Polystyrene (PS) nanoparticles were prepared via a nanoprecipitation process. The influence of the pH of the buffer solution used during the immobilization process on the loading of Candida antarctica lipase B (Cal-B) and on the hydrolytic activity (hydrolysis of p-nitrophenyl acetate) of the immobilized Cal-B was studied. The pH of the buffer solution has no influence on enzyme loading, while ...

In enzyme-catalyzed reactions, the choice of solvent often has a marked effect on the reaction outcome. In this paper, it is shown that solvent effects could be explained by the ability of the solvent to act as a competitive inhibitor to the substrate. Experimentally, the effect of six solvents, 2-pentanone, 3-pentanone, 2-methyl-2-pentanol, 3-methyl-3-pentanol, 2-methylpentane and 3-methylpent...

This thesis describes strategies for and examples of cellulose fiber modification. The ability of an engineered biocatalyst, a cellulose-binding module fused to the Candida antarctica lipase B, to catalyze ring-opening polymerization of εcaprolactone in close proximity to cellulose fiber surfaces was explored. The water content in the system was found to regulate the polymer molecular weight, w...

Enantioselective acylation of R-2-pentanol in a solid/gas reactor catalysed by lipase B from Candida antarctica. ABSTRACT The feasibility of the enzymatic enantioselective acylation of R-2-pentanol in a solid/gas reactor was demonstrated and compared to the same reaction carried out in liquid systems. This reaction was catalysed by lipase B from Candida antarctica (CALB) through transesterifica...

The ?-blocker (S)-bisoprolol hemifumarate has been synthesised in 96% enantiomeric excess with 19% total yield a six-step synthesis. A transesterification reaction of the racemic chlorohydrin 1-chloro-3-(4-((2-isopropoxyethoxy)methyl)phenoxy)propan-2-ol catalysed by lipase B from Candida antarctica resulted R-chlorohydrin high purity. Reaction this building block isopropylamine methanol gave (S...

A sustainable enzymatic strategy for the preparation of amides by using Candida antarctica lipase B as biocatalyst and cyclopentyl methyl ether a green safe solvent was devised. The method is simple efficient it produces with excellent conversions yields without need intensive purification steps. scope reaction extended to 28 diverse four different free carboxylic acids seven primary secondary ...

Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol). Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning imp...

The ultrasound-assisted hydrolysis of aspirin methyl ester (AME) was investigated using immobilized Candida antarctica lipase B (CALB) (1%) in the presence of solvents like triolein, chloroform (CHCl3) and dichloromethane (DCM). The effect of ultrasound and the role of water on the conversion rates have also been investigated. Proton nuclear magnetic resonance spectroscopic (1H NMR) was chosen ...

The main objective of the present work was to synthesize and characterize three novel lipase-friendly deep eutectic solvents (DESs) using cholinium dihydrogen phosphate (N1112OHDHP) as hydrogen bond acceptor ethylene glycol (EG) and/or glycerol (GL) donors in following proportions: N1112OHDHP:EG (molar ratio 1:2), N1112OHDHP:GL 1:2) N1112OHDHP:EG:GL 1:1:1). FTIR, 1H NMR, TGA DSC were employed s...