Natural products are a source for pesticide or drug discovery. In order to discover lead compounds with high fungicidal or herbicidal activity, new niacinamide derivatives derived from the natural product niacinamide, containing chiral flexible chains, were designed and synthesized. Their structures were confirmed by 1H NMR, 13C NMR and HRMS analysis. The fungicidal and herbicidal activities of these compounds were tested. The fungicidal activity results demonstrated that the compound (S)-2-(2-chloronicotinamido)propyl-2-methylbenzoate (3i) exhibited good fungicidal activity (92.3% inhibition) against the plant pathogen Botryosphaeria berengriana at 50 μg/mL and with an EC50 of 6.68 ± 0.72 μg/mL, which is the same as the positive control (fluxapyroxad). Compound 3i was not phytotoxic and could therefore be used as a fungicide on crops. Structure-activity relationships (SAR) were studied by molecular docking simulations with the succinate dehydrogenase of the fungal mitochondrial respiratory chain.

中文翻译：

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含有柔性手性链的新型烟酰胺衍生物的合成及其杀虫活性。

天然产物是杀虫剂或药物发现的来源。为了发现具有高杀菌或除草活性的先导化合物，设计并合成了源自天然产物烟酰胺的含有手性柔性链的新型烟酰胺衍生物。它们的结构通过1H NMR、13C NMR和HRMS分析得到证实。测试了这些化合物的杀真菌和除草活性。杀真菌活性结果表明，化合物 (S)-2-(2-chloronicotinamido)propyl-2-methylbenzoate (3i) 在 50 μg/mL 时对植物病原体 Botryosphaeria berengriana 表现出良好的杀真菌活性（92.3% 抑制），并且具有EC50 为 6.68 ± 0.72 μg/mL，与阳性对照（fluxapyroxad）相同。化合物 3i 没有植物毒性，因此可用作农作物的杀菌剂。