Design, Synthesis, Biochemical, and Antiviral Evaluations of C6 Benzyl and C6 Biarylmethyl Substituted 2‑Hydroxylisoquinoline-1,3-diones: Dual Inhibition against HIV Reverse Transcriptase-Associated RNase H and Polymerase with Antiviral Activities

• Published in: Journal of medicinal chemistry Vol. 58; no. 2; pp. 651 - 664
• Main Authors: Vernekar, Sanjeev Kumar V, Liu, Zheng, Nagy, Eva, Miller, Lena, Kirby, Karen A, Wilson, Daniel J, Kankanala, Jayakanth, Sarafianos, Stefan G, Parniak, Michael A, Wang, Zhengqiang
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 22.01.2015; Amer Chemical Soc
• Subjects: Antiviral Agents - chemical synthesis; Antiviral Agents - pharmacology; Chemistry, Medicinal; Drug Design; Escherichia coli; HIV Reverse Transcriptase - antagonists & inhibitors; Human immunodeficiency virus; Life Sciences & Biomedicine; Moloney murine leukemia virus; Nucleic Acid Synthesis Inhibitors - chemical synthesis; Nucleic Acid Synthesis Inhibitors - pharmacology; Pharmacology & Pharmacy; Reverse Transcriptase Inhibitors - chemical synthesis; Reverse Transcriptase Inhibitors - pharmacology; Ribonuclease H, Human Immunodeficiency Virus - antagonists & inhibitors; Science & Technology; Structure-Activity Relationship; NUCLEOSIDE; ACID; ACTIVE-SITE; INTEGRASE; IMMUNODEFICIENCY-VIRUS TYPE-1; ERADICATION; CLEAVAGE; 2-HYDROXYISOQUINOLINE-1,3(2H,4H)-DIONES; RIBONUCLEASE-H; STRATEGIES
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/jm501132s

Reverse transcriptase (RT) associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function not targeted by current chemotherapy against human immunodeficiency virus (HIV). Although numerous chemotypes have been reported to inhibit HIV RNase H biochemically, few show significant antiviral activity against HIV. We report herein the design, synthesis, and biological evaluations of a novel variant of 2-hydroxyisoquinoline-1,3-dione (HID) scaffold featuring a crucial C-6 benzyl or biarylmethyl moiety. The synthesis involved a recently reported metal-free direct benzylation between tosylhydrazone and boronic acid, which allowed the generation of structural diversity for the hydrophobic aromatic region. Biochemical studies showed that the C-6 benzyl and biarylmethyl HID analogues, previously unknown chemotypes, consistently inhibited HIV RT-associated RNase H and polymerase with IC50s in low to submicromolar range. The observed dual inhibitory activity remained uncompromised against RT mutants resistant to non-nucleoside RT inhibitors (NNRTIs), suggesting the involvement of binding site(s) other than the NNRTI binding pocket. Intriguingly, these same compounds inhibited the polymerase, but not the RNase H function of Moloney Murine Leukemia Virus (MoMLV) RT and also inhibited Escherichia coli RNase H. Additional biochemical testing revealed a substantially reduced level of inhibition against HIV integrase. Molecular docking corroborates favorable binding of these analogues to the active site of HIV RNase H. Finally, a number of these analogues also demonstrated antiviral activity at low micromolar concentrations.