Candida ring-opening polymerization

Various cyclic esters have been subjected to hpase-catalyzed ring-opening polymerization. Lipase catalyzed the ring-opening polymerization of 4- to 17-membered non-substituted lactones.In 1993, it was first demonstrated that medium-size lactones, 8-valerolactone (8-VL, six-membered) and e-caprolactone (e-CL, seven-membered), were polymerized by lipases derived from Candida cylindracea, Burkholderia cepacia (lipase BC), Pseudomonas fluorescens (lipase PF), and porcine pancreas (PPL). °... 

In polyester synthesis via ring-opening polymerizations, metal catalysts are often used. For medical applications of polyesters, however, there has been concern about harmful effects of the metallic residues. Enzymatic synthesis of a metal-free polyester was demonstrated by the polymerization of l,4-dioxan-2-one using Candida antarctica lipase (lipase CA). Under appropriate reaction conditions, the high molecular weight polymer (molecular weight = 4.1 x 10" ) was obtained. 

Baum, I., Schwab, L., Loos, K., and Fels, G. (2010), Mechanistic insight into the enzymatic ring-opening polymerization of unsubstituted P-lactam catalyzed by Candida antarctica lipase B, submitted for publication. 

In recent years, the enzymatic synthesis of biodegradable polyesters was focused on the polycondensation method (22,23). Among the very few successful example of enzymatic ring-opening polymerization for polyesters synthesis, Novozyme-435 (immobilized lipase B from Candida antartica) has been proved an effective catalyst for polycaprolactone (PCL) synthesis in toluene (24). Considering the low cost and high recyclablity of IPPL, we also... 

Hiroshi et al. reported [46] a high-performance immobilized lipase catalyst for polyester synthesis. A porous polypropylene was found to be a good support for immobilization of Candida antarctica lipase (enzyme). The immobilized lipase on polypropylene efficiently catalyzes ring opening polymerization of 15-pentadecanolide, polycondensation of divinyl sebacate, and 1,8-octanediol. 

Soiventless Enantioelective Ring-Opening Polymerization of Substituted e-Caprolactones by Novozym-435 (from Candida antartica) Catalysis... 

Fujioka et al. [100] conducted the ring-opening polymerization of L-lactide by using immobilized lipase Candida Antarctica (Novozym 435) as a catalyst at a... 

For example Kumar, A., and Gross, R. A., 2000, Candida antarctica Lipase B-Catalyzed Transesterification New Synthetic Routes to Copolyesters. J. Am. Chem. Soc. 122 11767-11770 Kumar, A., and Gross, R. A., 2000, Candida antartica lipase B catalyzed polycaprolactone synthesis effects of organic media and temperature. Biomacromolecules 1 133-138 Kobayashi, S, Uyama, H., Namekawa, S., and Hayakawa, H., 1998, Enzymic Ring-Opening Polymerization and Copolymerization of 8-Octanolide by Lipase Catalyst. Macromolecules 31 5655. 

Based on the specific reaction that they catalyze, enzymes have been classified into six groups, three of which have been reported to catalyze or induce polymerization in vitro, namely oxidoreductases, transferases and hydrolases. The latter class includes hpases, the natural role of which is the hydrolysis of fatty acid esters at the cell s water-Upid interface. In organic media, hpases can efficiently catalyze ester bond formation, and so have been used extensively in investigations of the in vitro synthesis of polyester by polycondensation or ring-opening polymerization (ROP), without the need for any cocatalyst. One enzyme that deserves special attention when discussing enzymatic ROP is Candida antarctica Lipase B (CALB). 

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