Study On The Application Of Rosin Chiral Derivatization Reagents In Enantioseperation By Capillary Electrophoresis

Chirality is universal phenomenon in nature. Many substance (including drugs) own chiral center. Amino acids are important biological compounds that are associated with peptides, proteins and enzymes. The D and L enantiomer of amino acid plays different role in the process of absorbency, digest, metab-olism and secretion in the organism for their different symmetry and optics act-ivity. And their functions in the course of the transferring of nerve information, adjusting of metabolize pathway, and the sythesis of peptides and proteins are vary. In the fields of medicine and pharmaceutics, there are 1850 drugs(inclu-ding natural and synthetical drugs) in the world and 1045 of them possess chi-ral center. Though the pharmacological activity is restricted to one of the enan-tiomers and unwanted side effects or even toxic effect can occur with the seco-nd enantiomer. Therefore chiral analysis of D,L-enantiomers is of great interest and of increasing importance in life science and many other related fields. In this paper, rosin chiral derivatization reagents were firstly applied to the enantioseperation by capillary electrophoresis. The derivatization and separ-ation conditions of amino acids, dopa and vigabatrin enantiomers were studied, and the new methods for indirect chiral separation of amino enantiomers by capillary electrophoresis were established. Vigabatrin enantiomers in the human plasma were also analysed. The research results are as follows: 1. The amino acids and dopa enantiomers were derivatized by the new chiral reagent, dehydroabietylisothiocyante. And the derivatives were separated in the nonchiral environment by capillary electrophoresis. The derivatives of amino acids can be separated in 50 mmol/L borate (pH 9.5) containing 5 mmol/L sodium dodecyl sulfate(SDS)and 20% CH3CN. The separation of dopa derivatives was performed in a buffer system containing 50 mmol/L Na2HPO4 (pH 8.0), 17 mmol/L SDS and 25% CH3CN. The effect of the additives, pH and the concentration of buffer, the temperature of capillary and the applied voltage on the migration time and resolution was discussed, and the optimal seperation condition was established. The resolutions of five DL-amino acids derivatives were in the range of 0.9-2.0, the resolution of dopa derivative was 1.4 . 2. The dehydroabietylisothiocyante was applied to derivatize the vigabatrin enantiomers, and the separation of the derivatives by capillary electrophoresis was detailedly studied. It was found that the derivatives obtained well separation in the nonchiral medium. And the optimal seperation condition was: 50 mmol/L Na2HPO4 (pH 9.0), containing 25%CH3CN and 17 mmol/L SDS, the applied voltage was 20 kV, and the temperature of capillary was 20℃. The separation of vigabatrin enantiomers in human plasma was analysed and the resolution was 2.1, and good reproducibility, precision and accuracy (96.7-108%) were obtained by using this method. 3. Amino acids enantiomers were reacted with another rosin chiral derivatization reagent, degrading-dehydroabietylisothiocyante. The derivatives were separation in nonchiral environment by capillary electrophoresis. The CE running buffer consisted of 50 mmol/L Na2HPO4 (pH 9.0), 18 mmol/L SDS and 25%CH3CN. The derivatazation conditions were optimized , the effect of the additive, pH and the concentration of buffer, the temperature of capillary and the applied voltage on seperation was studied. In the selected seperation condition, night amino acid enantiomers derivatives were seperated within 26 minutes, and the resolution were in the range of 0.95-8.9. The method has also been applied to the determination of vigabatrin enantiomers in plasma.