为了发现新的潜在候选农药,最近,天然生物活性产物的结构修饰备受关注。在这项工作中,基于从黑胡椒中分离的天然生物碱胡椒碱,区域和立体选择性合成了一系列新的胡椒碱型酯衍生物。它们的结构通过IR表征,mp,1HNMR(13CNMR),和高分辨率质谱(HRMS)。针对灰心叶蟹(Acari:Tetranychidae),化合物4e,4f,4u,和4v表现出最显著的杀螨活性,LC50值为0.155、0.117、0.177和0.164mg/mL,分别。特别是,化合物4f显示出比胡椒碱(LC50:14.198mg/mL)高>120倍的杀螨活性。值得注意的是,4f的杀螨活性与市售杀螨剂螺氯芬(LC50:0.115mg/mL)相当。此外,针对羊毛虫Hausmann(半翅目:蚜科),化合物4w和4b表现出1.8倍的胡椒碱杀虫活性。此外,通过扫描电子显微镜(SEM)成像方法,观察到4f处理的朱砂角质层的结构明显破坏。可以进一步研究化合物4f作为杀螨先剂。
To discover new potential pesticide candidates, recently, structural modification of natural bioactive products has received much attention. In this work, a series of new piperine-type ester derivatives were regio- and stereoselectively synthesized based on a natural alkaloid piperine isolated from Piper nigrum. Their structures were characterized by IR, mp, 1H NMR (13C NMR), and high-resolution mass spectrometry (HRMS). Against Tetranychus cinnabarinus Boisduval (Acari:
Tetranychidae), compounds 4e, 4f, 4u, and 4v displayed the most significant acaricidal activity with LC50 values of 0.155, 0.117, 0.177, and 0.164 mg/mL, respectively. Particularly, compound 4f showed >120-fold higher acaricidal activity than piperine (LC50: 14.198 mg/mL). Notably, the acaricidal activity of 4f was equivalent to that of the commercial acaricide spirodiclofen (LC50: 0.115 mg/mL). Additionally, against Eriosoma lanigerum Hausmann (Hemiptera: Aphididae), compounds 4w and 4b\' showed 1.8-fold aphicidal activity of piperine. Furthermore, via the scanning electron microscope (SEM) imaging method, the obvious destruction of the construction of the cuticle layer of 4f-treated T. cinnabarinus was observed. Compound 4f could be further studied as a lead acaricidal agent.