title: Isolation, antifungal activity, and structure elucidation of the glutarimide antibiotic, streptimidone, produced by Micromonospora coerulea.
abstract: The antibiotic Ao58A,which showed strong antifungal activity against some plant pathogenic fungi, was purified from the culture broth and mycelial mats of Micromonospora coerulea strain Ao58 using various chromatographic procedures. The molecular formula of the antibiotic Ao58A was deduced to be C(16)H(23)NO(4) (M + H, m/z 294.1707) by high-resolution FAB mass spectroscopy. Analyses of (1)H NMR, (13)C NMR, and 2D NMR spectral data revealed that the antibiotic Ao58A is the glutarimide antibiotic streptimidone, 4-(2-hydroxy-5, 7-dimethyl-4-oxo-6,8-nonadienyl)-2,6-piperidinedione. The antibiotic Ao58A was very effective in inhibiting growth of Phytophthora capsici,Didymella bryoniae, Magnaporthe grisea, and Botrytis cinerea in the range approximately 3-10 microg mL(-)(1) of MICs. In vivo evaluation of the antibiotic Ao58A under greenhouse condition showed strong control efficacies against the development of P. capsici, B. cinerea, and M. grisea on pepper, cucumber, and rice plants, respectively. The antibiotic Ao58A was equally as effective as metalaxyl, vinclozolin, and tricyclazole in the control of these plant diseases. However, it did not show any phytotoxicity on the plants even when treated with 500 microg mL(-)(1).
authors.affiliation: Department of Agricultural Biology, Korea University, Seoul.
authors.forename: B S
authors.initials: BS
authors.lastname: Kim
authors.forename: S S
authors.initials: SS
authors.lastname: Moon
authors.forename: B K
authors.initials: BK
authors.lastname: Hwang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D005658:Fungi / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D008847:Micromonospora / Q000145:classification / Q000254:growth & development* / Q000648:ultrastructure; D008968:Molecular Conformation; D010881:Piperidones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D010881:Piperidones; C005258:streptimidone