Solution properties of (1→3)‐α‐ D ‐glucan and its sulfated derivative from Poria cocos mycelia via fermentation tank

Qilin Huang; Lina Zhang

doi:10.1002/bip.20332

$From Poria cocos mycelia yielded via a pilot scale facility–fermentation tank, a water‐insoluble (1→3)‐α‐D‐glucan coded as Pi‐PCM3‐I was isolated by extraction with 0.5 M NaOH/0.01 M NaBH4 aqueous solution. Nine fractions from F1 to F9 with a weight‐average molecular mass (Mw) range from 7.75 × 104 to 57.3 × 104 were prepared from the Pi‐PCM3‐I sample by a nonsolvent addition method. The fractions were reacted with chlorosulfonic acid–pyridine complex to product water‐soluble sulfated derivatives coded as S1 to S8 with Mw from 2.36 × 104 to 14.5 × 104 and degree of substitution (DS) of 0.86–1.38. Mw, z‐average radius of gyration (⟨s2⟩ z1/2), the second virial coefficient (A2), and the intrinsic viscosity ((η)) of the native and sulfated Pi‐PCM3‐I were measured by laser light scattering (LLS), size‐exclusion chromatography combined with LLS (SEC–LLS), and viscometry at 25°C. The Mark–Houwink equations for Pi‐PCM3‐I in 0.25 M LiCl/dimethylsulfoxide (DMSO) (Me2SO) and for its sulfated derivative in 0.15 M NaCl aqueous solution at 25°C were established to be (η) = 1.33 × 10−2 Mw0.75±0.01 (mL g–1) and (η) = 1.46 × 10−4 Mw1.13±0.01 (mL g–1), respectively. On the basis of theories for a wormlike cylinder model, the conformational parameters of the native and sulfated Pi‐PCM3‐I were calculated to be 760 ± 50 and 1060 ± 30 nm–1 for the molar mass per unit contour length (ML), 6.3 ± 0.5 and 13.1 ± 1 nm for the persistence length (q), and 14.9 ± 0.2 and 31.8 ± 1 for the characteristic ratio (C∝), respectively. The results revealed that Pi‐PCM3‐I existed as an extended flexible chain in 0.25 M LiCl/Me2SO, and its sulfated derivative existed as a semistiff chain in 0.15 M NaCl aqueous solution. Furthermore, Pi‐PCM3‐I possessed similar structure and molecular parameters to wc‐PCM3‐I from a rotary shaker; this suggests promising industrialization of Poria cocos polysaccharides. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 28–38, 2005 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com$

Solution properties of (1→3)‐α‐ D ‐glucan and its sulfated derivative from Poria cocos mycelia via fermentation tank

Huang, Qilin; Zhang, Lina

Follow Biopolymers , Volume 79 (1) Wiley – Sep 1, 2005