Synthesis, Spectroscopic Characterization and DPPH Radical Scavenging a Vanillin-Derived Schiff Base

Abstract A vanillin Schiff base was made through a condensation reaction used at reflux. The compound was obtained as a stable crystalline solid and characterised using Fourier-transform infrared (FT-IR) and UV–Visible spectroscopy. This was confirmed by the development of the azomethine (-C=N)-linkage. The characteristic absorption band in the FT-IR spectrum, while the UV–Visible spectrum showed electronic transitions consistent with a conjugated imine system. The antioxidant activity of the synthesised compound was evaluated in vitro using the DPPH free radical scavenging assay. The compound exhibited concentration-dependent radical inhibition with an IC₅₀ value of 50.9 µg/mL. The observed activity may be associated with the existence of conjugated and phenolic functionality of the azomethine structure. These findings establish that the derivatives of vanillin as Schiff bases are easy to synthesise and have radical scavenging properties which can be measured. In Fig 1, the graphical abstract is presented.