In this study, Cyclocarya paliurus polysaccharides purified by DEAE-cellulose columns (CPP_0.05) were modified with chlorosulfonic acid–pyridine (CSA–Pyr) method to obtain the sulfation derivative (S-CPP_0.05), whose structures were characterized by methylation and NMR analysis. The backbone of S-CPP_0.05 was composed of →3)-β-D-Galp-(1→4)-α-D-Glcp-(1→ substituted by α-L-Araf-(1→, →4, 6)-β-D-Galp-(1→ and α-D-Glcp-(1→ at O-4/5/6 position, terminated with α-L-Araf-(1→ and occasionally by α-D-Glcp-(1→. Sulfate groups were substituted at C6 of →4)-α-D-Glcp-(1→. CPP_0.05 and S-CPP_0.05 had the potential to scavenge DPPH, ABTS, hydroxyl and radical showing reducing power in vitro. CPP_0.05 and S-CPP_0.05 were found to suppress oxidant stress by improving the enzyme activities of SOD and CAT in dendritic cells (DCs) in the presence of H₂O₂. Results indicated that S-CPP_0.05 showed stronger antioxidant activity compared with CPP_0.05. Meanwhile, we found that Nrf2 proteins were significantly increased by the stimulus of polysaccharides with Keap1 decreasing which proved that the antioxidant effect was possibly performed via the Keap1-Nrf2 pathway. The results confirmed that C6 of Cyclocarya paliurus polysaccharides is an effective substitution site for sulfate groups.

在这项研究中，用氯磺酸-吡啶（CSA-Pyr）方法对DEAE-纤维素柱（CPP _0.05）纯化的环孢多糖进行了改性，得到了硫酸化衍生物（S-CPP _0.05），其结构通过甲基化和NMR进行了表征。分析。S-CPP _0.05的骨架由→3）-β-D-Galp-（1→4）-α-D-Glcp-（1→替换为α-L-Araf-（1→，→4， 6）-β-D-Galp-（1→和α-D-Glcp-（1→在O-4 / 5/6位置，被α-L-Araf-（1→终止，偶尔被α-D- Glcp-（1→。硫酸基在→4的C6处被取代）-α-D-Glcp-（1→.CPP _0.05和S-CPP _0.05具有清除DPPH，ABTS，羟基和自由基的潜力，在其中体外。发现在存在H ₂ O ₂的情况下，CPP _0.05和S-CPP _0.05通过改善树突状细胞（DC）中SOD和CAT的酶活性来抑制氧化应激。结果表明，与CPP _0.05相比，S-CPP _0.05显示出更强的抗氧化活性。同时，我们发现随着Keap1的减少，多糖的刺激使Nrf2蛋白显着增加，这表明抗氧化作用可能是通过Keap1-Nrf2途径进行的。结果证实，Cyclocarya paliurus多糖的C6是硫酸盐基团的有效取代位点。