Resolution of DL-Phenylalanine by Papain and Immobilized Papain / 中国生物化学与分子生物学报

In order to separate chiral D-phenylalanine from L-phenylalanine,the enzyme catalytic method by papain and immobilized papain were used in this investigation.It indicated that the yield rate of N-acetyl-DL-phenylalanine synthesized from DL-phenylalanine was 88.7%.The ionic strength was the strongest influencing factor in the synthesis of N-acetyl-L-phenylalanylaniline by both papain and immobilized papain on sodium alginate-ehitosan(IPSAC).But the reaction temperature was the strongest influencing factor in the synthesis by immobilized papain on nylon cloth(IPN).The ionic strength and the pH were the important influencing factors in the synthesis.The yield rates of the best synthesis system of N-acetyl-L-phenylalanylaniline by papain,IPSAC,IPN were 61.2%,54.7%,36.3%,respectively.The yield rate of L-phenylalanine from N-acetyl-L-phenylalanylaniline hydrolyzation was 59.2%.The optical purity of the product was 96.6%.The vield rate of D-phenylalanine from N-acetyl-D-phenylalanine hydrolyzation was 61.7%.The optical purity was 95.7%.

Determination of Optical Purity of Lactic Acid by HPLC-CSP / 中国药房

OBJECTIVE:To establish a HPLC-chiral stationary phase(CSP) for separating the enantiomers of lactic acid and determining the optical purity of lactic acid.METHODS:Lactic acid samples of different optical purity were determined by HPLC-CSP vs.optical rotation method.The enantiomers of lactic acid were separated on Chirex 3126(D)-penicillamine chiral column.The mobile phase consisted of copper sulfate solution-isopropyl alcohol (85∶15) at a flow rate of 0.6 mL?min-1.The detection wavelength was set at 254 nm.RESULTS:A baseline separation of the enantiomers of lactic acid was achieved with a separation factor of greater than 1.2.The calibration curve was linear in the range of 0.75～48.24 mg?mL-1 (r=0.999 3),RSD=1.21%.The determination results determined by HPLC-CSP were similar to those determined by optical rotation method.CONCLUSION:The established method is simple,reliable in results and reproducible,and it is applicable for the separation of the enantiomers of lactic acid and determination of the optical purity of lactic acid.