title: Kinetic analysis of molecular interconversion of immunosuppressant FK506 by high-performance liquid chromatography.
abstract: High-performance liquid chromatography of FK506, a macrolide immunosuppressant, was performed on a reversed-phase column. The peak was broad with the column kept at room temperature, which was accounted for by slow interconversion between the two forms of FK506. With the use of a heated column, a sharp peak was observed because of the rapid interconversion at high temperature. When the column was cooled to 0 degree C, two sharp peaks were observed because essentially no interconversion occurred at 0 degree C during elution. Analysis of the chromatograms obtained at various eluant flow rates indicated that the conversion of the two forms follows first-order kinetics, and the apparent activation energies for the conversions were calculated. The interconvertibility between the two molecular forms may be related to the immunosuppressive activity.
authors.affiliation: Department of Clinical Pathology, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nishikawa
authors.forename: H
authors.initials: H
authors.lastname: Hasumi
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Kubo
authors.forename: H
authors.initials: H
authors.lastname: Ohtani
mesh_terms: D002851:Chromatography, High Pressure Liquid; D007166:Immunosuppressive Agents / Q000737:chemistry*; D007536:Isomerism; D007700:Kinetics; D008968:Molecular Conformation; D013056:Spectrophotometry, Ultraviolet; D016559:Tacrolimus / Q000737:chemistry*; D013696:Temperature
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus