Synthesis and Evaluation of Chalcone-Quinoline Based Molecular Hybrids as Potential Anti-Malarial Agents

Exploring the Recent Pioneering Developments of Small Molecules in Antimalarial Drug Armamentarium: A Chemistry Prospective Appraisal

Malaria is a very destructive and lethal parasitic disease that causes significant mortality worldwide, resulting in the loss of millions of lives annually. It is an infectious disease transmitted by mosquitoes, which is caused by different species of the parasite protozoan belonging to the genus Plasmodium. The uncontrolled intake of antimalarial drugs often employed in clinical settings has resulted in the emergence of numerous strains of plasmodium that are resistant to these drugs, including multidrug-resistant strains. This resistance significantly diminishes the effectiveness of many primary drugs used in the treatment of malaria. Hence, there is an urgent need for developing unique classes of antimalarial drugs that function with distinct mechanisms of action. In this context, the design and development of hybrid compounds that combine pharmacophoric properties from different lead molecules into a single unit gives a unique perspective towards further development of malaria drugs in the next generation. In recent years, the field of medicinal chemistry has made significant efforts resulting in the discovery and synthesis of numerous small novel compounds that exhibit potent antimalarial properties, while also demonstrating reduced toxicity and desirable efficacy. In light of this, we have reviewed the progress of hybrid antimalarial agents from 2021 up to the present. This manuscript presents a comprehensive overview of the latest advancements in the medicinal chemistry pertaining to small molecules, with a specific focus on their potential as antimalarial agents. As possible antimalarial drugs that might target both the dual stage and multi-stage stages of the parasite life cycle, these small hybrid molecules have been studied. This review explores a variety of physiologically active compounds that have been described in the literature in order to lay a strong foundation for the logical design and eventual identification of antimalarial drugs based on lead frameworks.

Exploring diverse frontiers: Advancements of bioactive 4-aminoquinoline-based molecular hybrids in targeted therapeutics and beyond

Amongst heterocyclic compounds, quinoline and its derivatives are advantaged scaffolds that appear as a significant assembly motif for developing new drug entities. Aminoquinoline moiety has gained significant attention among researchers in the 21stcentury. Considering the biological and pharmaceutical importance of aminoquinoline derivatives, herein, we review the recent developments (since 2019) in various biological activities of the 4-aminoquinoline scaffold hybridized with diverse heterocyclic moieties such as quinoline, pyridine, pyrimidine, triazine, dioxine, piperazine, pyrazoline, piperidine, imidazole, indole, oxadiazole, carbazole, dioxole, thiazole, benzothiazole, pyrazole, phthalimide, adamantane, benzochromene, and pyridinone. Moreover, by gaining knowledge about SARs, structural insights, and molecular targets, this review may help medicinal chemists design cost-effective, selective, safe, and more potent 4-aminoquinoline hybrids for diverse biological activities.

Recent developments in the synthesis of hybrid antimalarial drug discovery

In this 21st century, Malaria remains a global burden and causes massive economic trouble to disease-endemic nations. The control and eradication of malaria is a major challenge that requires an urgent need to develop novel antimalarial drugs. To overcome the aforementioned situation, several researchers have given significant effort to develop hybrid antimalarial agents in the search for new antimalarial drugs. Hence, we have summarized those developments of hybrid antimalarial agents from 2017 to till date. This review illustrates the current progress in the recent synthesis of hybrid antimalarial agents along with focusing on their antimalarial evaluation to find the most potent hybrids. This present mini-review will also be useful for the scientific community for the development of new antimalarial drugs to eradicate malaria.

Application of Quinoline Ring in Structural Modification of Natural Products

Natural compounds are rich in pharmacological properties that are a hot topic in pharmaceutical research. The quinoline ring plays important roles in many biological processes in heterocycles. Many pharmacological compounds, including saquinavir and chloroquine, have been marketed as quinoline molecules with good anti-viral and anti-parasitic properties. Therefore, in this review, we summarize the medicinal chemistry of quinoline-modified natural product quinoline derivatives that were developed by several research teams in the past 10 years and find that these compounds have inhibitory effects on bacteria, viruses, parasites, inflammation, cancer, Alzheimer's disease, and others.

Synthesis and Pharmacological Activities of Chalcone and Its Derivatives Bearing N-Heterocyclic Scaffolds: A Review

The incorporation of heterocyclic moieties into the standard chemical structure with a biologically active scaffold has become of crucial practice for the construction of pharmacologically potent candidates in the drug arena. Currently, numerous kinds of chalcones and their derivatives have been synthesized using the incorporation of heterocyclic scaffolds, especially chalcones bearing heterocyclic moieties that display improved efficiency and potential for drug production in pharmaceutical sectors. The current Review focuses on recent advances in the synthetic approaches and pharmacological activities such as antibacterial, antifungal, antitubercular, antioxidant, antimalarial, anticancer, anti-inflammatory, antigiardial, and antifilarial activities of chalcone derivatives incorporating N-heterocyclic moieties at either the A-ring or B-ring.

Recent developments in antimalarial activities of 4-aminoquinoline derivatives

Malaria is the fifth most lethal parasitic infection in the world. Antimalarial medications have played a crucial role in preventing and eradicating malaria. Numerous heterocyclic moieties have been incorporated into the creation of effective antimalarial drugs. The 4-aminoquinoline moiety is favoured in antimalarial drug discovery due to the diverse biological applications of its derivative. Since the 1960s, 4-aminoquinoline has been an important antimalarial drug due to its low toxicity, high tolerability, and rapid absorption after administration. This review focused on the antimalarial efficacy of the 4-aminoquinoline moiety hybridised with various heterocyclic scaffolds developed by scientists since 2018 against diverse Plasmodium clones. It could aid in the future development of more effective antimalarial agents.

Synthesis and Anticancer Evaluation of 4-Anilinoquinolinylchalcone Derivatives

A series of 4-anilinoquinolinylchalcone derivatives were synthesized and evaluated for antiproliferative activities against the growth of human cancer cell lines (Huh-7 and MDA-MB-231) and normal lung cells (MRC-5). The results exhibited low cytotoxicity against human lung cells (MRC-5). Among them, (E)-3-{4-{[4-(benzyloxy)phenyl]amino}quinolin-2-yl}-1-(4-methoxyphenyl) prop-2-en-1-one (4a) was found to have the highest cytotoxicity in breast cancer cells and low cytotoxicity in normal cells. Compound 4a causes ATP depletion and apoptosis of breast cancer MDA-MB-231 cells and triggers reactive oxygen species (ROS)-dependent caspase 3/7 activation. In conclusion, it is worth studying 4-anilinoquinolinylchalcone derivatives further as new potential anticancer agents for the treatment of human cancers.

New quinoline-based triazole hybrid analogs as effective inhibitors of α-amylase and α-glucosidase: Preparation, in vitro evaluation, and molecular docking along with in silico studies

The 7-quinolinyl-bearing triazole analogs were synthesized (1d–19d) and further assessed in vitro for their inhibitory profile against α-amylase andα-glucosidase. The entire analogs showed a diverse range of activities having IC₅₀ values between 0.80 ± 0.05 µM to 40.20 ± 0.70 µM (α-amylase) and 1.20 ± 0.10 µM to 43.30 ± 0.80 µM (α-glucosidase) under the positive control of acarbose (IC₅₀ = 10.30 ± 0.20 µM) (IC₅₀ = 9.80 ± 0.20 µM) as the standard drug. Among the synthesized scaffolds, seven scaffolds 12d, 10d, 8d, 9d, 11d, 5d, and 14d showed excellent α-amylase and α-glucosidase inhibitory potentials with IC₅₀ values of 4.30 ± 0.10, 2.10 ± 0.10, 1.80 ± 0.10, 1.50 ± 0.10, 0.80 ± 0.05, 5.30 ± 0.20, and 6.40 ± 0.30 µM (against α-amylase) and 3.30 ± 0.10, 2.40 ± 0.10, 1.20 ± 0.10, 1.90 ± 0.10, 8.80 ± 0.20, 7.30 ± 0.40, and 5.50 ± 0.10 µM (against α-glucosidase), respectively, while the remaining 12 scaffolds 19d, 8d, 17d, 16d, 15d, 7d, 4d, 3d, 1d, 2d, 13d and 6 d showed less α-amylase and α-glucosidase inhibitory potentials than standard acarbose but still found to be active. Structure–activity connection studies also showed that scaffolds with electron-withdrawing groups like -Cl, -NO₂, and -F linked to the phenyl ring had higher inhibitory potentials for -amylase and -glucosidase than scaffolds with -OCH₃, -Br, and -CH₃ moieties. In order to better understand their binding sites, the powerful scaffolds 11d and 9d were also subjected to molecular docking studies. The results showed that these powerful analogs provide a number of important interactions with the active sites of both of these targeted enzymes, including conventional hydrogen bonding, pi–pi stacking, pi–sulfur, pi–anion, pi–pi, pi–sigma, T-shaped, and halogen (fluorine). Furthermore, various techniques (spectroscopic), including 1H, ¹³C-NMR, and HREI-MS mass, were used to explore the correct structure of newly afforded hybrid scaffolds based on quinoline-bearing triazole ring.