Phase transitions in binary mixtures of cholesteryl esters.
Phase transitions in binary mixtures of cholesteryl esters.
复制标题
胆固醇酯二元混合物中的相变。
DOI：
--
复制
发表时间：
1972
期刊：
影响因子：
--
通讯作者：
B. Byrd
中科院分区：
文献类型：
--
作者：
S. G. Frank;B. Byrd
本文用可见热显微镜研究了胆甾醇酯液晶混合物的相变。饱和胆固醇酯（胆固醇壬酸酯、肉豆蔻酸酯和棕榈酸酯）的二元混合物和这些饱和胆固醇酯和芳香族胆固醇酯（胆固醇苯甲酸酯）的二元混合物显示在远低于任一纯化合物的相变温度的温度下从固相到介晶相的转变。然而，介晶到各向同性的相变温度几乎是混合物的组成的线性函数。其结果是，温度范围内的二元混合物是介晶的是大大扩大相比，观察到的单个组件的窄范围。这些混合物的固体到介晶相变发生在体温以上。然而，饱和胆固醇酯与不饱和胆固醇酯（油酸胆固醇酯和亚油酸胆固醇酯）的二元混合物在体温下是介晶的，除了在低浓度的不饱和酯。不饱和胆固醇酯沿着少量其他胆固醇酯是动脉粥样硬化病变中发现的脂滴的主要成分。胆固醇酯的混合物的介晶行为可能与它们在这些病变中的相互关联有关。
Phase transitions in mixtures of mesomorphic (liquid crystalline) cholesteryl esters were studied by visual thermal microscopy. Binary mixtures of saturated cholesteryl esters (cholesteryl nonanoate, myristate, and palmitate) and binary mixtures of these saturated cholesteryl esters and an aromatic cholesteryl ester (cholesteryl benzoate) show transitions from the solid phase to the mesomorphic phase at temperatures that are depressed well below the phase transition temperature of either pure compound. However, the mesomorphic to isotropic phase transition temperatures are virtually linear functions of the composition of the mixtures. The result is that the temperature range over which the binary mixtures are mesomorphic is greatly expanded when compared to the narrow range observed for the individual components. The solid to mesomorphic phase transitions of these mixtures occur above body temperature. However, binary mixtures of the saturated cholesteryl esters with unsaturated cholesteryl esters (cholesteryl oleate and linoleate) are mesomorphic at body temperature except at low concentrations of the unsaturated ester. The unsaturated cholesteryl esters along with small amounts of other cholesteryl esters are major components of lipid droplets found in atheromatous lesions. The mesomorphic behavior of mixtures of the cholesteryl esters may be related to their interassociations in these lesions.