Synthesis And Antimicrobial Activity Of Benzimidazole And Triazole Heterocyclic Derivatives

In recently years,the study of azole antimicrobial drugs has become one of the most popular areas in the field of research and development for new drugs.This thesis mainly explored the synthesis of a variety of benzimidazole and 1,2,3-triazole derivatives.At the same time,their antimicrobial activities in vitro were detailed studied.Novel benzimidazole compounds are divided into three different series:4,5-dihydro-isoxazolyl containing,isoxazolyl containing and 1,2,3-triazole containing compounds.In this thesis,the antimicrobial activities of the synthesized three series of benzimidazole derivatives were detailed studied.Meanwhile,the comparision of the antimicrobial activities among the synthesized benzimidazole derivatives and a variety of existing antimicrobial drugs were conducted.The results showed that the benzimidazole derivatives obtained all exhibited some antimicrobial activities.Among them,compounds a-2,a-3,a-5,a-7,a-9,a-12,a-13,b-1,b-5,b-6,b-9,c-3,c-4 and c-5 exhibited better antimicrobial activities against Bacillus subtilis than the referenced drug norfloxacin.And compounds a-5,a-10,b-9,b-13 exhibited much better antimicrobial activities against Staphylococcus aureus than the referenced drug norfloxacin.However,the three different series of benzimidazole derivatives synthesized exhibited relatively low antimicrobial activities against Escherichia coli.Further studies showed that the antimicrobial activities of the synthesized benzimidazole derivatives against bacteria are better than that of against fungi.What's more,compounds a-1,a-9,a-11,a-13,c-3,c-4 and c-7 exhibited better antimicrobial activities against Aspergillus fumigates,yet poor antimicrobial activities against Aspergillus niger than the referenced drug fluconazole.Through the study of thirteen 1,2,3-triazole containing derivatives of 1,3,4-oxadiazole compounds obtained through synthesis,we found that this kind of 1,2,3-triazole derivatives all have good antimicrobial activities against both bacteria and fungi.Among them,the IC50 of the antimicrobial activity of compound d-11 reached to 2 ?g/mL against Bacillus subtilis,which is as excellent as the existing drug norfloxacin.What's more,the antimicrobial activities of compounds d-6,d-7 and d-8 against Aspergillus fumigates are better than the existing drug fluconazole.The research indicate that,some of the benzimidazole derivatives obtained through synthesis have good antimicrobial activities against both bacteria and fungi,such as compound a-3 and c-3,etc.This research provides a new solution for solving the cross-infection of bacteria and fungi.At the same time,further structure-activity studies of novel benzimidazole derivatives will be conducive to the research and development for new antimicrobial drugs.