Synthesis And Biological Activity Of Acylhydrazones Schiff Bases And Its Metal Complexes

Schiff base and its metal complexes have been widely used in many fields suchas medical science, pharmacology and so on, for its features of sterilization,bacteriostat, antineoplastic, anticancer, antiviral, and oxygen-carrier. Some non-sterideanti-inflammatory drugs possess anti-inflammatory, anti-rheumatism, relieve pain,abatement of fever and anticoagulation. N-methylation of amide bonds is technologyto improve the pharmacological properties of synthetic drugs. Six acylhydrazines aresynthesized from steride drugs by esterification and hydrazinolysis reaction. Thereaction of acylhydrazines and aldehyde led to the formation of acylhydrazones Schiffbase. The reaction of N-acylhydrazone with Zn(OAc)2.2H2O or FeCl3.6H2O led to theformation of metal complexes. N-acylhydrazone ligands acting as tridentate ligandsthrough the imine-N, amide-O and the bridging phenolate-O atoms. This suggests thatthe nitrogen atom of amide is deprotonated and methylated easily with methylatingagents. In this paper, we describe the effects of the coordination to metal ion on themethylation of acylhydrazone Schiff base using dimethyl sulfate as a methylatingagent.(N-methyl)-acylhydrazone Schiff bases were characterized by IR, NMR and soon.Imidazole is the active center functional group of many important biologicallyactive molecules; it plays an important role in life activities. Metal complexes ofimidazole and its derivatives have antitumor activity. Hence we designed andsynthesized acylhydrazone Schiff base of imidazole. two synthetic methods were used.One,5-chloromethyl-salicylaldehyde was synthesized from salicylaldehyde bychlorine methylation, and then react with imidazole led to the formation5-(1-imidazolyl)-methylsalicylaldehyde. Ten new acylhydrazones Schiff bases ofimidazole were prepared from5-(1-imidazolyl)-methylsalicylaldehyde andacylhydrazines of non-steride anti-inflammatory drugs.Another, three acylhydrazineswith imidazole were synthesized from amino acid by esterification, cyclization andhydrazinolysis reaction. The reaction of these acylhydrazines and aldehyde led to theformation of ten new acylhydrazones Schiff base of imidazole. This method providesa good way for the synthesis of acylhydrazone Schiff base of imidazole and how toimprove the yield of acylhydrazine. These twenty new acylhydrazones Schiff base ofimidazole react with seven different metal salts to form a series of metal complexes.All compounds were characterized by IR, NMR and so on.In this thesis, we studied the interaction of acylhydrazones Schiff base,(N-methyl)acylhydrazones Schiff base and metal complexes with DNA. EB-DNAfluorescence quenching experiments have been made by UV spectrum fluorescencespectrum, the result of (N-methyl)acylhydrazones Schiff base and many metal complexes is obviously better than acylhydrazones Schiff base. DNA cleavageactivity has been operated by agarose gel electrophoresis, experimental result wasfavourable.