Antiviral Activity of Pyrimidine Containing Compounds: Patent Review.

Viruses are still the most prevalent infectious pathogens on a worldwide scale, with many of them causing life-threatening illnesses in humans. Influenza viruses, because of their significant morbidity and mortality, continue to pose a major threat to human health. According to WHO statistics, seasonal influenza virus epidemics are predicted to cause over 2 million severe illness cases with high death rates yearly. The whole world has been suffering from the COVID-19 epidemic for two years and is still suffering so far, and the deaths from this virus have exceeded three million cases. Because the great majority of viral infections do not have a specific medication or vaccination, discovering novel medicines remains a vital task. This review covers reports in the patent literature from 1980 to the end of 2021 on the antiviral activities of pyrimidine moieties. The patent database, SciFinder, was used to locate patent applications. A large variety of pyrimidine molecules have been produced and tested for antiviral activity over the last decade. These molecules were reported to inhibit a wide range of viruses, including influenza virus, respiratory syncytial virus, rhinovirus, dengue virus, herpes virus, hepatitis B and C, and human immunodeficiency virus. The cytotoxicity of the developed pyrimidine derivatives was tested in almost all reported studies and the selectivity index was calculated to show the selectivity and safety of such molecules. From the remarkable activity of pyrimidine compounds as antivirals for several dangerous viruses, we expect that these derivatives will be used as potent drugs in the very near future.

Nano-sized formazan analogues: Synthesis, structure elucidation, antimicrobial activity and docking study for COVID-19.

Three series of nanosized-formazan analogues were synthesized from the reaction of dithiazone with various types of α-haloketones (ester and acetyl substituted hydrazonoyl chlorides and phenacyl bromides) in sodium ethoxide solution. The structure and the crystal size of the new synthesized derivatives were assured based on the spectral analyses, XRD and SEM data. The antibacterial and antifungal activities were evaluated by agar diffusion technique. The results showed mild to moderate antibacterial activities and moderate to potent antifungal activities. Significant antifungal activities were observed for four derivatives 3a, 3d, 5a and 5g on the pathogenic fungal strains; Aspergillus flavus and Candida albicans with inhibition zone ranging from 16 to 20 mm. Molecular docking simulations of the synthesized compounds into leucyl-tRNA synthetase editing domain of Candida albicans suggested that most formazan analogues can fit deeply forming stable complexes in the active site. Furthermore, we utilized the docking approach to examine the potential of these compounds to inhibit SARS-CoV-2 3CLpro. The results were very promising verifying these formazan analogues as a hopeful antiviral agents.