Cyclodextrin modified micellar electrokinetic chromatography for the chiral direct resolution of (+), (-)-trans-1,2-dihydrodiol metabolite of chrysene in vitro activated by rat liver microsome S9 fraction

• Published in: Electrophoresis Vol. 16; no. 5; p. 784
• Main Authors: Desiderio, C, Fanali, S, Sinibaldi, M, Polcaro, C
• Format: Journal Article
• Language: English
• Published: Germany 1995
• Subjects: Animals; Biotransformation; Chromatography - methods; Chrysenes - analysis; Chrysenes - chemistry; Cyclodextrins - chemistry; Electrophoresis, Polyacrylamide Gel - methods; gamma-Cyclodextrins; Kinetics; Micelles; Microsomes, Liver - metabolism; Molecular Conformation; Rats
• ISSN: 0173-0835
• DOI: 10.1002/elps.11501601128

A gamma-cyclodextrin (gamma-CD) modified electrokinetic micellar capillary chromatography (MEKC) method was used for the enantiomer separation of a racemic trans-1,2-dihydro-1,2-dihydroxy-chrysene (chry-trans-1,2-diOH) mixture. The chiral resolution was strongly influenced by several important parameters: surfactant concentration and addition of organic modifier to the background electrolyte (BGE). An optimized electrophoretic system was used, consisting of the following conditions: 25 mM phosphate buffer, pH 7.8, 50 mM sodium dodecyl sulfate, 20 mM gamma-CD, 7.4% v/v 2-propanol as BGE; the applied voltage, 18 kV, corresponded to 37 microA at a constant temperature of 25 degrees C. This electrophoretic method was applied for monitoring the chry-trans-1,2-diOH enantiomer formation in a real sample, obtained from in vitro metabolic activation of chrysene by phenobarbital-beta-naphthoflavone-induced rat microsomes. The (+) and (-) enantiomers were identified by the racemate and the single enantiomer standard addition method and by spectra comparison with the synthetic compound. Under the experimental conditions used for chrysene activation, the (+) optical isomer was the prevailing form. The CD-MEKC system showed high reproducibility and selectivity, allowing a fast and interference-free analysis even of the in vitro metabolic sample extract, without any pretreatment.