Structure And Chain Conformation Characterization Of Arabinoglucan From By-Product Of Peanut Oil Processing

A neutral polysaccharide (NPP) from peanut sediment of aqueous extraction process was purified via anion-exchange and gel-filtration chromatography. The weight-average molecular weight and polydispersity index were 3.36 x 10(4) Da and 1.06. Composition of glucose (82.66 %, molar percentage) and arabinose (17.34 %) suggested an arabinoglucan structure. Multiple medium-length chains consisting of many 1,4-linked alpha-Glcp and a few 1,5-linked alpha-Araf maintained the main chain structure. The backbone was substituted at O-6 and O-3 positions, attached by side chains consisting of two to six alpha-Glcp and terminated with Araf and Glcp. Degree of branching was 42.50 %. Aggregates formed in NPP aqueous solution. They were eliminated by DMSO combining with sonication. Consequently, the average radius of gyration (R-g), hydrodynamic radius (R-h), and R-g/R-h ratio were 17.0 nm, 5.8 nm and 2.93, respectively, indicating extended rigid chain conformation. The backbone substituted at O-3 and short branching chains probably together induced this conformation.