Synthesis And Inhibitory Activity Of Subsitituted 5-(Substituent Group)-1H-pyrazole-3-earboxylic Acid (x-hydroxy-ethyl)-amide

Population problem is a severe problem in modem society, especially for developing countries, the effect is more serious. China is the most populous developing country in the world, and family planning has being a basic national policy from the last century. At present, the contraceptive drug applied in the clinical are all for women, they could bring a lot of side effects if long-term administration of them. Meanwhile, there is no safe, efficient, reversible male contraceptive in clinical. Therefore, having a developing research of male contraceptive which has better clinical applied is important, and it has profound significance that male share the responsibility for contraception with female.Acrosin is a serine protease releasing by sperm in acrosome reaction, it could promote sperm motility, as well as hydrolyze the zona pellucida for oocytes, which facilitate sperm-egg binding. Inhibiting acrosin could block sperm-egg binding and achieve the effect of contraception, therefore, in the world recent years, it has become research focus of male contraceptive that acrosin play a role as the target of male contraceptive.Human acrosin inhibitor is the research focus in our laboratory for a long time. In the previous studies, the homologous 3D model of human acrosin was built on the crystal coordinates of ram and boar acrosin, and analyzed the properties of the activity site of human acrosin by the method of multiple copy simultaneous search（MCSS） method, its reliability through the Ramachandran map and profile₃D Figure verification. It was found that active cavity can be divided into three parts:P1 pocket is depth, but a small opening for the polar regions, and the hydrophobic of P1 side could target the ligand to the active site.P2 pocket is light, but a larger opening, in which several important residues form hydrogen-binding interactions and electrostatic interactions.G-cavity is on the right a narrow, hydrophobic interaction in G groove takes the leading position.T216, Q218, S221, R199, E120 is a reactive cavity of the more important hydrogen bonds with residues. Based on this platform, a series of new structure and small molecule inhibitors, which has human acrosin inhibition, was designed.This research design, synthesis new 5-substituted-pyrazole-3-carboxylate amide alcohols as sperm acrosin inhibitor, which is mainly based on the 3D structure of men’s acrosin, and through assisting drug design by computer, introducing more hydrogen bond donor to enhance the hydrogen bonding interaction with PI, and improve the suppression of enzyme activity. Based on the synthetic route,36 target compounds were synthesized via three steps from p-methoxyacetophenone, p-Nitroacetophenon, p-Bromoacetophenones,3-Nitroacetophenone, phenyl methyl ketone. And all the compounds are reported by frist time. All the structures of the compounds were comfirmed by 1HNMR and MS, compound AQ-A1 were determined by single crystal X-ray diffraction analyse. All the target compounds had good inhibitory activities against acrosin in vitro determined, part of the target compounds are more better than that of the lead compound, and the best inhibitory enzyme activity of pyrazole compounds is AQ-E5, which is 0.001μmol/mL. According to preliminary analysis, the results of our study coincide with the earlier conclusion. In this study, a new type structure was got, for human acrosin inhibitor research and further structural optimization, highly efficient and low toxicity of male anti-fertility compounds is supposed to get.