Design,Synthesis And Biological Evaluation Of Novel HIV-1 Non-nucleoside Reverse Transcriptase Inhibitors And Latency Promoting Agents

Acquired immunodeficiency syndrome(AIDS)is a global infectious disease that caused by human immunodeficiency virus(HIV)infection.Inhibiting HIV replication by directly blocking key steps in the HIV replication cycle is a practical and effective treatment strategy.Reverse transcriptase(RT)is a popular target for anti-HIV-1 drug design.Non-nucleoside reverse transcriptase inhibitors(NNRTIs),acting on RT,have high efficiency,low toxicity and high selectivity.However,in clinical applications,NNRTIs exhibited severe drug resistance and toxic side effects,which have seriously reduced the clinical efficacy.Therefore,there is an urgent need to develop new generation HIV-1 NNRTIs with high drug resistance and safety.On the other hand,HIV can form a latent reservoir in the patient’s body,which is the key obstacle to curing AIDS."Shock and Kill" and "Block and Lock" are two treatment strategies for latent HIV infection.Clinical evidence showed that "Shock and Kill" have limited effect and cannot effectively reduce the scale of the HIV latent reservoir in patients."Block and Lock"uses latency promoting agents(LPAs)to block the reactivation of the HIV latent reservoir in the long term and eventually achieve a functional cure.However,the development of drugs for this strategy is still in a early stage,so it is of great scientific importance to explore it.This thesis is an exploration of the above scientific questions in two ways:Design,synthesis and biological evaluation of DAPY derivatives as NNRTIs based on privileged fragment hybridization strategy.Diarylpyrimidine(DAPY)derivatives are an important component of HAART.However,excessive aromatic structures of this class of compounds have in turn caused its poor pharmacokinetic properties.In addition,HIV-1 has developed varying degrees of resistance to these NNRTIs during long-term clinical use.Therefore,there is an urgent need to develop new generation NNRTIs with high efficiency,anti-resistance and good pharmacokinetic properties.Based on the conformational exploration of DAPY-like NNRTIs by our group,36 structurally novel DAPY derivatives were designed and synthesized in this chapter.Luciferase assay(TZM-bl cells/HIV-1 pNL4.3)showed that all compounds in this series exhibited efficient antiviral activity(EC50=3.50-39.9 nM)and low cytotoxicity.IC-14b showed the best antiviral activity with EC50 values of 3.50 nM,comparable to the positive drug RPV(EC50=0.63 nM).Further antiviral activity testing by MTT assay showed an EC50 of 1.38 nM for IC-14b against HIV-1 ⅢB,and excellent inhibitory activity against clinically common mutant strains(EC50=2.86 nM(L100I);1.61 nM(K103N);11.1 nM(Y181C);117 nM(Y188L);7.10 nM(E138K);25.7 nM(F227L+V106A);119 nM(K103N+Y181C)).ELISA assay showed that IC-14b(IC50=0.22 μM)had RT inhibitory activities comparable to RPV(IC50=0.23 μM),validating that the designed compounds were targeting HIV-1 RT.Molecular simulations showed that IC-14b was bound to RT in the classical "U"conformation of DAPY-like NNRTIs,and formed extensive interactions with surrounding amino acid residues.In addition,the aqueous solubility of IC-14b(3.35 μg/mL)was greatly improved compared to the marketed drug ETR(<<1 μg/mL)and RPV(0.02 μg/mL).The results of the druggability prediction showed that the physicochemical properties and ADMET properties of IC-14b were within a reasonable range and it had good druggability potential.Ligand-based discovery of HIV-1 latency-promoting agentsTranscriptional elongation is a key step in the reactivation of HIV latent virus.It is mediated by the Tat/TAR RNA/P-TEFb complex,where Tat binds to the Cyclin T1 subunit of P-TEFb directly.The quinolin-2(1H)-one derivative C3 blocks HIV transcription by inhibiting the Tat/Cyclin T1 interaction.However,the antiviral activity of C3 is weak and its binding mode on Cyclin T1 is unclear,so further modifications and studies are needed.In this chapter,C3 was used as lead compound,its binding pocket on Cyclin T1 was predicted.Subsequently,a molecular docking-based virtual screening of the virtual library of C3 derivatives was performed.The most frequently occurring groups in compounds with high docking score are privileged structural fragments.Based on the privileged structural fragment hybridization strategy,48 structurally novel C3 derivatives were designed and synthesized.The antiviral activity of this series of compounds was tested in vitro by luciferase assay(SupT1 cells/HIV-1 pNL4.3).The results showed that compounds ⅡA-10f and ⅡB-10a were effective in inhibiting HIV-1 latent provirus transcription under natural and TNF-α stimulated conditions.SPR molecular interaction experiment verified that the target of compounds ⅡA10f and ⅡB-10a is Cyclin T1.Molecular docking simulations showed that the representative compound IIA-10f bound to the Tat/Cyclin T1 interface on Cyclin T1,maintaining a similar conformation to the lead compound C3.Its binding curtailed the distance between R254 and N43,resulting in a "closed" conformation at the binding interface of Cyclin T1,thus preventing Cyclin T1 from binding to Tat.