Abdul Rahman Mohd Basyaruddin, Chaibakhsh Naz, Basri Mahiran
Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Malaysia.
Biotechnol Res Int. 2011;2011:162987. doi: 10.4061/2011/162987. Epub 2011 Dec 27.
Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol). Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning important reaction parameters which include time, temperature, substrate molar ratio, and amount of enzyme. Reactions under optimized conditions has yielded a high percentage of esterification (>96%) for n-butanol, iso-butanol, and sec-butanol, indicating that extent of esterification is independent of the alcohol structure for primary and secondary alcohols at the optimum conditions. Minimum reaction time (135 min) for achieving maximum ester yield was obtained for iso-butanol. The required time for attaining maximum yield and also the initial rates in the synthesis of di-n-butyl and di-sec-butyl adipate were nearly the same. Immobilized Candida antarctica lipase B was also capable of esterifying tert-butanol with a maximum yield of 39.1%. The enzyme is highly efficient biocatalyst for the synthesis of adipate esters by offering a simple production process and a high esterification yield.
固定化南极假丝酵母脂肪酶B（诺维信435）被用作生物催化剂，用于己二酸与四种不同丁醇异构体（正丁醇、仲丁醇、异丁醇和叔丁醇）的酯化反应。采用响应面法，通过四因素五水平的中心复合设计，针对包括时间、温度、底物摩尔比和酶量在内的重要反应参数，获得了己二酸酯合成的最佳条件。在优化条件下的反应中，正丁醇、异丁醇和仲丁醇的酯化率较高（>96%），这表明在最佳条件下，伯醇和仲醇的酯化程度与醇的结构无关。异丁醇达到最大酯产率所需的最短反应时间为135分钟。获得最大产率所需的时间以及合成己二酸二正丁酯和己二酸二仲丁酯的初始速率几乎相同。固定化南极假丝酵母脂肪酶B也能够使叔丁醇酯化，最大产率为39.1%。该酶通过提供简单的生产工艺和高酯化产率，是合成己二酸酯的高效生物催化剂。
