Laboratory of Pesticidal Design & Synthesis, Department of Plant Protection, College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, 471023, China.
Chem Biodivers. 2022 Jun;19(6):e202200255. doi: 10.1002/cbdv.202200255. Epub 2022 May 27.
To discover novel molecules with unique mechanism against plant pathogenic oomycetes, sixteen new sulfonate derivatives of ethyl maltol (3a-p) were synthesized by structural modification of 2-ethyl-3-hydroxy-4H-pyran-4-one, and their anti-oomycete activity against a serious agricultural disease, Phytophthora capsici Leonian was determined in this study. Among all tested compounds, derivatives 3e, 3m and 3p exhibited the most potent anti-oomycete activity against P. capsici with EC values of 19.40, 21.04 and 31.10 mg/L, respectively; especially 3e and 3m showed the best promising and pronounced anti-oomycete activity than zoxamide (EC =26.87 mg/L). The results further proved that 4-tert-butylphenylsulfonyl group, 3-nitro-4-chlorophenylsulfonyl group and 8-quinolinesulfonyl group introduced at the hydroxy position of ethyl maltol or maltol were necessary for obtaining the most potent compounds. Further mechanism studies of P. capsici treated with 3e demonstrated that this compound can affect the growth of mycelia by disrupting the integrity of the membrane, and the higher the concentration of the compound is, the greater the degree of membrane integrity damage. These important results will pave the way for further modification of ethyl maltol to develop potential new fungicides.
为了发现具有独特作用机制的新型抗植物病原卵菌的分子，通过对 2-乙基-3-羟基-4H-吡喃-4-酮的结构修饰，合成了十六种乙基麦芽酚的新型磺酸盐衍生物（3a-p），并在本研究中测定了它们对一种严重的农业病害——辣椒疫霉的抗卵菌活性。在所测试的所有化合物中，衍生物 3e、3m 和 3p 对 P. capsici 的抗卵菌活性最强，EC 值分别为 19.40、21.04 和 31.10 mg/L；特别是 3e 和 3m 比唑酰胺（EC = 26.87 mg/L）表现出更好的、显著的抗卵菌活性。结果进一步证明，在乙基麦芽酚或麦芽酚的羟基上引入 4-叔丁基苯磺酰基、3-硝基-4-氯苯磺酰基和 8-喹啉磺酰基是获得活性最强的化合物所必需的。用 3e 处理辣椒疫霉的进一步机制研究表明，该化合物可以通过破坏膜的完整性来影响菌丝的生长，化合物的浓度越高，膜完整性的破坏程度越大。这些重要的结果将为进一步修饰乙基麦芽酚以开发潜在的新型杀菌剂铺平道路。
