Characterization ofAnacardiumoccidentale exudate polysaccharide

✍ Scribed by de Paula, Regina C. M.; Heatley, Frank; Budd, Peter M.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 297 KB
• Volume: 45
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199801)45:1<27::aid-pi900>3.0.co;2-9

✦ Synopsis

The composition, structure and molar mass distribution of Anacardium occidentale exudate polysaccharide of Brazilian origin was investigated. The composition from gasÈliquid chromatography (GLC) and 13C NMR was 72% b-D-galactopyranose, 14% a-D-glucopyranose, 4É6% a-L-arabinofuranose, 3É2% a-L-rhamnopyranose and 4É5% b-D-glucuronic acid. A thorough analysis of high resolution 13C NMR spectra from intact, partially hydrolysed and Smithdegraded 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 0É1 M aqueous NaCl at 25¡C was found to depend on molar mass according to : [g]/(cm3 g~1) \ 0É052M0Õ42. The molar mass distribution for the whole polysaccharide, determined by GPC using a universal calibration, exhibited two main peaks at 28 000 and 67 000 g mol~1, together with traces of much higher molar mass material.

1998 SCI.