Novel approach to the study of the chiral discrimination.  Mechanism in a series of imidazole derivatives using HPLC.
In high performance liquid chromatography (HPLC) using poly (octadecylsiloxane) as a stationary phase, phosphate buffer as a mobile phase, a series of R-S imidazole derivatives as solutes, and beta-CD (beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD) as chiral selectors, a study on the hydrophobic effect on both the solute complexation with the chiral selector and chiral discrimination mechanisms was carried out by varying the sucrose concentration c in the mobile phase and the column temperature T. An original mathematical treatment was developed to calculate the degree of complexation, rho (the percent of complexed guest solute), and the number of sucrose molecules excluded from both the uncomplexed solute-RP18 stationary phase interface (when the solute transfer occurred) and the solute-CD interface during the complexation process. This number of sucrose molecules was an image of the relative intensity of the hydrophobic effect and the inclusion degree of the solute in the chiral selector. Different Van't Hoff plot shapes of the degree of complexation and sucrose molecule number were observed with beta-CD and HP-beta-CD indicating a change in the solute inclusion and chiral discrimination.
Guillaume
Y C
YC
Laboratoire de Chimie Analytique, Faculté de Médecine et de Pharmacie, Place Saint-Jacques, 25030 Besançon, France.
Robert
J F
JF
Guinchard
C
C
D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D003505:Cyclodextrins; D007093:Imidazoles / Q000737:chemistry* / Q000302:isolation & purification; D007202:Indicators and Reagents; D015203:Reproducibility of Results; D013237:Stereoisomerism; D013696:Temperature; D047392:beta-Cyclodextrins
D000935:Antifungal Agents; D003505:Cyclodextrins; D007093:Imidazoles; D007202:Indicators and Reagents; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C031215:betadex