Design, synthesis, and biological evaluation of novel water-soluble quinoline-based conjugates with antioxidant, antimicrobial, and DNA-binding activities

Considering the extremely valuable biological and pharmaceutical properties of quinolines, novel water-soluble quinoline-based conjugates were designed and synthesized. In vitro antioxidant activities, such as free radical scavenging, metal chelating, and reducing-power activities, of the newly synthesized compounds (WQ-1, WQ-2, WQ-3, WQ-4, and WQ-5) were determined. Although the highest scavenging activity (41.21 ± 1.18%) and chelating activity (23.53 ± 0.97%) at a concentration of 500.0 µg/ml were observed in WQ-4, it was determined that WQ-5 had the highest reducing-power ability (0.417 ± 0.0116). The synthesized compounds were also tested for their antimicrobial activities against two Gram-positive and two Gram-negative bacteria, and it was determined that only WQ-3 showed low activity against Enterococcus hirae and Staphylococcus aureus. DNA-binding activities of the compounds were also studied using calf thymus DNA (CT-DNA). Additionally, the three-dimensional geometries and some electronic properties of the synthesized compounds were investigated with the density functional theory approach at B3LYP/6-31++G(d,p) level of theory.