Molecular mass and chain conformations of Rhizoma Panacis Japonici polysaccharides

作者：Huang Zhiping; Huang Yinan; Li Xubing; Zhang Lina^*

来源：Carbohydrate Polymers, 2009, 78(3): 596-601.

DOI：10.1016/j.carbpol.2009.05.027

• Rhizoma Panacis Japonici
• Polysaccharides
• Molecular mass
• Chain conformation
• Molecular size
• alpha-D-(1 -> 4)-Glucan

The molecular mass and size of five water-soluble polysaccharides isolated from Rhizoma Panacis Japonici (RPJ) were determined with laser light scattering (LLS), size-exclusion chromatography (SEC) combined with LLS (SEC-LLS), dynamic light scattering (DLS), as well as transmission electron microscope (TEM). Their weight-average molecular masses (M(w)) were 3.5 x 10(4), 1.47 x 10(5), 1.24 x 10(6), 9.26 x 10(5) and 1.36 x 10(6), radii of gyration ((1/2)(z)) were 14.7, 31.7, 50.8, 41.8 and 40.4 nm, and hydrodynamic radii (Rh) were 19.9, 37.5, 66.2, 52.1, and 55.2 nm, respectively. The results showed that molecular masses and sizes of the polysaccharides were influenced by the pH and temperature of the extraction mediums. The conformation parameters were calculated from the above data according to polymer solution theory. The values of rho (= (1/2)(z)/R(h)) were from 0.7 to 0.8, exponents (nu) of (1/2)(z) = k M(w)(nu) were from 0.31 to 0.43, and fractal dimension (d(f)) were from 2.3 to 3.2, respectively. The results revealed that all of the polysaccharides existed as spheres in 0.15 M NaCl aqueous solution. TEM and atomic force microscope (AFM) further confirmed the spherical morphologies of these molecules. The spherical conformations of the polysaccharides were a result of their highly branched structures.

• 出版日期2009-10-15
• 单位武汉大学; 湖北航天化学技术研究所