BACKGROUNDCeratocystis fimbriata is a fungal pathogen that infects sweet potato roots, producing enormous economic losses. Cyclic polyhydroxy compound quinic acid is a common metabolite synthesized in plant tissues, including sweet potato tubers, showing weak antifungal properties. Although several O‐acylated quinic acid derivatives have been synthesized and found in nature and their antifungal properties have been explored, derivatives based on modification of the carboxylic acid have never been evaluated.RESULTSIn this study, amide derivatives were synthesized via linkage of amines with the carboxylic acid moiety of quinic acid. Derivatives with high dipolar moments and a low number of rotatable bonds showed greater antifungal activities toward C. fimbriata in vitro than quinic and chlorogenic acids. Derivative 5b, which was synthesized by coupling p‐aminobenzoic acid (pABA) with quinic acid, had the greatest antifungal activity. 5b showed iron(II)‐chelating properties and reduced ergosterol content in C. fimbriata cells, causing irregularities in the fungal cell wall and inhibiting conidia agglutination. Application of 3 mm 5b reduced black rot symptoms in sweet potatoes by 70.1%.CONCLUSIONSCollectively, derivatization of the carboxylic acid from quinic acid was demonstrated to be a suitable strategy to improve the antifungal properties of this compound. This study reveals a new efficient strategy for management of the sweet potato pathogen C. fimbriata. © 2024 Society of Chemical Industry.

中文翻译：

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奎宁酸新型酰胺衍生物的合成及抗真菌活性


背景Ceratocystis fimbriata 是一种真菌病原体，可感染甘薯根部，造成巨大的经济损失。环状多羟基化合物奎宁酸是在植物组织中合成的常见代谢产物，包括甘薯块茎，表现出较弱的抗真菌特性。尽管已经在自然界中合成并发现了几种 O-酰化奎宁酸衍生物，并且已经探索了它们的抗真菌特性，但基于羧酸修饰的衍生物从未被评估过。结果本研究通过胺与奎宁酸的羧酸部分键合合成酰胺衍生物。具有高偶极矩和少量可旋转键的衍生物在体外显示出比奎因酸和绿原酸更大的对 C. fimbriata 的抗真菌活性。通过将对氨基苯甲酸 （pABA） 与奎宁酸偶联合成的衍生物 5b 具有最大的抗真菌活性。5b 在 C. fimbriata 细胞中显示出铁 （II） 螯合特性和麦角甾醇含量降低，导致真菌细胞壁不规则并抑制分生孢子凝集。施用 3 mm 5b 可将甘薯的黑腐病症状降低 70.1%。结论从奎宁酸衍生羧酸被证明是改善该化合物抗真菌性能的合适策略。本研究揭示了一种管理甘薯病原体 C. fimbriata 的新有效策略。© 2024 化工学会.