| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 89 === Optical active phenylglycine (PG) is important in medical, agriculture and food industries. The stereoselectivity of enzyme is employed for the hydrolysis of DL-benzylcarbonyl-PG ethyl ester. PG is insoluble in non-polar solvent, amino group of PG is protected by benzylcarbonyl group for increasing the solubility of PG in solvent. The effects of reaction conditions on the reaction rate and enantionselectivity of the hydrolysis of DL-benzylcarbonyl-PG ethyl ester were investigated.
When 100 mg Rhizopus delemar lipase was used as the catalyst , with hexane as the solvent and at a reaction temperature of 37℃, the conversion is 47.9 % after 12 h with enantioexcess (ees) and enantioselectivity (E) of 88.9 % and 170.6, respectively. If the lipase is immobilized, the same conversion can be attained within 6 h with E value of ca. 100 which is independent of the amount of immobilized enzyme. The hydrolysis of DL-benzylcarbonyl-PG ethyl ester can be described by Michaelis-Menten kinetics with Vmax = 0.128μmol ester/h mg enzyme and Km = 0.43 mM.
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