Gum Jeol: The Structure of the Degraded Gum Derived From It

Gum Jeol has been shown to be composed of residues of D-galactose, L-arabinose, and D-galacturonic acid. On mild acid hydrolysis the gum gave an aldobiouronic acid, viz. 3-O-(D-galactopyranosyl uronic acid)-D-galactopyranose. Hydrolysis of the fully methylated degraded gum yielded 2,3,4,6-terra-(3 moles); 2,3,4-tri-(2 moles); 2,4-di-(1 mole); and 2-O-methyl-D-galactose (1 mole) in the neutral fraction of the hydrolyzate. The reduced acidic fraction yielded 2,3,4-tri-(2 moles) and 2,4-di-O-methyl-D-galactose (2 moles). Based on these results a partial structure of the degraded gum has been proposed, the additional evidence of which was deduced from periodate oxidation studies of the degraded gum.