Assessing the potential of NS2B/NS3 protease inhibitors biomarker in curbing dengue virus infections: In silico vs. In vitro approach

An increase in the occurrence of viral infectious diseases is a global concern for human health. According to a WHO report, dengue virus (DENV) is one of the most common viral diseases affecting approximately 400 million people annually, with worsening symptoms in nearly 1% of cases. Both academic and industrial researchers have conducted numerous studies on viral epidemiology, virus structure and function, source and route of infection, treatment targets, vaccines, and drugs. The development of CYD-TDV or Dengvaxia^® vaccine has been a major milestone in dengue treatment. However, evidence has shown that vaccines have some drawbacks and limitations. Therefore, researchers are developing dengue antivirals to curb infections. DENV NS2B/NS3 protease is a DENV enzyme essential for replication and virus assembly, making it an interesting antiviral target. For faster hit and lead recognition of DENV targets, methods to screen large number of molecules at lower costs are essential. Similarly, an integrated and multidisciplinary approach involving in silico screening and confirmation of biological activity is required. In this review, we discuss recent strategies for searching for novel DENV NS2B/NS3 protease inhibitors from the in silico and in vitro perspectives, either by applying one of the approaches or by integrating both. Therefore, we hope that our review will encourage researchers to integrate the best strategies and encourage further developments in this area.

(E)-5-Benzyl-7-(3,4-dimethoxybenzylidene)-3-(3,4-dimethoxyphenyl)-2-phenyl-3,3a,4,5,6,7-hexahydro-2H-pyrazolo[4,3c] Pyridine

A new pyrazolo-pyridine analogue (title compound) was synthesized in two steps. The first stage was synthesis of monoketone curcumin analogue through Claisen–Schmidt reaction. The second stage was synthesis of the title compound through intermolecular cyclization under reflux condition. The structure of the title compound has been confirmed by spectroscopic analysis including UV, FT-IR, HRMS, 1D NMR (1H-NMR, 13C-NMR, 1D-TOCSY), and 2D NMR (COSY, HSQC, HMBC). Based on the DPPH assay, the compound has moderate antioxidant activity, with an IC50 value of 194.06 ± 7.88 µg/mL (0.337 mM).

5-(4-Fluorophenyl)-3-(naphthalen-1-yl)-1-phenyl-1H-pyrazole

A new fluorinated pyrazole, 5-(4-fluorophenyl)-3-(naphthalen-1-yl)-1-phenyl-1H-pyrazole was successfully synthesized via a two-step reaction. Firstly, the synthesis of pyrazoline was performed via one-pot three-component reaction under microwave irradiation. Secondly, the synthesis of pyrazole was performed via oxidative aromatization of pyrazoline under conventional heating. The structure of the synthesized compound was confirmed by spectroscopic analysis, including FT-IR, HR-MS, 1D and 2D NMR analysis. Then, molecular docking study showed that the binding affinity of the synthesized compound to human estrogen alpha receptor (ERα) was close to 4-OHT as a native ligand.

(E)-4-(3-(3-(4-Methoxyphenyl)acryloyl)phenoxy)butyl 2-Hydroxybenzoate

A new hybrid compound of chalcone-salicylate (title compound) has been successfully synthesized using a linker mode approach under reflux condition. The structure of the title compound has been established by spectroscopic analysis including UV-Vis, FT-IR, HRMS, 1D, and 2D NMR. Then, computational approach was also applied in this study through molecular docking and MD simulation to explore its potency against breast cancer. The results of the molecular docking study showed that the title compound exhibited more negative value of binding free energy (−8.15 kcal/mol) than tamoxifen (−7.00 kcal/mol). In addition, no striking change in the positioning of the interacting residues was recorded before and after the MD simulations. Based on the studies, it can be predicted that the title compound has a cytotoxic activity potency against breast cancer through ERα inhibition and it presumably can be developed as anticancer agent candidate.