RESUMO
We report here the application of subcritical water in chiral separations on two popular polysaccharide chiral stationary phases (CSPs): Chiralpak AD and Chiralcel OD. The behavior of these two CSPs was studied under reversed phase conditions at room temperature to discover the maximum percentage of water in the mobile phase, which provided the separation of enantiomers of flavanone and benzoin, respectively, in a reasonable time (i.e., less than 1 h). Then, the stability of Chiralpak AD and Chiralcel OD versus temperature was investigated and discussed. Chiralcel OD separation of flavanone racemate was obtained at 120 °C with water and 2-propanol (80/20) as the mobile phase, while benzoin racemate was separated in pure water at 160 °C. Separations of several racemates were also presented, and advantages and limitations of the technique were discussed.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , 2-Propanol/química , Amilose/análogos & derivados , Amilose/química , Benzoína/química , Cromatografia/métodos , Química Verde , Peso Molecular , Compostos Orgânicos/química , Fenilcarbamatos/química , Polissacarídeos/química , Solventes/química , Estereoisomerismo , Temperatura , Termodinâmica , Água/químicaRESUMO
The beta-adrenergic agonist 1 (zilpaterol) is used as production enhancer in cattle. Binding experiments of separated enantiomers on recombinant human beta(2)-adrenergic and mu-opioid receptors and functional studies showed that the (-)-1 enantiomer accounts for essentially all the beta(2)-adrenergic agonist activity and that it exhibits less affinity toward the mu-opioid receptor than (+)-1, which is a mu-opioid receptor antagonist. X-ray crystallography revealed the absolute configuration of (-)-1 to be 6R,7R.
