The Chemistry and Applications of Quinoline: A Comprehensive Review

Quinoline and its derivatives represent a vital class of heterocyclic compounds with wide-ranging pharmacological properties, including antimalarial, antimicrobial, anticancer, and anti-inflammatory activities. This comprehensive review explores the chemistry, isolation, biosynthesis, identification, and bioactivity of quinoline-based compounds, with a particular focus on quinine, a natural alkaloid derived from cinchona bark. The isolation and identification techniques of quinine are detailed, alongside a discussion of its complex stereochemistry and chemical reactivity. Biosynthetic pathways highlight the enzymatic and molecular transformations leading to the quinoline core. Furthermore, the review evaluates the bioactivity of quinine and its derivatives, particularly their antimicrobial and anti-inflammatory potentials, and their applications in the treatment of infectious and inflammatory diseases. The development of quinoline-based therapeutics, including fluoroquinolones, underscores the scaffold's importance in modern medicinal chemistry. Despite their broad utility, challenges such as toxicity and drug resistance remain, necessitating continued interdisciplinary research for the optimization of quinoline-based drug design and application.