Phospholipids. XVII. Synthesis of ethylene glycolphosphonic acid analogues of lecithins

Abstract

The synthesis of ethylene glycolphosphonic acid analogues of lecithins, a new type of pbosphonolipids, is reported. The preparation of myristoyl, palmitoyl, and stearoyl ethylene glycol-(2-trimethylammoniumethyl)phosphonate is described in detail. They were obtained by phosphonylating the corresponding esters of ethylene glycol with (2-bromoethyl)phosphonic acid monochloride and triethylamine, and treating the resulting acyl glycol-(2-bromoethyl)phosphonates in dimethylformamide with trimethylamine at 50–55° for 3 days. The glycolphosphonolecithins (phosphonic acid analogues of glycollecithin) are highly soluble in water and possess strong hemolytic activity. On hydrolysis by lecithinase C (Clostridium welchii) or alkali (Dawson procedure) they yield the corresponding monoacyl glycols and ethylene glycol-(2-trimethylammoniumethyl)phosphonate, respectively. The identification of ethylene glycolphosphonolecithins in the presence of phosphonolecithins, glycollecithins, and lecithins by descending paper chromatography of their saponification products, obtained by mild alkaline hydrolysis, is described.