Studies on uronic acid materials : Part XVI 1. Inter-nodule variation and the acidic components in Acacia nilotica gum

Abstract

Inter-nodule variations in the composition and properties of Acacia nilotica gum have been investigated. The results confirm the value of this type of analytical survey of a species, prior to structural studies on a single, representative nodule. The acidic components of the gum have been examined in detail. For the first time in the genus Acacia, four aldobiouronic acids, two of which contain 4- O-methyl- d-glucuronic acid, were present and were identified as 4- O-(4- O-methyl-α- d-glucopyranosyluronic acid)- d-galactose) ( A), 6- O-(4- O-methyl-β- d-glucopyranosyluronic acid)- d-galactose ( B), 6- O-(β- d-glucopyranosyluronic acid)- d-galactose ( C), and 4- O-(α- d-glucopyranosyluronic acid)- d-galactose ( D). The analytical data indicate that there is an inter-nodule variation in the proportions of acids A and B, and, further, in the proportions of the monomethyl acids ( A + B) and the unsubstituted acids ( C + D).