MONOLAYERS OF LYSOLECITHINS AND ANALOGS

1) The interfacial characteristics of lysolecithins are highly dependent on chain length and unsaturation of the fatty acid chain. (Stearoyl) and (oleoyl) lysolecithins form stable monolayers with high collapse pressures (35 dynes/cm) whereas (palmitoyl) (myristoyl), and (linoleoyl) lysolecithin monolayers show low collapse pressures ({less-than but not equal to}12.4 dynes/cm). 2) Deoxylysolecithins show an interfacial behavior similar to that of lysolecithins. The lysolecithins and deoxylysolecithins studied revealed a much higher area per molecule as would be expected if fatty acid chains were to limit the surface area. (Stearoyl) and (oleoyl) lysolecithin occupy an area which is 15 A2/molecule smaller than that of (stearoyl-oleoyl) lecithin. 3) The effect of the free hydroxyl group, the elongation of the alkane diol part of palmitoyl ωω′ alkane diol phosphorylcholines, and the elongation of the zwitter ionic phosphate-quaternary ammonium distance were studied. © 1969.