On the ampholytic nature of phospholipins

Abstract

Of the N-containing phospholipins (Levene and Rolf, 1921; McLean and McLean, 1927; Thierfelder and Klenk, 1930; Magistris, 1931, Robison, 1932; Klenk, 1933) at present three groups have been fairly accurately defined and isolated in an almost pure state:— O= Ρ—O. diglyceride O= Ρ—O. diglyceride O= Ρ—O. (fatty acid) sphingosine O= Ρ —O. choline O= Ρ—O. colamine O=Ρ —O. choline O= Ρ —OH O= Ρ—OH O= Ρ—OH I II III Lecithin Cephalin Sphingomyelin These compounds are diesters of phosphoric acid. One acid group is esterified with an alcoholic base which may be either colamine (aminoethylalcohol NH 2 . CH 2 . CH 2 . OH) or the corresponding quaternary ammonium base choline (OHN(CH 2 ) 3 . CH 2 . CH 2 . OH). The second acid group is linked in the sphingomyelin with sphingosine, the amino group of which is substituted by a fatty acid radical, or in lecithin and cephalin with a diglyceride. The analogous compounds lysolecithin and lysocephalin contain a monoglyceride instead of a diglyceride.