Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus CEIA3, School of Science , University of Cádiz , C/República Saharaui, 7 , 11510 Puerto Real Cádiz , Spain.
Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias , Universidad de Cádiz , 11510 Cádiz , Spain.
ACS Appl Mater Interfaces. 2019 Nov 13;11(45):41925-41934. doi: 10.1021/acsami.9b14714. Epub 2019 Nov 1.
Agrochemical encapsulation agents used up to now are commonly based on polymeric compounds or metal particles, but the employment of other natural products such as host structures has not been tackled in detail. In the work reported here, fully organic nanotubes composed of human bile acid (lithocholic acid) have been synthesized. These nanotubes were employed to encapsulate potential disulfide herbicide mimics that have previously shown relevant inhibitory activity against weeds. The three-dimensional chemical information from scanning transmission electron microscope analytical tomography with subnanometer scale resolution convincingly demonstrates for the first time the occurrence of efficient encapsulation within a fully organic nanotube of different organic molecules with activity as herbicides. The encapsulation was achieved in a one-pot synthesis, in an aqueous environment and under in situ conditions without using any marker or coating with contrast materials, which renders the process greener than those routinely used. The nanotubes allow complete water solubilization, with an encapsulation percentage of up to 78% in all of the herbicide compounds. Furthermore, nanotubes showed a flattened arrangement due to the host-guest interaction. The synthetic approach represents a step forward in solving the key problem of the quite limited solubility of natural agrochemicals in aqueous environments. In addition, the process presents a breakthrough in the use of natural products produced by the human body as encapsulating agents, which expands possible future applications. The preliminary docking approach clarifies that the 2o01 transmembrane transport protein seems to be the prior channel of the organic nanotube in the delivery process to vegetable cells. The etiolated wheat coleoptile bioassay demonstrated that the encapsulated herbicides have improved the bioactivity of free compounds, keeping 60% of inhibition of the weed at least for every disulfide, a requisite for their fruitful application as agrochemicals.
迄今为止，农用化学品包膜剂通常基于聚合化合物或金属颗粒，但其他天然产物（如主体结构）的应用尚未得到详细研究。在本报告的工作中，已合成了由人胆酸（石胆酸）组成的全有机纳米管。这些纳米管被用于包裹先前表现出对杂草有相关抑制活性的潜在二硫代除草剂模拟物。扫描透射电子显微镜分析层析术具有亚纳米级分辨率的三维化学信息，首次令人信服地证明了不同有机分子的有效包膜，这些有机分子具有作为除草剂的活性。包膜是在一锅合成、水相环境和原位条件下实现的，无需使用任何标记物或对比材料进行涂层，这使得该过程比常规使用的过程更加环保。纳米管允许完全水溶，所有除草剂化合物的封装率高达 78%。此外，由于主客体相互作用，纳米管呈扁平化排列。该合成方法代表了解决天然农用化学品在水相环境中溶解度相当有限的关键问题的重要一步。此外，该方法在利用人体产生的天然产物作为包膜剂方面取得了突破，这扩大了未来可能的应用。初步对接方法阐明，2o01 跨膜转运蛋白似乎是有机纳米管在向植物细胞输送过程中的初始通道。暗培养小麦胚芽鞘生物测定表明，包裹的除草剂提高了游离化合物的生物活性，每种二硫代物至少保持 60%的杂草抑制率，这是它们作为农用化学品有效应用的必要条件。
