The SARS-CoV-2 pandemic at the end of 2019 had major worldwide health and economic consequences. Until effective vaccination approaches were created, the healthcare sectors endured a shortage of operative treatments that might prevent the infection’s spread. As a result, academia and the pharmaceutical industry prioritized the development of SARS-CoV2 antiviral medication. Pyranopyrazoles have been shown to play a prominent function in pharmaceutical chemistry and drug sighting because of their significant bioactive properties. We provide herein a novel sequence of pyranopyrazoles and their annulated systems whose antiviral efficacy and cytotoxicity were explored versus human coronavirus 229E (HCoV-229E) Vero-E6 cell lines as a model for the Coronaviridae family. Fifteen synthetic congeners pointed out miscellaneous antiviral efficacies against HCoV-229E with variable inhibition degrees. Compound 18 showed a high selectivity index (SI = 12.6) that established spectacular inhibitory capacity against human coronavirus 229E. Compounds 6, 7, and 14 exposed moderate efficacies. Compounds 6, 7, 14, and 18 exhibited substantial antiviral action through the replication phase with reduction percentages extending from 53.6%, 60.7%, and 55% to 82.2%, correspondingly. Likewise, when assessed to the positive control tipranavir (88.6%), the inhibitory efficiency of compounds 6, 7, 14, and 18 versus the SARS-CoV2 Mpro provided high percentages of 80.4%, 73.1%, 81.4% and up to 84.5%, respectively. In silico studies were performed to investigate further the biological activity and the target compounds’ physical and chemical features, including molecular dynamic (MD) simulations, protein–ligand docking, ADME studies, and density functional theory (DFT) calculations. These inquiries demonstrated that this series of metabolically stable pyranopyrazoles and their annulated systems are effective human coronavirus inhibitors that inhibit the viral M^pro protein and may have emerged as a novel COVID-19 curative option.

The corrosion inhibition of (N ¹ E)-N ¹,N ²-bis(4-(dimethylamino)benzylidene)-ethane-1,2-diamine, DMAB, against the destruction of C-steel in dilute HCl media (1.0 M) was examined. The techniques of gravimetry, gasometry, potentiodynamic, and electrochemical impedance spectroscopy are utilized. The rate of corrosion is found to decrease with more additions of the DMAB compound. The inhibition efficacy increases with concentrations to reach 97.7% at 5.0 mM and 298 K. The protection of metal destruction is controlled by the adsorption of the DMAB molecules on the metallic surface obeying Langmuir's pattern. The computed ΔG°_ads values are characterized by negative sign, explaining the spontaneity of the adsorption process. These values vary between -38.70 and -35.13 kJ mol^-1 depending on the temperature, which proves the physio- and chemisorption mechanisms. The reduction in K _ads values with T can be attributed to the desorption of some DMAB molecules from the electrode surface. Theoretical quantum computation confirms the adsorption of the DMAB compound in concurrence with the data obtained by practical techniques.

The inhibitive effect of E-2-(1-methylpyrrolidin-2-ylidene) hydrazine carbo-thioamide Schiff base (MPHCA) towards the corrosion of carbon steel in hydrochloric acid media was examined using various chemical and electrochemical techniques. The rate of metal destruction in the HCl solution is reduced in the presence of the MPHCA. The inhibition efficiency is increased with more additions of MPHCA to reach 97.68 % at 5.0 mM concentration, at 25 °C. The inhibition process is controlled by the adsorption of inhibitive molecules on the carbon steel surface, obeying the Langmuir model. The computed ΔGoads values with the negative sign confirm the spontaneous nature of the adsorption process. Such values varied between -34.45 and -36.77 kJ mol-1, supporting the mixed chemo and physisorption mechanisms. The lowering in Kads values with the increase in temperature could confirm the escape of a few adsorbed MPHCA molecules from the metallic surface into the examined solution. The theoretical studies by the DFT method and conductor-like polarizable con­tinuum determined the inhibitor's optimized geometries, providing insights into their mole­cular structure and potential properties. Monte Carlo and molecular dynamics simulations assessed the inhibitors' adsorption energy and comprehensive adsorption characteristics. MPHCA showed the highest adsorption energy, suggesting superior corrosion inhibition characteristics.

3-Amino-1,2,4-triazole (AT), 3,5-diamino-1,2,4-triazole (DT), and 5-(4-pyridyl)-1H-1,2,4-triazole-3-thiol (PTT) were investigated as inhibitors towards the general and pitting corrosion of Ni in dilute sulfuric acid solutions contaminated with Br^- ions. The utilized techniques are open circuit potential, galvanostatic polarization, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization supplemented by surface analysis using SEM. The galvanostatic polarization curves in 0.01 M H₂SO₄ indicate various oxidation regions followed by the passive region and O₂ evolution. Additions of Br^- ions initiate the pitting corrosion at E_b. The presence of the triazole compounds inhibits pitting corrosion by shifting E_b into the more positive potential with a decrease in the consumed electricity, Q. The potentiodynamic polarization proved that the triazole inhibitors behave as mixed inhibitors. The inhibition efficacy is raised with higher additions of triazole concentrations to follow the order AT < DT < PTT. The protection performance is illustrated by blocking the active sites on the Ni metal via an adsorption mechanism that obeys the Langmuir isotherm. The free energy of adsorption, ∆[Formula: see text] was computed to be -36.92, -36.18, and - 35.99 kJ. mol^-1 for PTT, DT, and AT suggests a mixed adsorption mechanism.