The use of enzymes to catalyze chemical reactions has increased these recent years. Several models have been developed express the kinetics over biocatalysts. most well-known them, Michaelis-Menten, is used when only one substrate adsorbs on enzyme. In case esterification reaction, i.e., bimolecular system, a more complex kinetic model such as Ping-Pong Bi-Bi should be applied. advanced essenti...

Este trabalho avaliou a influência de fatores que afetam a síntese de ésteres glicéricos, tais como: razão molar entre os reagentes, fonte de lipase e tipo de agente de ativação do suporte obtido pela técnica sol-gel. Foram empregadas preparações comerciais de lipases imobilizadas em partículas de polissiloxano-álcool polivinílico (POS-PVA) previamente ativadas com diferentes agentes (glutarald...

The enzymatic transesterification of several triand tetrasaccharides with vinyl laurate is described. The lipases from Candida antarctica B (Novozym 435) and Thermomyces lanuginosus (Lipozyme TL IM) and the alkaline protease from Bacillus licheniformis (subtilisin Carlsberg) have been used with each carbohydrate to obtain different regioisomers. By using the sugars in their amorphous form, comp...

Ammonolysis of fatty acids to the corresponding fatty acid amides is efficiently catalysed by Candida antartica lipase (Novozym 435). In the present paper lipase-catalysed synthesis of erucamide by ammonolysis of erucic acid and urea in organic solvent medium was studied and optimal conditions for fatty amides synthesis were established. In this process erucic acid gave 88.74 % pure erucamide a...

In this paper, extensive study of ring-opening polymerization ε-caprolactone (ε-CL) using lipase Novozym 435 as catalyst in flask level and reactor level were conducted. The polymerization rates increase with an increase in time up to 4 h after which there has been a steep decrease for all temperature from 50 to 100 °C in the flask level. The conclusion out of flask level and reactor level stud...

Herein, an efficient epoxidation of 1-nonene is described. In a simple epoxidation system, commercially available Novozym 435, an immobilized Candida antarctica lipase B, and hydrogen peroxide (H(2)O(2)) were utilized to facilitate the in situ oxidation of phenylacetic acid to the corresponding peroxy acid which then reacted with 1-nonene to give 1-nonene oxide with high yield and selectivity....

The use of immobilized lipase from Candida antarctica (Novozym 435) to catalyze ferulic acid of esterification was investigated in this study. The synthesis product was analyzed using HPLC. The results revealed that the major product was 2-ethylhexyl ferulate. Response surface methodology and 3-level-3-factor central composite rotatable design were adopted to evaluate the effects of synthesis v...

An improved gram-scale synthesis of Bn5CpRu(CO)2Cl is reported based on heating of pentabenzylcyclopentadiene with Ru3(CO)12 at 160 °C under argon atmosphere in mesitylene followed by addition of chloroform, continued heating, and evaporation of the solvents. Subsequent washing of unreacted ligand precursor with hexane provided pure title compound in 77 % yield. In combination with Candida anta...

We have studied experimentally within the pH range of 3.65-5.5 at 50 degrees C the hydrolysis of cellobiose with Novozym 188, a commercial product with high beta-1,4-glucosidase activity derived from Aspergillus niger. We used wide variations in the conversion to be able to apply the integral method and thus determine that there is substrate and mixed product inhibition. Whether the SES triple ...

In this study, we developed a metal-free biosynthetic strategy of enzymatic polymerization to fabricate aliphatic poly(pentamethylene carbonate) (PPMC). Novozym-435 lipase showed considerably high catalytic efficiency, and high molecular weights (Mn) of up to 6.0 104 g mol 1 were readily achieved through the ring-opening polymerization of cyclobis(pentamethylene carbonate). The reaction paramet...