title: Structures and biosynthesis of the pyridinopyrones, polyenepyrones from a marine-derived Streptomyces species.
abstract: Three polyenylpyrone metabolites, pyridinopyrones A to C (1-3), have been isolated from the culture broth of a marine-derived Streptomyces sp., strain CNQ-301. The structures of the pyridinopyrones were assigned on the basis of chemical modification and combined spectroscopic methods, focusing on interpretation of 1D and 2D NMR data. Pyridinopyrones B and C (2, 3), examined as an inseparable mixture of methyl positional isomers, were ultimately defined by hydrogenation and NMR analysis of a saturated derivative. The biosynthesis of these metabolites was defined by the incorporation of stable isotope-labeled precursors, revealing that the biosynthetic starter unit is nicotinic acid, while the polyene chain and pendant methyl groups are acetate- and methionine-derived, respectively.
authors.affiliation: Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0204, USA.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukuda
authors.forename: Eric D
authors.initials: ED
authors.lastname: Miller
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Clark
authors.forename: Ali
authors.initials: A
authors.lastname: Alnauman
authors.forename: Cormac D
authors.initials: CD
authors.lastname: Murphy
authors.forename: Paul R
authors.initials: PR
authors.lastname: Jensen
authors.forename: William
authors.initials: W
authors.lastname: Fenical
mesh_terms: D008386:Marine Biology; D015394:Molecular Structure; D009525:Niacin / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D011090:Polyenes / Q000737:chemistry / Q000302:isolation & purification*; D011725:Pyridines / Q000737:chemistry / Q000302:isolation & purification*; D011753:Pyrones / Q000737:chemistry / Q000302:isolation & purification*; D013237:Stereoisomerism; D013302:Streptomyces / Q000737:chemistry*
chemical_list: D011090:Polyenes; D011725:Pyridines; D011753:Pyrones; C562124:pyridinopyrone A; C562125:pyridinopyrone B; D009525:Niacin