Synthesis,Characterization And Biological Activity Of Transition Metal Complexes With Pyridine Acylhydrazone Ligands

Acylhydrazones are a kind of special Schiff bases,which are the product of nucleophilic addition of hydrazide and aldehyde or ketone.Acylhydrazones can readily coordinate with most of metal ions to form acylhydrazone complexes.These complexes generally have excellent biological activities,such as antibacterial,antiviral and antitumor.Acylhydrazone complexes have the advantages of relatively simple syntheses and high yields,which makes them more widely studied and applied by researchers.Urease can quickly decompose urea and release ammonia,The rate of ammonia volatilization exceeds that of the crop absorption,resulting in the reduced utilization of urea.Urease inhibitors can inhibit urease activity,thereby slowing the rate of urea hydrolysis.Studies indicated that some complexes of Schiff bases and transition metal ions have good inhibition of urease activity.In addition,there are reports that acylhydrazone compounds also have good inhibition of urease activity.In order to study the application of complexes in the field of urease inhibitors,24 acylhydrazone-containing metal complexes were designed and synthesized,and their urease inhibitory activity was studied.(1)Six acylhydrazones were prepared by the reaction of 2-pyridinecarboxaldehyde with six hydrazides.Then,eleven new complexes were prepared by the reaction of the acylhydrazones with various metal ions.(2)Four acylhydrazones were prepared by the reaction of 2-acetylpyridine with four hydrazides.Then,thirteen new complexes were prepared by the reaction of the acylhydrazones with various metal ions.(3)The complexes were characterized by IR,UV and thermal analysis.Structures of the complexes were further confirmed by single crystal X-ray determination.(4)The inhibitory activity of the complexes on urease was studied.