Quinoline hybrid derivatives as effective structural motifs in the treatment of tuberculosis: Emphasis on structure-activity relationships

Mycobacterium tuberculosis (MTB/Mtb) is the causative agent of tuberculosis (TB), a highly infectious serious airborne illness. TB usually affects the lungs, in 25 % of patients (children or immune impaired adults), mycobacteria can enter the blood stream and infect other bodily areas such the meninges, pleura, lymphatic system, genitourinary system, bones, and joints. Currently, the most challenging aspect of treating this illness is the ineffectiveness of the most potent first-line anti-TB medications, isoniazid, rifampin, pyrazinamide, and ethambutol, which can result in multidrug-resistant TB (MDR-TB), extensively drug-resistant TB (XDR-TB), and in rare instances, completely drug-resistant TB (TDR-TB). As a result, finding new pharmaceutical compounds to treat these diseases is a significant challenge for the scientific community. A number of bio-active molecules have been investigated in this quest, including quinoline, which is considered a promising candidate for the development of TB drugs. It is known that quinoline are low in toxicity and have a wide range of pharmacological properties. Researchers have investigated quinoline scaffolds as anti-TB drugs based on their biological spectrum. The objective of this review is to examine the recent development of quinoline and its structural characteristics crucial to its antitubercular (anti-TB) activity. A molecular analog of the TB treatment can be designed and identified with this information. As a result, future generation quinoline-based anti-TB agents with greater potency and safety can also be explored.