title: Coumabiocins A-F, aminocoumarins from an organic extract of Streptomyces sp. L-4-4.
abstract: Bioassay-directed fractionation of the butanol extract of Streptomyces sp. L-4-4, using the hyphae formation inhibition assay of a prokaryotic whole cell, led to the isolation of six new aminocoumarins, coumabiocins A-F (1-6), along with two known compounds, novobiocin (7) and isonovobiocin (8). Coumabiocins A-E (1-5) contain three structural elements, a central 3-amino-7-hydroxycoumarin that is linked at the 3-amino group to a prenylated 4-hydroxybenzoic acid moiety and at the 7-position to an l-noviosyl sugar, while coumabiocin F (6) lacks the sugar moiety. Their structures were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques and mass spectrometric analyses. Coumabiocins A-E (1-5) exhibited significant inhibitory activity against Streptomyces 85E and gave a 10-15 mm clear zone of inhibition at 20 microg/disk and a 10 mm bald and a 10 mm clear zone of inhibition at 5 and 10 microg/disk, respectively, whereas coumabiocin F (6) was inactive.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Hawaii at Hilo, 34 Rainbow Drive, Hilo, Hawaii 96720.
authors.forename: Sarot
authors.initials: S
authors.lastname: Cheenpracha
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Vidor
authors.forename: Wesley Y
authors.initials: WY
authors.lastname: Yoshida
authors.forename: Julian
authors.initials: J
authors.lastname: Davies
authors.forename: Leng Chee
authors.initials: LC
authors.lastname: Chang
mesh_terms: D049933:Aminocoumarins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009675:Novobiocin / Q000737:chemistry / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular; D013302:Streptomyces / Q000737:chemistry* / Q000187:drug effects
chemical_list: D049933:Aminocoumarins; D000900:Anti-Bacterial Agents; C017443:isonovobiocin; D009675:Novobiocin