Synthesis And Biological Activity Evaluation Of Cyclic Guanosine Adenosine And Its Deoxy Analog

C-di-GMP,c-di-AMP,3',3'-cGAMP and other cyclic dinucleotides,as the second messenger of microorganisms,play an important role in the regulation of microbial physiological activities,morphology,and disease and other aspects.In humans the synthesis of 2',3'-cGAMP catalyzed by cGAS?cyclic adenosine adenosine synthase?binds to the STING protein and induces the secretion of interferon.2',3'-cGAMP as an agonist of STING is a lead compound against in vitro microbial infection,intrinsic immunotherapy for cancer drugs.Therefore,studying the conformational relationship of cyclic dinucleosides and its analogs can provide afoundation for targeting STING.The first chapter,a brief review of the discovery and biological functions of CDN was talked.The progress of medicinal chemistry of CDN as a STING agonist was reviewed,and the small molecules of non-nucleoside-targeted STING were summarized.So we put forward the basis for the project.In the second chapter,based on the CDN synthesis method reported in the literature,we established a one-pot synthesis method for the synthesis of cGAMP,and its deoxy analogs of cGAMP:3',3'-cdGAMP,3',3'-cGdAMP,3',3'-cdGdAMP.The synthesized compound was characterized by ¹H NMR,³¹P NMR,¹³C NMR,HRMS,and the purity of the compound was analyzed by HPLC to a purity of 95%or more.In the third chapter,in order to synthesize 2',3'-cGAMP and its deoxy analogs.The 3'deoxyphosphoramidazide guanosine monomers were synthesized firstly.then2',3'-cGAMP and its deoxy analogs were synthesized by one-pot method according to the synthesis process in chapter two.The synthesized compound was characterized by1H NMR,31P NMR,13C NMR,HRMS,and the purity of the compound was analyzed by HPLC to a purity of 95%or more.In the last chapter,the stability of synthetic CDN and its deoxy analogs in snake venom phosphodiesterase was investigated.The results showed that the stability of the monodeoxy analog was higher than the natural CDN,and the dideoxy analog was the most stable.cGAMP and its deoxygenated analogs still have more than 60%remaining in human serum at 37°C for 24 h.Bioactivity evaluation using THP-1 and RAW showed that 2',3'-cGAMP and its deoxy analog have the same activity in THP-1,but the activity of dideoxy analog is decreased.Both cGAMP and its deoxy analog activity did not have good activity than 2',3'-cGAMP.cGAMP deoxy analog activity is superior to natural cGAMP in RAW,but 2',3'-cGAMP and its deoxy analog activity were not as active as cGAMP.Affinity studies of compounds with STING are still ongoing.