Synthesis, Characterization And Relevant Activities Of Two Kinds Of Benzaldehyde Schiff Bases

Objective: Synthesize six taurine Schiff bases and four benzoyl hy-drazones,characterize all of the compounds and test their antibacterial and antioxidant activities invitro.Methods:(1) According to the synthesis principle of Schiff bases, t-he products weresynthesized and were characterized by Infrared anal-ysis, elemental analysis, and NMRspectral analysis.(2) Antibacterial activities of the compounds on Klebsiella pneumoniaand Staphylococcus aureus were screened by micro-dilution method and tube method.The results were evaluated by MIC value, MBC value, and the killing curve.And mechanisms of inhibition were studied by scanning electron micr-oscopy andtransmission electron microscopy.(3) Three anti-oxidative systems were evaluated for theanti-oxidative activities of compounds, namely DPPH, FRAP, ABTS.Results:1. Ten new compounds were synthesized, they are5-Bromosali cylaldehyde taurine Schiff base (Sodium2-{[1-(5-Bromo-2-hydr-oxy-phenyl)-meth-(Z)-ylidene]-amino}-ethanesulfonic acid,Ⅰ),5-chloros-alicylaldehydetaurine Schiff base(sodium2-{[1-(5-Chloro-2-hydroxyl-phenyl)-meth-(Z)-ylidene]-amino}-ethanesulfonic acid,Ⅱ),3,5-dichloro-salicylaldehyde taurine Schiff base (sodium2-{[1-(3,5-dichloro-2-hydroxy-phenyl)-meth-(E)-ylidene]-amino}-ethanesulfonic acid, Ⅲ),2,4-dichlorobenzaldehyde taurine Schiff base (sodium2-{[1-(2,4dichlorophenyl)-meth-(Z)-yl-idene]-amino}-ethanesulfonic acid, Ⅳ),2-Bromobenzaldehyde taurine Schiff base(sodium2-{[1-(2-Bromo-phenyl)-meth-(Z)-ylidene]-amino}-ethanesulfonic acid,Ⅴ),4-nitro-benzaldehyde reduction taurine Schiff bas-e (sodium2-{[1-(4-Nitro-phenyl)-meth-(E)-ylidene]-amino}-ethanesulfonic acid, Ⅵ),2,4-dihydroxy-N’-(5-chloro-2-hydroxybenzylidene) benzohydr-azide, Ⅶ),2,4-dihydroxy-N’-(5-Bromo-2-hydroxybenzylidene)benzohyd-razide, Ⅷ),3,4-dihydroxy-N’-(5-chloro-2-hydroxybenzylidene) benzohyd- razide, Ⅸ),3,4-dihydroxy-N’-(5-Bromo-2-hydroxybenzylidene) benzohy-drazide, Ⅹ).2. All the compounds have antibacterial activities on Kle--bsiella pneumoniae and Staphylococcus aureus. The inhibitory effect of Compound Ⅰ and compoundⅡ were most significant. For KP, the MIC of Ⅰ was0.125mg/ml, MBC was0.600mg/ml. As for Ⅱ, MIC was0.320mg/ml, MBC was0.960mg/ml. For SA, the MIC of Ⅰ was0.180mg/ml, MBC was0.540mg/ml. As for Ⅱ, MIC was0.260mg/ml, MBC was0.780mg/ml.3.Results of the three antioxidant systems hadshowed that both of compound Ⅰ and compound Ⅱ had good antiox-idative effects. When the concentration of Ⅰor Ⅱwas60mM, the FeS-O4equivalent of Ⅰ was0.672mM. As for compound Ⅱ, it was0.491mM. In ABTS system, the IC50of compound Ⅰ was0.502mM. As for compound Ⅱ, it was0.407mM. In DPPHsystem, the IC50of compound Ⅰ was4.91mM. As for compound Ⅱ, it was5.23mM.Conclusion: Six taurine Schiff bases and four Benzoyl hydrazones weresynthesized correctly. Taurine Schiff bases had significant antibac-terial effect and fineantioxidant activity.