Discovery of Antibacterial Compounds against Xanthomonas citri subsp. citri from a Marine Fungus Aspergillus terreus SCSIO 41202 and the Mode of Action

作者：Jun Zhang, Liangliang Gao, Huiting Lin, Yan Liang, Mingnan You, Lijian Ding, Fangjian Feng, Bin Yang, Yonghong Liu · 发表于：Journal of Agricultural and Food Chemistry · 年份：2024 · DOI：10.1021/acs.jafc.4c02769 · 被引用次数：17 · 研究领域：Plant-Microbe Interactions and Immunity、Microbial Natural Products and Biosynthesis、Plant Pathogenic Bacteria Studies

Citrus canker, caused by Xanthomonas citri subsp. citri ( Xcc ), is a severe citrus disease. Currently, copper-containing pesticides are widely used to manage this disease, posing high risks to the environment and human health. This study reports the discovery of naturally occurring anti- Xcc compounds from a deep-sea fungus, Aspergillus terreus SCSIO 41202, and the possible mode of action. The ethyl acetate extract of A. terreus was subjected to bioassay-guided isolation, resulting in the discovery of eight anti- Xcc compounds ( 1 – 8 ) with minimum inhibitory concentrations (MICs) ranging from 0.078 to 0.625 mg/mL. The chemical structures of these eight metabolites were determined by integrative analysis of various spectroscopic data. Among these compounds, Asperporonin A ( 1 ) and Asperporonin B ( 2 ) were identified as novel compounds with a very unusual structural skeleton. The electronic circular dichroism was used to determine the absolute configurations of 1 and 2 through quantum chemical calculation. A bioconversion pathway involving pinacol rearrangement was proposed to produce the unusual compounds ( 1 – 2 ). Compound 6 exhibited an excellent anti- Xcc effect with a MIC value of 0.078 mg/mL, which was significantly more potent than the positive control CuSO 4 (MIC = 0.3125 mg/mL). Compound 6 inhibited cell growth by disrupting biofilm formation, destroying the cell membrane, and inducing the accumulation of reactive oxygen species. In vivo tests indicated that comp...