title: Ultrasonic treatment for improved solution properties of a high-molecular weight exopolysaccharide produced by a medicinal fungus.
abstract: High-power ultrasound (20 kHz) was applied to modify the physicochemical properties of a high-molecular weight (MW) exopolysaccharide (EPS) from mycelial culture of a medicinal fungus. At 35 W/cm(2) or higher ultrasound power, the apparent and intrinsic viscosities of EPS solution dropped by nearly 85% within 10 min, and the water solubility was increased by more than fourfold. The ultrasonic treatment led to a notable reduction of the maximum MW and a more uniform MW distribution, but no significant change in the primary structure of the EPS molecules. In contrast, the intrinsic viscosity of EPS was reduced by only 20% in 1.0M sulfuric acid at 50 degrees C for 9h. Ultrasound was proven an effective and favorable means for improving the solution properties of high-MW bioactive polysaccharides in mild conditions.
authors.affiliation: Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
authors.forename: Zhao-Mei
authors.initials: ZM
authors.lastname: Wang
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Cheung
authors.forename: Po-Hong
authors.initials: PH
authors.lastname: Leung
authors.forename: Jian-Yong
authors.initials: JY
authors.lastname: Wu
mesh_terms: D002460:Cell Line; D003224:Congo Red / Q000494:pharmacology; D005658:Fungi / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D018625:Microscopy, Atomic Force / Q000379:methods; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry*; D012995:Solubility; D013010:Sonication; D013055:Spectrophotometry, Infrared / Q000379:methods; D013696:Temperature; D013997:Time Factors; D014465:Ultrasonics; D014783:Viscosity
chemical_list: D011134:Polysaccharides; D003224:Congo Red