Synthesis And Antimicrobial Activity Of Chalcone Incorporated With Triazole Moiety

Chalcone is a kind of compounds with a variety of biological activities,the conjugated system in its structure can interfere with the DNA replication of bacteria,thus it shows good antibacterial activity against a variety of pathogenic bacteria.Triazole is a five membered heterocyclic compound containing three nitrogen atoms,the nitrogen atoms can be combined with a variety of targets in organisms,so it has a variety of biological activities.In the meanwhile,triazole is the most stable structure in azole compounds and can maintain its good stability under the general reaction conditions of hydrolysis,oxidation,reduction and enzyme degradation,so it has become an important pharmacophore for modifying drug molecules.Based on the excellent bioactivity of chalcone and triazole,if the two kinds of active structures can be placed in one molecule,it is possible to expand its bioactivity spectrum and improve its efficacy.In this paper,36 chalcones containing triazole were synthesized and their antibacterial activities were also tested.To our surprise,the 36 compounds had a certain degree of inhibitory effect on fungi and bacteria especially for S.aureus which were more outstanding than that the positive control ciprofloxacin hydrochloride.The main research contents of this paper were as follows:Firstly,the number of the first kind of chalcones is 18 and is named 1-aryl-2-（1H-1,2,3/2H-1,2,3/1H-1,2,4-triazolemethyl）2-propene-1-one（4a-4f、4’a-4’f、12a-12f）.The compounds were synthesized by four steps including F-C acylation reaction,Mannich reaction,amine exchange reaction and Mannich reaction,in which the substituted benzene was used as the starting materials.The last Mannich reaction was studied in detail.Three new compounds were separated,the yields of the reaction were improved through analyzing of the structure of the new compounds,then the reaction mechanism of the Mannich reaction were explained.Secondly,the other kind of 18 chalcones were synthesized by four steps including F-C acylation,α-H bromination,nucleophilic substitution and Mannich reaction,in which substituted benzene were used as the starting materials.Thirdly,the structures of the new compounds were characterized by ¹H NMR,¹³C NMR,elemental analysis and X-ray single crystal diffraction.Finally,the inhibitory effects of the target compounds on C.neoformans stand,C.neoformans clinical,C.albicans,E.coli and S.aureus were tested.The lead compounds with high inhibition effect on fungi and bacteria were screened out and the structure-activity relationship analysis were performed as well.