Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.
Org Biomol Chem. 2004 Feb 21;2(4):524-7. doi: 10.1039/b312212c. Epub 2004 Jan 20.
Lipase-catalyzed alcoholysis between vinyl cinnamate and benzyl alcohol in fluorous solvents was investigated. This is the first report of a lipase-catalyzed reaction in a fluorous solvent. Forming the poly(ethylene glycol)(PEG)-lipase PL complex enhanced lipase activity over 16-fold over that of native lipase powder. The PEG-lipase PL complex exhibited markedly higher alcoholysis activities in fluorous solvents than in conventional organic solvents such as isooctane and n-hexane. The optimum reaction temperature for FC-77 (perfluorooctane) was 55 [degree]C and the optimum pH for the preparation of the PEG-lipase complex was 9.0; similar to the conditions for lipase PL-catalyzed reaction in aqueous solution. The alcoholysis reaction in fluorous solvent requires the addition of a FC77-miscible organic solvent (isooctane) in order to dissolve non-fluorinated substrates. Lipase activity in the fluorous solvent was significantly influenced by the volume ratio of isooctane in the reaction medium. Vinyl cinnamate inhibition of the lipase-catalyzed reaction occurred at a much lower concentration in the fluorous solvent than in isooctane. These results can be explained by the localization of substrates around lipase molecules, induced by adsorption of the substrates to the PEG layer of the PEG-lipase complex.
研究了在氟相溶剂中，肉桂酸乙烯酯与苄醇之间的脂肪酶催化的醇解反应。这是首次在氟相溶剂中报道脂肪酶催化反应。形成聚乙二醇（PEG）-脂肪酶 PL 配合物使脂肪酶的活性比天然脂肪酶粉末提高了 16 倍以上。PEG-脂肪酶 PL 配合物在氟相溶剂中的醇解活性明显高于异辛烷和正己烷等常规有机溶剂。对于 FC-77（全氟辛烷），最佳反应温度为 55°C，PEG-脂肪酶配合物制备的最佳 pH 值为 9.0；与水溶液中脂肪酶 PL 催化反应的条件相似。氟相溶剂中的醇解反应需要加入 FC77 混溶性有机溶剂（异辛烷）以溶解非氟化底物。在氟相溶剂中，脂肪酶的活性受到反应介质中异辛烷体积比的显著影响。在氟相溶剂中，肉桂酸乙烯酯对脂肪酶催化反应的抑制作用的浓度比在异辛烷中低得多。这些结果可以通过底物在 PEG 层的吸附，诱导底物在脂肪酶分子周围的定位来解释。
