Selectivity of R-α-monobenzoate glycerol synthesis catalyzed by Candida antarctica lipase B immobilized on heterofunctional supports

• DOI: 10.1016/j.procbio.2015.06.025
• Publication Date: 2015-07-10T17:53:02Z
• Authors: N. Guajardo; C. Bernal; L. Wilson; Z. Cabrera
• Keywords: 0106 biological sciences; 01 natural sciences; 3. Good health; 0104 chemical sciences

Abstract The main goal of this work was to study different strategies of immobilization of Candida antarctica lipase B (CALB) in order to evaluate changes in the selectivity of this enzyme when R -α-monobenzoate glycerol ( R -α-MBG) is obtained through of asymmetric esterification. CALB was immobilized on sepharose and silica functionalized with octyl groups (monofunctional supports) and undecanol–glyoxyl and octyl-epoxide groups (heterofunctional supports). Our results showed that the enzyme could be immobilized by all carriers, with activity yields ranging from 52% to 83%. CALB immobilized on silica octyl was the most active (367 IU g −1 biocatalyst ) with immobilization yields in terms of protein and expressed activity of 72% and 50% respectively and exhibited a higher half-life in 100% 1,4-dioxane at 50 °C (85,000 h). In contrast, CALB immobilized on heterofunctional silica support was the most selective biocatalyst, reaching an enantiomeric excess of 99% of R -α-MBG in 100% 1,4-dioxane. In terms of configuration the sepharose biocatalysts results in a S -enantiomer, while silica biocatalysts results in a R -enantiomer. The catalysis of asymmetric esterification of glycerol with benzoic acid to obtain R -α-MBG by CALB immobilized in heterofunctional silica is highly selective and, to our knowledge, is the most selective reported to date.