Posa Mihalj, Kevresan Slavko, Mikov Momir, Cirin-Novta Vera, Kuhajda Ksenija
Department of Pharmacy, Faculty of Medicine, University of Novi Sad, Hajduk Veljkova 3, 21000 Novi Sad, Serbia.
Colloids Surf B Biointerfaces. 2008 Jul 15;64(2):151-61. doi: 10.1016/j.colsurfb.2008.01.017. Epub 2008 Jan 31.
The knowledge of the process of formation of molecular aggregates of bile acids in aqueous media and of the corresponding critical micellar concentrations (CMCs) is of great significance because of the biological importance of these compounds and their pharmacological applications. In view of this, the present study is concerned with the determination of CMCs of cholic and chenodeoxycholic acids and their keto derivatives at different temperatures with the aim to calculate the standard thermodynamic functions of micelle formation. Based on the molecular descriptors for tested compounds and entropy of micelle formation, the method of principal component analysis (PCA) allowed grouping of the behavior of tested molecules at 30, 50 and 70 degrees C. To one group belong cholic acid and its keto derivatives, the other group consisting of chenodeoxycholic and deoxycholic acids and their keto derivatives. For each group, the derived multiple linear regression equations of the entropy dependence on temperature contains different independent variables. A main difference between the two groups of tested bile acids is in the energy of dipole-dipole interaction, which appears to be temperature dependent, and in the case of the latter group comes into play as an independent variable already in the regression equation derived for 30 degrees C. The most remarkable changes of the descriptors with temperature were observed in the group of cholic acid and its derivatives.
由于胆汁酸这些化合物的生物学重要性及其药理学应用，了解胆汁酸在水性介质中分子聚集体的形成过程以及相应的临界胶束浓度（CMC）具有重要意义。鉴于此，本研究旨在测定胆酸和鹅去氧胆酸及其酮衍生物在不同温度下的CMC，以便计算胶束形成的标准热力学函数。基于受试化合物的分子描述符和胶束形成的熵，主成分分析（PCA）方法能够对受试分子在30、50和70摄氏度下的行为进行分组。胆酸及其酮衍生物属于一组，另一组由鹅去氧胆酸、脱氧胆酸及其酮衍生物组成。对于每组，推导得到的熵对温度的多元线性回归方程包含不同的自变量。两组受试胆汁酸之间的一个主要差异在于偶极 - 偶极相互作用能，它似乎与温度有关，并且在后一组中，在为30摄氏度推导的回归方程中就已作为自变量起作用。在胆酸及其衍生物组中观察到描述符随温度的最显著变化。
