Spectroscopic characterization of Ca-ceftriaxonate salt synthesized and its free-radical scavenging and antibacterial activities

Ca–Ceftriaxone salt with water of crystallization was prepared, and its structure, antioxidant, and antibacterial properties were investigated. Infrared (IR) and 1H-NMR confirmed the deprotonation of H2CFE to CFE2-. Morphological and structural features were investigated using scanning electron microscopy (SEM), TEM, and XRD. The salt demonstrated potent antioxidant activity, exhibiting a DPPH radical scavenging capacity of 24.07 µM Trolox equivalents/mg. Furthermore, it showed strong antibacterial effects against Staphylococcus aureus (Gram-positive), Klebsiella pneumoniae, and Pseudomonas aeruginosa (Gram-negative) at low concentrations of 0.0625-0.25 mg/mL. Overall, the Ca–Ceftriaxone chelates displayed enhanced biological activity, suggesting their potential as a promising antibacterial and antioxidant agent through the inhibition of bacterial growth and the generation of reactive oxygen species. KEY WORDS: Ceftriaxone, Ca- Ceftriaxone salt, Antibiotics, Bacterial resistance, Antioxidant activity Bull. Chem. Soc. Ethiop. 2026, 40(3), 551-561. DOI: https://dx.doi.org/10.4314/bcse.v40i3.5