title: Bioactivity-guided identification of antimicrobial metabolites in Alnus glutinosa bark and optimization of oregonin purification by Centrifugal Partition Chromatography.
abstract: 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%.
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France; Biomatériaux et Inflammation en Site Osseux, EA 4691, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne Ardenne, Reims, France.
authors.forename: Amin
authors.initials: A
authors.lastname: Abedini
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France; CPC Engineering, Capacité SAS, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Chollet
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France; Division of Pharmacognosy and Natural Products Chemistry, School of Pharmacy, University of Athens, Panepistimioupolis, Zographou, Athens, Greece.
authors.forename: Apostolis
authors.initials: A
authors.lastname: Angelis
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Borie
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Nuzillard
authors.affiliation: Division of Pharmacognosy and Natural Products Chemistry, School of Pharmacy, University of Athens, Panepistimioupolis, Zographou, Athens, Greece.
authors.forename: Alexios-Leandros
authors.initials: AL
authors.lastname: Skaltsounis
authors.affiliation: Soliance-Givaudan SAS, Route de Bazancourt, 51110 Pomacle, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Reynaud
authors.affiliation: Biomatériaux et Inflammation en Site Osseux, EA 4691, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne Ardenne, Reims, France.
authors.forename: Sophie C
authors.initials: SC
authors.lastname: Gangloff
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France.
authors.forename: Jean-Hugues
authors.initials: JH
authors.lastname: Renault
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, SFR CAP'santé, UFR de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France. Electronic address: jane.hubert@univ-reims.fr.
authors.forename: Jane
authors.initials: J
authors.lastname: Hubert
mesh_terms: D029661:Alnus / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000302:isolation & purification* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D002177:Candidiasis / Q000188:drug therapy; D005591:Chemical Fractionation / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D036381:Diarylheptanoids / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D024301:Plant Bark / Q000737:chemistry*; D015003:Yeasts / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D036381:Diarylheptanoids; C409456:oregonin
keywords: Alnus glutinosa; Antimicrobial activity; Centrifugal partition extraction; NMR-based dereplication; Oregonin