Isolation and characterization of a novel polysaccharide from seeds of Peltophorum pterocarpum

Peltophorum pterocarpum seeds yielded similar to 20% water soluble polysaccharide. The polysaccharide is a galactomannan with mannose:galactose ratio of 4.4:1. The polysaccharide had an intrinsic viscosity of 3.14 dl/g and weight average molecular weight of 2.49 x 10(5) g/mol. The polysaccharide solutions were non-Newtonian at concentrations above 1%. A double logarithmic plot of the zero shear specific viscosity versus volume concentration gave a coil overlap concentration, c* of 2.6/[eta], with slope C-1.4 in the dilute regime and C-4.3 in the concentrated regime. The experimental data were fitted to different viscosity models with the Martin model giving the best fit. The Cox-Merz empirical rule gave close superimposition of the data from steady shear viscosity eta(gamma) over dot and complex viscosity eta*(omega) (C) 2014 Elsevier Ltd. All rights reserved.