%0 Journal Article
%T Sulfation and Enhanced Antioxidant Capacity of an Exopolysaccharide Produced by the Medicinal Fungus Cordyceps sinensis
%A Jing-Kun Yan
%A Wen-Qiang Wang
%A Hai-Le Ma
%A Jian-Yong Wu
%J Molecules
%D 2013
%I MDPI AG
%R 10.3390/molecules18010167
%X 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¨C1.38) and molecular weights (17.1¨C4.1 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.
%K Cordyceps sinensis
%K exopolysaccharide
%K sulfation
%K molecular weight
%K antioxidant activity
%U http://www.mdpi.com/1420-3049/18/1/167