Glyceryl side chains

The repulsion between molecules having oily or aqueous properties is the basis for membrane construction. The lipids found in membranes are mostly based on glyceryl phosphate and normally contain three different side chains—one saturated, one unsaturated, and one very polar. 

Irreversible attachment of side chains is achieved by O- and Ai-alkylation and creation of carbon-carbon bonds. The grafted side chains can be basic (dimethylaminoethyl or morpholinoethyl chains), acidic (carboxylic, sulfonic, etc.) or neutral (glyceryl). 

The chemistry of complex lipids is dominated by regioselective hydrolysis reactions of (1) the glyceryl fatty acid esters and (2) phosphate diesters. Both types of reactions are routinely performed with the corresponding esterases. A large variety of lipid active transferase enzymes is also commercially available. Phospholipases Aj, A, C, and D, for example, split any of the four ester bonds of a phospholipid regioselectively. The product without a fatty acid side chain at C2 of glycerol is called a lysophospholipid. Lecithin-cholesterol-acyltransferase transfers the fatty acid at C2, often linoleic acid, to the OH group at C3 of cho-... 

Non-covalent functionalisation approaches also enable the preparation of polymer composites with significantly improved mechanical properties. For example, in the recent work of Yuan et al three different polymers such as polyimide without side-chain (PI), polyimide-graft-glyceryl 4-nonylphenyl... 

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