Synthesis And Antibacterial Activity Of Fusaric Acid And Its Derivatives

Fusaric acid is one of metabolites of Fusarium,modern research showed that it has bactericidal,insecticidal and herbicidal activity.In this paper,fusaric acid(FA)was being as a reference,studied the method of synthesizing it and then modificated it’s structure to get fusaric acid derivatives.Measuring the antibacterial activity to explore the C-2 group effect on the biological activity of fusaric acid.The results are as follows:1.A total of 11 fusaric acid derivatives(W1-W11)were synthesized.Identified by 1H NMR,13C NMR and HRMS,the 11 compounds synthesized were the target product of the experimental design,4 compounds are not reported,respectively W5,W8,W10,W11.(The specific structure of W1-W11 were shown in Appendix Fig.-1)2.The inhibition test showed that the antibacterial rate of W10 was better than that of FA in the concentration of 50 μg/mL in the inhibition of Thanatephorus cucumeris(Frank)Donk,respectively 58.90%and 54.76%.In the inhibition of Helminthosporium maydis,inhibition of W7,W9,W10,W11 were better than that of FA,respectively 31.17%,35.71%,37.14%,47.14%and 28.39%.When the carbonyl group were replaced with methyl groups,ethoxy groups,ethyl groups or pentyl groups,the antibacterial activity of the carbonyl group decreased.It was possible that the extension of the carbon chain increased the steric hindrance and made it more difficult to table with the complexes in the cells;The antibacterial activity of esters was better than that of FA after replacing with phenoxy group.The extension of N-substituent could not improve the antibacterial activity,but the activity was increased by introducing naphthenic and aromatic rings,such as N-cyclohexyl,N-phenyl and N-benzyl.In summary,found two new unreported compounds(W10,W11)which antibacterial activities were better than that of FA.The antibacterial activity of W10 was better than that of azoxystrobin.