Immunochemical properties of hualtaco gum

Hualtaco gum, from the South American plant Loxopterygium huasango, yields D-galactose, D-glucuronic acid, L-rhamnose and small quantities of arabinose and aldobiuronic acid on hydrolysis with strong acid. Like gum arabic, hualtaco yields a highly immunologically reactive product after mild degradation, while stronger hydrolysis furnishes an aldobiuronic acid, 6-O-(β-D-glucuronopyranosyl)-D-galactose, identical with that isolated similarly from gum arabic. Quantitative data are given on some of the precipitin reactions of the gum in antipneumococcal sera and the chemical basis for the reactivity in each system is discussed insofar as present knowledge permits.

The capsular polysaccharide of pneumococcus type IX

The capsular polysaccharide of Type IX pneumococcus contains D-glucose, N-acetyl-D-glucosamine, and D-glucuronic acid. Complete hydrolysis is difficult. All of the N-acetylglucosamine is resistant to oxidation by periodate, but the other two sugars are degraded in part. Chemical and quantitative serological data are consistent with the linkage of two D-glucose residues 1 --> 4, as in maltose; others may be linked 1 --> 3. Part, at least, of the glucuronic acid and N-acetylglucosamine is linked to glucose.