Synthesis,Structure And Biological Activities Of Derivatives And Complexes Derived From Protocatechuic Acid

In this study,two hydrazone derivatives were synthesized with protocatechuic acid as raw material.Then,eight complexes,which were named as 1-8,were synthesized with hydrazone derivatives as ligand.The structure of the complexes was characterized by C,H,N elemental analysis,IR and single crystal X-ray diffraction,it was found that the eight complexes were mononuclear structures.The inhibition of urease activity and antibacterial activity of the complexes were tested.Insulin-mimetic activity of complex 7 and 8 were tested,which were vanadium compounds.The results of urease test showed that the IC₅₀of the complex 1,3,6 were 45.9,11.64and 0.86μM,respectively.It was proved that the three complexes had obvious inhibitory activity to urease.Comparing to the positive control acetohydroxamic acid(IC₅₀=10.1μM),complex 6 showed a stronger inhibitory activity to urease.Four bacteria species:Bacillus subtilis,Escherichia coli,Staphylococcus aureus and Proteus species were used in the antibacterial test.It was proved that the complex 1 had obvious inhibitory activity to Bacillus subtilis,the IC₅₀value was 17.27μM.It was proved that the complex 6 had obvious inhibitory activity to three bacterias,the IC₅₀of the complex 6 to Bacillus subtilis,Staphylococcus aureus,Proteus species were 1.612,2.718 and 2.031μM,respectively.The IC₅₀of the complex 2,4,5,7,8 to the test bacteria species were>50μM,the results of antibacterial activity test showed that they had no obvious inhibitory activity.The IC₅₀of the positive control（ampicillin）to Bacillus subtilis,Escherichia coli,Staphylococcus aureus,Proteus species were 2.33,30.45,12.11,and 4.97μM,respectively.Studies on insulin-mimetic activity of vanadium complex 7 and 8 showed that the two complexes had certain hypoglycemic effect.After two weeks of treatment,the blood glucose of diabetic mice decreased 2-4 values,and the difference between model and experimental mice was prominent.Hypoglycemic mechanism of the two complexes will be explored later.