BACKGROUNDA recent increase in severe fever with thrombocytopaenia syndrome (SFTS) virus cases in Korea has been observed. This virus attacks humans and animals, and no drug is available for its treatment. This study is investigating potential control measures targeting the causative agent, Haemaphysalis longicornis.RESULTSLepidium meyenii oil was ≈8.3‐, 4.2‐ and 4.1‐fold more active than diethyltoluamide against H. longicornis larvae, nymphs and adults, respectively. The major components of L. meyenii oil were identified as benzyl nitrile (71.64%), followed by ethyl linoleic acid (13.32%), ethyl palmitate (7.81%) and 3‐methoxybenzyl nitrile (2.10%). In testing individual components of the oil were tested against H. longicornis adults, the half‐maximal lethal dose (LD50) values for benzaldehyde, benzyl nitrile and benzyl isothiocyanate were found to be 9.21, 9.19 and 18.26 μg cm−3, respectively. The acaricidal component was isolated and identified as benzyl nitrile. To establish the structure–activity relationships between nitrile analogues and acaricidal activities, benzyl nitrile (LD50: 0.56, 6.38 and 9.19 μg cm−3) exhibited the highest acaricidal activities against H. longicornis larvae, nymphs and adults, followed by benzoyl nitrile (3.24, 8.36 and 15.47 μg cm−3), phenyl nitrile (5.45, 9.35 and 17.48 μg cm−3) and diethyltoluamide (7.95, 14.81 and 22.12 μg cm−3). However, the presence of allyl, methyl or vinyl functional groups bound to the nitrile group abolished the acaricidal activity.CONCLUSIONThese results demonstrate that L. meyenii oil, benzyl nitrile, benzoyl nitrile and phenyl nitrile represent suitable options for the secure management of H. longicornis. Nevertheless, additional research is essential to develop formulations that enhance the efficacy and safety of the aforementioned acaricides. © 2024 Society of Chemical Industry.

中文翻译：

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丁腈类似物与抗长角血螨杀螨活性的结构-活性关系


背景最近在韩国观察到严重发热伴血小板减少症综合征 （SFTS） 病毒病例的增加。这种病毒攻击人类和动物，没有可用于治疗的药物。本研究正在调查针对病原体 Haemaphysalis longicornis 的潜在控制措施。结果Lepidium meyenii 油对长角蚜幼虫、若虫和成虫的活性分别是二乙基甲苯酰胺的 ≈8.3 倍、4.2 倍和 4.1 倍。梅耶腈油的主要成分为腈苄酯 （71.64%），其次是亚油酸乙酯 （13.32%）、棕榈酸乙酯 （7.81%） 和 3-甲氧基苄基腈 （2.10%）。在对 H. longicornis 成虫测试油的单个成分时，发现苯甲醛、腈苄和异硫氰酸苄酯的半数最大致死剂量 （LD50） 值分别为 9.21、9.19 和 18.26 μg cm-3。分离杀螨成分并鉴定为苄基腈。为了建立丁腈类似物与杀螨活性之间的构效关系，苄基腈（LD50：0.56、6.38 和 9.19 μg cm-3）对长角腈幼虫、若虫和成虫表现出最高的杀螨活性，其次是苯甲酰腈（3.24、8.36 和 15.47 μg cm-3）、苯基腈（5.45、9.35 和 17.48 μg cm-3）和二乙基甲苯酰胺（7.95、14.81 和 22.12 μg cm-3）。然而，与腈基结合的烯丙基、甲基或乙烯基官能团的存在消除了杀螨活性。结论结果表明，梅耶腈乳杆菌油、苄基腈、苯甲酰腈和苯腈是安全管理长腈的合适选择。 然而，额外的研究对于开发提高上述杀螨剂的有效性和安全性的配方至关重要。© 2024 化工学会.