Promising Schiff bases in antiviral drug design and discovery

Abstract

Emerging and re-emerging illnesses will probably present a new hazard of infectious diseases and have fostered the urge to research new antiviral agents. Most of the antiviral agents are analogs of nucleosides and only a few are non-nucleoside antiviral agents. There is quite a less percentage of marketed/clinically approved non-nucleoside antiviral medications. Schiff bases are organic compounds that possess a well-demonstrated profile against cancer, viruses, fungus, and bacteria, as well as in the management of diabetes, chemotherapy-resistant cases, and malarial infections. Schiff bases resemble aldehydes or ketones with an imine/azomethine group instead of a carbonyl ring. Schiff bases have a broad application profile not only in therapeutics/medicine but also in industrial applications. Researchers have synthesized and screened various Schiff base analogs for their antiviral potential. Some of the important heterocyclic compounds like istatin, thiosemicarbazide, quinazoline, quinoyl acetohydrazide, etc. have been used to derive novel Schiff base analogs. Keeping in view the outbreak of viral pandemics and epidemics, this manuscript compiles a review of Schiff base analogs concerning their antiviral properties and structural-activity relationship analysis.

Synthesis and Spectroscopic Characterization of Schiff Base Metal Complexes, Biological Activity, and Molecular Docking Studies

“…A few azo-azomethine metal complexes have been used extensively in technology due to their photophysical and energy-transfer capabilities. Because of their stability, electroactivity, thermochromism, and photochromism, Schiff base compounds make excellent intermediates for a variety of uses. − Numerous reviews revealed that the metallo-organic chemistry of such compounds significantly affected how they acted biologically, highlighting the role played by metals as catalysts in a variety of biological processes. − Higher electronegative atoms’ connected bonding orbitals and electrons can be adsorbed on metal surfaces due to their electrons’ C=N faction planarity. This substance contributes significantly to the development of inorganic biochemistry and is used as a substrate in ring closure, cycloaddition, and replacement reactions to produce a variety of biologically active compounds. − …”

Recent advances on the DNA interaction properties of Schiff bases and their metal complexes

“…Many SBs are known to be used in a broad range of fields, including electroluminescence, 14–17 luminescence, 18–20 energy materials, 21 analytical chemistry, 22 food industry, 23 catalysis, 24–26 dye industries, 27,28 manufacturing of polymer‐based substances, 29,30 use as detectors, 31–33 organic optoelectronic substances, 34,35 and pharmacological agents 36 . Pharmacological applications include anti‐inflammatory, 37,38 anti‐tumor, 39,40 anti‐convulsant, 41–44 anti‐fungal, 44–46 painkillers, 47 anti‐bacterial, 48–50 anti‐malarial, 51,52 anti‐viral, 53–57 anti‐helminthic, 58,59 anti‐oxidants, 60–62 and DNA interaction 63 and further along (Scheme 2). Because of their DNA‐binding characteristics, SB metal complexes have garnered significant interest over the past 10 years 64,65 …”

Synthesis of Cobalt(III) Complexes Derived from Pyridoxal: Structural Cleavage Evaluations and In Silico Calculations for Biological Targets

“…Interestingly, some reports correlated the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with increasing probability of cancer development in different organs [38][39][40] and due to the unique mechanisms of action and the versatility of metallodrugs in interacting with biological molecules, e.g., targeting specific crucial steps for cancer cells and also interfering with the viral replication process, either by directly targeting viral components or by modulating host cellular mechanisms, metallodrugs might represent a promising frontier in both cancer and antiviral therapies [41,42]. In this sense, cobalt Schiff base complexes have gained attention, mainly due to their ability to induce apoptosis in cancer cells [43,44] and inhibit viral replication by targeting different viral enzymes [45,46], which offers a promising avenue for the development new therapies.…”