Abstract
The coprophilic ascomycete Coniochaeta ellipsoidea DSM 13856 forms the new antibiotic coniosetin (1) in surface cultures grown on a medium containing malt extract and oatmeal. The structure of the compound C25H35NO4, MW 413, was determined by 2D-NMR and mass spectrometric studies. Coniosetin belongs to the class of tetramic acids; it consists of a substituted aliphatic bicyclic ring system linked to a tetramic acid subunit through a carbonyl center. The absolute configuration was determined by measuring its circular dichroism spectrum and comparing the data with those of equisetin. Coniosetin has a pronounced antibacterial and antifungal action, inhibiting even multi drug-resistant strains of Staphylococcus aureus at a concentration of 0.3 microg/ml, though it is inactive against Gram-negative bacteria.
MeSH terms
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Anti-Bacterial Agents / biosynthesis
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Anti-Bacterial Agents / chemistry*
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Anti-Bacterial Agents / isolation & purification
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Anti-Bacterial Agents / pharmacology
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Ascomycota / chemistry
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Ascomycota / metabolism*
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Chromatography, High Pressure Liquid
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Circular Dichroism
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Fermentation
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Microbial Sensitivity Tests
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Molecular Structure
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Molecular Weight
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Naphthalenes / chemistry*
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Naphthalenes / isolation & purification
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Naphthalenes / pharmacology
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Nuclear Magnetic Resonance, Biomolecular
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Optical Rotation
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Pyrrolidinones / chemistry*
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Pyrrolidinones / isolation & purification
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Pyrrolidinones / metabolism
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Pyrrolidinones / pharmacology
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Spectrometry, Mass, Fast Atom Bombardment
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Spectrophotometry, Infrared
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Spectrophotometry, Ultraviolet
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Staphylococcus aureus / metabolism
Substances
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Anti-Bacterial Agents
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Naphthalenes
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Pyrrolidinones
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coniosetin