Ferrer M, Cruces M A, Bernabé M, Ballesteros A, Plou F J
Instituto de Catálisis, CSIC, Campus Universidad Autónoma, 28049 Madrid, Spain.
Biotechnol Bioeng. 1999 Oct 5;65(1):10-6. doi: 10.1002/(sici)1097-0290(19991005)65:1<10::aid-bit2>3.0.co;2-l.
The enzymatic synthesis of 6-O-lauroylsucrose and 6-O-palmitoylsucrose was performed by transesterification of sucrose with the corresponding vinyl esters in a medium constituted by two solvents. More specifically, the acylation was carried out in 2-methyl-2-butanol (tert-amyl alcohol) containing a low percentage (not higher than 20%) of dimethyl sulfoxide. Several lipases were able to catalyze the transesterification, but that from Humicola lanuginosa (adsorbed on diatomaceous earth) was particularly useful. We optimized the synthesis of 6-O-lauroylsucrose varying the percentage and nature of the cosolvent, the molar ratio sucrose/vinyl laurate, the nature of bulk solvent and the enzyme content. Under the best conditions (2-methyl-2-butanol/DMSO 4:1 v/v), a sucrose conversion of 70% to 6-O-lauroylsucrose was achieved in 24 h using 50 mg biocatalyst/mL. As a side process, a low percentage (<5% in 24 h) of the initial sucrose is converted into the diesters 6,1'-di-O-lauroylsucrose and 6,6'-di-O-lauroylsucrose. The above methodology was also extended to the synthesis of 6-O-palmitoylsucrose. The acylation process was even faster, giving rise to an 80% conversion to monoester in 48 h using 25 mg biocatalyst/mL. This study shows that the use of two-solvent mixtures may become a feasible alternative for the synthesis of sucrose esters, allowing to exploit the catalytic potential of lipases.
通过在由两种溶剂构成的介质中，使蔗糖与相应的乙烯基酯进行酯交换反应，实现了6-O-月桂酰蔗糖和6-O-棕榈酰蔗糖的酶促合成。更具体地说，酰化反应是在含有低百分比（不高于20%）二甲基亚砜的2-甲基-2-丁醇（叔戊醇）中进行的。几种脂肪酶能够催化酯交换反应，但来自疏棉状嗜热丝孢菌（吸附在硅藻土上）的脂肪酶特别有用。我们通过改变助溶剂的百分比和性质、蔗糖/月桂酸乙烯酯的摩尔比、主体溶剂的性质和酶含量，优化了6-O-月桂酰蔗糖的合成。在最佳条件下（2-甲基-2-丁醇/二甲基亚砜 4:1 v/v），使用50 mg生物催化剂/mL，在24小时内蔗糖转化为6-O-月桂酰蔗糖的转化率达到70%。作为一个副反应，初始蔗糖的低百分比（24小时内<5%）转化为二酯6,1'-二-O-月桂酰蔗糖和6,6'-二-O-月桂酰蔗糖。上述方法也扩展到了6-O-棕榈酰蔗糖的合成。酰化过程甚至更快，使用25 mg生物催化剂/mL，在48小时内单酯转化率达到80%。这项研究表明，使用双溶剂混合物可能成为合成蔗糖酯的一种可行替代方法，从而能够发挥脂肪酶催化潜力。
