N-苄氧羰基氨基酸配位萃取拆分外消旋苯丙氨酸

以外消旋中性氨基酸苯丙氨酸为研究对象,以N-苄氧羰基手性氨基酸为手性配体,研究其配位萃取拆分特性。着重考察了有机稀释剂、手性配位剂和配位离子种类、被萃取水相中苯丙氨酸初始浓度、萃取时的温度、萃取相pH值等因素对拆分过程的影响。结果表明:以低碳醇类正丁醇作有机稀释剂,所用5种N-苄氧羰基氨基酸(分别为Z-Phe、Z-Hyp、Z-Pro、Z-Glu、Z-Val)与Cu2+或Ni2+形成手性配位体后,以Z-Val作手性配体,萃取相pH值接近苯丙氨酸等电点时,萃取拆分效果最佳.

Resolution of D,L-Phenylalaine by Enantioselective Solvent Extraction with N-Carbobenzyloxy-L-Amino Acid

Resolution of D,L-phenylalanine by ligand exchange extraction, first using N-carbobenzyloxy-L-amino acid as chiral ligand, was studied in this paper. Factors including organic solvent, chiral complex and complex ion, initial phenylalanine concentration in aqueous, extraction temperature, and (extraction) pH were mainly investigated. The experiment results indicate that higher phase splitting speed (and extraction) factor can be achieved when low-carbon alcohols such as n-butanol are used as organic solvents; by using five different N-carbobenzyloxy-L-amino acids as chiral ligands that are formated with Cu~(2+) or Ni~(2+), it is found that as a ligand, Z-Phe has a low extraction factor, while Z-Hyp, Z-Pro, Z-Glu, Z-Val have higher extraction factors, and among these, Z-Val has the highest distribution coefficient; pH value of extractant, when near to the PI of phenylalanine, helps to improve extraction resolution effect; temperature has no obvious effect on the resolution result. The result that extraction factor exceed to 1.5 reveals that extraction resolution with N-carbobenzyloxy-valanine is superior to that with N-n-dodecyl-proline.