(R)-Ketone-cyanohydrins (R)-2 are obtained with high enantioselectivity from aliphatic ketones 1 and HCN in organic solvents using (R)-oxynitrilase (EC 4.1.2.10) as catalyst. Acid catalyzed hydrolysis of the cyanohydrins (R)-2 affords the corresponding (R)-alpha-hydroxy-alpha-methyl-carboxylic acids (R)-3 without measurable racemization.
<i>Linum usitatissimum</i>Hydroxynitrile Lyase Cross-Linked Enzyme Aggregates: A Recyclable Enantioselective Catalyst
作者:Fabien L. Cabirol、Pei Loo Tan、Benson Tay、Shiryn Cheng、Ulf Hanefeld、Roger A. Sheldon
DOI:10.1002/adsc.200800309
日期:2008.10.6
An immobilized form of the hydroxynitrile lyase from Linum usitatissimum (LuHNL) as cross-linkedenzymeaggregate (CLEA) with high specific activity (303.5 U/g) and recovery (33%) was developed. Molecular imprinting using 2-butanone as additive in the immobilization process improved the synthetic activity of the biocatalyst. LuCLEA could be partially recycled for the synthesis of (R)-2-butanone cyanohydrin
开发了固定化形式的亚麻属(Linum usitatissimum)的羟腈裂解酶(Lu HNL)作为具有高比活性(303.5 U / g)和回收率(33%)的交联酶聚集体(CLEA)。在固定化过程中使用2-丁酮作为添加剂的分子印迹提高了生物催化剂的合成活性。Lu CLEA可以部分循环用于制备规模为两批的(R)-2-丁酮氰醇的合成。将得到的对映体富集的氰醇进一步水解以得到(R)-2-羟基-2-甲基丁酸,产率为85%(得自2-丁酮)和87%ee。