Quinoline plays a crucial role in drug development and pharmaceutical synthesis. This review highlights quinoline-based medications and their therapeutic potential, especially for malaria and cancer, impacting millions worldwide.

An efficient thiocarbohydrazide based fluorescencesensor S5 for the selective detection of Hg ²⁺ in semi‐aqueous medium has been successfully designed and synthesized. The absorption (UV‐Vis) and emission (fluorescence) properties of S5 were studied in various solvents. The sensor S5 displayed no distinct changes in absorption with various solvents; however some remarkable changes were noticed in fluorescence studies. Solvent dependent spectral characterization of S5 was explored via the Lippert‐Mataga plot. UV‐Vis and fluorescence studies also revealed that the sensor S5 could selectively detect Hg ²⁺ ion over the other tested metal ions. The interaction of S5 with Hg ²⁺ leads to colour change from colourless to yellow. The observed quenching in fluorescence intensity may be due to chelation enhanced fluorescence quenching (CHEQ). The sensing mechanism was arrived through DFT and ¹ H NMR titration studies. The limit of detection was found to be 1.26 nM with a wide pH range of 4–10. Moreover, sensor S5 could demonstrate sensing efficiency for lower concentrations of Hg ²⁺ in real sample analysis. Its performance, as a test strip and in analysis of various water samples conferred its superior selectivity.

A series of novel 24 phenylhydrazono phenoxyquinoline derivatives were synthesized with moderate to excellent yield and screened for their efficacy against the α-amylase enzyme through in silico studies. The structures were characterized using spectroscopic techniques such as ¹HNMR, ¹³CNMR, and HREI-MS. Comprehensive computational studies including, drug-likeness and ADMET profiling, quantum chemical calculations, molecular docking, and molecular dynamics (MD) simulation studies, were performed. A density functional theory study of the synthesized compounds indicated a favorable reactivity profile. The synthesized novel analogues were docked against α-amylase (PDB 6OCN) enzymes to investigate the binding interactions. Based on the docking studies, one of the compounds was found to be the hit with the highest negative binding affinity for α-amylase. A MD simulation study indicated stable binding throughout the simulation.