Enantioresolution of DL-selenomethionine by thin silica gel plates impregnated with (-) quinine and reversed-phase TLC and HPLC separation of diastereomers prepared with difluorodinitrobenzene based reagents having L-amino acids as chiral auxiliaries

摘要

(-)-Quinine was used as a chiral selector by adopting three approaches in TLC for direct enantioresotu of DL-selenomethionine; these included impregnation of plate by chiral selector and its use as CMPA. Ef of pH, temperature and concentration of chiral selector on enantioresolution is studied. The spots detected with ninhydrin and iodine vapors. Optically pure amino acids L-phenylalanine, S-benz cysteine, and L-methionine were used to synthesize chiral derivatizing reagents (CDRs) based fluorodinitrobenzene; these CDRs were used to synthesize diastereomers of DL-selenomethionine nucleophilic substitution of the remaining fluorine atom in these reagents under microwave irradia for 55 s at 75% (of 800 W) and also by stirring for 50 min at 45 °C. The diastereomers were separatee reversed-phase high-performance liquid chromatography on a C_(18) column with detection at 340 using aq. triftuoroacetic acid and acetonitrile as mobile phase under gradient elution while triethylamine buffer and acetonitrile was successful as mobile phase for separation of diastereomer reversed-phase thin layer chromatography. The conditions of derivatization and chromatograi separation were optimized. The method was validated for accuracy, precision, limit of detection and I of quantification.