Exploring the dual effect of novel 1,4-diarylpyranopyrazoles as antiviral and anti-inflammatory for the management of SARS-CoV-2 and associated inflammatory symptoms.

COVID-19 and associated substantial inflammations continue to threaten humankind triggering death worldwide. So, the development of new effective antiviral and anti-inflammatory medications is a major scientific goal. Pyranopyrazoles have occupied a crucial position in medicinal chemistry because of their biological importance. Here, we report the design and synthesis of a series of sixteen pyranopyrazole derivatives substituted with two aryl groups at N-1 and C-4. The designed compounds are suggested to show dual activity to combat the emerging Coronaviruses and associated substantial inflammations. All compounds were evaluated for their in vitro antiviral activity and cytotoxicity against SARS-CoV infected Vero cells. As well, the in vitro assay of all derivatives against the SARS-CoV Mpro target was performed. Results revealed the potential of three pyranopyrazoles (22, 27, and 31) to potently inhibit the viral main protease with IC50 values of 2.01, 1.83, and 4.60 µM respectively compared with 12.85 and 82.17 µM for GC-376 and lopinavir. Additionally, in vivo anti-inflammatory testing for the most active compound 27 proved its ability to reduce levels of two cytokines (TNF-α and IL-6). Molecular docking and dynamics simulation revealed consistent results with the in vitro enzymatic assay and indicated the stability of the putative complex of 27 with SARS-CoV-2 Mpro. The assessment of metabolic stability and physicochemical properties of 27 have also been conducted. This investigation identified a set of metabolically stable pyranopyrazoles as effective anti-SARS-CoV-2 Mpro and suppressors of host cell cytokine release. We believe that the new compounds deserve further chemical optimization and evaluation for COVID-19 treatment.

In vitro and computational investigations of novel synthetic carboxamide-linked pyridopyrrolopyrimidines with potent activity as SARS-CoV-2-MPro inhibitors† † Electronic supplementary information (ESI) available. See https://doi.org/10.1039/d2ra04015h

An essential target for COVID-19 is the main protease of SARS-CoV-2 (Mpro). With the objective of targeting this receptor, a novel set of pyrido[1,2-a]pyrrolo[2,3-d]pyrimidines with terminal carboxamide fragments was designed, synthesized, and considered as an initial motif for the creation of effective pan-coronavirus inhibitors. Accordingly, nine derivatives (21–29) have been introduced for in vitro assay to evaluate their antiviral activity and cytotoxicity effect against COVID-19 virus using Vero cells. The obtained data revealed that the majority of these derivatives showed potent cellular anti-COVID-19 activity and prevent viral growth by more than 90% at two different concentrations with weak or even no detectable cytotoxic effect on Vero cells. Extensive molecular docking simulations highlighted proper non-covalent interaction of new compounds within the binding pocket of Mpro as a potential target for their antiviral activity. In vitro assay for all the synthesized derivatives against the viral Mpro target indicated that compounds 25 and 29 have promising inhibitory activity with IC50 values at low micromolar concentrations. The molecular dynamic simulation results predicted the stability of compound 29 in the binding cavity of SARS-CoV-2 Mpro and hence supported the high inhibitory activity shown by the In vitro assay. These results suggested that compounds 25 and 29 merit further investigations as promising drug candidates for the management of SARS-CoV-2. An essential target for COVID-19 is the main protease of SARS-CoV-2 (Mpro).

In vitro and computational investigations of novel synthetic carboxamide-linked pyridopyrrolopyrimidines with potent activity as SARS-CoV-2-MPro inhibitors.

An essential target for COVID-19 is the main protease of SARS-CoV-2 (Mpro). With the objective of targeting this receptor, a novel set of pyrido[1,2-a]pyrrolo[2,3-d]pyrimidines with terminal carboxamide fragments was designed, synthesized, and considered as an initial motif for the creation of effective pan-coronavirus inhibitors. Accordingly, nine derivatives (21-29) have been introduced for in vitro assay to evaluate their antiviral activity and cytotoxicity effect against COVID-19 virus using Vero cells. The obtained data revealed that the majority of these derivatives showed potent cellular anti-COVID-19 activity and prevent viral growth by more than 90% at two different concentrations with weak or even no detectable cytotoxic effect on Vero cells. Extensive molecular docking simulations highlighted proper non-covalent interaction of new compounds within the binding pocket of Mpro as a potential target for their antiviral activity. In vitro assay for all the synthesized derivatives against the viral Mpro target indicated that compounds 25 and 29 have promising inhibitory activity with IC50 values at low micromolar concentrations. The molecular dynamic simulation results predicted the stability of compound 29 in the binding cavity of SARS-CoV-2 Mpro and hence supported the high inhibitory activity shown by the In vitro assay. These results suggested that compounds 25 and 29 merit further investigations as promising drug candidates for the management of SARS-CoV-2.

Chaetomugilins and Chaetoviridins-Promising Natural Metabolites: Structures, Separation, Characterization, Biosynthesis, Bioactivities, Molecular Docking, and Molecular Dynamics.

Fungi are recognized as luxuriant metabolic artists that generate propitious biometabolites. Historically, fungal metabolites have largely been investigated as leads for various therapeutic agents. Chaetomugilins and the closely related chaetoviridins are fungal metabolites, and each has an oxygenated bicyclic pyranoquinone core. They are mainly produced by various Chaetomaceae species. These metabolites display unique chemical features and diversified bioactivities. The current review gives an overview of research about fungal chaetomugilins and chaetoviridins regarding their structures, separation, characterization, biosynthesis, and bioactivities. Additionally, their antiviral potential towards the SARS-CoV-2 protease was evaluated using docking studies and molecular dynamics (MD) simulations. We report on the docking and predictive binding energy estimations using reported crystal structures of the main protease (PDB ID: 6M2N, 6W81, and 7K0f) at variable resolutions-i.e., 2.20, 1.55, and 1.65 Å, respectively. Chaetovirdin D (43) exhibited highly negative docking scores of -7.944, -8.141, and -6.615 kcal/mol, when complexed with 6M2N, 6W81, and 7K0f, respectively. The reference inhibitors exhibited the following scores: -5.377, -6.995, and -8.159 kcal/mol, when complexed with 6M2N, 6W81, and 7K0f, respectively. By using molecular dynamics simulations, chaetovirdin D's stability in complexes with the viral protease was analyzed, and it was found to be stable over the course of 100 ns.

Phytoconstituents, In Vitro Anti-Infective Activity of Buddleja indica Lam., and In Silico Evaluation of its SARS-CoV-2 Inhibitory Potential.

Phytochemical investigation of Buddleja indica Lam. leaves methanol extract (BIT) resulted in the isolation of six known compounds for the first time from the plant, namely, p-hydroxybenzoic acid 1), caffeic acid 2), quercetin 3-O-ß-D glucoside-7-O-α-L-rhamnoside 3), kaempferol 3-O-ß-D glucoside-7-O-α-L-rhamnoside 4), quercetin 7-O-ß-D glucoside 5) and kaempferol 6). BIT extract showed potent antibacterial activity with MIC values ranging between 0.48 and 1.95 µg/ml with Bacillus subtilis was the most susceptible to the BIT effect. It showed a notable antimycobacterial and anti-Helicobacter pylori activity with MIC values of 100 and 80 µg/ml, respectively. Vesicular stomatitis virus (VSV) was more sensitive to the antiviral activity of BIT comparable to herpes simplex virus type 1 (HSV-1), showing 48.38 and 41.85% inhibition of the viral replication at a dose of 50 µg/ml for VSV and HSV-1, respectively. In silico molecular docking of the isolated compounds revealed that caffeic acid 2) showed the highest fitting within the active sites of DNA-gyrase, topoisomerase IV, and SARS-CoV-2 MPro. Quercetin 7-O-ß-D glucoside 5) revealed the best fitting in dihydrofolate reductase active site with ∆ G value equals -36.53 Kcal/mol. Kaempferol 6) exhibited the highest fitting towards ß-lactamase, SARS-CoV-2PLpro, and SARS-CoV-2 3CLpro active sites. Thus, B. indica Lam. can be considered as a future source of cheap, substantially safe, and credible antibacterial, antifungal, and antiviral candidate of natural origin that could effectively participate in solving the problem of COVID-19 pandemic. These findings provide a scientific consolidation for the ethnomedicinal uses of Buddleja indica Lam. as a topical antiseptic.