In this paper, a series of phenoxypyridine-containing chalcone derivatives (L1–L28) were designed and synthesized, characterized on NMR and HRMS. Ningnanmycin (NNM) was used as a control agent. The results of the antiviral activity testing showed that the curative activity EC₅₀ values of L1 and L4 against TMV were 140.5 and 90.7 μg/mL, respectively, which were superior to that of NNM (148.3 μg/mL). The EC₅₀ values of 154.1, 102.6 and 140.0 μg/mL for the anti-TMV protective activities of L1, L4 and L15 were superior to that of NNM (188.2 μg/mL). The mechanism of action between L4 and NNM and tobacco mosaic virus capsid protein (TMV-CP) was preliminarily investigated. The results of microscale thermophoresis (MST) experiments showed that L4 had a strong binding affinity for TMV-CP with a dissociation constant Kd value of 0.00149 µM, which was better than that of NNM (2.73016 µM). The results of molecular docking experiments showed that L4 formed shorter hydrogen bonds with amino acid residues of TMV-CP than NNM and formed more amino acid residues than NNM, which indicated that L4 was more tightly bound to TMV-CP. This study suggested that phenoxypyridine-containing chalcone derivatives can be used as new anti-TMV drugs through further research and development.

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中文翻译：

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苯氧基吡啶查耳酮衍生物的抗病毒活性评价及作用机制

本文设计并合成了一系列含苯氧基吡啶的查尔酮衍生物( L1 – L28 )，并通过NMR和HRMS进行了表征。宁南霉素（NNM）用作对照剂。抗病毒活性测试结果显示，L1和L4对TMV的疗效EC ₅₀值分别为140.5和90.7 μg/mL，优于NNM（148.3 μg/mL）。L1、L4和L15的抗TMV保护活性的EC ₅₀值分别为154.1、102.6和140.0μg/mL，优于NNM(188.2μg/mL)。初步探讨了L4和NNM与烟草花叶病毒衣壳蛋白(TMV-CP)的作用机制。微尺度热泳（MST）实验结果表明，L4对TMV-CP有很强的结合亲和力，解离常数Kd值为0.00149 µM，优于NNM（2.73016 µM）。分子对接实验结果表明，L4与TMV-CP的氨基酸残基形成的氢键比NNM更短，形成的氨基酸残基比NNM更多，这表明L4与TMV-CP的结合更紧密。本研究提示含苯氧基吡啶的查耳酮衍生物通过进一步研究开发可作为新型抗TMV药物。

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