Group of phospholipids found in all living organisms. Significant constituent of nervous tissue and brain substance. Cephalins consist of glycerophosphoric acid in which the two free hydroxyls are esterified with long-chain fatty acid residues, and ethanolamine forms an ester linkage with the phosphate group. α-Isomers are derivatives of α-glycerophosphoric acid, q.v.; β-isomers are derivatives of β-glycerophosphoric acid, q.v. Natural products occur in the α-form, while the β-form is now recognized to be an artifact. Prepn from commercial “soybean lecithin”: Scholfield, Dutton, Biochem. Prep. 5, 5 (1957); US 2801255 (1957 to USDA). Diagnostic use: C. R. Ratliff et al., Am. J. Gastroenterol. 55, 589 (1971). Reviews on natural and synthetic cephalins: E. Baer in Progress in the Chemistry of Fats and Other Lipids vol. 6, (MacMillan, New York, 1963) pp 39-44; Van Deenen, de Haas in Advances in Lipid Research vol. 2 (Academic Press, New York, 1964) pp 183-189; Verkade, Bull. Soc. Chim. Fr. 1963, 1993.
Hemostatic (local).
Hemostatic