The gum exudate from the Brazilian cashew-nut tree (Anacardium occidentale) contained traces of the reducing sugars, rhamnose (0.005%), arabinose (0.03%), mannose (0.007%), galactose (0.03%), glucose (0.02%), β- D-Galp-(l → 6)-αβ-D-Gal (0.05%), α-L-Rhap-(l → 4)-αβ-D-GlcA (0.008%) and α-L-Rhap-(1 → 4)-β-D-GlcpA-(l → 6)-β-D-Galp-(l → 6)-αβ-D-Gal (0.008%). Rhamnose, arabinose, glucose and the three oligosaccharides are components of the side-chains of the gum polysaccharide, which has a main chain of (1 → 3)-linked β-D-Galp units. The structure of this polysaccharide was determined and found to differ from that previously reported for the gum of a tree growing in India, lacking units of 4-O- methylglucuronic acid. Other new side-chain structures were characterized, particularly -α-D-Galp-(l → 6)-D-Galp- and α-L-Araf-(1 → 6)-D-Galp-.
polysaccharide, Oligosaccharides, monosaccharides, Anacardiaceae, Anacardium occidentale, cashew-nut tree, gum
NCBI PubMed ID: 9542167Publication DOI: 10.1016/S0031-9422(97)00666-3Journal NLM ID: 0151434Publisher: Elsevier
Institutions: National Institute for Biological Standart and Controls, Potters Bar, Herts, UK, Departamento de Bioquímica, University Federal do Paraná, Curitiba, Brazil
Methods: 13C NMR, 1H NMR, methylation, GC-MS, TLC, Smith degradation, light scattering, optical rotation measurement, precipitation, HMQC, DEPT, COSY
Found