title: 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.
abstract: 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.
authors.affiliation: Center for Drug Design, Academic Health Center, University of Minnesota , 516 Delaware Street SE, PWB 7-224, MMC 204 Minneapolis, Minnesota 55455, United States.
authors.forename: Sanjeev Kumar V
authors.initials: SK
authors.lastname: Vernekar
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Eva
authors.initials: E
authors.lastname: Nagy
authors.forename: Lena
authors.initials: L
authors.lastname: Miller
authors.forename: Karen A
authors.initials: KA
authors.lastname: Kirby
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Wilson
authors.forename: Jayakanth
authors.initials: J
authors.lastname: Kankanala
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Sarafianos
authors.forename: Michael A
authors.initials: MA
authors.lastname: Parniak
authors.forename: Zhengqiang
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D015195:Drug Design; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors*; D019384:Nucleic Acid Synthesis Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D018894:Reverse Transcriptase Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D054309:Ribonuclease H, Human Immunodeficiency Virus / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship
chemical_list: D000998:Antiviral Agents; D019384:Nucleic Acid Synthesis Inhibitors; D018894:Reverse Transcriptase Inhibitors; D054303:HIV Reverse Transcriptase; D054309:Ribonuclease H, Human Immunodeficiency Virus