title: Isolation of doxycycline, 6-epidoxycycline and 2-acetyl-2- decarboxamidometacycline from commercial metacycline by preparative column liquid chromatography on silica gel.
abstract: Isolation of doxycycline, 6-epidoxycycline and 2-acetyl-2-decaboxamidometacycline from commercial metacycline was achieved by preparative column liquid chromatography on silica gel, previously impregnated with edetate (EDTA). Careful control of the pH of EDTA allowed fine tuning of the separation. The mobile phases were composed of dichloromethane, methanol and .1 mM EDTA at pH 9.0 or 6.0. Structures were confirmed with nuclear magnetic resonance spectroscopy. The presence of doxycycline and its 6-epimer in commercial metacycline has not previously been described. The presence of the 2-acetyl derivative was not surprising since analogous 2-acetyl derivatives have been identified in other tetracyclines.
authors.affiliation: Katholieke Universiteit Leuven, Institut voor Farmaceutische Wetenschappen, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Naidong
authors.forename: K
authors.initials: K
authors.lastname: Verresen
authors.forename: R
authors.initials: R
authors.lastname: Busson
authors.forename: E
authors.initials: E
authors.lastname: Roets
authors.forename: J
authors.initials: J
authors.lastname: Hoogmartens
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004318:Doxycycline / Q000302:isolation & purification; D004340:Drug Contamination / Q000517:prevention & control; D008690:Methacycline / Q000302:isolation & purification*; D058428:Silica Gel; D012822:Silicon Dioxide; D013754:Tetracyclines / Q000302:isolation & purification*
chemical_list: D013754:Tetracyclines; D058428:Silica Gel; D012822:Silicon Dioxide; D008690:Methacycline; D004318:Doxycycline