Chemical structure and mechanism of polysaccharide on Pb 2+ tolerance of Cordyceps militaris after Pb 2+ domestication

• Published in: International journal of biological macromolecules Vol. 165; no. Pt A; p. 958
• Main Authors: Song, Qiaoying, Zhu, Zhenyuan
• Format: Journal Article
• Language: English
• Published: Netherlands 15.12.2020
• Subjects: Adsorption - drug effects; Carbohydrates - chemistry; Carbohydrates - isolation & purification; Carbohydrates - toxicity; Cordyceps - chemistry; Cordyceps - drug effects; Dietary Carbohydrates; Galactose - chemistry; Glucose - chemistry; Glucuronic Acid - chemistry; Hexuronic Acids - chemistry; Lead - chemistry; Lead - toxicity; Molecular Weight; Polysaccharides - chemistry; Rhamnose - chemistry; Extracellular polysaccharide; Cordyceps militaris; Mechanism research; Structure analysis
• ISSN: 1879-0003

In this study, the purified polysaccharide (DCP-I) was extracted from Cordyceps militaris domesticated with Pb . After that, the structural feature and mechanism of lead resistance of DCP-I were investigated using novel approaches. The results showed that the average molecular weight of DCP-I was 1.206 × 10  kDa and mainly consist of Rhamnose, Galactose, Glucose, Galacturonic acid and Glucuronic acid in a molar ratio of 0.130:47.687:40.784:1.795:0.48. Besides, the main chain of DCP-I was composed by →6)-Galp-(1→, →4)-Glcp-(1→ and →1,4)-Glcp-(6→, while the side chain was →1)-Rhaf-(2→ and D-Glcp-(1→, and the DCP-I contained Alacturonic acid and Glucuronic acid. In addition, the result of Congo red test showed that DCP-I did not exist triple-helical structures. SEM, EDX and XPS analyses results showed that the functional groups of DCP-I related to C, H and O (-OH, -COOH and -C=O) could combined with Pb effectively. The adsorption processes were described by the Pseudo-second-order kinetic model (R  = 0.9978) and Langmuir isotherm (R  = 0.9979) for Pb indicating that adsorption process of DCP-I to Pb was a kind of single molecular layer chemical adsorption.