含1,3,4-噁二唑-2-硫基片段的蛇床子素类衍生物的合成及其杀虫/杀螨活性

Synthesis and insecticidal/acaricidal activities of osthole derivatives containing the 1,3,4-oxadiazol-2-ylsulfenyl fragment

为进一步提高蛇床子素的利用价值,设计合成了26个含有1,3,4-噁二唑-2-硫基片段的新型蛇床子素类衍生物(6a~6z),并测定了其杀虫、杀螨活性,同时通过扫描电子显微镜进一步研究了化合物6h对朱砂叶螨Tetranychus cinnabarinus体壁表皮角质层的影响。结果表明:化合物6h(R=3-OCH_(3)Ph)对朱砂叶螨雌成螨的杀螨活性最高,其72 h LC_(50)值为0.466 mg/mL,是蛇床子素(LC_(50)值1.200 mg/mL)的2.6倍;化合物6u(R=4-CF_(3)Ph)和6v(R=3-CNPh)对3龄小菜蛾幼虫的杀虫活性最优,48 h LC_(50)值分别为0.617和0.853 mg/mL,其中化合物6u的杀虫活性是蛇床子素(LC_(50)值1.503 mg/mL)的2.4倍。扫描电子显微镜结果显示,经化合物6h处理后,朱砂叶螨雌成螨体壁角质层在24 h内出现皱褶塌陷,且症状随时间推移明显加重。该研究结果可为蛇床子素类衍生物作为杀螨剂和杀虫剂的应用提供参考。

To further enhance the utility of osthole,we designed and synthesized 26 novel osthole derivatives containing the 1,3,4-oxadiazol-2-ylsulfenyl fragment,and measured their insecticidal and acaricidal activities.Meanwhile,through scanning electron microscope(SEM),the effects of compound 6h on the cuticle layer of Tetranychus cinnabarinus Boisduval were observed.The results shown that compound 6h(R=3-OCH_(3)Ph)exhibited the highest acaricidal activity against female adults of T.cinnabarinus with a 72 h LC_(50) value of 0.466 mg/mL,which was 2.6-fold activity of osthole(LC_(50) value 1.200 mg/mL);compounds 6u(R=4-CF_(3)Ph)and 6v(R=3-CNPh)displayed the most potent insecticidal activity against the 3rd instar larvae of Plutella xyllostella Linnaeus with 48 h LC_(50) values of 0.617 and 0.853 mg/mL,respectively;compound 6u showed 2.4-fold insecticidal activity of osthole(LC_(50) value 1.503 mg/mL).The SEM results showed that the cuticle layer of female adults of T.cinnabarinus was folded and collapsed within 24 h after treatment with compound 6h,and this distinct symptom persisted over time.Overall,this study establishes a framework for the application of osthole derivatives as acaricidal and insecticidal agents.