tetano
Editor, Senior Moderator
mBio
. 2020 Aug 20;11(4):e01833-20.
doi: 10.1128/mBio.01833-20.
GRL-0920, an Indole Chloropyridinyl Ester, Completely Blocks SARS-CoV-2 Infection
Shin-Ichiro Hattori[SUP] 1 [/SUP], Nobuyo Higshi-Kuwata[SUP] 1 [/SUP], Jakka Raghavaiah[SUP] 2 3 [/SUP], Debananda Das[SUP] 4 [/SUP], Haydar Bulut[SUP] 4 [/SUP], David A Davis[SUP] 5 [/SUP], Yuki Takamatsu[SUP] 1 [/SUP], Kouki Matsuda[SUP] 1 [/SUP], Nobutoki Takamune[SUP] 6 [/SUP], Naoki Kishimoto[SUP] 7 [/SUP], Tadashi Okamura[SUP] 8 [/SUP], Shogo Misumi[SUP] 7 [/SUP], Robert Yarchoan[SUP] 5 [/SUP], Kenji Maeda[SUP] 1 [/SUP], Arun K Ghosh[SUP] 2 3 [/SUP], Hiroaki Mitsuya[SUP] 9 4 10 [/SUP]
Affiliations
Abstract
We assessed various newly generated compounds that target the main protease (M[SUP]pro[/SUP]) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and various previously known compounds reportedly active against SARS-CoV-2, employing RNA quantitative PCR (RNA-qPCR), cytopathicity assays, and immunocytochemistry. Here, we show that two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, exerted potent activity against SARS-CoV-2 in cell-based assays performed using VeroE6 cells and TMPRSS2-overexpressing VeroE6 cells. While GRL-0820 and the nucleotide analog remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred. No significant anti-SARS-CoV-2 activity was found for several compounds reportedly active against SARS-CoV-2 such as lopinavir, nelfinavir, nitazoxanide, favipiravir, and hydroxychroloquine. In contrast, GRL-0920 exerted potent activity against SARS-CoV-2 (50% effective concentration [EC[SUB]50[/SUB]] = 2.8 μM) and dramatically reduced the infectivity, replication, and cytopathic effect of SARS-CoV-2 without significant toxicity as examined with immunocytochemistry. Structural modeling shows that indole and chloropyridinyl of the derivatives interact with two catalytic dyad residues of M[SUP]pro[/SUP], Cys145 and His41, resulting in covalent bonding, which was verified using high-performance liquid chromatography-mass spectrometry (HPLC/MS), suggesting that the indole moiety is critical for the anti-SARS-CoV-2 activity of the derivatives. GRL-0920 might serve as a potential therapeutic for coronavirus disease 2019 (COVID-19) and might be optimized to generate more-potent anti-SARS-CoV-2 compounds.IMPORTANCE Targeting the main protease (M[SUP]pro[/SUP]) of SARS-CoV-2, we identified two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, active against SARS-CoV-2, employing RNA-qPCR and immunocytochemistry and show that the two compounds exerted potent activity against SARS-CoV-2. While GRL-0820 and remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred as examined with immunocytochemistry. In contrast, GRL-0920 completely blocked the infectivity and cytopathic effect of SARS-CoV-2 without significant toxicity. Structural modeling showed that indole and chloropyridinyl of the derivatives interacted with two catalytic dyad residues of M[SUP]pro[/SUP], Cys145 and His41, resulting in covalent bonding, which was verified using HPLC/MS. The present data should shed light on the development of therapeutics for COVID-19, and optimization of GRL-0920 based on the present data is essential to develop more-potent anti-SARS-CoV-2 compounds for treating COVID-19.
Keywords: COVID-19; SARS-CoV-2; antiviral agents; main protease.
. 2020 Aug 20;11(4):e01833-20.
doi: 10.1128/mBio.01833-20.
GRL-0920, an Indole Chloropyridinyl Ester, Completely Blocks SARS-CoV-2 Infection
Shin-Ichiro Hattori[SUP] 1 [/SUP], Nobuyo Higshi-Kuwata[SUP] 1 [/SUP], Jakka Raghavaiah[SUP] 2 3 [/SUP], Debananda Das[SUP] 4 [/SUP], Haydar Bulut[SUP] 4 [/SUP], David A Davis[SUP] 5 [/SUP], Yuki Takamatsu[SUP] 1 [/SUP], Kouki Matsuda[SUP] 1 [/SUP], Nobutoki Takamune[SUP] 6 [/SUP], Naoki Kishimoto[SUP] 7 [/SUP], Tadashi Okamura[SUP] 8 [/SUP], Shogo Misumi[SUP] 7 [/SUP], Robert Yarchoan[SUP] 5 [/SUP], Kenji Maeda[SUP] 1 [/SUP], Arun K Ghosh[SUP] 2 3 [/SUP], Hiroaki Mitsuya[SUP] 9 4 10 [/SUP]
Affiliations
- PMID: 32820005
- DOI: 10.1128/mBio.01833-20
Abstract
We assessed various newly generated compounds that target the main protease (M[SUP]pro[/SUP]) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and various previously known compounds reportedly active against SARS-CoV-2, employing RNA quantitative PCR (RNA-qPCR), cytopathicity assays, and immunocytochemistry. Here, we show that two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, exerted potent activity against SARS-CoV-2 in cell-based assays performed using VeroE6 cells and TMPRSS2-overexpressing VeroE6 cells. While GRL-0820 and the nucleotide analog remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred. No significant anti-SARS-CoV-2 activity was found for several compounds reportedly active against SARS-CoV-2 such as lopinavir, nelfinavir, nitazoxanide, favipiravir, and hydroxychroloquine. In contrast, GRL-0920 exerted potent activity against SARS-CoV-2 (50% effective concentration [EC[SUB]50[/SUB]] = 2.8 μM) and dramatically reduced the infectivity, replication, and cytopathic effect of SARS-CoV-2 without significant toxicity as examined with immunocytochemistry. Structural modeling shows that indole and chloropyridinyl of the derivatives interact with two catalytic dyad residues of M[SUP]pro[/SUP], Cys145 and His41, resulting in covalent bonding, which was verified using high-performance liquid chromatography-mass spectrometry (HPLC/MS), suggesting that the indole moiety is critical for the anti-SARS-CoV-2 activity of the derivatives. GRL-0920 might serve as a potential therapeutic for coronavirus disease 2019 (COVID-19) and might be optimized to generate more-potent anti-SARS-CoV-2 compounds.IMPORTANCE Targeting the main protease (M[SUP]pro[/SUP]) of SARS-CoV-2, we identified two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, active against SARS-CoV-2, employing RNA-qPCR and immunocytochemistry and show that the two compounds exerted potent activity against SARS-CoV-2. While GRL-0820 and remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred as examined with immunocytochemistry. In contrast, GRL-0920 completely blocked the infectivity and cytopathic effect of SARS-CoV-2 without significant toxicity. Structural modeling showed that indole and chloropyridinyl of the derivatives interacted with two catalytic dyad residues of M[SUP]pro[/SUP], Cys145 and His41, resulting in covalent bonding, which was verified using HPLC/MS. The present data should shed light on the development of therapeutics for COVID-19, and optimization of GRL-0920 based on the present data is essential to develop more-potent anti-SARS-CoV-2 compounds for treating COVID-19.
Keywords: COVID-19; SARS-CoV-2; antiviral agents; main protease.