Institution: | a Bereich Enzymtechnologie/Naturstoffchemie der GBF, Gesellschaft für Biotechnologische Forschung mbH, Mascheroder Weg 1, D-38124 Braunschweig, Germany b Institut für Technische Biochemie, Universität Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany |
Abstract: | Diacylglycerophosphocholines containing (R)-3-, (R)-12-, (R)-17-hydroxy octadeca(e)noic acids and the corresponding racemates were synthesized and purified to homogeneity. The influence of the position of the hydroxy group on the monolayer packing properties of these fatty acids and their phosphatidylcholines was studied by Langmuir techniques and 1,2-di-(R)-12-hydroxy-octadec-cis-9-enyl]-sn-glycero-3-phosphocholine displayed the largest lift-off area (330 Å2/molecule). This result was in line with the thermotropic phase behavior of these phospholipids, as measured by differential scanning calorimetry (DSC): the gel- to liquid-crystalline phase transition temperature (Tm) passed through a minimum of −15.1°C for 1,2-di-(R)-12-hydroxy-octadec-cis-9-enyl]-sn-glycero-3-phosphocholine. |