几丁质水解酶抑制剂的设计、合成及其灭蝇活性研究

There is a bright future for study of chitinase inhibitors, because the drugs which target to chitinase are harmless to human and farm animal. Ofhex1 is generally recognized as a key chitinase which catalyze the hydroxylation of chitin. In this project, Ofhex1 was chosen as potential drug target for discovering chitinase inhibitor by using computer-aided virtual screening technique based on lead compound N-acetylglucosamine-thiazoline(NGT). 37 compounds which are derived at the 6-position of NGT had high scores. Based on the docking result and possibility of chemical synthesis, this project will (1) construct a universal method for derivations at 6-position of NGT selectively; (2) synthesize the 37 compounds by this method, and the chitinase inhibitory activity and killing ability of 37 compounds will be screened on Musca domestica which is the mian species of fly in animal house to obtain the most active compound; (3) analyze the quantitative structure-activity relationship; the compound which has best inhibitory on chitinase will be chosen as new lead compound; then the new library with about 40 compounds will be build by optimization of the new lead compounds with bioisostere based on rational drug design and the quantitative structure-activity relationship. Finally，the inhibitory activity of 40 the new compounds will be also screened on chitinase from Musca domestica. The accomplishment of this projet would be expected to provide theoretical foundation for developing green veterinary drugs for killing flies.

几丁质水解酶抑制剂因其具有对人、畜无害的优点而被公认为是新型选择性绿色兽用灭蝇剂发展的方向。本项目以几丁质水解酶Ofhex1为靶标，通过计算机虚拟筛选出了一批得分高的N-乙酰氨基葡萄糖噻唑啉(NGT)的6位羟基衍生物。为了评价并优化这些被优选的化合物的实际生物活性，本研究拟（1）建立选择性地在NGT的6位上化学衍生化的通用方法；（2）以此方法构建37种得分高的NGT衍生物，并测试这37种化合物对家蝇几丁质水解酶的抑制活性和对家蝇的杀灭能力，筛选出具有高灭蝇活性的化合物；（3）分析总结这37种化合物的构效关系，在合理药物设计的指导下，以本次筛选得到的最佳化合物为新的先导物，通过生物电子等排体替换原则重新设计并合成约40种新化合物，并研究这些化合物的生物活性，以期筛选出更高活性的化合物，为开发新型高选择性绿色兽用灭蝇剂提供实验基础。

几丁质代谢系统的正常运转对于苍蝇至关重要，而哺乳动物则不以几丁质代谢作为生命活动的必需系统，故以几丁质水解酶作为靶标的药物具有对人、畜无害的优点。本项目首先通过分析几丁质水解酶的工作机制，并研究了几丁质酶的结构特点及其与配体的相互作用模式，对酶的结合和催化活性中心进行分子建模, 设定相关的结构及静电参数，计算机辅助药物设计的方法, 筛选出了一批具有潜在的几丁质酶抑制活性的高得分含噻唑啉环的N-乙酰氨基葡萄糖噻唑啉(N-acetylglucosamine-thiazoline、NAG-thiazoline、NGT)6位取代衍生物；除此之外，本研究还基于几丁质水解酶的工作机制，通过生物电子等排体替换的方式，设计并化学合成了烷基噻唑啉类和含硫壳聚糖2类NGT衍生物，最后通过体外活性评价结果发现以甲基噻唑啉的活性显著地优于包括NGT在内的合成化合物，该结构为发现绿色灭蝇剂提供了实验基础和研究方向。