Twenty-eight imidazo[1,2-c]pyrimidin-5(6H)-one nucleoside derivatives incorporating a sulfonamide scaffold with preferable inactivating activities on pepper mild mottle virus (PMMoV) were designed and synthesized. Then, compound B29 with illustrious inactivating activity against PMMoV was received on the basis of the three-dimensional quantitative structure–activity relationship (3D-QSAR) model, with the EC₅₀ of 11.4 μg/mL, which was superior to ningnanmycin (65.8 μg/mL) and template molecule B16 (15.3 μg/mL). Furthermore, (1) transmission electron microscopy (TEM) indicated that B29 could cause severe fracture of virions; (2) microscale thermophoresis (MST) and molecular docking further demonstrated that B29 had faintish binding affinities with PMMoV CP^R62A (K_d = 202.84 μM), PMMoV CP^L144A (K_d = 141.57 μM), and PMMoV CP^R62A,L144A (K_d = 332.06 μM) compared to PMMoV CP (K_d = 4.76 μM); and (3) western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results of pCB-GFP-PMMoV CP^R62A, pCB-GFP-PMMoV CP^L144A, and pCB-GFP-PMMoV CP^R62A,L144A were consistent with MST and confocal. In brief, the above results indicated that the amino acids at positions 62 and 144 of PMMoV CP might be the key amino acid sites of B29 acted on.

中文翻译：

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含磺胺支架的咪唑并[1,2-c]嘧啶-5(6H)-一个核苷衍生物的灭活活性和机制

设计并合成了28 种咪唑并[1,2- c ]嘧啶-5(6 H )-1 核苷衍生物，它们结合了磺胺类支架，对胡椒轻斑驳病毒 (PMMoV) 具有较好的灭活活性。然后，基于三维定量构效关系（3D-QSAR）模型得到对PMMoV具有显着灭活活性的化合物B29 ，EC ₅₀为11.4 μg/mL，优于宁南霉素（65.8 μg） /mL) 和模板分子B16 (15.3 μg/mL)。此外，(1) 透射电子显微镜 (TEM) 表明B29可能导致病毒颗粒严重破裂；(2) 微量热泳(MST)和分子对接进一步证明B29与PMMoV CP ^R62A ( K _d = 202.84 μM), PMMoV CP ^L144A ( K _d = 141.57 μM), PMMoV CP ^R62A,L144A ( K _{d = 332.06 μM) 与 PMMoV CP (} K _d = 4.76 μM)相比；^{(3) pCB-GFP-PMMoV CP R62A}、pCB-GFP-PMMoV CP ^L144A和 pCB-GFP-PMMoV CP R62A ^,L144A的蛋白质印迹和逆转录定量聚合酶链反应 (RT-qPCR) 结果与 MST 和共聚焦一致。综上所述，上述结果表明PMMoV CP的62位和144位氨基酸可能是B29作用的关键氨基酸位点。