马铃薯三糖熊果酸衍生物抑制H5N1流感病毒进入靶细胞

3-O-β-chacotriosyl benzyl ursolate inhibits entry of H5N1 influenza virus into target cells

目的研究马铃薯三糖熊果酸衍生物能否通过抑制H5N1流感病毒进入靶细胞,作为潜在的新型抗流感药物进行研发。方法以马铃薯三糖熊果酸甲酯1为先导化合物,设计并合成4个目标化合物,利用建立的H5N1假病毒活性检测方法,测试化合物的抑制活性。结果化合物1b,1c和1d对源自A/Thailand/Kan353/2004的H5N1假病毒毒株有明显的抑制作用且化合物1 d的活性最好,其IC50达到0.96±0.10μmol/L。结论初步构效关系研究表明,熊果酸的C-17位羧基被酯化后可显著提高其抗病毒活性;将羧基转化成酰胺后可提高抗病毒活性并降低对靶细胞MDCK的细胞毒性。

Objective To study the inhibitory activities of 3-O-β-chacotriosyl benzyl ursolate and its derivatives as potential new anti-influenza virus agents against the entry of H5N1 influenza viruses into the target cells. Methods Four target compounds were designed and synthesized, which were structurally related to the lead compound 3-O-β-chacotriosyl methyl ursolate（1）.The inhibitory activities of these compounds were tested at a cellular level psuedovirus system targeting H5N1 influenza viruse entry. Results and Conclusion The compounds 1b, 1c and 1d showed potent inhibitory activities against the entry of A/Thailand/Kan353/2004 pseudovirus into the target cells, and among them compound 1d showed the strongest inhibitory activity with an IC50 value of 0.96±0.10 μmol/L. The structure-activity relationship analysis of these compounds indicated that when 17-COOH of ursolic acid was esterified, introduction of Me groups rather than aryl groups more strongly enhanced the inhibitory activity. Changing 17- COOH of ursolic acid into amide could increase the antiviral activity and decrease the cytotoxicity of the compounds in MDCK cells.