Department of Pesticide Science, Plant Protection College, Shenyang Agricultural University, Shenyang 110866, Liaoning, China.
Department of Pesticide Science, Plant Protection College, Shenyang Agricultural University, Shenyang 110866, Liaoning, China.
Bioorg Med Chem Lett. 2019 Jun 1;29(11):1345-1349. doi: 10.1016/j.bmcl.2019.03.047. Epub 2019 Mar 29.
To develop more valuable and effective fungicide candidates, a novel series of 3,4-dichloroisothioxazole-based cycloalkylsulfonamides were synthesized and their structures were identified by H NMR, C NMR, MS and elemental analysis. Compound 3k was further confirmed by X-ray single crystal diffraction. The in vitro bioassay results demonstrated that the target compounds showed significant fungicidal activity on mycelial growth and spore germination of Botrytis cinerea. Especially, compound 3j, with prominent inhibition effect on mycelial with EC and EC values of 1.4 and 23.7 μg/mL respectively, was comparable to the selected commercial fungicide. Moreover, at 50 μg/mL, the inhibition rate of compound 3j on spore germination was recorded up to 89.7%. The further in vivo bioassay results indicated compound 3j continued to show high control effect on tomato leaves, flowers and fruit at 200 μg/mL, with control efficiencies of 94.3%, 89.3% and 91.9%, respectively. The structure-activity relationship showed that the compound with a five-membered ring possessed the best activity after the introduction of the active fragment of the 3,4-dichloroisothioxazole, provided a valuable idea for further creation of new fungicides.
为了开发更有价值和有效的杀菌剂候选物，我们合成了一系列新型的基于 3,4-二氯异噻唑的环烷基磺酰胺，并通过 H NMR、C NMR、MS 和元素分析确定了它们的结构。化合物 3k 进一步通过 X 射线单晶衍射得到了证实。体外生物测定结果表明，目标化合物对灰葡萄孢菌的菌丝生长和孢子萌发具有显著的杀菌活性。特别是化合物 3j 对菌丝的抑制效果显著，EC 和 EC 值分别为 1.4 和 23.7μg/mL，与选定的商业杀菌剂相当。此外，在 50μg/mL 时，化合物 3j 对孢子萌发的抑制率高达 89.7%。进一步的体内生物测定结果表明，化合物 3j 在 200μg/mL 时对番茄叶片、花朵和果实仍表现出很高的防治效果，防治效率分别为 94.3%、89.3%和 91.9%。构效关系表明，在引入 3,4-二氯异噻唑的活性片段后，五元环化合物具有最佳活性，为进一步创制新型杀菌剂提供了有价值的思路。
