Quinoline: A Promising Scaffold in Recent Antiprotozoal Drug Discovery

Abstract

Protozoal infections malaria and leishmania have become most prevalent in recent times. A high death rate is reported world‐wide because of these diseases. Although there are only a few antiprotozoal drugs but could not be used anymore to cure protozoal diseases because of their toxic effects. Despite the non‐ceasing attempts to discover the drugs to cure malaria and leishmania, efficient drug‐design with low toxicity could not be achieved. A wide range of heterocyclic pharmacophores have been utilized to design efficient drugs. Amongst these heterocycles, quinoline bicycle is given a high priority, since a vast literature of quinoline derivatives relevant to potent pharmacological properties is available. The efficacy of the drugs lies upon the good bioavailability, favorable pharmacokinetics, and pharmacodynamics of the molecule. In view of these, the continual efforts are being put to bring about potent anti‐protozoal agents to clinical stage. In this review, the potential research done recently towards the anti‐protozoal drug‐design and discovery is compiled comprehensively. The importance of structural features attributed to remarkable activity is described taking consideration of structure‐activity relationship. Safety Index (SI), crucial for clinical efficiency of a drug is compared amongst a set of derivatives which involve inhibitory properties, in addition to the cytotoxic effects.

Arylselenyl Radical-Mediated Cyclization of N-(2-Alkynyl)anilines: Access to 3-Selenylquinolines

“…Quinolines are a class of N -heterocyclic aromatic compounds that are embedded in numerous natural products, including alkaloids . The quinoline skeleton is considered a privileged scaffold in medicinal chemistry as it is routinely present in compounds that exhibit promising anticancer, antiviral, antiprotozoal, and antibacterial activities. − Accordingly, new synthetic methods that provide rapid access to, and further functionalization of, quinolines remain an area of supreme interest within the fields of synthetic organic and medicinal chemistry. − …”

Environmentally Benign Approaches towards the Synthesis of Quinolines

“…The quinoline-based compounds exhibit plethora of biological activities [13] [14] that include anti-cancer, [15] anti-tubercular, [16] antiprotozoal, [17] anti-viral, [18] anti-asthmatic, [19] anti-hypertensive, [20] inhibition of the enzyme phosphodiesterase, and anti-inflammatory. [21,22] Figure 2 comprises of various biologically active quinoline derivatives.…”

“…Hasaninejad and co-workers developed a highly efficient, facile and relatively greener solvent-free methodology for the Friedländer annulation of 2-aminoaryl ketones (13) and carbonyl compounds (14) in the presence of silica-supported P 2 O 5 (P 2 O 5 /SiO 2 ) catalyst to give rise to substituted quinolones 15 (Scheme 4). [58] Mali and co-workers devised a facile, solvent-free, one pot sulfated polyborate catalyzed Friedländer products in the reaction of 2-aminoaryl ketones ( 16) with carbonyl compounds (17) to generate 18 (Scheme 5). The catalyst was further recycled for 4 times without loss of catalytic activity.…”

Generation of Aurachin Derivatives by Whole-Cell Biotransformation and Evaluation of Their Antiprotozoal Properties

“…Furthermore, it served as a lead structure for the development of several synthetic antimalarial drugs featuring a quinoline scaffold, such as chloroquine [ 9 ]. In recent years, quinolines and quinolones have gained increasing attention as trypanocidal agents [ 10 ]. In this study, we set out to assess the activity of aurachin D against human infective forms of pathogenic trypanosomatids and malaria.…”