorioallantoic membrane assays. The compounds with a significant antiangiogenic activity in both assays were ß-hydroxyipolamiide (2: ), ipolamiide (3: ), and buddlejoside A5 (8: ). 6-O-α-l-(3â³-O-p-Methoxycinnamoyl-4â³-O-acetyl)rhamnopyranosyl catalpol (13: ) and 6-O-α-l-(2â³-trans-caffeoyl)rhamnopyranosyl catalpol (6: ) showed the best antiangiogenic response on blood vessel growth in zebrafish embryos, whereas saccatoside (10: ) and 6-O-α-l-(2â³-O - : p-methoxycinnamoyl-3â³-O-acetyl)rhamnopyranosyl catalpol (14: ) resulted in a strong reduction of capillary formation in the chorioallantoic membrane assay.
