Key Laboratory of Green Prevention and Control of Tropical Agriculture and Forestry BioDisasters of Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
Int J Mol Sci. 2024 Aug 25;25(17):9209. doi: 10.3390/ijms25179209.
Southern root-knot nematodes are among the most pernicious phytoparasites; they are responsible for substantial yield losses in agricultural crops worldwide. The limited availability of nematicides for the prevention and control of plant-parasitic nematodes necessitates the urgent development of novel nematicides. Natural products have always been a key source for the discovery of pesticides. Waltherione A, an alkaloid, exhibits potent nematocidal activity. In this study, we designed and synthesized a series of quinoline and quinolone derivatives from Waltherione A, leveraging a strategy of structural simplification. Bioassays have revealed that the quinoline derivatives exhibit better activity than quinolone derivatives in terms of both nematocidal and fungicidal activities. Notably, compound D1 demonstrated strong nematocidal activity, with a 72 h LC of 23.06 μg/mL, and it effectively controlled the infection of root-knot nematodes on cucumbers. The structure-activity relationship suggests that the quinoline moiety is essential for the nematocidal efficacy of Waltherione A. Additionally, compound D1 exhibited broad-spectrum fungicidal activity, with an EC of 2.98 μg/mL against . At a concentration of 200 μg/mL, it significantly inhibited the occurrence of on tomato fruits, with an inhibitory effect of 96.65%, which is slightly better than the positive control (90.30%).
南方根结线虫是最有害的植物寄生线虫之一；它们导致全球农业作物的大量减产。由于预防和控制植物寄生线虫的杀线虫剂的有限可用性，迫切需要开发新型杀线虫剂。天然产物一直是发现农药的主要来源。生物碱 Waltherione A 具有很强的杀线虫活性。在这项研究中，我们设计并合成了一系列从 Waltherione A 衍生而来的喹啉和喹诺酮衍生物，采用了简化结构的策略。生物测定表明，与喹诺酮衍生物相比，喹啉衍生物在杀线虫和杀菌活性方面都表现出更好的活性。值得注意的是，化合物 D1 表现出很强的杀线虫活性，72 h LC 为 23.06 μg/mL，有效控制了黄瓜根结线虫的感染。构效关系表明，喹啉部分是 Waltherione A 杀线虫活性所必需的。此外，化合物 D1 表现出广谱杀菌活性，对 的 EC 为 2.98 μg/mL。在 200 μg/mL 浓度下，它显著抑制番茄果实上的发生，抑制率为 96.65%，略优于阳性对照（90.30%）。
