Studies on molecular weights of polysaccharides of Auricularia auricula-judae

Abstract Three d -glucans (A, C, and E) and two acidic heteropolysaccharides (D and B), isolated from the fruit bodies of Auricularia auricula-judae (which grows in Fangshan, Hubei, China) were analysed by paper chromatography, gas chromatography, and IR and 13 C NMR. Glucans A, C, and E consist mainly of a backbone chain of β-(1 → 3)- d - glucose residues, with various branched groups. Polysaccharides D and B contain residues of d -xylose, d -mannose, d -galactose, d -glucose, and d -glucuronic acid. The weight-average molecular weights M w , number-average molecular weights M w , intrinsic viscosities [ν], and Huggins constants k ′ of these polysaccharides were studied by light scattering, membrane osmometry, and viscometry. The values of M w for samples of A, C, E, D, and B are 117 × 10 4 , 144 × 10 4 , 200 × 10 4 , 30 × 10 4 , and 50 × 10 4 , respectively. Analysis of the M w , M n , [ ν ], and k ′ data indicates polysaccharides A and E to have stiff chains, and C, D, and B flexible chains in aqueous solutions.