l-Galactose as a Component of a Polysaccharide of Animal Origin

Abstract

IN the course of a study of the products obtained by the methanolysis of methylated galactogen, the parent polysaccharide having been prepared from the albumin glands of Helix pomatia, we obtained by distillation in a high vacuum certain fractions the properties of which indicated that they consisted wholly of pentamethyl hexose, apparently 2: 3: 4: 6-tetramethyl-methyl-d-galactoside. One of us¹ has recently investigated the (in water) relationship of mixtures of the α and β-forms of this galactoside; on making use of these observations, it was found that the [α]D values of our fractions were much smaller than was to be expected from the observed values. Thus in one fraction showing 1.4494, the [α]_D was found to be +55˙6° as against the expected value of +118°. This suggested that the fraction in question must have contained only about 75 per cent of 2: 3: 4: 6-tetramethyl-methyl-d-galactosides, together with 25 per cent of the corresponding derivatives of l-galactose: no sugars other than d- and l-galactoses appeared to be present from consideration of the yields of mucic acid produced on oxidation of the galactogen by nitric acid.