Conformational properties of high molecular weight heteropolysaccharide isolated from seeds of Artemisia sphaerocephala Krasch

The conformational properties of a high molecular weight polysaccharide (60P) extracted from Artemisia sphaerocephala Krasch (ASK) were investigated. The Mw and Rg of 60P were obtained using both static light scattering and HPSEC techniques, which were 590 kDa and 56 nm, respectively. Dynamic light scattering measurement indicated that 0.5 M NaOH solvents exhibited the ability to reduce/eliminate aggregates of 60P. 60P in 0.5 M NaOH showed strong concentration dependence, but minimal angular dependence. The average structure parameter ρ (Rg/Rh) value of 1.75 indicated that 60P exhibited a random coil conformation in 0.5 M NaOH solution. The conformational parameters (derived from Rg vs Mw and Rh vs Mw) from HPSEC also suggested a random coil conformation of 60P in 0.1 M NaNO3 solution (eluent for HPSEC). The characteristic ratio and the persistence length obtained from the random flight model and wormlike cylinder model both indicated a semi-flexible structure of 60P.