Synthesis,Theoretical Calculation And Antibacterial Activity Of Novel Thiosemicarbazone Derivatives

Thiosemicarbazone compounds have a special molecular configuration,which contain heteroatoms such as N,S atom and groups such as C=S and C=N.Hence,they have many biological activities such as antibacterial,antiviral and anticancer properties,which has attracted extensive attention from scholars in various fields of biology,chemistry and medicine all over the world.Therefore,the study on the synthesis and bioactivity of thiosemicarbazone Schiff bases is of great significance for the development of new efficient and low toxicity bactericidal and anticancer drugs.In this paper,12 novel unreported thiosemicarbazone derivatives were synthesized.And their structures were characterized by analysis methods such as FT-IR,NMR and elemental analysis,then through X-ray single crystal diffraction analysis to further determine their structures.Powder:(E)-N-(3,5-dimethylphenyl)-2-benzylidene thiosemicarbazone(Ⅰ)(E)-N-(3,5-dimethylphenyl)-2-(4-methylbenzyl)thiosemicarbazone(Ⅲ)(E)-N-(3,5-dimethylphenyl)-2-(4-chlorobenzyl)thiosemicarbazone(Ⅶ)(E)-N-(3,5-dimethylphenyl)-2-(4-bromobenzyl)thiosemicarbazone(Ⅷ)(E)-N-(3,5-dimethylphenyl)-2-(4-hydroxybenzyl)thiosemicarbazone(Ⅸ)(E)-N-(3,5-dimethylphenyl)-2-(4-trifluoromethylbenzyl)thiosemicarbazone(Ⅹ)(E)-N-(3,5-dimethylphenyl)-2-(4-methoxybenzyl)thiosemicarbazone(Ⅶ)Crystals:(E)-N-(3,5-dimethylphenyl)-2-(3-methylbenzyl)thiosemicarbazone(Ⅱ)(E)-N-(3,5-dimethylphenyl)-2-(3-fluorobenzyl)thiosemicarbazone(Ⅳ)(E)-N-(3,5-dimethylphenyl)-2-(4-fluorobenzyl)thiosemicarbazone(Ⅴ)(E)-N-(3,5-dimethylphenyl)-2-(3-chlorobenzyl)thiosemicarbazone(Ⅵ)(E)-N-(3,5-dimethylphenyl)-2-(4-isopropylbenzyl)thiosemicarbazone(Ⅵ)In this paper,compound Ⅱ and Ⅳ were taken as the research objects to optimize the molecular configuration of the single crystal data which obtained from the experiment,and then the calculated parameters of the compounds structure were compared with the experimental data.In addition,the frontier molecular orbital theory and UV-visible spectroscopy analysis of the compounds were carried out using the quantum chemical calculation method,and the HOMO-LUMO energy gap was used to obtain the parameter values of the global chemical reactivity,which are used for theoretical analysis of the properties of the compounds.In order to further comprehend the weak interaction of compounds,Hirshfeld surface analysis and its related 2D fingerprint,reduced density gradient function(RDG)and independent gradient model analysis(IGM)were introduced in this paper to comprehensively explore the weak interaction between thiosemicarbazone molecules.Finally,this article explored the antifungal biological activity of the synthetic thiosemicarbazone derivatives against five different plant fungus by the mycelial rate growth method.At the same time,in the theoretical aspect,computer simulation was used to screen out the fungal protein 4C2 L macromolecule,and the theoretical molecular docking simulation experiment was conducted with each small molecular compound to be tested,so as to further explore its mechanism and site theoretically.