(ω-2,ω-2,ω-3,ω-3)-Tetradeuterio-fatty acids for mechanistic studies of enzyme-catalyzed hydroxylation reactions
作者:John H. Horner、Martin Newcomb
DOI:10.1002/jlcr.2959
日期:2012.9
Among the thousands of cytochrome P450 enzymes known, many selectively hydroxylate the hydrocarbon tail of fatty acids at the terminal (ω) position and the ω-1, ω-2, and ω-3 positions. A general method for synthesis of (ω-2,ω-2,ω-3,ω-3)-tetradeuterio-fatty acids that can be used in mechanistic studies of cytochromes P450 is illustrated by the synthesis of 9,9,10,10-tetradueteriododecanoic (lauric) acid and 13,13,14,14-tetradeuteriohexadecanoic (palmitic) acid. Deuterium is introduced early in the synthesis by reduction of the THP ether of 4-heptyn-1-ol with deuterium gas to give a common labeled intermediate, 4,4,5,5-tetradeuterioheptan-1-ol. This alcohol is converted to the corresponding tosylate that is used to alkylate O-protected (ω-1)-alkyn-1-ols to give, eventually, long-chain alcohols that are oxidized to the corresponding fatty acids. An important experimental detail is that relatively large amounts of Wilkinson's catalyst were used to limit isotopic scrambling. Copyright © 2012 John Wiley & Sons, Ltd.
在已知的数千种细胞色素P450酶中,许多能选择性地在脂肪酸的碳氢链末端(ω)位以及ω-1、ω-2和ω-3位进行羟基化。图中展示了合成(ω-2, ω-2, ω-3, ω-3)-四氘代脂肪酸的一般方法,这种方法可用于细胞色素P450的机理研究,具体实例包括9,9,10,10-四氘代十二酸(月桂酸)和13,13,14,14-四氘代十六酸(棕榈酸)的合成。在合成的早期阶段,通过用氘气还原4-庚炔-1-醇的THP醚,引入氘原子,得到一种通用的标记中间体——4,4,5,5-四氘代庚-1-醇。然后将该醇转化为相应的甲苯磺酸酯,用于烷基化O-保护的(ω-1)-炔-1-醇,最终得到长链醇,再氧化得到相应的脂肪酸。一个重要的实验细节是使用了相对大量的Wilkinson催化剂,以限制同位素交换。版权所有 © 2012 John Wiley & Sons, Ltd.