High-throughput screening of SARS-CoV-2 main and papain-like protease inhibitors

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (Mpro) and papain like protease (PLpro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851Mpro inhibitors and 205 PLpro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both Mpro and PLpro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of Mpro inhibitors and over 20% of PLpro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 Mpro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.

Multi-level scoring approach to discover multi-targeting potency of medicinal plant phytochemicals against protein targets in SARS-CoV-2 and human ACE-2 receptor

SARS-CoV-2 pandemic has become a major threat to human healthcare and world economy. Due to the rapid spreading and deadly nature of infection, we are in a situation to develop quick therapeutics to combat SARS-CoV-2. In this study, we have adopted a multi-level scoring approach to identify multi-targeting potency of bioactive compounds in selected medicinal plants and compared its efficacy with two reference drugs, Nafamostat and Acalabrutinib which are under clinical trials to treat SARS-CoV-2. In particular, we employ molecular docking and implicit solvent free energy calculations (as implemented in the Molecular Mechanics -Generalized Born Surface Area approach) and QM fragmentation approach for validating the potency of bioactive compounds from the selected medicinal plants against four di?erent viral targets and one human receptor (Angiotensin-converting enzyme 2 -ACE-2) which facilitates the SARS-CoV-2entry into the cell. The protein targets considered for the study are viral 3CL main protease (3CLpro), papain-like protease (PLpro), RNA dependent RNA polymerase (RdRp), and viral spike protein-human hACE-2 complex (Spike:hACE2)including human protein target (hACE-2). Herein, thereliable multi-level scoring approach was used to validate the mechanism behind the multi-targeting potency of selected phytochemicals from medicinal plants. The present study evidenced that the phytochemicals Chebulagic acid, Stigmosterol, Repandusinic acid and Geranin exhibited efficient inhibitory activity against PLpro while Chebulagic acid was highly active against 3CLpro. Chebulagic acid andGeranin also showed excellent target specific activity against RdRp.Luteolin, Quercetin, Chrysoeriol and Repandusinic acid inhibited the interaction of viral spike protein with human ACE-2 receptor. Moreover Piperlonguminine and Piperine displayed significant inhibitory activity against human ACE-2 receptor. Therefore, the identified compounds namely Chebulagic acid, Geranin and Repandusinic acid can serve as potent multi-targeting phytomedicine for treating COVID-19

High-throughput screening identifies established drugs as SARS-CoV-2 PLpro inhibitors

A new coronavirus (SARS-CoV-2) has been identified as the etiologic agent for the COVID-19 outbreak. Currently, effective treatment options remain very limited for this disease; therefore, there is an urgent need to identify new anti-COVID-19 agents. In this study, we screened over 6,000 compounds that included approved drugs, drug candidates in clinical trials, and pharmacologically active compounds to identify leads that target the SARS-CoV-2 papain-like protease (PLpro). Together with main protease (M

Preprocesamiento de los fármacos antivirales candidatos contra COVID-19 en modelos de SARS cov2. Objetivos / Preprocessing of the candidate antiviral drugs against COVID-19 in models of SARS cov2 targets

Although many viral infections are self-limiting, other are real health challenges like COVID-19 since many viruses possess just few drug gable targets to be treated with small drug molecules. Corona virus genome encodes for up to 17 main proteins. Orf1ab encodes for polyprotein. COVID-19 structural proteins are the spike S, membrane M, envelope E and the nucleocapsid N protein while other are non-structural proteins designated as NSP1-13 for non-structural proteins. Among NSP the most important corona virus targets for developing antiviral drugs are the papain-like protease, PDB ID: 6m03 and RNA polymerase NSP12, PDB ID: 6nur. NCBI, NIH Genbank, Uniprot, PDB, DrugBank, ChemSpider databases and bioinformatics editor softwares like ICM Mol soft pro and Swiss Dock were used in addition to the in vitro lab model of viral protease were integrated to retrieve and analyze corona virus targets and to select the candidate ligands in an attempt to evaluate the inhibitory efficacy of different experimental and approved drugs which were further optimized and searched for the highly similar approved drug. This step aims to adopt drug repurposing to speed the development of antiviral drugs and recommend rational in vivo and clinical studies. After COVID-19 targets had been analyzed the drugs that shared > 70% similarity to the binding sites of those targets were reversin, pentagastrin, remdesivir, norfloxacin and nitazoxanide against COVID-19 papain-like protease whereas benzyl glutathione, lopinavir and hydroxymethylglutathione against RNA polymerase. The anti-resistance reversin showed the highest inhibitory efficacy against COVID-19 papain-like protease as indicated by the ligand-protease binding energy with Mol soft pro analysis. The calculated inhibitory binding was -137.30 kJ/mol z > 1.9 as compared with the tetrazapentadecanoate -129.57 kJ/mol z = 4.0, whereas remdesivir, pentagastrin, nitazoxanide and norfloxacin had a moderate antiprotease activity (>- 100 kJ/mol). Norfloxacin shoresults showed a slight consistency between in vitro and in silico models. Although benzyl glutathione is an experimental compound, however it had the highest RNA polymerase inhibiting efficacy with -129 kJ/mol binding energy which is even higher than lopinavir and Favinavir. From the overall results, reversin, oligopeptides, quinolones and antiviral drugs may widen the treatment options for COVID-19 if further evaluated in clinical studies

Discovery of human coronaviruses pan-papain-like protease inhibitors using computational approaches / 药物分析学报

The papain-like protease (PLpro) is vital for the replication of coronaviruses (CoVs), as well as for escaping innate-immune responses of the host. Hence, it has emerged as an attractive antiviral drug-target. In this study, computational approaches were employed, mainly the structure-based virtual screening coupled with all-atom molecular dynamics (MD) simulations to computationally identify specific inhibitors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PLpro, which can be further developed as potential pan-PLpro based broad-spectrum antiviral drugs. The sequence, structure, and functional con-serveness of most deadly human CoVs PLpro were explored, and it was revealed that functionally important catalytic triad residues are well conserved among SARS-CoV, SARS-CoV-2, and middle east respiratory syndrome coronavirus (MERS-CoV). The subsequent screening of a focused protease in-hibitors database composed of ～7,000 compounds resulted in the identification of three candidate compounds, ADM_13083841, LMG_15521745, and SYN_15517940. These three compounds established conserved interactions which were further explored through MD simulations, free energy calculations, and residual energy contribution estimated by MM-PB(GB)SA method. All these compounds showed stable conformation and interacted well with the active residues of SARS-CoV-2 PLpro, and showed consistent interaction profile with SARS-CoV PLpro and MERS-CoV PLpro as well. Conclusively, the re-ported SARS-CoV-2 PLpro specific compounds could serve as seeds for developing potent pan-PLpro based broad-spectrum antiviral drugs against deadly human coronaviruses. Moreover, the presented infor-mation related to binding site residual energy contribution could lead to further optimization of these compounds.

Study on screening potential traditional Chinese medicines against 2019-nCoV based on Mpro and PLP / 中国中药杂志

With the rapid outbreak of COVID-19, traditional Chinese medicine(TCM) has been playing an active role against the epidemic. However, the screening of TCM is limited by the development cycle and laboratory conditions, which greatly limits the screening speed. This study established optimization docking models and virtual screening to discovery potential active herbs for the prevention and treatment of the novel coronavirus based on molecular docking technology. The crystal structures of 3 CL protease(Mpro) and papain-like protease(PLP) were obtained from PDB database and homologous modeling respectively, and were used to conduct virtual screening of TCMD 2009 database by CDOCKER program. The ingredients scored in the top 100 were selected respectively, and the candidate herbs were ranked by the numbers of hit molecules. Based on Mpro inhibitors screening, 12 322 potential active components were obtained, and the representative active components included aster pentapeptide A, ligustrazine, salvianolic acid B, etc., and Zingiberis Rhizoma Recens, Asteris Radix et Rhizoma, Notoginseng Radix et Rhizoma, Chuanxiong Rhizoma, Salviae Miltiorrhizae Radix et Rhizoma, Zingiberis Rhizoma, Dianthi Herba, Rhei Radix et Rhizoma, Cistanches Herba were obtained. While 11 294 potential active ingredients were obtained by PLP inhibitor screening, representative active ingredients included gingerketophenol, ginkgol alcohol, ferulic acid, etc., and Codonopsis Radix, Notopterygii Rhizoma et Radix, Zingiberis Rhizoma Recens, Ginkgo Semen, Chuanxiong Rhizoma, Trichosanthis Fructus, Paeoniae Radix Alba, Psoraleae Fructus, Sophorae Flavescentis Radix, Notoginseng Radix et Rhizoma, Angelicae Sinensis Radix were chosen. By combining the diagnosis and treatment scheme of Hunan province's and angiotensin converting enzyme 2(ACE2) inhibitors screening from literature, present study also discussed the rational application of candidate herbs to this epidemic situation. Trichosanthis Fructus obtained by PLP inhibitors screening and Fritillaria verticillata obtained by ACE2 inhibitors screening were parts of the Sangbei Zhisou Powder and Xiaoxianxiong Decoction, which might be applicable to the syndromes of cough and dyspnea. Rhei Radix et Rhizoma screened by Mpro and Trichosanthis Fructus screened by PLP were contained in Maxing Shigan Decoction and Xuanbai Chengqi Decoction, and could be applied to the syndromes of epidemic virus blocking lung. Mori Folium, Lonicerae Japonicae Flos and Forsythiae Fructus obtained by ACE2 inhibitors screening were included in the Sangju Decoction and Yinqiaosan, which might be applicable to the syndromes of warm pathogen attacking lung and cough and dyspnea. The results of this study are intended to provide a reference for the further development of traditional Chinese medicine to deal with the new epidemic.