Characterization ofAnadenanthera macrocarpa exudate polysaccharide

✍ Scribed by Paula, Regina C. M. de; Budd, Peter M.; Rodrigues, Judith F.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 253 KB
• Volume: 44
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199709)44:1<55::aid-pi815>3.0.co;2-m

✦ Synopsis

Exudate gum from Anadenanthera macrocarpa Benth. trees was puri-Ðed and fractionated using 0É1 M aq. NaCl/ethanol as a solvent/non-solvent system. The composition of the polysaccharide was determined as 67% arabinose, 24% galactose, 2% rhamnose and 7% glucuronic acid, by a combination of high performance liquid chromatography of fully hydrolysed gum and colorimetric analysis of uronic acid. Molecular characteristics of the polysaccharide and its fractions were investigated by light scattering intensity, dilute solution viscometry and gel permeation chromatography (GPC). The whole gum was shown to possess a broad molar mass distribution with and M 1 w \ 3É7 ] 106 g mol~1 [g] \ 11 cm3 g~1. Hydrodynamic properties indicated a highly branched structure. Fractions were obtained covering a range of molar masses. The intrinsic viscosity in 1É0 M aq. NaCl at 25¡C was found to depend on molar mass according to : [g]/cm3 g~1 \ 0É0145 M0Õ44. The hydrodynamic volume parameter [g]M gave a common GPC calibration for branched polysaccharide fractions and linear poly(oxyethylene) standards.