Design,Synthesis And Biological Evaluation Of Heterocvcle Derivatives As Modulators Of HBV Capsid Assembly

Chronic hepatitis B,caused by the hepatitis B virus(HBV)infection,could lead to serious liver diseases that threaten human health,such as liver failure,cirrhosis and hepatocellular carcinoma.Currently,the treatment of hepatitis B virus(HBV)infection mainly relies on interferon(IFN)and nucleoside/nucleotide analogues(NAs),these medicines still have some defects,including kidney and marrow toxicity,drug resistance after long term treatment.Therefore,it is necessary to develop novel mechanism anti-HBV agents.The assembly of HBV capsids is an essential step in HBV life cycle and the interruption of normal capsid assembly can block HBV replication Therefore,capsid assembly modulators could achieve functional cure for HBV infection via intervening the key step of HBV replication,and may provide a novel way to resolve nucleoside-resistant HBV mutation.Upto now,the development of HBV capsid assembly modulator has become one of the hotspots in anti-HBV drugs researchBased on the SAR of heteroaryldihydropyrimidine(HAP)derivatives and the analysis of the structure of HBV core protein,a novel series of 3-cyanodihydropyridine derivatives were designed,synthesized and evaluated as capsid assembly modulators by using the bioisosterism strategy.The in vitro biological evaluation revealed that most of these novel compounds exhibited moderate to potent anti-HBV activities.Among them,compound I-37 was the most potent compound with IC50 value of 0.25 μM.The further mechanism study of compound I-37 revealed that it might affect the process of HBV capsid assembly without depleting HBV core proteins.On the other hand,the four modulator-HBV core protein co-crystal structures were carefully analyzed and 5E0I and 5WRE were chosen as the models for virtual screening through redocking and cross-docking.Several hits with novel scaffolds were picked out in Specs molecular library with moderate inhibitory activities against HBV-DNA replication through virtual screening and similarity searching.Compound Ⅱ-2-12 was selected as a lead compound and a series of 2-aryl-4-quinolyl amide derivatives were designed and synthesized as novel HBV capsid assembly modulators.Most of these newly synthesized compounds demonstrated moderate to potent activities against HBV-DNA replication.Among them,Ⅱ-38 displayed the most promising inhibitory activity against HBV-DNA replication(IC50＝0.46 μM).The further mechanism study of compound Ⅱ-38 confirmed that it might affect HBV capsid assembly with the depletion of HBV core proteins.Compound Ⅱ-38 exhibited moderate stability in artificial intestinal and gastric fluid,as well as liver microsomes,while it only showed low oral bioavailability(F%=6.37%)in rat.It prompts further structural modification to improve PK profilesIn summary,two series of novel HBV capsid assembly modulators were designed,synthesized and exhibited moderate anti-HBV activities in vitro.Meanwhile,the preliminary SAR of these two series was discussed and the pharmacological mechanism and pharmacokinetic study of representative molecules was performed.Our research provides a solid foundation to develop HBV capsid assembly modulator with novel scaffold.