Immunochemical properties of hualtaco gum.

Hualtaco gum, from the South American plant , 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--(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.