Exploration of Molecular Structure, DFT Calculations, and Antioxidant Activity of a Hydrazone Derivative

The hydrazine derivatives are known to possess several biological activities including anticancer, antibacterial and anti-fungal, anticonvulsant, and antioxidant. This communication presents the synthesis, X-ray crystal structure analysis, DFT calculations, cell cytotoxicity, and antioxidant activity of the Schiff base 4,4 '-((1E,1 ' E)-hydrazine-1,2-diylidenebis(ethan-1-yl-1-ylidene))bis(benzene-1,3-diol) (compound 2). We have also isolated the side product compound 1 and characterized it using single X-ray crystallography. The crystal structure of compound 1 depicts that the ensuing C-H center dot center dot center dot N hydrogen bonding interaction is presented and discussed herein. In addition, the calculations using density functional theory (DFT) approximation supported by experimental H-1 and C-13 NMR studies on the key compound 2 are reported. The results of theoretical and experimental H-1 and C-13 NMR were concordant. The antioxidant activity of compound 2 was determined by using 2,2 '-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(center dot+)) radical cation assays and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay. Compound 2 demonstrated excellent antioxidant activity in ABTS assay (IC50 = 4.30 +/- 0.21 mu M) and DPPH assay (IC50 = 81.06 +/- 0.72 mu M) with almost no cytotoxicity below 25 mu M.

Automated summary

This study synthesized Schiff base compound 2 and determined its crystal structure and molecular structure. The antioxidant activity of this compound was confirmed through calculations and experiments. The compound exhibited excellent antioxidant activity and low cytotoxicity.