Chemical and 13C NMR studies of Enterolobium cyclocarpum gum and its degradation products

A structural study of the gum exudate from Enterolobium cyclocarpum has been carried out using chemical methods and 13C NMR spectroscopy. The results reveal that the structure of this gum is essentially a β-(1→3)-galactan. Some galactoses are 6- O-linked and others also occur as terminal residues. There is evidence that supports the presence of α- L-arabinofuranose and β- L-arabinopyranose. β- D-Glucuronic acid may be present as terminal and internal residues, while the 4- O-methyl-α- D-glucuronic acid residues exist predominantly in internal positions.