Search

In this study, a Taguchi experimental design was used for optimzing the immobilization of the lipase Eversa® Transform 2.0 (EVS) onto a hybrid support consisting of chitosan (CHI) and agarose (AGA), with glutaraldehyde (GLU) used as the support activator. The biocatalyst obtained was characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TGA), Energy Dispersive Spectroscopy (EDS), and Scanning Electron Microscopy (SEM). The optimized reaction conditions (60 min, 5 mM ionic strength, 1% GLU concentration, and 5 mg protein load per g of support) resulted in a highly active biocatalyst (74.39 ± 0.48 U/g) and delivered an immobilization yield of 74.20 ± 0.28%. The biocatalyst produced was observed to lose only 15.3% of its activity after 61 days of storage. The activity was also observed to increase by 96.70% ± 0.76, 27.34% ± 2.34, and 84.35% ± 1.68 in the presence of the organic solvents hexane, cyclohexane, and methanol, respectively. Additionally, the byocatalist showed more pronounced activity at temperatures above 50 °C and was still able to retain approximately 30% of it at 70 °C. These values were found to be higher at alkaline pHs, as the activity of Eversa® 2.0 Transform saw an increase of up to 140% at pH 9. The desorption tests performed did not reveal any enzymatic detachment from the support. The novel biocatalyst also showed promising ester-lubricating properties. Furthermore, the in silico study revealed a binding affinity of −5.1 kcal/mol between oleic acid and the enzyme, suggesting that the combination of the substrate and the lipase was more stable and therefore, suitable for esterification. [ABSTRACT FROM AUTHOR]

Kaolin is a mineral composed of hydrated aluminum silicates, clayey and with high bioavailability. The choice of this mineral as immobilization matrix took into account these aspects mentioned above and its high surface area conducive to enzymatic immobilization, containing many OH- binding groups on its surface. Subsequently, the kaolin was functionalized with carboxymethylcellulose and polyethyleneimine (K-CMC-BPEI) and activated with Glutaraldehyde (K-CMC-BPEI-GLU) as a support to immobilize CAL-A. The K-CMC-BPEI-GLU@CAL-A was characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TGA), and Scanning Electron Microscopy (SEM). K-CMC-BPEI-GLU@CAL-A, in the temperature range of 50–80 ºC, has a half-life 2–3 times longer than soluble CAL-A, that is, the immobilization process conferred greater stability thermal to the biocatalyst. Furthermore, docking studies showed that the immobilization of CAL-A on the support surface was favorable, since CAL-A has binding affinity to the protein-anchored ligand, estimated at −4.3 to −3.7 kcal/mol. Experiments were performed to verify the catalytic potential of K-CMC-BPEI-GLU@CAL-A at a kinetic resolution of rac -1-(triisopropylsilyl) penta-1,4-diyn-3-ol (1) in an organic medium via an acylation reaction. All experiments yielded the product ((R)- 1 -Ac) with an excellent enantiomeric excess (ee >99%) and enantioselectivity (E > 200). [Display omitted] • Kaolin has been modified with carboxymethylcellulose and polyethyleneimine. • Taguchi method optimizes the immobilization of lipase A from Candida antarctica. • The half-life of CAL-A by 2–3 times over the temperature range 50 – 80 °C. • Molecular coupling was conducted to the interaction between glutaraldehyde /enzyme. • The kinetic resolution of rac-1-(triisopropylsilyl)penta-1,4-diyn-3-ol was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Taguchi design-assisted Co-immobilization of Lipase. • Co-immobilization of Lipase A and B from Candida antarctica onto Chitosan (CALA-CALB-CHI). • CALA-CALB-CHI derivative evaluated in the kinetic resolution of halohydrins acetates. • (S)-chlorohydrin 3b produced with 98% ee, conversion of 46% and E > 200. • Molecular docking was performed to elucidate the hydrolysis interaction reaction. In the present communication, the simultaneous co-immobilization by covalent binding of lipase A from Candida antarctica (CALA) and lipase B from Candida antarctica (CALB) in glutaraldehyde (GLU) activated chitosan (CHI) was optimized using the Taguchi method. Under optimized conditions (pH 9, 5 mM, 6:1 (protein load/g of support and 1 h), it was possible to reach 80.00 ± 0.01% for the immobilization yield (IY) and 46.01 ± 0.35 U/g for the activity of the derivative (AtD); in this case, load protein and ionic strength were the only statistically significant parameters and, therefore, those that most influenced the immobilization process. Furthermore, at pH 7, CALA-CALB-CHI had a half-life 2–6 times longer than the mixture of CALA and CALB for a temperature range of 50−80 °C. CALA-CALB showed the highest activity at pH 7, whereas CALA-CALB-CHI, except at pH 7, was more active than the soluble lipase mixture in the pH range (5–9), especially at pH 9. CHI, CHI-GLU, and CALA-CALB-CHI were characterized by X-ray powder diffraction (XRPD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Thermogravimetry (TGA), and Energy Dispersive Spectroscopy (EDS), proving the immobilization of CALA and CALB in chitosan. CALA-CALB-CHI derivative evaluated in the kinetic resolution of halohydrins acetates rac -2-bromo-1-(2-chlorophenyl) ethyl acetate (2a) and rac -2-chloro-1-(2,4-dichlorophenyl) ethyl acetate (2b), to produce the corresponding halohydrins 3a-b , which are intermediates in the synthesis of the drugs chlorprelanine (antiarrhythmic) and luliconazol (antifungal), respectively. (S)-bromohydrin 3a was obtained with 79% enantiomeric excess (ee), whereas (S)-chlorohydrin 3b produced with 98% ee , conversion of 46% and E > 200. Additionally, molecular docking was performed to elucidate the hydrolysis interaction reaction between β-halohydrin acetates and lipases CALA-CALB. [ABSTRACT FROM AUTHOR]