Lipase-catalyzed enantioselective synthesis of (R,R)-lactide from alkyl lactate to produce PDLA (poly D-lactic acid) and stereocomplex PLA (poly lactic acid)

• Published in: Journal of Biotechnology
• Main Authors: Jeon, Byoung Wook, Lee, Jumin, Kim, Hyun Sook, Cho, Dae Haeng, Lee, Hyuk, Chang, Rakwoo, Kim, Yong Hwan
• Format: Article in Journal/Newspaper
• Language: English
• Published: ELSEVIER SCIENCE BV 2016
• Subjects: (R,R)-lactide; Alkyl (R)-lactate; Lipase; Molecular sieve; Novozym 435; Antarc*; Antarctica
• Online Access: https://scholarworks.unist.ac.kr/handle/201301/20351; http://www.sciencedirect.com/science/article/pii/S0168165613002770; https://doi.org/10.1016/j.jbiotec.2013.06.021

R-lactide, a pivotal monomer for the production of poly (D-lactic acid) (PDLA) or stereocomplex poly (lactic acid) (PLA) was synthesized from alkyl (R)-lactate through a lipase-catalyzed reaction without racemization. From among several types of lipase, only lipase B from Candida antarctica (Novozym 435; CAL-B) was effective in the reaction that synthesized (R,R)-lactide. Enantiopure (R,R)-lactide, which consisted of over 99% enantiomeric excess, was synthesized from methyl (R)-lactate through CAL-B catalysis. Removal of the methanol by-product was critical to obtain a high level of lactide conversion. The (R, R)lactide yield was 56% in a reaction containing 100 mg of Novozym 435, 10 mM methyl (R)-lactate and 1500 mg of molecular sieve 5 A in methyl tert-butyl ether (MTBE). The important monomer (R,R)-lactide that is required for the production of the widely recognized bio-plastic PDLA and the PLA stereocomplex can be obtained using this novel synthetic method. close