Vázquez Tato, María del PilarSeijas Vázquez, Julio AntonioMeijide del Río, Francisco ÁngelFraga López, FranciscoFrutos del Río, Santiago deMiragaya Otero, JavierTrillo Novo, Juan VenturaJover Ramos, AidaSoto Tellini, Victor HugoVázquez Tato, José2021-08-102021-08-102021Int. J. Mol. Sci. 2021, 22(13), 6684; https://doi.org/10.3390/ijms22136684http://hdl.handle.net/10347/26740Lipophilicity of 15 derivatives of sodium cholate, defined by the octan-1-ol/water partition coefficient (log P), has been theoretically determined by the Virtual log P method. These derivatives bear highly hydrophobic or highly hydrophilic substituents at the C3 position of the steroid nucleus, being linked to it through an amide bond. The difference between the maximum value of log P and the minimum one is enlarged to 3.5. The partition coefficient and the critical micelle concentration (cmc) are tightly related by a double-logarithm relationship (VirtuallogP=−(1.00±0.09)log(cmcmM)+(2.79±0.09)), meaning that the Gibbs free energies for the transfer of a bile anion from water to either a micelle or to octan-1-ol differ by a constant. The equation also means that cmc can be used as a measurement of lipophilicity. The demicellization of the aggregates formed by three derivatives of sodium cholate bearing bulky hydrophobic substituents has been studied by surface tension and isothermal titration calorimetry. Aggregation numbers, enthalpies, free energies, entropies, and heat capacities, ΔCP,demic, were obtained. ΔCP,demic, being positive, means that the interior of the aggregates is hydrophobiceng© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)Atribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/Bile acids and saltsPartition coefficientIsothermal titration calorimetryHydrophilic-lipophilic balanceLipophilicityDemicellization thermodynamicsjournal article10.3390/ijms221366841422-0067open access