Evaluation of the hydrophobicity of perfluoroalkyl chains in amphiphilic compounds that are incorporated into cell membrane

Incubation of animal cells in the presence of amphiphilic glycosides having a lactoside residue (hydrophilic moiety) and various kinds of perfluoroalkyl chain (hydrophobic moiety) resulted to glycosylation of the saccharide chain by cellular enzymes and afforded glycolipid-like compounds. The amounts of amphiphilic glycoside and glycolipid-like compounds found in the cell and culture medium fractions, respectively, varied depending on the fluorine content of the perfluoroalkyl chain. To investigate further, the hydrophobicity of the perfluoroalkyl chain was estimated from the critical micelle concentration values and was found to be 1.5 times larger in hydrophobicity than the hydrocarbon chain [CF2 = 1.5CH2]. Liposomes resembling cells in size were also prepared and the amphiphilic glycosides were introduced. Results showed a positive correlation between hydrophobicity and localization of amphiphilic glycoside into liposomes. The amount of amphiphilic glycosides localized in liposomes increased with increasing hydrophobicity that is attributed mainly to the fluorine content of the aglycon. In spite of the low affinity of fluorous chain for hydrocarbon chain, the amphiphilic fluorous compounds showed high affinity for cell membrane that is composed of amphiphilic phospholipids.