title: Resolution of gram quantities of racemates by high-speed counter-current chromatography.
abstract: Gram quantities of (+/-)-dinitrobenzoyl amino acids were separated by high-speed counter-current chromatography (CCC) using N-dodecanoyl-L-proline-3,5-dimethylanilide as a chiral selector (CS). Standard and pH-zone-refining CCC techniques were compared. By using the standard technique, 10 mg to a maximum of 1 g of samples was resolved in 2-9 h simply by increasing the concentration of the CS in the stationary phase. By using pH-zone-refining CCC, even more sample (2 g) was efficiently separated in less time (3 h). In both techniques, leakage of CS from the column was negligible. The method requires no solid support and the same column can be used repeatedly to separate a variety of enantiomers by dissolving appropriate chiral selectors in the stationary phase.
authors.affiliation: Laboratory of Biophysical Chemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: A
authors.initials: A
authors.lastname: Foucault
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification*; D002845:Chromatography / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000031:analogs & derivatives / Q000302:isolation & purification; D008433:Mathematics; D009579:Nitrobenzoates / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D009579:Nitrobenzoates; C051872:N-(3,5-dinitrobenzoyl)leucine; D007930:Leucine