具有四氢苯并[4,5]咪唑并[1,2-a]吡嗪骨架凝血酶抑制剂的设计合成及生物活性研究

Design,Synthesis and Biological Evaluation of Thrombin Inhibitors with 1,2,3,4-Tetrahydrobenzo [4,5]imidazo [1,2-a]pyrazine Nucleus

以具有四氢苯并[4,5]咪唑并[1,2-a]吡嗪新骨架的凝血酶抑制剂1为先导化合物,设计合成了14个氨基甲酸酯衍生物(2a^6a,2b^6b和7~10).同时,在化合物1结构的基础上,引入具有抗血栓活性的川芎醇(HTMP),设计合成了新型结构的化合物11.目标化合物的结构均经1H NMR,13C NMR和HRMS确证.生物活性测试结果显示,所有目标化合物对凝血酶诱导的血小板聚集均有一定的抑制活性,其中化合物4b的抑制活性[IC50=(0.11±0.08)μmol/L]强于对照药达比加群酯[IC50=(0.60±0.05)μmol/L].在体内抗血栓活性测试中,化合物4b能以剂量依赖的方式减少大鼠静脉血栓的形成.化合物11对凝血酶诱导的血小板聚集的抑制活性较弱,但其抑制大鼠静脉血栓形成的作用与达比加群酯相当,这可能是由于化合物11在体内水解为川芎醇和化合物1,两者协同产生抗血栓作用所致.

Compound 1, a new thrombin inhibitor with 1,2,3,4-tetrahydrobenzo [ 4,5 ] imidazo [ 1,2-a ] pyrazine nucleus, was selected as lead compound, and fourteen carbamate derivatives derivatives （2a-6a, 2b-rb, 7-10） were designed and prepared. Furthermore, a twin drug（11） was synthesized by coupling compound 1 with 2-hydroxymethy]-3, 5, 6-trimethylpyrazine （HTMP）. The structures of all the target compounds were confirmed by 1H NMR, 13C NMR and HRMS. Preliminary biological activity test results indicated that all of the tested compounds exhibit a certain degree of inhibitory effect on thrombin-induced platelet aggregation, among which compound 4b [ IC50 = （0. 11 ±0. 08 ） μmol/L ] show better anti-platelet aggregation activity than dabigatran etexilate [ IC50 = （0. 60±0. 05） μmol/L]. The in vivo experimental results in rat venous thrombosis model demonstrated compound 4b can significantly reduce thrombosis in a dose-response manner. Compound 11, which showed weak inhibitory effect on thrombin-induced platelet aggregation, also displayed comparable inhibitory effect on rat venous thrombosis with dabigatran etexilate. The study points out that the enhanced potency of compound 11 may be the synergetic effect of HTMP and compound I which are generated by hydrolysis in vivo.