The fractionation of lecithins and cephalins.

The lecithins and cephalins are complex mixtures of chemical entities differing from each other (a) in their component fatty acids, (h) in the case of the cephalins, in the nitrogenous constituent, and (c) in the point of substitution of t.he phosphoric acid-base group in the molecule. Power and Tutin (I) were the first to question the uniformity of the glycerophosphoric acids of lecithin. In 1912 Fourneau and Piettre (2) separated the calcium salts of the acid into two fractions and proposed that the glycerophosphoric acid of lecithin was a mixture of the (Y and fl acids. Bailly (3) showed that two compounds, one a crystalline sodium salt of fl-glycerophosphoric acid, the other an amorphous sodium salt of (Yglycerophosphoric acid, could be isolated from egg and brain lecithin. In 1926 Iiarrer and Salomon (4) presented a method for the separation of (Yand P-glycerophosphoric acid and obtained both compounds from lecithin. Finally, in a series of papers (1930--34) Suzuki, Yokoyama, and Nishimoto (5-8) reported methods for the separation of the LY and /3 isomeric forms of lecithin and cephalin. We have used their methods, with a few modifications, on the phospholipids obtained from the heart, liver, and brain of rats, cats, guinea pigs, and beef and recently on the phospholipids obtained from the livers of fasted mice (9).