Computational study of nitro-benzylidene phenazine as dengue virus-2 NS2B-NS3 protease inhibitor

Synthesis and biological activity of imidazole phenazine derivatives as potential inhibitors for NS2B-NS3 dengue protease

A series of new imidazole-phenazine derivatives were synthesized via a two-step process. The condensation of 2,3-diaminophenazine and benzaldehyde derivatives proceeds with intermediate formation of an aniline Schiff base, which undergoes subsequent cyclodehydrogenation in situ. The structures of the synthesized compounds were characterized by 1D and 2D NMR, FTIR and HRMS. A total of thirteen imidazole phenazine derivatives were synthesized and validated for their inhibitory activity as anti-dengue agents by an in vitro DENV2 NS2B-NS3 protease assay using a fluorogenic Boc-Gly-Arg-Arg-AMC substrate. Two para-substituted imidazole phenazines, 3e and 3k, were found to be promising lead molecules for novel NS2B-NS3 protease inhibitors with IC50 of 54.8 μM and 71.9 μM, respectively, compared to quercetin as a control (IC50 104.8 μM). The in silico study was performed using AutoDock Vina to identify the binding energy and conformation of 3e and 3k with the active site of the DENV2 NS2B-NS3 protease Wichapong model. The results indicate better binding properties of 3e and 3k with calculated binding energies of -8.5 and -8.4 kcal mol-1, respectively, compared to the binding energy of quercetin of -7.2 kcal mol-1, which corroborates well with the experimental observations.

The brief overview, antivirus and anti-SARS-CoV-2 activity, quantitative methods, and pharmacokinetics of cepharanthine: a potential small-molecule drug against COVID-19

To effectively respond to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an increasing number of researchers are focusing on the antiviral activity of cepharanthine (CEP), which is a clinically approved drug being used for over 70 years. This review aims to provide a brief overview of CEP and summarize its recent findings in quantitative analysis, pharmacokinetics, therapeutic potential, and mechanism in antiviral and anti-SARS-CoV-2 activity. Given its remarkable capacity against SARS-CoV-2 infection in vitro and in vivo, with its primary target organ being the lungs, and its good pharmacokinetic profile; mature and stable manufacturing technique; and its advantages of safety, effectiveness, and accessibility, CEP has become a promising drug candidate for treating COVID-19 despite being an old drug.