基于酮醇酸还原异构酶的新型哌嗪类衍生物的设计合成和生物活性研究

Piperazine derivatives possess versatile physicological and biological activities, while their researches in pesticide chemistry area are relatively little. Ketol-acid reductoisomerase (KARI) is one of the key enzymes invovled in the biosynthesis of the branched-chain amino acids that exsit in plants and microorganisms, and can be used as target for designing herbicides and fungicides. At present, there are few KARI inhibitors reported, which offers us broad research space for designing agrochemicals targeting at KARI. Accordingly, based on our existing work, this project will carry out studies as follows: (1) To design and synthesize series of novel heterocyclic Mannich bases and heterocyclic bis- Mannich bases containing piperzine moiety according to strucuture of the lead compound recently discovered in our lab; (2) To design and synthesize other series of novel piperazine derivatives referring to the hit structural information of database virtual screening based on the crystal structure of KARI complex; (3) To systematically test and investigate fungicidal and herbicidal activities (or other activities) of new compounds and KARI in vitro activity for target validation; (4) To use CADD method to study the structure-activity relationship rule of compounds, and make relevant structural optimization according to their guidance. Through this project that focus on the design, synthesis and biological activities of series of novel piperazine derivatives targeting at KARI enzyme, it is expected to discover some novel heterocyclic compounds that have high fungicidal and herbicidal activities, which will be of great significance for the R & D of novel green agrochemicals and the selectivity and resistance problems of pesticides as well.

哌嗪类化合物具有多样的生理、生物活性，其在农药领域的研究相对较少。酮醇酸还原异构酶(KARI)是植物和微生物体内支链氨基酸生物合成关键酶之一，可作为设计除草剂和杀菌剂的靶标。目前KARI抑制剂种类数量稀少，以其为靶标开展农药分子设计有广阔的研究空间。我们基于前期工作拟开展以下研究: (1)根据近期发现的先导结构设计合成多系列含哌嗪环的杂环Mannich碱及杂环双Mannich碱类新化合物;(2)利用基于KARI晶体结构虚拟筛选所得结构信息，设计合成其它类哌嗪新衍生物;(3)系统测试化合物杀菌、除草等生物活性，对高活性化合物进行KARI离体活性测试;(4)利用计算机辅助研究并总结化合物构效关系规律，以其指导化合物结构优化。本课题基于KARI开展多系列哌嗪新衍生物设计合成及生物活性的研究，有望发现一些杀菌、除草等高活性的杂环新化合物，对于创制新型绿色农药以及选择性、抗药性等问题具有重要意义。

酮醇酸还原异构酶（KARI）是植物和微生物体内催化支链氨基酸生物合成的关键酶之一，可作为设计除草剂和杀菌剂的靶标。本项目基于KARI酶靶标以及前期发现的先导结构和数据库虚拟筛选所得潜在KARI抑制剂结构信息，重点开展了各类新型哌嗪类衍生物的设计合成和生物活性研究，基本按照原计划较好地完成了各项工作。通过项目的实施，共设计合成了多个系列计约400个新化合物，经1H NMR，13C NMR，IR，元素分析，高分辨质谱以及X-射线单晶衍射等手段确证了结构，测试了新化合物对小麦纹枯病菌、油菜菌核病菌、苹果轮纹病菌、黄瓜霜霉病菌等多种植物病菌，对油菜、稗草等双、单子叶代表性杂草模式植物，对东方粘虫等的农药生物活性，以及对KARI酶的抑制活性。通过计算机辅方法例如CoMFA，分子对接等研究分析了化合物结构-活性的关系规律，为进一步优化设计提供了指导。本项目发现了含三氟甲基三唑并[4,3-a]哌嗪的1,2,4-三唑Mannich碱类等一批杀菌活性优良、具有一定应用价值的新化合物，以及含哌嗪和芳磺酰基甲酰胺类、含哌嗪的三氟甲基咪唑并噻二唑Mannich碱类等一些除草、杀虫活性突出的新化合物，其中有许多可以作为新的农药先导开展深入研究；获得了诸多结构新颖的KARI酶抑制剂，例如含哌嗪的1,3,4-噁二唑Mannich碱类，值得后续继续研究。本项目系统开展的包括杂环Mannich碱在内的含哌嗪环的多系列新化合物的合成研究及在农药化学领域的新发现，对于今后相关新型农药的研究和开发具有重要意义。在项目资助下共发表SCI收录研究论文20篇，申请专利5项（1项获得授权）；培养博士生1人，硕士生4人。