Eggers K, Fyles T M, Montoya-Pelaez P J
Department of Chemistry, University of Victoria, Victoria, B.C. Canada V8 W 3P6.
J Org Chem. 2001 May 4;66(9):2966-77. doi: 10.1021/jo0056848.
The synthesis of four lipids containing the hemithioindigo chromophore as part of the fatty acid is described. Heck reaction of bromophenyl thioacetate esters with acrylonitrile, followed by reduction, ester hydrolysis, and Friedel--Craft acylation--cyclization gave a substituted thioindoxyl that condensed with an alkoxy benzaldehyde to produce the hemithioindigo. "Solventless" nitrile hydrolysis followed by mixed anhydride coupling of the acid with glycerophosphocholine produced lipids bearing two hemithioindigo chromophores. The photochemistry of various hemithioindigo derivatives was studied to confirm the expected photoisomerization in both homogeneous organic solution, and in vesicle bilayer membranes. Characteristic changes in the UV--visible spectra are consistent with fully reversible Z--E photoisomerization. Chromatographic separation of the Z and E isomers of a compound containing a single hemithioindigo chromophore confirmed the spectroscopic analysis and provided a quantitative analysis of the compositions of Z--E isomer mixtures.
本文描述了四种将半硫靛发色团作为脂肪酸一部分的脂质的合成方法。溴苯基硫代乙酸酯与丙烯腈发生Heck反应，随后进行还原、酯水解以及傅克酰基化-环化反应，得到一种取代硫代吲哚酚，该取代硫代吲哚酚与烷氧基苯甲醛缩合生成半硫靛。“无溶剂”腈水解后，酸与甘油磷酸胆碱进行混合酸酐偶联反应，生成带有两个半硫靛发色团的脂质。研究了各种半硫靛衍生物的光化学性质，以证实其在均相有机溶液和囊泡双分子层膜中均会发生预期的光异构化。紫外-可见光谱的特征变化与完全可逆的Z-E光异构化一致。对含有单个半硫靛发色团的化合物的Z和E异构体进行色谱分离，证实了光谱分析结果，并对Z-E异构体混合物的组成进行了定量分析。
