Department of Chemistry, P.O. Box 35, FI-40014 University of Jyväskylä, Finland.
J Colloid Interface Sci. 2011 Aug 15;360(2):633-44. doi: 10.1016/j.jcis.2011.04.112. Epub 2011 May 10.
A series of amino- and hydroxyalkyl amides of bile acids have been synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), (1)H and (13)C nuclear magnetic resonance spectroscopy (NMR), as well as electrospray ionization mass spectrometry (ESI-MS) measurements. The ability of the synthesized molecules to promote gel formation was systematically investigated. Out of 396 combinations formed by 11 compounds and 36 different solvents, 22 gel-containing systems were obtained with 1% (w/v) gelator concentration. Apart from one exception, the gelator compounds were lithocholic acid derivatives. This challenges the general trend of bile acid-based physical gelators, according to which the gelation ability of lithocholic acid derivatives is poor. A correlation between the values of Kamlet-Taft parameters and solvent preferences for gelators was observed. The morphologies of the solid and gel structures studied with scanning electron microscopy (SEM) showed variability from fibers to spherical microscale aggregates, the latter of which are unique among bile acid-based organogels. The gels exhibited more complex behavior than was previously established with bile acid derivatives, judging by the microscale diversity present in gelating and non-gelating systems and the tendency for polymorphism. This study underlines the importance of both the molecular and colloidal scale aspects of the gelation phenomenon.
已通过傅里叶变换红外光谱（FTIR）、（1）H 和（13）C 核磁共振光谱（NMR）以及电喷雾电离质谱（ESI-MS）测量，对一系列胆酸的氨基和羟烷基酰胺进行了合成和表征。系统研究了合成分子促进凝胶形成的能力。在由 11 种化合物和 36 种不同溶剂组成的 396 种组合中，用 1%（w/v）凝胶剂浓度得到了 22 种含凝胶的体系。除了一个例外，凝胶剂化合物都是石胆酸衍生物。这与基于胆酸的物理凝胶剂的一般趋势相矛盾，根据该趋势，石胆酸衍生物的凝胶形成能力很差。观察到 Kamlet-Taft 参数值与凝胶剂溶剂偏好之间的相关性。通过扫描电子显微镜（SEM）研究固态和凝胶结构的形态显示出从纤维到球形微观级聚集体的可变性，后者在基于胆酸的有机凝胶中是独特的。与以前用胆酸衍生物建立的相比，这些凝胶表现出更复杂的行为，这可以从凝胶形成和非凝胶形成系统中存在的微观多样性以及多态性倾向来判断。这项研究强调了凝胶化现象的分子和胶体尺度方面的重要性。
