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Characterization of Anacardium occidentale exudate polysaccharide
Author(s) -
de Paula Regina C. M.,
Heatley Frank,
Budd Peter M.
Publication year - 1998
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199801)45:1<27::aid-pi900>3.0.co;2-9
Subject(s) - molar mass , chemistry , intrinsic viscosity , polysaccharide , gel permeation chromatography , glucuronic acid , chromatography , molar mass distribution , viscometer , aqueous solution , analytical chemistry (journal) , viscosity , organic chemistry , materials science , polymer , composite material
The composition, structure and molar mass distribution of Anacardium occidentale exudate polysaccharide of Brazilian origin was investigated. The composition from gas–liquid chromatography (GLC) and 13 C NMR was 72% β‐ D ‐galactopyranose, 14% α‐ D ‐glucopyranose, 4·6% α‐ L ‐arabinofuranose, 3·2% α‐ L ‐rhamnopyranose and 4·5% β‐ D ‐glucuronic acid. A thorough analysis of high resolution 13 C NMR spectra from intact, partially hydrolysed and Smith‐degraded polysaccharide enabled reliable chemical shift assignments to be made, and indicated the presence of three types of unit within the branched galactan core: linked at C‐1 and C‐3, at C‐1 and C‐6, and at C‐1, C‐3 and C‐6. The polysaccharide was fractionated with respect to molar mass using water/ethanol as a solvent/non‐solvent system. The polysaccharide and fractions were characterized by gel permeation chromatography (GPC), intensity light scattering, dilute solution viscometry and sedimentation velocity. The intrinsic viscosity in 0·1 M aqueous NaCl at 25°C was found to depend on molar mass according to: [η]/(cm 3 g ‐1 )=0·052 M 0·42 . The molar mass distribution for the whole polysaccharide, determined by GPC using a universal calibration, exhibited two main peaks at 28000 and 67000gmol ‐1 , together with traces of much higher molar mass material. © 1998 SCI.