title: Structural Characterization of a Novel Antioxidant Pigment Produced by a Photochromogenic Microbacterium oxydans Strain.
abstract: The Microbacteriaceae family, such as Microbacterium, is well known for its ability to produce carotenoid-type pigments, but little has been published on the structure of such pigments. Here, we isolated the yellow pigment that is responsible for the yellowish color of a Microbacterium oxydans strain isolated from a decomposing stump of a resinous tree. The pigment, which is synthesized when the bacterium is grown under light, was purified and characterized using several spectroscopic analyses, such as ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR),1H and13C nuclear magnetic resonance (1H NMR,13C NMR), and high-resolution mass spectrometry (HRMS). From these analysis, a molecular formula (C27H42O2) and a chemical structure (8-hydroxymethyl-2,4,12-trimethyl-14-(2,6,6-trimethyl-cyclohex-2-enyl)-teradeca-3,7,9,11,13-pentan-2-ol) were deduced. The chemical properties of the pigment, such as aqueous stability at different pH, stability in different organic solvents, and antioxidant capacity, are also reported. Together, these data and previous studies have resulted in the identification of a new antioxidant pigment produced by M. oxydans. To the best of our knowledge, this is the first thorough investigation of this carotenoid-like pigment in the Microbacterium genera.
authors.affiliation: Centre de Recherche sur les Matériaux Lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec, G9A 5H7, Canada. fatma.meddeb@uqtr.ca.|PROTEO, Université Laval , Québec, G1V 4G2, Canada. fatma.meddeb@uqtr.ca.
authors.forename: Fatma
authors.initials: F
authors.lastname: Meddeb-Mouelhi
authors.affiliation: Centre de Recherche sur les Matériaux Lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec, G9A 5H7, Canada.|PROTEO, Université Laval , Québec, G1V 4G2, Canada.
authors.forename: Jessica Kelly
authors.initials: JK
authors.lastname: Moisan
authors.affiliation: Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, G9A 5H7, Canada.
authors.forename: Jodrey
authors.initials: J
authors.lastname: Bergeron
authors.affiliation: Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, G9A 5H7, Canada.
authors.forename: Benoit
authors.initials: B
authors.lastname: Daoust
authors.affiliation: Centre de Recherche sur les Matériaux Lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec, G9A 5H7, Canada.|PROTEO, Université Laval , Québec, G1V 4G2, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Beauregard
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001951:Brevibacterium / Q000378:metabolism* / Q000528:radiation effects; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D009930:Organic Chemicals / Q000737:chemistry; D055668:Photochemical Processes; D010860:Pigments, Biological / Q000737:chemistry* / Q000302:isolation & purification; D066244:Proton Magnetic Resonance Spectroscopy; D012997:Solvents / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D009930:Organic Chemicals; D010860:Pigments, Biological; D012997:Solvents
keywords: Carotenoid; Culture; Microbacterium oxydans; Photochromogenic bacteria; Spectroscopy; Wood decay