Discovery of novel benzoquinazolinones and thiazoloimidazoles, inhibitors of influenza H5N1 and H1N1 viruses, from a cell-based high-throughput screen.
A highly reproducible and robust cell-based high-throughput screening (HTS) assay was adapted for screening of small molecules for antiviral activity against influenza virus strain A/Vietnam/1203/2004 (H5N1). The NIH Molecular Libraries Small Molecule Repository (MLSMR) Molecular Libraries Screening Centers Network (MLSCN) 100,000-compound library was screened at 50 µM. The "hit" rate (>25% inhibition of the viral cytopathic effect) from the single-dose screen was 0.32%. The hits were evaluated for their antiviral activity, cell toxicity, and selectivity in dose-response experiments. The screen yielded 5 active compounds (SI value >3). One compound showed an SI(50) value of greater than 3, 3 compounds had SI values ranging from greater than 14 to 34, and the most active compound displayed an SI value of 94. The active compounds represent 2 different classes of molecules, benzoquinazolinones and thiazoloimidazoles, which have not been previously identified as having antiviral/anti-influenza activity. These molecules were also effective against influenza A/California/04/2009 virus (H1N1) and other H1N1 and H5N1 virus strains in vitro but not H3N2 strains. Real-time qRT-PCR results reveal that these chemotypes significantly reduced M1 RNA levels as compared to the no-drug influenza-infected Madin Darby canine kidney cells.
Department of Organic Chemistry, Southern Research Institute, Birmingham, AL, USA.
Joseph A
JA
Maddry
Xi
X
Chen
Colleen B
CB
Jonsson
Subramaniam
S
Ananthan
Judith
J
Hobrath
Donald F
DF
Smee
James W
JW
Noah
Diana
D
Noah
Xiaolin
X
Xu
Fuli
F
Jia
Clinton
C
Maddox
Melinda I
MI
Sosa
E Lucile
EL
White
William E
WE
Severson
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D001717:Birds; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D004285:Dogs; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects; D005585:Influenza in Birds; D007251:Influenza, Human; D020128:Inhibitory Concentration 50; D052999:Quinazolinones / Q000494:pharmacology; D012313:RNA / Q000378:metabolism; D054852:Small Molecule Libraries / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology; D014779:Virus Replication / Q000187:drug effects*
D000998:Antiviral Agents; D007093:Imidazoles; D052999:Quinazolinones; D054852:Small Molecule Libraries; D013844:Thiazoles; D012313:RNA