Synthesis, Characterisation and Antioxidant Study of Thiosemicarbazide Schiff Base Derived from 4-Hydroxychalcone

Chew, Yun Kee (2024) Synthesis, Characterisation and Antioxidant Study of Thiosemicarbazide Schiff Base Derived from 4-Hydroxychalcone. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

The goal of this project is to investigate the ligand's antioxidant activity and evaluate whether it will result in synergistic antioxidant activity. Through a condensation reaction between thiosemicarbazide and 4-hydroxychalcone in a 1:1 molar ratio, a novel Schiff base ligand known as (Z)-N-phenyl-2-((E)-3-phenyl allylidene) hydrazine-1-carbothioamide (PTCA) was created in this effort. A melting point apparatus, differential scanning calorimetry (DSC), ultraviolet-visible (UV-Vis) spectroscopy, and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy were used to characterise the synthesised ligands. Characterization revealed that the 4HC-TS Schiff base was mostly present in the thione tautomer, which contains the imine bond (-N=CH-), in both solid and liquid phases. The antioxidant activity of the synthesised ligand, 4HC-TS, was also assessed using the 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging activity assay. Based on the findings, the IC50 value of the synthesis Schiff base, TSHC, was 0.1410 ppm, which is lower than the ascorbic acid IC50 value, which was 0.1465 ppm. This suggested that TSHC had more antioxidant properties than AA.