RESUMEN
Polysaccharides were extracted from bovine placenta at different stages of pregnancy, namely terms of 3, 6, 8, and 9 months, with aqueous HgCl2. Tjhe protein-free material was then purified by selective precipitation with Cetavlon in the presence of sodium borate at pH 8,5. The fractions obtained from 3, 6, 8, and 9 month-old placentas wera designated PL-3, PL-8, and PL-9 respectively and wereeach homobeneous on electrophoresis, molecular-sieve chromatography, and on treatment with Concanavalin A. Polysaccharide contents of the fractions were uniform and acyd hydrolisis provided, in each case, galactose and glucose as principal monosaccharides. G.l.c. analysis of derived alditol acetates showed no variation between the D-glucose: D-galactose ratio obtanined from PL-3 and PL-6, being 68:32, but there was a gradual decreasein the D-glucose content of the PL-8 (58:42) and PL-9 (45:55) fractions