Mathpati Ashwini C, Badgujar Kirtikumar C, Bhanage Bhalchandra M
Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Enzyme Microb Technol. 2016 Mar;84:1-10. doi: 10.1016/j.enzmictec.2015.12.003. Epub 2015 Dec 7.
The present work deals with the kinetic modeling and docking study for the furfuryl acetate synthesis using immobilized Burkholderia cepacia (BCL) lipase. Initially various lipases were immobilized on hydroxypropyl methyl cellulose (HPMC) and poly vinyl alcohol (PVA) base hybrid polymer matrix. After screening of various immobilized biocatalysts, HPMC:PVA:BCL was found to be a robust biocatalyst. Various reaction conditions were optimized using response surface methodology (RSM) based on a four-factor-three-level Box-Behnken design. The optimal conditions were obtained at molar ratio of 1:2 of furfuryl alcohol to acyl donor, temperature 50°C with catalyst loading of 30mg in 3mL of non-aqueous media toluene. Under these conditions 99.98% yield was obtained in 3h. The Arrhenius plot showed that the activation energy for furfuryl acetate synthesis was 10.68kcal/mol. The kinetics of reaction was studied close to optimized conditions which obey order bi-bi model. Molecular docking study was carried out to understand the active site of BCL which is responsible for the reaction. It was observed that the reaction proceeds via acylation of the active serine of BCL and demonstrating strong hydrogen bond between the substrate and histidine site. The catalyst recyclability study was carried up to five cycles.
本研究涉及使用固定化洋葱伯克霍尔德菌（BCL）脂肪酶合成乙酸糠酯的动力学建模和对接研究。最初，将各种脂肪酶固定在羟丙基甲基纤维素（HPMC）和聚乙烯醇（PVA）基混合聚合物基质上。在筛选各种固定化生物催化剂后，发现HPMC:PVA:BCL是一种强大的生物催化剂。基于四因素三水平的Box-Behnken设计，使用响应面方法（RSM）优化了各种反应条件。在糠醇与酰基供体的摩尔比为1:2、温度为50°C、在3mL非水介质甲苯中催化剂负载量为30mg的条件下获得了最佳条件。在这些条件下，3小时内产率达到99.98%。阿累尼乌斯图表明，乙酸糠酯合成的活化能为10.68kcal/mol。在接近优化条件下研究了反应动力学，该反应遵循双底物双产物模型。进行了分子对接研究以了解负责该反应的BCL的活性位点。观察到反应通过BCL活性丝氨酸的酰化进行，并证明底物与组氨酸位点之间存在强氢键。对催化剂的可回收性进行了多达五个循环的研究。
