Teichoic mixture

A small proportion of O-D-glucosylribitol was produced directly by hydrolysis of the teichoic acid with alkali ( see Fig. 16) this product is identical with that obtained by dephosphorylation of the hydrolysis mixture. The major products of such a hydrolysis with alkali were the isomeric monophosphates (58) and (59), in which R = 0-D-glucopyranosyl, both of which gave the O-D-glucosylribitol on enzymic dephosphorylation. The isomer (58) reduced 3 molar proportions of periodate, and the ribitol residue was oxidized, whereas the isomer (59) reduced 2 molar proportions of periodate, the ribitol residue being resistant to oxidation. Small proportions of the diphosphates (56) and (57) were also produced. Oxidation of the diphosphate (57) with periodate, followed by treatment with alkali to remove the aldehydic residues, gave a ribitol diphosphate. 

Approximately equimolar proportions of unsubstituted, monosub-stituted, and disubstituted ribitol residues were present in the teichoic acid examined. However, the proportions differed in other samples, and there is no apparent, regular sequence along the chain. In fact, it is not yet known whether all three types of unit occur in the same polymer molecules, or whether the teichoic acid is a mixture of different molecular species. 

Alkaline hydrolysis of the teichoic acid gave a mixture of monophosphates of 0-D-glucosyl-D-ribitol (XVII), only traces of diphosphates, and no phos-pho diesters. Removal of D-glucose by 8-D-glucosidase gave ribitol 1-phosphate and ribitol 2-phosphate (and no ribitol 3-phosphate). Thus, the phospho diester linkages are at positions 1 and 5 in the polymer. 

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