Bioactivity-guided identification of antimicrobial metabolites in Alnus glutinosa bark and optimization of oregonin purification by Centrifugal Partition Chromatography.
Fiche publication
Date publication
septembre 2016
Journal
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
Auteurs
Membres identifiés du Cancéropôle Est :
Pr GANGLOFF Sophie, Dr NUZILLARD Jean-Marc
Tous les auteurs :
Abedini A, Chollet S, Angelis A, Borie N, Nuzillard JM, Skaltsounis AL, Reynaud R, Gangloff SC, Renault JH, Hubert J
Lien Pubmed
Résumé
Barks from conifers and broadleaved trees constitute abundant wastes generated from wood harvesting and logging activities. Extracts of such residues obtained from Alnus trees have been reported as interesting resources with potent antibacterial activities. The present study aims to determine the antimicrobial activity of a crude methanol extract prepared from the bark of Alnus glutinosa against a panel of 22 bacteria and yeasts and to optimize a purification method enabling the high production of the most active substances. Fractionation of the crude extract was performed by Centrifugal Partition Chromatography (CPC) using a three-phase solvent system composed of n-heptane, methyl-ter-butyl ether, acetonitrile and water. The major known compounds contained in the fractions produced by CPC were chemically profiled by (13)C NMR dereplication, resulting in the unambiguous identification of oregonin, hirsutanonol, betulinic acid, and alusenone 1a. The antibacterial evaluation of the fractions by bioautography on Staphylococcus aureus revealed that oregonin, in addition to being the major metabolite of the crude extract (∼32% w/w), was the most active with an antibacterial inhibitory effect comparable to antibiotics. The purification of oregonin was optimized at the laboratory-scale by CPC. A single injection of 3.7g of crude extract resulted in a recovery of 72% (850mg) of the available oregonin at purity higher than 94%.
Mots clés
Alnus, chemistry, Anti-Infective Agents, isolation & purification, Bacteria, drug effects, Bacterial Infections, drug therapy, Candidiasis, drug therapy, Chemical Fractionation, methods, Chromatography, Liquid, methods, Diarylheptanoids, isolation & purification, Humans, Plant Bark, chemistry, Yeasts, drug effects
Référence
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.. 2016 Sep;1029-1030:121-7