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.
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.
Desiderio
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Istituto di Cromatografia, C.N.R., Monterotondo Scalo, Roma, Italy.
Fanali
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Sinibaldi
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Polcaro
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D000818:Animals; D001711:Biotransformation; D002845:Chromatography / Q000379:methods*; D002911:Chrysenes / Q000032:analysis* / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D007700:Kinetics; D008823:Micelles; D008862:Microsomes, Liver / Q000378:metabolism*; D008968:Molecular Conformation; D051381:Rats; D047408:gamma-Cyclodextrins
D002911:Chrysenes; D003505:Cyclodextrins; D008823:Micelles; D047408:gamma-Cyclodextrins; C031180:chrysene; C016307:chrysene-1,2-dihydrodiol; C023792:gamma-cyclodextrin