title: Parameters and mechanistic studies on the oxidative ring cleavage of synthetic heterocyclic naphthoquinones by Streptomyces strains.
abstract: Screening of fungal and bacterial strains allowed selection of two Streptomyces strains ( S. platensis and S. cinnamonensis) that oxidatively cleave, in moderate to high yields (up to 65% in 24 h), the quinonic ring of a thiazole fused 1,4-naphthoquinone compound, INO5042, used as a model compound for a series of homologous substituted heterocyclic naphthoquinones. The respective products of these whole-cell biotransformations were identified as isomeric phenol-carboxylic acids resulting from a C-C bond cleavage at a position vicinal to each one of the carbonyl groups. The culture and incubation conditions have been optimised and the mechanism of this biotransformation investigated using oxygen isotope incorporation. The results of 18O2 incorporation indicate a dioxygenase reaction, the mechanism of which is discussed in relation with that of hydroquinone-epoxidases, a family of oxygenating enzymes involved in the biosynthesis of polyketide antibiotics in Streptomyces.
authors.affiliation: Groupe Biocatalyse et Chimie Pharmacologique, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601, Université René Descartes-Paris V, 45 rue des Saints-Pères, 75006, Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Fosse
authors.forename: Laurence
authors.initials: L
authors.lastname: Le Texier
authors.forename: Sébastien
authors.initials: S
authors.lastname: Roy
authors.forename: Marcel
authors.initials: M
authors.lastname: Delaforge
authors.forename: Sébastien
authors.initials: S
authors.lastname: Grégoire
authors.forename: Michel
authors.initials: M
authors.lastname: Neuwels
authors.forename: Robert
authors.initials: R
authors.lastname: Azerad
mesh_terms: D001711:Biotransformation; D002264:Carboxylic Acids / Q000378:metabolism; D009285:Naphthoquinones / Q000378:metabolism*; D010084:Oxidation-Reduction; D010103:Oxygen Isotopes / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism; D013302:Streptomyces / Q000378:metabolism*
chemical_list: D002264:Carboxylic Acids; D009285:Naphthoquinones; D010103:Oxygen Isotopes; D010105:Oxygenases