The ribitol teichoic acid from Lactobacillus arabinosus Walls: isolation and structure of ribitol glucosides

Abstract

It is confirmed that the teichoic acid from the walls of Lactobacillus arabinosus is composed of ribitol, phosphate, D-glucose and D-alanine. Hydrolysis in alkali, followed by removal of phosphate from the products with a phosphatase, gave mainly a mono- and a di-glucosylribitol. Small amounts of anhydroribitol and an isomeric monoglucosylribitol are also formed, and occasionally traces of an isomeric diglucosylribitol have been detected. Teichoic acid preparations from some batches of microorganisms but not others yield appreciable amounts of ribitol. The principal monoglucosylribitol has the structure 4-O-([alpha]-D-glucopyranosyl)-D-ribitol. This has been established by studies on optical rotation, hydrolysis, periodate oxidation and the stereochemistry of degradation products. A general method is described for determining the stereo-chemical series of sugars from their glycosides on a microscale. This depends upon oxidation of the glycoside with periodate then bromine, hydrolysing the product with acid, and determining the configuration of the resulting glyceric acid by enzymic phosphorylation then oxidation of reduced diphosphopyridine nucleotide in the presence of a rabbit-muscle preparation. The monoglucosylribitol formed in small amounts is 3-O-([alpha]-D-glucopyranosyl)ribitol. The structure of this compound was established by methods similar to those adopted for the isomeric 4-glucoside. The diglucoside is 3,4-di-O-([alpha]-D-glucopyranosyl)-D-ribitol. On careful acid hydrolysis it yields glucose and a mixture of 3- and 4-glucosylribitol identical with those isolated before. The teichoic acid from the walls of Lactobacillus arabinosus differs markedly from the other ribitol teichoic acid which has been studied in detail, i.e. that from Bacillus subtilis, in that both mono- and di-glucoside residues are present and the glycosidic linkages all have the a-configuration.