Candida antartica lipase

Chemo-enzymatic epoxidation of unsaturated fatty acids with aqueous H2O2 has been conducted with considerable success and here we have a remarkable situation that undesirable ring opening of the epoxide does not occur. Excellent activity and stability has been realized with Novozym 435, a Candida antartica lipase B immobilized on polyacryl. This enzyme is readily separable, can be used several times without loss of activity, and has a turnover of more than 2,00,000 moles of products per mole of catalyst (Bierman et al., 2000). 

De Diego, T., Lozano, R, Gmouh, S., Vaultier, M., Iborra, J.L., Understanding structure-stability relationships of Candida antartica lipase B in ionic liquids, Biomacromol., 6,1457-1464, 2005. 

The DKR hydrolysis of thioesters described previously has also been extended to transesterifications in toluene, using triethylamine and Candida antartica lipase.28 This general approach can therefore be applied to the resolution of a wide range of both water-soluble and water-insoluble thioesters by selecting an appropriate solvent, base, and enzyme system. 

To achieve better results a series of lipases was screened using the Chirazyme screening kit and analysis by gas chromatography with a chiral stationary phase. Candida antartica Lipase B, available as Novozyme 435, was chosen for further development with the acyl transfer agent vinyl propionate. 

Candida antartica lipase B Na2C03 (1 mmol) AcOCMe=CH2 (1.5 mmol) toluene, 25 °C... 

Regioselective acylations of polyhydroxylated compounds such as carbohydrates, glycerols, steroids, or alkaloids have been carried out with lipases, esterases, and proteases [13, 20]. One example is the Candida antartica lipase (immobilized on acrylic resin) catalyzed monoacylation of the signalling steroid ectysone (1) giving selectively the 2-C)-acetate 2 (eq. (1)). Using vinyl acetate for this transesterification the reaction was irreversibly pushed to the product side, since the liberated enol instantaneously isomerizes to acetaldehyde [21]. The sometimes unfavorable aldehyde is avoided when 1-ethoxyvinyl acetates [22], trichloro- or -fluoroethyl esters [23 a, b], oxime esters [23 c] or thioesters [23 d] are employed for the quasi-irreversible reaction courses. 

Kumar, A., and Gross, R.A. (2000) Candida antartica lipase B catalyzed polycaprolactone synthesis effects of organic media and temperature. Biomacromolecules, 1, 133-138. 

Diester 275 was prepared according to the method of Ward [111]. Reduction of the diester with lithium aluminium hydride furnished the desired meso diol 276. Diol 276 was subjected to the enzymatic esterification reaction by treatment with Candida antartica lipase (CAL)... 

The synthesis of DPP-IV inhibitor Saxagliptin 5 also required (55)-5-amino-carbonyl-4,5-dihydro-lH-pyrrole-l-carboxylic acid, l-(l,l-dimethylethyl)ester 10 (Figure 16.3C). Direct chemical ammonolyses were hindered by the requirement for aggressive reaction conditions, which resulted in unacceptable levels of amide race-mization and side-product formation, while milder two-step hydrolysis-condensation protocols using coupling agents such as 4-(4,6-dimethoxy-l,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) [41] were compromised by reduced overall yields. To address this issue, a biocatalytic procedure was developed based on the Candida antartica lipase B (CALB)-mediated ammonolysis of (55)-4,5-dihydro-lH-pyrrole-l,5-dicarboxylic acid, l-(l,l-dimethylethyl)-5-ethyl ester 9 with ammonium carbamate to furnish 10 without racemization and with low levels of side-product formation. 

Vaidya, A. Xie, W. Gao, W. Bohling, J.C. Miller, M.E. Gross, R. A. Enzyme immobilization without a support Candida antartica lipase B (CALB) Self-crosslinked aggregates ACS Polymer Preprints, 2006, 47(2), 236. 

Table 1. Candida antartica Lipase B (CALB) immobilization on MM A resins of differing particle size enzyme loading, fraction of active lipase,...

Zhou, Y, Oostenbrink, C., van Maanen, E.M.T., Hagen, W.R., de Leeuw, S.W., Jongejan, J.A. Molecular modeling of the enantioselectivity of Candida antartica lipase b— free energy calculation, J. Comp. Chem, in press. 

Biocatalysts can also be used in the complete absence of water. Candida antartica lipase B (CaLB), used either as the free enzyme or in an immobilized form, catalyzes transesterification, ammonolysis andperhydrolysis. For example, octanoic acid was quantitatively transformed to amide 107 in 4 days (Scheme 46) - a significant rate... 

Lozano P, Pdrez-Mann A B, De Diego T, Gomez D, Paolucci-Jeanjean D, Belleville M P, Rios G M, Iborra J L (2002), Active membranes coated with Candida antartica Lipase B preparation and application for continuous butyl butirate synthesis in organic media , J. Membrane Sci., 201,55-64. 

Enzyme The catalyst used was Novozym 435. It is a Candida Antartica lipase, immobilised on a macroporous acrylic resin. The product consists of bead-shaped particles with the diameter in the range of 0.3-0.9 mm. The product was delivered with the water content of 1-2% w/w. It was kindly donated from Novo Nordisk AS (Copenhagen, Denmark). 

Chiral phosphonous acid diester induces the kinetic resolution of racemic a-substituted y-unsaturated carboxylic acids through asymmetric protolac-tonization (Scheme 53) (130L2838). Dinamic kinetic resolution with Candida antartica lipase B and the ruthenium catalyst [RuCl(CO)2(T -C5Ph5)] of several homoallylic alcohols is applied in the key step to the synthesis of enantiomericaUy pure 5,6-dihydro-2ff-pyran-2-ones ( [13CEJ13859]). 

A popular and effective lipase is Novozym 435, an immobilized Candida antartica Lipase B (CALB), available commercially fi om Novozymes A/S. This enzyme was invoked in at least 11 of the articles in this book (16,20,25-33). 

The modification of polysaccharides using enzymes has been studied to attain more uniformly substituted products under mild reaction conditions. Hydroxyethylcellulose (HEC) particles were suspended in dimethylacetamide and acylated with vinyl stearate using Candida antartica Lipase B (CAL-B) as the catalyst. After 48 hrs, a product with degree of substitution (D.S.) of 0.1 was formed(8). HEC in film or powder form was modified using lipase-catalysis and e-caprolactone (CL) to form low D.S. HEC-g-PCL copolymers(9). Problems that limit the utility of these reactions include the use of polar aprotic solvents that strip the critical water from enzymes lowering their activities(lO) and the use of heterogeneous reaction conditions that restrict the modification of large particles and films to a small fraction of the substrate that resides at die surface. 

Cyclofcts- (decamethylene carbonate) Candida antartica lipase (Novozyme-435), M = 54,000, yield 99% [61]... 

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. 

Various lipases can be used, the most employed being Candida antartica lipase A (CAL-A). Nevertheless, the best results have been obtained with CAL-B immobilized on a Celite R-633 support, yielding 97% of conversion in the synthesis of mandelonitrile acetate 12 with an ee of 98%. Many applications can be envisaged considering that numerous hydrophobic compounds, from aliphatic chains to various aromatics, can be used as substrates, and both (R)- and (5)-enantiomers can be obtained by an appropriate choice of the enzyme (examples of (R)-enantiomers with CAL-A,Burkholderia cepiaca lipase [BCL], Candida rugosa lipase [CRL], " S) with CAL-B, BCL, and porcine pancreas lipase [PPL] " ). 

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