title: Separation of keto-enol tautomers of chlortetracycline and 4-epichlortetracycline by liquid chromatography on poly(styrene-divinylbenzene)copolymer.
abstract: Keto and enol tautomers of chlortetracycline and 4-epichlortetracycline were successfully separated by low temperature high-performance liquid chromatography on poly(styrene-divinylbenzene)copolymer. The keto-enol tautomerism occurs between C-11a and C-12. The elucidation of the chemical structure of the tautomers was realized with the help of on-line and off-line UV-spectrophotometry and of 13C and 1H NMR spectrometry. The kinetics of the equilibrium reaction were investigated.
authors.affiliation: Katholieke Universiteit Leuven, Instituut voor Farmaceutische Wetenschappen, Belgium.
authors.lastname: Weng Naidong
authors.forename: E
authors.initials: E
authors.lastname: Roets
authors.forename: R
authors.initials: R
authors.lastname: Busson
authors.forename: J
authors.initials: J
authors.lastname: Hoogmartens
mesh_terms: D002021:Buffers; D002751:Chlortetracycline / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007536:Isomerism; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011137:Polystyrenes; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D002021:Buffers; D007202:Indicators and Reagents; D011137:Polystyrenes; C003771:Amberlite XAD-2 resin; D002751:Chlortetracycline