Affordable Access

Publisher Website

Synthesis and polymorphic phase behaviour of polyunsaturated phosphatidylcholines and phosphatidylethanolamines

Authors
Journal
Chemistry and Physics of Lipids
0009-3084
Publisher
Elsevier
Publication Date
Volume
33
Issue
1
Identifiers
DOI: 10.1016/0009-3084(83)90012-9
Keywords
  • Polyunsaturated Phosphatidylcholines
  • Phosphatidylethanolamines
  • Lipid Polymorphism
  • Hexagonal Hiiphase
  • 31P-Nmr
  • Freeze-Fracture Electron Microscopy
  • Cholesterol
Disciplines
  • Engineering

Abstract

Abstract A series of phosphatidylcholines and phosphatidylethanolamines was synthesized containing two acyl chains of the following polyunsaturated fatty acids: linoleic acid (18:2), linolenic acid (18:3), arachidonic acid (20:4) and docosahexaenoic acid (22:6). In addition two phospholipids with mixed acid composition were synthesized: 16:0/18:1 c phosphatidylcholine and 16:0/18:1 c phosphatidylethanolamine. The structural properties of these lipids in aqueous dispersions in the absence and in the presence of equimolar cholesterol were studied using 31P-NMR, freeze fracturing and differential scanning calorimetry (DSC). The phosphatidylcholines adopt a bilayer configuration above 0°C. Incorporation of 50 mol% of cholesterol in polyunsaturated species induces a transition at elevated temperatures into structures with 31P-NMR characteristics typical of non-bilayer organizations. When the acyl chains contain three or more double bonds, this non-bilayer organization is most likely the hexagonal H II phase, 16:0/15:1 c phosphatidylethanolamine shows a bilayer to hexagonal transition temperature of 75°C. The polyunsaturated phosphatidylethanolamines exhibit a bilayer to hexagonal transition temperature below 0°C which decreases with increasing unsaturation and which is lowered by approximately 10°C upon incorporation of 50 mol% of cholesterol. Finally, it was found that small amounts of polyunsaturated fatty acyl chains in a phosphatidylethanolamine disproportionally lower its bilayer to hexagonal transition temperature.

There are no comments yet on this publication. Be the first to share your thoughts.