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Acetylation of vitamin E by Candida antarctica lipase B immobilized on different carriers

Paper ID Volume ID Publish Year Pages File Format Full-Text
35586 45097 2008 9 PDF Available
Title
Acetylation of vitamin E by Candida antarctica lipase B immobilized on different carriers
Abstract

We describe for the first time the enzymatic acylation of the phenolic group of tocopherols (vitamin E) by transesterification with vinyl acetate in 2-methyl-2-butanol (2M2B). Out of 15 hydrolases screened, only the lipase B from Candida antarctica (Novozym 435) catalyzed the acylation. The acetylation of δ-tocopherol was faster than that of α-tocopherol, probably due to its lower methylation degree. A series of experiments using (R)-Trolox and p-cresol as competitive acceptors of tocopherols showed that reaction rate notably diminished when increasing acceptor size. To maximize the potential of this reaction, three immobilization carriers for C. antarctica lipase B were studied: the ion-exchange resin Lewatit (the support in Novozym 435), a biodegradable polymer (Purasorb) and polypropylene (Accurel EP100). The acetylation of α-tocopherol was faster with the enzyme immobilized in polypropylene, which was correlated with its higher porosity. A mixture hexane/2M2B 90:10 (v/v) was found to be the optimum medium composition, as it represents a compromise between substrates solubility and biocatalyst efficiency. The acylation process was no enantioselective, probably due to the fact that the chiral centers are separated from the phenolic group by a minimum of six bonds.

Keywords
Immobilization; Lipases; Transesterification; Novozym 435; Tocopherols; Antioxidants modification
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Acetylation of vitamin E by Candida antarctica lipase B immobilized on different carriers
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Publisher
Database: Elsevier - ScienceDirect
Journal: Process Biochemistry - Volume 43, Issue 2, February 2008, Pages 145–153
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us