A comprehensive review on the biological interest of quinoline and its derivatives.

Amongst heterocyclic compounds, quinoline is an advantaged scaffold that appears as a significant assembly motif for the development of new drug entities. Quinoline and its derivatives tested with diverse biological activity constitute an important class of compounds for new drug development. Therefore, many scientific communities have developed these compounds as intent structure and evaluated their biological activities. The present, review provides brief natural sources of quinoline and including a new extent of quinoline-based marketed drugs. This review also confers information about the biological activities of quinoline derivatives such as antibacterial, antifungal, antimycobacterial, antiviral, anti-protozoal, antimalarial, anticancer, cardiovascular, CNS effects, antioxidant, anticonvulsant, analgesic, anti-inflammatory, anthelmintic and miscellaneous activities.

A review on possible mechanistic insights of Nitazoxanide for repurposing in COVID-19.

The global pandemic of Coronavirus Disease 2019 (COVID-19) has brought the world to a grinding halt. A major cause of concern is the respiratory distress associated mortality attributed to the cytokine storm. Despite myriad rapidly approved clinical trials with repurposed drugs, and time needed to develop a vaccine, accelerated search for repurposed therapeutics is still ongoing. In this review, we present Nitazoxanide a US-FDA approved antiprotozoal drug, as one such promising candidate. Nitazoxanide which is reported to exert broad-spectrum antiviral activity against various viral infections, revealed good in vitro activity against SARS-CoV-2 in cell culture assays, suggesting potential for repurposing in COVID-19. Furthermore, nitazoxanide displays the potential to boost host innate immune responses and thereby tackle the life-threatening cytokine storm. Possibilities of improving lung, as well as multiple organ damage and providing value addition to COVID-19 patients with comorbidities, are other important facets of the drug. The review juxtaposes the role of nitazoxanide in fighting COVID-19 pathogenesis at multiple levels highlighting the great promise the drug exhibits. The in silico data and in vitro efficacy in cell lines confirms the promise of nitazoxanide. Several approved clinical trials world over further substantiate leveraging nitazoxanide for COVID-19 therapy.

Therapeutic Potential of Ursonic Acid: Comparison with Ursolic Acid.

Plants have been used as drugs to treat human disease for centuries. Ursonic acid (UNA) is a naturally occurring pentacyclic triterpenoid extracted from certain medicinal herbs such as Ziziphus jujuba. Since the pharmacological effects and associated mechanisms of UNA are not well-known, in this work, we attempt to introduce the therapeutic potential of UNA with a comparison to ursolic acid (ULA), a well-known secondary metabolite, for beneficial effects. UNA has a keto group at the C-3 position, which may provide a critical difference for the varied biological activities between UNA and ULA. Several studies previously showed that UNA exerts pharmaceutical effects similar to, or stronger than, ULA, with UNA significantly decreasing the survival and proliferation of various types of cancer cells. UNA has potential to exert inhibitory effects in parasitic protozoa that cause several tropical diseases. UNA also exerts other potential effects, including antihyperglycemic, anti-inflammatory, antiviral, and antioxidant activities. Of note, a recent study highlighted the suppressive potential of UNA against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Molecular modifications of UNA may enhance bioavailability, which is crucial for in vivo and clinical studies. In conclusion, UNA has promising potential to be developed in anticancer and antiprotozoan pharmaceuticals. In-depth investigations may increase the possibility of UNA being developed as a novel reagent for chemotherapy.

Discovery, Design, Synthesis, and Application of Nucleoside/Nucleotides.

For decades, nucleosides and nucleotides have formed the cornerstone of antiviral, antiparasitic and anticancer therapeutics and have been used as tools in exploring nucleic acid structure and function [...].

Quinoline-based Compounds as Key Candidates to Tackle Drug Discovery Programs of Microbicidal Agents.

Quinolines are heterocyclic nitrogen compounds, ubiquitous in nature and largely used as a structural component of dyes, solvent for resins, terpenes as well as during the production of several other chemical stuffs, including pesticides. Quinolines, such as quinine and chloroquine, exhibit various pharmacological properties, acting as antimalarial drugs, antiparasitic, antibacterial, antiviral, antifungal, and anticancer agents, besides being in clinical use for autoimmune diseases. A brief review has been presented regarding the biological effect and clinical use of quinolines and derivatives upon three trypanosomatids agents of important neglected tropical diseases; Trypanosoma cruzi, Trypanosoma brucei spp and Leishmania spp, which trigger Chagas disease, sleeping sickness and leishmaniasis, respectively, also extending to a glance update of their potential application towards other microbes relevant for emerging illness caused by fungi, bacteria and virus, including the pandemic Covid-19.