title: Reversed-phase high-performance liquid chromatography of tenuazonic acid and related tetramic acids.
abstract: A reversed-phase high-performance liquid chromatographic system for the determination of the fungal toxin, tenuazonic acid, (5S,8S)-3-acetyl-5-sec.-butyltetramic acid, is described. The system utilizes a column packed with deactivated end-capped C18 silica with a high carbon load to overcome the problem of poor chromatographic performance of this beta-diketone on reversed-phase liquid chromatography which previously necessitated the use of anion-exchange, ligand-exchange or ion-pairing methods. The reversed-phase system allows the separation of tenuazonic acid from its (5R,8S)-diastereomer, allo-tenuazonic acid and was applied to the detection of tenuazonic acid in cultures of Alternaria alternata and Phoma sorghina. By means of diode-array ultraviolet detection, (5S)-3-acetyl-5-isopropyltetramic acid was observed in extracts of culture material. This metabolite was purified using the analytical reversed-phase system and was identified by 1H and 13C nuclear magnetic resonance spectroscopy.
authors.affiliation: Research Institute for Nutritional Diseases, South African Medical Research Council, Tygerberg.
authors.forename: G S
authors.initials: GS
authors.lastname: Shephard
authors.forename: P G
authors.initials: PG
authors.lastname: Thiel
authors.forename: E W
authors.initials: EW
authors.lastname: Sydenham
authors.forename: R
authors.initials: R
authors.lastname: Vleggaar
authors.forename: W F
authors.initials: WF
authors.lastname: Marasas
mesh_terms: D000528:Alternaria / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D013237:Stereoisomerism; D013720:Tenuazonic Acid / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry; D013098:Xylariales / Q000378:metabolism
chemical_list: C070660:3-acetyl-5-isopropyltetramic acid; D013720:Tenuazonic Acid