Kinetic resolution of (R,S)-1,2-isopropylidene glycerol (solketal) ester derivatives by lipases

AbstractA study on the enantioselective hydrolysis of (R,S)-1,2-isopropylidene glycerol (4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane, solketal) octanoate catalyzed by different lipases was carried out. Among them, Pseudomonas sp. lipase proved to be the most effective. It was shown that the ester bearing the longer octanoyl acyl chain is a more suitable substrate for this lipase compared to the acetate counterpart. By properly combining enzyme load, temperature and reaction time, either the (S)-alcohol or the remaining ester could be obtained in moderate to high selectivities. Ethyl acetate was found to be the best solvent for the kinetic resolutions effected by such lipase but our results show that toluene may prove useful

Accurel MP 1000 as a support for the immobilization of lipase from Burkholderia cepacia: Application to the kinetic resolution of myo-inositol derivatives

Lipase from Burkholderia cepacia (PS) has been immobilized on Accurel MP 1000, and their performance has been compared to that of the most widely used immobilized commercial preparation of this enzyme. The maximum loading was 18 mg protein/g support, and its thermal and solvent stability was much higher than that of the commercial. PS preparations were used in hydrolysis of triacetin and methyl mandelate, in the esterification of oleic acid and ethanol and in the kinetic resolution of 1,3,4-tri-O-benzyl-myo-inositol (DL-1) using vinylacetate as activated acyl donor. For all reactions studied, PS on Accurel was more active than PS-IM. The conversion in the kinetic resolution of racemic DL-1 was optimized using response surface methodology. Optimal conditions were determined to be 2.0 mg/mL of substrate, temperature of 40 °C, 2.0 mL of vinyl acetate and without water addition. Under these conditions, maximum loaded Accurel-PS preparation permitted to improve the activity in this kinetic resolution compared to the PS commercial preparation by a 55-fold factor, and compared to Novozym 435 (the most active described in literature for this reaction) by a 23-fold factor. The conversion attained was 49.9% ± 0.3 of conversion and ee of 99% after 24 h. The reusability studies showed maintenance of conversion and ee during eight cycles.We gratefully recognize the support from the MINECO of Spanish Government, by the grant CTQ2013-41507-R, and Brazilian FAPERJ, CNPq and CAPES for funding and/or fellowships, including a PVE project for R. Fernandez-Lafuente.Peer Reviewe

Preparation of core-shell polymer supports to immobilize lipase B from Candida antarctica: Effect of the support nature on catalytic properties

Core–shell supports have been prepared and utilized to immobilize lipase B from Candida antarctica. The hydrophobic nature of the supports permitted to immobilize the enzyme via interfacial activation at low ionic strength. Different supports were prepared having different hydrophobicity and crosslinking degree, and compared to the commercially available. Accurel MP 1000 (hydrophobic macroporous polymer of propylene) is a commercial support described as advantageous in different circumstances and it was used as comparative control in the process of immobilization. The immobilized lipase preparations were evaluated in the hydrolysis of p-nitro-phenyl laurate and the esterification of oleic acid with ethanol. On the kinetic resolution of (±)-1,2-O-isopropylidene-3,6-di-O-benzyl-myo-inositol, vinyl acetate was used as activated acyl donor. Results were very diverse, as the lipase properties may be easily tuned via immobilization, and some of the supports permitted to obtain activities even a two fold factor higher than the same amount of lipase immobilized in Accurel MP 1000. Moreover, in many instances, the loading of the support with enzyme produced reduced total activity in some reactions while not in other. This was explained by changes in the physical properties of the support surface that may alter the entry of substrates. Supports PS-co-DVB/PS-co-DVB 25% and PMMA-co-DVB/PMMA-co-DVB 25% presented very good features to immobilize CALB.This work was supported by grants from Petrobras, CNPq and CTQ2009-07568 from Spanish Ministerio de Ciencia e Innovación.Peer Reviewe

Preparation of core-shell polymer supports to immobilize lipase B from Candida antarctica: Effect of the support nature on catalytic properties

Core–shell supports have been prepared and utilized to immobilize lipase B from Candida antarctica. The hydrophobic nature of the supports permitted to immobilize the enzyme via interfacial activation at low ionic strength. Different supports were prepared having different hydrophobicity and crosslinking degree, and compared to the commercially available. Accurel MP 1000 (hydrophobic macroporous polymer of propylene) is a commercial support described as advantageous in different circumstances and it was used as comparative control in the process of immobilization. The immobilized lipase preparations were evaluated in the hydrolysis of p-nitro-phenyl laurate and the esterification of oleic acid with ethanol. On the kinetic resolution of (±)-1,2-O-isopropylidene-3,6-di-O-benzyl-myo-inositol, vinyl acetate was used as activated acyl donor. Results were very diverse, as the lipase properties may be easily tuned via immobilization, and some of the supports permitted to obtain activities even a two fold factor higher than the same amount of lipase immobilized in Accurel MP 1000. Moreover, in many instances, the loading of the support with enzyme produced reduced total activity in some reactions while not in other. This was explained by changes in the physical properties of the support surface that may alter the entry of substrates. Supports PS-co-DVB/PS-co-DVB 25% and PMMA-co-DVB/PMMA-co-DVB 25% presented very good features to immobilize CALB.This work was supported by grants from Petrobras, CNPq and CTQ2009-07568 from Spanish Ministerio de Ciencia e Innovación.Peer Reviewe