Biological activity of azo quinoline dye and its palladium(II) complex

Azo dye derived from 8-hydroxyquinoline and 3-aminopyridine namely (E)-5-(pyridin-3-yldiazenyl)quinolin-8-ol (PQ8OL) and its palladium complex were prepared and was characterized by H-NMR, UV-Vis, and mass spectroscopies. The value of conductivity indicates that the palladium complex is non-ionic. The structure of PQ8OL dye has been solved from powder X-Ray by using Material Studio. The structure has been indicated to hydrazone form of PQ8OL dye. The PQ8OL has coordinated via nitrogen and oxygen atoms of quinoline. The UV-Vis transitions indicated that the palladium complex is square planer. The palladium complex appeared biological activity more than PQ8OL ligand. The prepared compounds appeared potential biological activity in the range of 0.6-2.0 mm against Staphylococcus aureus and E. coli bacteria. The PQ8OL ligand and its palladium complex showed potential inhibition where the inhibition was 1.0 and 6.0 mm for PQ8OL ligand and palladium complex respectively against Staphylococcus aureus. The inhibition for E. coli, by the ligand and its palladium complex was 2.0, and 7.0 mm, respectively. KEY WORDS: Biological activity, Palladium(II) complex, Quinoline, Crystal, Pyridine Bull. Chem. Soc. Ethiop. 2025, 39(1), 91-100. DOI: https://dx.doi.org/10.4314/bcse.v39i1.7