Design and statistical optimisation of emulsomal nanoparticles for improved anti-SARS-CoV-2 activity of N-(5-nitrothiazol-2-yl)-carboxamido candidates: in vitro and in silico studies.

In this article, emulsomes (EMLs) were fabricated to encapsulate the N-(5-nitrothiazol-2-yl)-carboxamido derivatives (3a-3g) in an attempt to improve their biological availability and antiviral activity. Next, both cytotoxicity and anti-SARS-CoV-2 activities of the examined compounds loaded EMLs (F3a-g) were assessed in Vero E6 cells via MTT assay to calculate the CC50 and inhibitory concentration 50 (IC50) values. The most potent 3e-loaded EMLs (F3e) elicited a selectivity index of 18 with an IC50 value of 0.73 µg/mL. Moreover, F3e was selected for further elucidation of a possible mode of action where the results showed that it exhibited a combination of virucidal (>90%), viral adsorption (>80%), and viral replication (>60%) inhibition. Besides, molecular docking and MD simulations towards the SARS-CoV-2 Mpro were performed. Finally, a structure-activity relationship (SAR) study focussed on studying the influence of altering the size, type, and flexibility of the α-substituent to the carboxamide in addition to compound contraction on SARS-CoV-2 activity.HighlightsEmulsomes (EMLs) were fabricated to encapsulate the N-(5-nitrothiazol-2-yl)-carboxamido derivatives (3a-3g).The most potent 3e-loaded EMLs (F3e) showed an IC50 value of 0.73 µg/mL against SARS-CoV-2.F3e exhibited a combination of virucidal (>90%), viral adsorption (>80%), and viral replication (>60%) inhibition.Molecular docking, molecular dynamics (MD) simulations, and MM-GBSA calculations were performed.Structure-activity relationship (SAR) study was discussed to study the influence of altering the size, type, and flexibility of the α-substituent to the carboxamide on the anti-SARS-CoV-2 activity.

DFT investigation of atazanavir as potential inhibitor for 2019-nCoV coronavirus M protease.

Atazanavir (ATZ) is an antiviral drug synthesized.ATZ is being investigated for potential application against the Coronavirus 2019-nCoV. To find candidate drugs for 2019-nCoV, we have carried out a computational study to screen for effective available drug ATZ which may work as an inhibitor for the Mpro of 2019-nCoV. In the present work, the first time the molecular structure of ATZ molecule has been studied using Density Functional Theory (CAMB3LYP/6-31G*) in solvent water. The electronic properties, atomic charges, MEP, NBO analysis, and excitation energies of ATZ have also been studied. The interaction of ATZ compound with the Coronavirus was performed by molecular docking studies.

Anticoagulants as Potential SARS-CoV-2 Mpro Inhibitors for COVID-19 Patients: In Vitro, Molecular Docking, Molecular Dynamics, DFT, and SAR Studies.

In this article, 34 anticoagulant drugs were screened in silico against the main protease (Mpro) of SARS-CoV-2 using molecular docking tools. Idraparinux, fondaparinux, eptifibatide, heparin, and ticagrelor demonstrated the highest binding affinities towards SARS-CoV-2 Mpro. A molecular dynamics study at 200 ns was also carried out for the most promising anticoagulants to provide insights into the dynamic and thermodynamic properties of promising compounds. Moreover, a quantum mechanical study was also conducted which helped us to attest to some of the molecular docking and dynamics findings. A biological evaluation (in vitro) of the most promising compounds was also performed by carrying out the MTT cytotoxicity assay and the crystal violet assay in order to assess inhibitory concentration 50 (IC50). It is worth noting that ticagrelor displayed the highest intrinsic potential for the inhibition of SARS-CoV-2 with an IC50 value of 5.60 µM and a safety index of 25.33. In addition, fondaparinux sodium and dabigatran showed promising inhibitory activities with IC50 values of 8.60 and 9.40 µM, respectively, and demonstrated safety indexes of 17.60 and 15.10, respectively. Moreover, the inhibitory potential of the SARS-CoV-2 Mpro enzyme was investigated by utilizing the SARS-CoV-2 Mpro assay and using tipranavir as a reference standard. Interestingly, promising SARS-CoV-2 Mpro inhibitory potential was attained for fondaparinux sodium with an IC50 value of 2.36 µM, surpassing the reference tipranavir (IC50 = 7.38 µM) by more than three-fold. Furthermore, highly eligible SARS-CoV-2 Mpro inhibitory potential was attained for dabigatran with an IC50 value of 10.59 µM. Finally, an SAR was discussed, counting on the findings of both in vitro and in silico approaches.

Anti-SARS-CoV-2 activities of tanshinone IIA, carnosic acid, rosmarinic acid, salvianolic acid, baicalein, and glycyrrhetinic acid between computational and in vitro insights† † Electronic supplementary information (ESI) available. See DOI: 10.1039/d1ra05268c

Six compounds namely, tanshinone IIA (1), carnosic acid (2), rosmarinic acid (3), salvianolic acid B (4), baicalein (5), and glycyrrhetinic acid (6) were screened for their anti-SARS-CoV-2 activities against both the spike (S) and main protease (Mpro) receptors using molecular docking studies. Molecular docking recommended the superior affinities of both salvianolic acid B (4) and glycyrrhetinic acid (6) as the common results from the previously published computational articles. On the other hand, their actual anti-SARS-CoV-2 activities were tested in vitro using plaque reduction assay to calculate their IC50 values after measuring their CC50 values using MTT assay on Vero E6 cells. Surprisingly, tanshinone IIA (1) was the most promising member with IC50 equals 4.08 ng μl−1. Also, both carnosic acid (2) and rosmarinic acid (3) showed promising IC50 values of 15.37 and 25.47 ng μl−1, respectively. However, salvianolic acid (4) showed a weak anti-SARS-CoV-2 activity with an IC50 value equals 58.29 ng μl−1. Furthermore, molecular dynamics simulations for 100 ns were performed for the most active compound from the computational point of view (salvianolic acid 4), besides, the most active one biologically (tanshinone IIA 1) on both the S and Mpro complexes of them (four different molecular dynamics processes) to confirm the docking results and give more insights regarding the stability of both compounds inside the SARS-CoV-2 mentioned receptors, respectively. Also, to understand the mechanism of action for the tested compounds towards SARS-CoV-2 inhibition it was necessary to examine the mode of action for the most two promising compounds, tanshinone IIA (1) and carnosic acid (2). Both compounds (1 and 2) showed very promising virucidal activity with a most prominent inhibitory effect on viral adsorption rather than its replication. This recommended the predicted activity of the two compounds against the S protein of SARS-CoV-2 rather than its Mpro protein. Our results could be very promising to rearrange the previously mentioned compounds based on their actual inhibitory activities towards SARS-CoV-2 and to search for the reasons behind the great differences between their in silico and in vitro results against SARS-CoV-2. Finally, we recommend further advanced preclinical and clinical studies especially for tanshinone IIA (1) to be rapidly applied in COVID-19 management either alone or in combination with carnosic acid (2), rosmarinic acid (3), and/or salvianolic acid (4). Tanshinone IIA shows the most promising anti-SARS-CoV-2 biological activity: molecular docking, molecular dynamics, in vitro, and SAR studies.

Revisiting activity of some glucocorticoids as a potential inhibitor of SARS-CoV-2 main protease: theoretical study† † Electronic supplementary information (ESI) available. See DOI: 10.1039/d0ra10674g

The global breakout of COVID-19 and raised death toll has prompted scientists to develop novel drugs capable of inhibiting SARS-CoV-2. Conducting studies on repurposing some FDA-approved glucocorticoids can be a promising prospective for finding a treatment for COVID-19. In addition, the use of anti-inflammatory drugs, such as glucocorticoids, is a pivotal step in the treatment of critical cases of COVID-19, as they can provoke an inflammatory cytokine storm, damaging lungs. In this study, 22 FDA-approved glucocorticoids were identified through in silico (molecular docking) studies as the potential inhibitors of COVID-19's main protease. From tested compounds, ciclesonide 11, dexamethasone 2, betamethasone 1, hydrocortisone 4, fludrocortisone 3, and triamcinolone 8 are suggested as the most potent glucocorticoids active against COVID-19's main protease. Moreover, molecular dynamics simulations followed by the calculations of the binding free energy using MM-GBSA were carried out for the aforementioned promising candidate-screened glucocorticoids. In addition, quantum chemical calculations revealed two electron-rich sites on ciclesonide where binding interactions with the main protease and cleavage of the prodrug to the active metabolite take place. Our results have ramifications for conducting preclinical and clinical studies on promising glucocorticoids to hasten the development of effective therapeutics against COVID-19. Another advantage is that some glucocorticoids can be prioritized over others for the treatment of inflammation accompanying COVID-19. The global breakout of COVID-19 and raised death toll has prompted scientists to develop novel drugs capable of inhibiting SARS-CoV-2.

Revisiting activity of some glucocorticoids as a potential inhibitor of SARS-CoV-2 main protease: theoretical study.

The global breakout of COVID-19 and raised death toll has prompted scientists to develop novel drugs capable of inhibiting SARS-CoV-2. Conducting studies on repurposing some FDA-approved glucocorticoids can be a promising prospective for finding a treatment for COVID-19. In addition, the use of anti-inflammatory drugs, such as glucocorticoids, is a pivotal step in the treatment of critical cases of COVID-19, as they can provoke an inflammatory cytokine storm, damaging lungs. In this study, 22 FDA-approved glucocorticoids were identified through in silico (molecular docking) studies as the potential inhibitors of COVID-19's main protease. From tested compounds, ciclesonide 11, dexamethasone 2, betamethasone 1, hydrocortisone 4, fludrocortisone 3, and triamcinolone 8 are suggested as the most potent glucocorticoids active against COVID-19's main protease. Moreover, molecular dynamics simulations followed by the calculations of the binding free energy using MM-GBSA were carried out for the aforementioned promising candidate-screened glucocorticoids. In addition, quantum chemical calculations revealed two electron-rich sites on ciclesonide where binding interactions with the main protease and cleavage of the prodrug to the active metabolite take place. Our results have ramifications for conducting preclinical and clinical studies on promising glucocorticoids to hasten the development of effective therapeutics against COVID-19. Another advantage is that some glucocorticoids can be prioritized over others for the treatment of inflammation accompanying COVID-19.

Molecular docking, molecular dynamics, and in vitro studies reveal the potential of angiotensin II receptor blockers to inhibit the COVID-19 main protease.

Drug repurposing is the most rapid and economic way nowadays to rapidly provide effective drugs for our pandemic coronavirus disease 2019 (COVID-19). It was a great debate about ARBs whether to be stopped or continued for patients using them especially at the beginning of the COVID-19 pandemic. In this study, we carried out a virtual screening for almost all members of ARBs (nine) against COVID-19 main protease. Molecular docking as one of the important computational techniques was performed in this work. Interestingly, the tested compounds showed variable binding affinities in the order of N3 inhibitor (10, docked) > Fimasartan (8) > Candesartan (2) > Olmesartan (7) > Azilsartan (9) > Eprosartan (5) > Valsartan (3) > Losartan (1) > Irbesartan (6) > Telmisartan (4). Moreover, Fimasartan (8), Candesartan (2), and Olmesartan (7) were additionally estimated through molecular dynamic simulations monitored via computing the binding free energy using MM-GBSA. The results are promising for rapidly repurposing such drugs (especially, Fimasartan (8) and Candesartan (2)) after further preclinical and clinical studies either alone or in combination with others for the treatment of COVID-19 virus especially known to cause vasodilatation (to prevent blood coagulation) and to reduce inflammation and fibrosis (to prevent pulmonary fibrosis), with well-known safety profiles. In vitro, the virtual findings were consistent with the experimental testing of four representative ARBs. Out of the tested compounds, Olmesartan (7) showed the most promising anti-SARS-CoV-2 activity (IC50 = 1.808 µM, and CC50 = 557.6 µM) with high selectivity index (308.4) against SARS-CoV-2 in Vero E6 cells. This work may clarify and approve not only the safety of ARBs used by a large group of patients worldwide but also their possible effectiveness against the COVID-19 virus either as a prophylactic or treatment option. It intended also to give a clear spot on the structure-activity relationship (SAR) required for the future design of new drugs targeting the newly emerged SARS-CoV-2 protease by medicinal chemists.