Ultrasonic degradation of aqueous dextran: Effect of initial molecular weight and concentration

• Published in: Carbohydrate polymers Vol. 90; no. 1; pp. 447 - 451
• Main Authors: Zou, Qingsong, Pu, Yuanyuan, Han, Zhong, Fu, Nan, Li, Suxia, Liu, Mei, Huang, Lei, Lu, Angen, Mo, Jianguang, Chen, Shan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-09-2012; Elsevier
• Subjects: Applied sciences; Concentration; Dextran; Dextrans - analysis; Dextrans - chemistry; Dextrans - metabolism; Exact sciences and technology; High performance gel permeation chromatography (HPGPC); Initial molecular weight (IMW); Molecular Weight; Natural polymers; Physicochemistry of polymers; Sound; Starch and polysaccharides; Ultrasonic degradation; Water - analysis; Water - chemistry; Water - metabolism; Dextran; High performance gel permeation chromatography (HPGPC); Initial molecular weight (IMW); Concentration; Ultrasonic degradation; Sonochemical reaction; Chemical degradation; Experimental study; Reaction rate; Depolymerization; Concentration effect; Oside polymer; Aqueous solution; Ultrasound
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2012.05.064

► Ultrasonic degradation proceeded faster in higher IMW dextrans. ► Dextran depolymerized faster in dilute solutions. ► The polydispersity of dextran was improved by ultrasonic treatment.
Seven dextrans with different initial molecular weight (IMW) were depolymerized by ultrasonic treatment. The effects of IMW in a wide range from 9.3×103Da to 1.7×106Da and solution concentration (1, 10 and 20mg/mL) on dextran degradation were investigated. Changes in weight-average molecular weight (Mw) and polydispersity index (D value) were monitored as a function of ultrasonic time. Results showed that Mw and D value decreased with increasing time of ultrasonic treatment. Moreover, the degradation proceeded faster for higher IMW dextrans and more dilute solutions, yielding lower molecular weight dextrans and more homologous solutions. Percentage variation of dextran fragments at different molecular weight divisions showed that most of the degradation took place in larger molecular weight fragments. Ultrasonic treatment is a simple and controllable method for producing dextrans with low molecular weight, which are more suitable for clinical use.