Phospholipids with a stimuli-responsive thermotropic liquid-crystalline moiety

Kiyoshi Kanie, Junji Sekiguchi, Xiangbing Zeng, Goran Ungar, Atsushi Muramatsu
2011 Chemical Communications  
All reagents of the highest commercial quality and solvents (Aldrich Chemicals, Wako Pure Chemicals, Nakalai Tesque, Kanto Chemicals, or Tokyo Kasei) were used as received. Water was doubly distilled and deionized prior to use. All of the organic reactions were carried out under an argon atmosphere in a dry solvent. Glass vessels for the organic reactions were well-dried by heating under reduced pressure. Completion of the reactions was monitored by thin-layer chromatography using 0.25 mm E.
more » ... ck silica-gel plates (Silica Gel F254) were used, and were visualized by UV light and/or by dipping the plates in an ethanolic sodium phosphomolybdate followed by heating. Purification of phospholipids containing a thremotropic liquid-crystalline moiety prepared in the present study was carried out by Yamazen Fast Flow Liquid Chromatography system using High-Flash columns (SiO 2 and ODS). Measurements of phase transition temperatures and determinations of liquid-crystalline phases were carried out with an Olympus BX51 optical polarizing microscope equipped with a Mettler FP82 HT hot stage or with a custom-made high pressure hot stage. Thermal characterization was performed with a TA Instruments MDSC Q-100 equipped with a refrigerated cooling system. The scanning rate was 10 °C/min. To prevent evaporation of solvents, high pressure capsule kit was used for the DSC measurements. Infrared (IR) spectra were conducted on a Bruker FTS-7000 equipped with a microscope UMA-600. IR
doi:10.1039/c1cc11843a pmid:21584327 fatcat:vyp4pzyvjzgtlhprztfdzjtbs4