Covalently Immobilized Lipase on a Thermoresponsive Polymer with an Upper Critical Solution Temperature as an Efficient and Recyclable Asymmetric Catalyst in Aqueous Media

• Published in: ChemCatChem Vol. 10; no. 5; pp. 1166 - 1172
• Main Authors: Lou, Lan‐Lan, Qu, Huaxin, Yu, Wenjun, Wang, Bei, Ouyang, Lezi, Liu, Shuangxi, Zhou, Wuzong
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 07.03.2018
• Subjects: Acrylamide; Catalysts; Catalytic converters; Decantation; Enantiomers; Enzymes; Glutaraldehyde; Immobilization; kinetic resolution; Lipase; lipase from Pseudomonas cepacia; thermoresponsive polymers; upper critical solution temperature
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201701512

A thermoresponsive lipase catalyst with an upper critical solution temperature (UCST) of about 26 °C was exploited by covalent immobilization of an enzyme, Pseudomonas cepacia lipase (PSL), onto poly(acrylamide‐co‐acrylonitrile) by glutaraldehyde coupling. The experimental conditions for the PSL immobilization were optimized. The immobilized PSL was much more stable for wide ranges of temperature and pH than free PSL. The material was also evaluated as an asymmetric catalyst in the kinetic resolution of racemic α‐methylbenzyl butyrate at 55 °C in an aqueous medium and exhibited high catalytic performance and stability. Up to 50 % conversion and 99.5 % product enantiomeric excess were achieved, thus providing highly pure enantiomers. This biocatalyst could be easily recovered by simple decantation for reuse based on temperature‐induced precipitation. It showed good reusability and retained 80.5 % of its original activity with a well reserved enantioselectivity in the 6th cycle. This work would shed light on the future development of new UCST‐type enzyme catalysts. Thermoresponsive lipase catalyst: A UCST‐type thermoresponsive polymer–lipase conjugate was exploited and applied as an asymmetric biocatalyst in the kinetic resolution of racemic α‐methylbenzyl butyrate, exhibiting high catalytic performance, easy recovery, and good durability.