Bioassay-guided fractionation of the supernatant of the biocontrol strain Bacillus amyloliquefaciens W1 led to the isolation of eight acaricidal cyclodipeptides from the active fractions by column chromatography separation and HPLC purification. The chemical structures of these compounds were identified as cyclo-(Gly-l-Phe), 2, cyclo-(l-Phe-trans-4-OH-l-Pro), 3, cyclo-(Gly-l-Tyr), 4, cyclo-(l-Ala-l-Pro), 5, cyclo-(l-Pro-trans-4-OH-l-Pro), 6, cyclo-(Gly-l-Pro), 7, cyclo-(l-Pro-l-Pro), 8, and cyclo-(l-Tyr-trans-4-OH-l-Pro), 9. Those cyclodipeptides displayed significant acaricidal activities with LC₅₀ values of 13.85–98.24 μM. Cyclo-(l-Tyr-trans-4-OH-l-Pro) (LC₅₀ 13.85 μM) was five times more effective than the positive control abamectin (LC₅₀ 72.06 μM). The results indicated that the hydroxyl group is an important component. This is the first report on the acaricidal capabilities of cyclodipeptides against Tetranychus urticae. The results revealed that the acaricidal activity of the biocontrol strain B. amyloliquefaciens W1 was dependent on its constituent cyclodipeptides, which have the potential to be safe and environmentally friendly acaricides.

中文翻译：

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解淀粉芽孢杆菌W1的环二肽对荨麻疹的杀螨活性

生物控制菌株解淀粉芽孢杆菌W1的上清液的生物测定指导的分馏导致通过柱色谱分离和HPLC纯化从活性馏分中分离出八个杀螨环二肽。这些化合物的化学结构被鉴定为环-（Gly- 1- Phe），2，环-（1 - Phe-反式-4-OH- 1 - Pro），3，环-（Gly- 1- Tyr） ，4，环- （升-Ala-升-Pro），5，环- （升-Pro-反式-4- OH-升-Pro），6，环- （Gly-升-Pro），7，环- （升-Pro-升-Pro），8，和环- （升-Tyr-反式-4- OH-升-Pro），9。这些环二肽显示出显着的杀螨活性，LC ₅₀值为13.85–98.24μM。环-（1 - Tyr-反式-4-OH- 1 - Pro）（LC ₅₀ 13.85μM ）比阳性对照阿维菌素（LC ₅₀）有效五倍72.06μM）。结果表明，羟基是重要的组分。这是关于环二肽对荨麻螨的杀螨能力的第一份报告。结果表明，生物控制菌株解淀粉芽孢杆菌W1的杀螨活性取决于其构成的环二肽，它们有可能是安全和环境友好的杀螨剂。