Department of Biotechnology, Southern Taiwan University, Tainan, Taiwan.
Biotechnol Lett. 2011 Nov;33(11):2247-53. doi: 10.1007/s10529-011-0692-7. Epub 2011 Jul 10.
Isooctane was the best reaction medium for the enantioselective esterification of (R,S)-2-methylalkanoic acid with n-butanol using Carica papaya lipase as catalyst. Increasing linear alkyl-chain length of racemic 2-methylalkanoic acids from ethyl to hexyl increased the enantioselectivity (E) from 2.1 to 98.2 for the esterification of racemic 2-methylalkanoic acids with n-butanol at 35°C. Decreasing reaction temperature from 40 to 20°C increased the enantioselectivity (E) from 14 to 33 for the esterification of racemic 2-methylhexanoic acids with n-butanol. We obtained a maximum enantioselectivity, of E = 24.3, for the enantioselective esterification of racemic 2-methylhexanoic acids with n-butanol in isooctane at water activity 0.33, and at 35°C.
异辛烷是（R，S）-2-甲基烷酸与正丁醇进行对映选择性酯化反应的最佳反应介质，使用木瓜蛋白酶作为催化剂。当用正丁醇对消旋 2-甲基烷酸进行酯化反应时，将反应温度从 40°C 降低到 20°C，会使 2-甲基己酸的对映选择性（E）从 14 增加到 33。增加手性 2-甲基烷酸的直链烷基链长度，从乙基到己基，会使（R，S）-2-甲基烷酸与正丁醇的对映选择性（E）从 2.1 增加到 98.2。在水活度为 0.33，温度为 35°C 的条件下，在异辛烷中，我们获得了最大的对映选择性，E = 24.3，用于对映选择性酯化消旋 2-甲基己酸和正丁醇。
