可清除P-选择素活性口袋内自由基的专属性抗血栓药物的设计、合成和机理研究

Of the diseases, thrombosis has been known as a leading cause of morbidity and mortality around the world. Among the othrombi, one is triggered by free radicals accumulated in the active pocket of P-selectin stored in the α-granule of platelet.So far, no any anti-thrombotic agent targets on this pathway. Here, the free radical scavenger capable of docking towards the active pocket of P-selectin was used to block the pathway. Accordingly, 6,7-dihydroxyl-tetrahydro- isoqunoline-3-carboxylic acid was evidenced to be a good lead,of which the hydroxyl groups and isoqunoline ring were responsible for scavenging free radicals and docking towards the active pocket of P-selectin, respectively.Molecular modelling studies showed that the modification of the 3-carboxylic group of the lead with L-amino acid residue will imlrove the docking of the isoqunoline ring towards the pocket. Thus the present project will modify the 3-carboxylic group with 20 amino acids,evaluate their activities of scavenging free radicals,their activities of inhibiting the expression of P-selectin, and their anti-thrombotic activities.By practising this project we will be able to explore the relationships of free radicals in the pocket and the thrombosis from the ischemia/reperfusion,to renew the strategy of the anti-thrombotic drug design, to establish new in vitro models for anti-thrombotic assay, and to provide candidate of specifically anti-thrombotic agent

应激和缺血/再灌注使P-选择素活性口袋里滋生自由基，造成血小板膜内不溶型P-选择素随α-粒外吐、表达、剪切、转化为溶解型-P选择素进入血液循环，生成大量稳定的血栓。这是抗血栓药物设计必须面对的重要通路。本项目确认了6,7-二羟基-四氢异喹啉-3-羧酸是理想的先导化合物，它用羟基清除自由基，用母核与P-选择素活性口袋对接，可阻断这条血栓通路。分子模型揭示，它的3位羧基若与天然氨基酸偶联，不会降低自由基清除活性，却会改善与活性口袋对接。本项目拟制备它的3位羧基与20种天然氨基酸的偶联物、评价它们的清除自由基活性、抑制P选择素表达活性和抗血栓活性。以清除自由基为本，阻断自由基-P选择素表达-血栓这条发病通路，是本项目创新性的本质。实施本项目，可揭示P-选择素活性口袋里自由基堆积与缺血/再灌注性血栓的关联性、创新抗血栓药物设计策略、建立体外抗血栓的新模型，发现可进入临床前研究的优秀抗血栓化合物。

本项目主要围绕三个要点展开研究： 展开计算机模拟的分子对接，对DOXIQCA的结构进行优化，锁定20种新化合物（5a-t）；5a-t作为目标化合物进行药物设计、药物合成、药物纯化、药物结构鉴定、药效学评价，以及药物作用机理研究；在第一轮5a-t的筛选之后，选择其中活性最好的化合物，以其结构作为新一轮的先导结构，再以20种天然氨基酸进行修饰，并完成药物合成、纯化、结构鉴定、药效学评价，以及机理研究等工作。经药物化学先导结构的两轮优化，推出1~2种抗自由基性血小板-纤维蛋白原-白细胞型血栓临床前的优秀的候选化合物。经过4年实施，本项目设计/合成/评价了40种具有自主知识产权的6,7-二羟基-四氢异喹啉-3-羧酸类先导化合物，发表了15篇 SCI 论文、获得15项国家发明专利授权，超额完成任务书预期指标。具体情况在研究工作主要进展和所取得的研究成果中描述。