title: Sulfation and enhanced antioxidant capacity of an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis.
abstract: EPS-1 was an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis (Cs-HK1). In the present study, EPS-1 was sulfated with chlorosulfonic acid (CSA)-pyridine (Pyr) at different volume ratios, yielding four sulfated derivatives, SEPS-1A, B, C and D, with different degrees of substitution (DS: 0.25-1.38) and molecular weights (17.1-4.1 kDa). The sulfation of EPS-1 occurred most frequently at the C-6 hydroxyl groups due to their higher reactivity. In aqueous solution, the native EPS-1 formed random coils or aggregated networks, but the sulfated derivatives formed single helices. The antioxidant activities of the sulfated EPS-1 derivatives for scavenging hydroxyl radicals (•OH) and 2,2-azinobis-3-ehtylbenzothiazolin-6-sulfonic acid radicals (ABTS•+) were significantly increased with increasing DS and decreasing molecular weight (MW). Sulfation has thus been shown to be an effective and favorable strategy for improving the physico-chemical properties and bioactivities of fungal polysaccharides.
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China.
authors.forename: Jing-Kun
authors.initials: JK
authors.lastname: Yan
authors.forename: Wen-Qiang
authors.initials: WQ
authors.lastname: Wang
authors.forename: Hai-Le
authors.initials: HL
authors.lastname: Ma
authors.forename: Jian-Yong
authors.initials: JY
authors.lastname: Wu
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D052160:Benzothiazoles / Q000737:chemistry; D032661:Cordyceps / Q000737:chemistry*; D062610:Fungal Polysaccharides / Q000737:chemistry*; D008970:Molecular Weight; D010084:Oxidation-Reduction; D013431:Sulfates / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D062610:Fungal Polysaccharides; D013431:Sulfates; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C013880:chlorosulfonic acid