Synthesis and interfacial behavior of three homologous glycero neoglycolipids with various chain lengths

Three neoglycolipids la-e derived from glycerol were synthezised and their molecular arrangements were studied at the air/water interface through Langmuir-Blodgett technique. The common structural features of these neoglycolipids are: a triethyleneglycol spacer at C-2 of glycerol, a GlcNAc hydrophilic head group at the end of the spacer, two saturated aliphatic chains at C-l and C-3 of glycerol, linked by ether bonds. Compounds la-e differ only by the length of their lipid moieties. By increasing the hydrocarbon chain length from C-11 to C-16, a densely packed state was reached in the monolayer. The compression isotherms displayed an expanded state during the whole compression for compounds la and Ic bearing two C-11 or one C-11 and one C-16 chains. Compound 1b bearing two C-16 chains displayed a quite different interfacial behavior. The transfer of these monolayers onto a solid substrate can be obtained only with a trigger molecule, a phosphatidic acid. (C) 1997 Elsevier Science Ireland Ltd.