title: Natural phenolic metabolites from endophytic Aspergillus sp. IFB-YXS with antimicrobial activity.
abstract: Prompted by the pressing necessity to conquer phytopathogenic infections, the antimicrobial compounds were characterized with bioassay-guided method from the ethanol extract derived from the solid-substrate fermentation of Aspergillus sp. IFB-YXS, an endophytic fungus residing in the apparently healthy leave of Ginkgo biloba L. The aim of this work was to evaluate the antimicrobial activity and mechanism(s) of these bioactive compounds against phytopathogens. Among the compounds, xanthoascin (1) is significantly inhibitory on the growth of the phytopathogenic bacterium Clavibacter michiganense subsp. Sepedonicus with a minimum inhibitory concentration (MIC) value of 0.31μg/ml, which is more potent than streptomycin (MIC 0.62μg/ml), an antimicrobial drug co-assayed herein as a positive reference. Moreover, terphenyl derivatives 3, 5 and 6 are also found to be active against other phytopathogens including Xanthomonas oryzae pv. oryzae Swings, Xanthomonas oryzae pv. oryzicola Swings, Erwinia amylovora and Pseudomonas syringae pv. lachrymans etc. The antibacterial mechanism of xanthoascin (1) was addressed to change the cellular permeability of the phytopathogens, leading to the remarkable leakage of nucleic acids out of the cytomembrane. The work highlights the possibility that xanthoascin (1), an analogue of xanthocillin which is used to be an approved antibiotic, may find its renewed application as a potent antibacterial agrichemical. This study contributes to the development of new antimicrobial drugs, especially against C. michiganense subsp. Sepedonicus.
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Shi
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China.
authors.forename: Chaojun
authors.initials: C
authors.lastname: Chen
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China.
authors.forename: Guoyan
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China. Electronic address: rhjiao@nju.edu.cn.
authors.forename: Ruihua
authors.initials: R
authors.lastname: Jiao
authors.affiliation: Nanjing University, School of Life Sciences, Xianlin Road 163, Nanjing 210023, China.
authors.forename: Renxiang
authors.initials: R
authors.lastname: Tan
mesh_terms: D039903:Actinobacteria / Q000187:drug effects; D016573:Agrochemicals / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D001230:Aspergillus / Q000737:chemistry* / Q000302:isolation & purification; D002070:Butadienes / Q000737:chemistry / Q000494:pharmacology; D055808:Drug Discovery; D060026:Endophytes / Q000737:chemistry / Q000302:isolation & purification; D005285:Fermentation; D020441:Ginkgo biloba / Q000382:microbiology; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D010935:Plant Diseases / Q000382:microbiology; D010944:Plants / Q000382:microbiology; D013329:Structure-Activity Relationship
chemical_list: D016573:Agrochemicals; D000890:Anti-Infective Agents; D002070:Butadienes; D010636:Phenols; C014250:xanthoascin
keywords: Antimicrobial activity; Bioassay-guided fractionation; Terphenyl derivatives; Xanthoascin