Akademik Veri Yönetim Sistemi
JOURNAL OF MOLECULAR STRUCTURE, cilt.1364, 2026 (SCI-Expanded, Scopus)
Primary amine condensation reactions with various carbonyl compounds were used to create water-soluble Schiff bases in this work. In the preparation of Schiff bases, 3-amino-4-hydroxybenzene sulfonic acid was used as an amine, and 5-bromo salicylaldehyde (L1), 5-chloro salicylaldehyde (L2), 2-hydroxy-3-methoxy benzaldehyde (L3), and salicylaldehyde (L4) were used as aldehydes. The ligands were characterized using FTIR, 1H NMR, ICP-OES, elemental analysis and X-ray diffraction. The in vitro antibacterial activities of L1-L4 ligands were assessed against Gram-positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria using the agar well diffusion method. L1 and L2 ligands demonstrated significant antibacterial activity, exhibiting inhibition zones of 26 mm against B. cereus and 22-25 mm against K. pneumoniae, yielding results comparable to standard antibiotics (ampicillin, neomycin and streptomycin). Although the L3 ligand showed limited effect, the L4 ligand did not exhibit any antibacterial activity. Antioxidant properties were investigated using metal chelation and free radical scavenging tests. L1 and L2 showed metal chelation activity of 70.4-74.4 per cent in the range of 30-60 & micro;g/mL, demonstrating comparable results to alpha-tocopherol. In the free radical scavenging test, the L3 ligand exhibited the highest scavenging activity at 37.5 & micro;g/mL with 56.6%. In contrast, the L4 ligand did not show significant activity in either antioxidant test. The results demonstrate that the biological activities of the ligands vary depending on the type of substituent in the aromatic ring and that there is a clear structure-activity relationship (SAR).