Sialic acids. VII. Composition and modifications of the content of the neuramine derivatives from human colostrum

Abstract

After confirmation that the N-acetyl-neuraminic acid (NANA) is the sialic acid existing in human colostrum, the variations in the values of the total NANA of this secretion, the NANA of the so­luble fraction in ethanol of 80 % (F.S.- 80) and the NANA of the glycoprotein precipitate (Pp-80) are studied, from the first to the ninth day after delivery. It can be deduced that the concentration of NANA from the neuraminoligosaccharides of the soluble fraction does not vary practically, but that of the glycoprotein NANA and total NANA does, and it de­creases deeply and parallely. Other aspects referring to the concentration of the free and bound NANA of the soluble fraction, facility of its split, etc., are discussed.