TY - JOUR
T1 - Hydrolytic resolution of (R,S)-3-hydroxy-3-phenylpropionates by esterase from Klebsiella oxytoca
T2 - Effects of leaving alcohol, covalent immobilization and aqueous pH
AU - Wang, Pei Yun
AU - Tsai, Shau Wei
PY - 2009/7
Y1 - 2009/7
N2 - The kinetic analysis for hydrolytic resolution of (R) and (S)-ethyl 3-hydroxy-3-phenylpropionate in biphasic media is carried out via a thermally stable esterase (SNSM-87) from Klebsiella oxytoca. The resultant kinetic constants are compared with those using (R,S)-ethyl 2-substituted carboxylic acid ester as the substrate. An optimal enantioselectivity of VS/VR = 16 for 4 using free SNSM-87 is rationalized via the structure-reactivity correlations in terms of logarithms of specificity constants varied with the inductive parameter of leaving alcohol moiety, and can further increase to an acceptable value of VS/VR = 37 using SNSM-87 immobilized on Sepabeads@ EC-HA. The pH-reactivity profiles for all enzyme preparations are analyzed in order to elucidate the modest enantioselectivity of VS/VR = 26 for 2 containing a 3-hydroxy moiety in comparison with VS/VR = 323 for (R,S)-ethyl 2-hydroxy-2-phenylacetate containing a 2-hydroxy moiety using SNSM-87 immobilized on Eupergit C 250L.
AB - The kinetic analysis for hydrolytic resolution of (R) and (S)-ethyl 3-hydroxy-3-phenylpropionate in biphasic media is carried out via a thermally stable esterase (SNSM-87) from Klebsiella oxytoca. The resultant kinetic constants are compared with those using (R,S)-ethyl 2-substituted carboxylic acid ester as the substrate. An optimal enantioselectivity of VS/VR = 16 for 4 using free SNSM-87 is rationalized via the structure-reactivity correlations in terms of logarithms of specificity constants varied with the inductive parameter of leaving alcohol moiety, and can further increase to an acceptable value of VS/VR = 37 using SNSM-87 immobilized on Sepabeads@ EC-HA. The pH-reactivity profiles for all enzyme preparations are analyzed in order to elucidate the modest enantioselectivity of VS/VR = 26 for 2 containing a 3-hydroxy moiety in comparison with VS/VR = 323 for (R,S)-ethyl 2-hydroxy-2-phenylacetate containing a 2-hydroxy moiety using SNSM-87 immobilized on Eupergit C 250L.
KW - (R,S)-3-Hydroxy-3-phenylpropionates
KW - Hydrolytic resolution
KW - Immobilized enzymes
KW - Klebsiella oxytoca esterase
UR - http://www.scopus.com/inward/record.url?scp=64649091702&partnerID=8YFLogxK
U2 - 10.1016/j.molcatb.2009.01.001
DO - 10.1016/j.molcatb.2009.01.001
M3 - 文章
AN - SCOPUS:64649091702
SN - 1381-1177
VL - 59
SP - 70
EP - 75
JO - Journal of Molecular Catalysis B: Enzymatic
JF - Journal of Molecular Catalysis B: Enzymatic
IS - 1-3
ER -