24902-45-2Relevant academic research and scientific papers
Thermal behavior of long-chain alkanoylcholine soaps
Tolentino, Ainhoa,Alla, Abdelilah,Martinez De Ilarduya, Antxon,Font-Bardia, Merce,Leon, Salvador,Munoz-Guerra, Sebastian
, p. 10738 - 10750 (2014)
Long-chain alkanoylcholines prepared from fatty acids (nACh) are fully sustainable cationic surfactants that are known for their biological and medicinal properties. In the present work the thermal behavior of the homologous series of alkanoylcholine iodides with n = 12, 14, 16 and 18, has been examined within the 25-200 °C range of temperatures. Up to three thermotropic phases have been identified, and the thermal transitions implied in their interconversion have been characterized by DSC and simultaneous WAXS and SAXS analysis carried out in real-time. All three phases consist of a bilayered structure with alkanoyl chains confined in the space between the head group layers and interdigitated to a greater or lesser extent. Melting-crystallization of either the polymethylene segments or the choline iodide groups is involved in such transitions. Additionally, a crystal phase consisting also of a bilayered structure but excluding side chain interdigitation was observed upon crystallization from solution and its structure was elucidated by single-crystal X-ray diffraction direct methods. The close correlation existing between thermal properties, phase structure and n has been brought into evidence.
Effect of hofmeister series anions on the thermotropic phase behavior of bioactive O -acylcholines
Tarafdar, Pradip K.,Reddy, S. Thirupathi,Swamy, Musti J.
, p. 9900 - 9909 (2013)
O-Acylcholines (OACs), which are true cationic lipids due to the quaternary ammonium functionality in the headgroup, exhibit interesting biological activities and medicinal properties. In the present study, a homologous series of OACs with even chain lengths (n = 12-20) have been synthesized, and their thermotropic and chaotropic phase transitions have been characterized. The role of various anions (Cl-, Br-, I-, NO 3-, SO42-, ClO3 -, ClO4-) on the phase behavior of O-stearoylcholine was investigated by calorimetric, spectroscopic, and turbidimetric approaches. The results obtained revealed that in aqueous dispersion O-stearoylcholine undergoes a cooperative phase transition from a gel phase to a micellar structure and that the transition temperature increases when the counterions are changed in the Hofmeister series. Single-crystal X-ray diffraction studies showed that O-stearoylcholine iodide forms an interdigitated bilayer structure, with the polymethylene chain adopting an all-trans conformation. The Hofmeister effect and phase behavior were explained using the concepts of matching water affinities, water penetration into the bilayer, and electrostatic repulsion. It was also observed that one counterion per molecule is sufficient to strongly modulate the phase properties of the lipid/surfactant.
Improved LC-MS method for the determination of fatty acids in red blood cells by LC-orbitrap MS
Li, Xingnan,Franke, Adrian A.
, p. 3192 - 3198 (2011/11/04)
We report a new method for fast and sensitive analyses of biologically relevant fatty acids (FAs) in red blood cells (RBC) by liquid chromatography mass spectrometry (LC-MS). A new chemical derivatization approach was developed forming picolylamides from FAs in a quantitative reaction. Fourteen derivatized FA standards, including saturated and unsaturated FAs from C14 to C22, were efficiently separated within 15 min. In addition, the use of a recently introduced benchtop orbitrap mass spectrometer under positive electrospray ionization (ESI) full scan mode showed a 2-10-fold improvement in sensitivity compared with a conventional tandem MS method, with a limit of detection in the low femtomole range for saturated and unsaturated FAs. The developed method was applied to determine FA concentrations in RBC with intra- and interday coefficients of variation below 10%.
Cationic amphiphiles with G-protein-stimulatory activity: Studies on the role of the basic domain in the activation process
Detert,Seifert,Schunack
, p. 67 - 72 (2007/10/02)
2-Substituted histamines, which are cationic-amphiphilic, activate pertussis toxin-sensitive G-proteins by a receptor-independent mechanism. Lipophilicity is an important determinant for this G-protein activation, but the influence of basicity remained unclear. We prepared four imidazole-containing compounds and nine alkylamines with different basicity and studied their effects on high-affinity GTP hydrolysis in HL-60 membranes. The substances contained a lipophilic domain (L) and polar (P) and/or cationic (C) domains. Compared to 2-substituted histamines (L-P-C), the corresponding L-C-P type compounds were less potent and effective which, however, were still more active than L-P-P type substances. Among alkylamines, 2-octadecylaminoethyl-N,N-diethylamine (11) was the most potent GTPase activator (pEC50 = 5.7; 100% stimulation above basal). Conversely, 3-(5-hydroxyundecylamino)propylamine (15) was the most efficient compound (pEC50 = 4.3; 160% stimulation above basal). Compared to compounds 11 and 15, which belong to the L-C-C type, the corresponding L-P-C type compounds were less active. Thus, among 2-substituted histamines and alkylamines, a terminal cationic domain is critical for potent and/or effective receptor-independent G-protein activation. An L-C-X structure (X = P or C) is more favorable for G-protein activation than a L-P-X structure. Potency and efficiency of receptor-independent G-protein activators are independently determined drug parameters.
