Thio/carbohydrazone derivatives from iso(thio)/cyanates: preparation, structure elucidation, DFT studies, antimicrobial activity and DNA interactions

New thio/carbohydrazone derivatives ( 1–10 ) have been synthesized from various iso(thio)/cyanates. The chemical structures of synthesized compounds were elucidated with UV–Vis, IR, 1 H NMR, 13 C NMR spectroscopic methods, and elemental analysis. Antimicrobial activities of all synthesized compounds against Gram-positive, Gram-negative mold and yeast were screened by disc diffusion and microdilution methods. Ground state structures were obtained with the DFT approach, and also, experimental data were supported by spectroscopy calculations. In addition to calculating the reactivity parameters, intramolecular interactions and electron density distributions were analyzed and approaches to the antimicrobial properties of the compounds were presented. Furthermore, the interaction between the compounds and pBR322 plasmid DNA was investigated by gel electrophoresis. In this study to investigate the antibacterial and antifungal activity of new thio/carbohydrazone derivatives ( 1–10 ), it was determined that compound 7 has a remarkable inhibitory effect on S. aureus (12.66 ± 1.52 mm) and compound 10 on S. aureus (20.33 ± 0.57 mm), S. mutans (16.33 ± 0.57 mm) and A. niger (15.33 ± 0.57 mm). The interaction results of compounds 1–10 with plasmid pBR322 DNA showed that compounds 1 , 8 , and 10 caused a reduction in the densities of form I and form II DNA. Compounds 2–7 , 9 caused a double-stranded break of plasmid DNA (Form III). Graphical abstract New thio/carbohydrazone derivatives have been synthesized. Structures of all compounds have been elucidated with spectroscopic approaches. Antimicrobial activities of all synthesized compounds were determined. The interaction between the compounds and pBR322 plasmid DNA was investigated by gel electrophoresis. DFT studies were performed about reactivity parameters, intramolecular interactions and electron density distributions.