title: Dereplicating and Spatial Mapping of Secondary Metabolites from Fungal Cultures in Situ.
abstract: Ambient ionization mass spectrometry techniques have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. These techniques retain invaluable spatial and temporal details that are lost through traditional extraction processes. However, most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/vis spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the droplet-liquid microjunction-surface sampling probe (droplet-LMJ-SSP) was coupled with UPLC-PDA-HRMS-MS/MS, thus providing separation, retention times, MS data, and UV/vis data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites can be confidently and rapidly assigned in situ. Using the droplet-LMJ-SSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. Furthermore, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture.
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Sica
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
authors.forename: Huzefa A
authors.initials: HA
authors.lastname: Raja
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
authors.forename: Tamam
authors.initials: T
authors.lastname: El-Elimat
authors.affiliation: Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Vilmos
authors.initials: V
authors.lastname: Kertesz
authors.affiliation: Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Van Berkel
authors.affiliation: Mycosynthetix, Inc. , 505 Meadowlands Drive, Suite 103, Hillsborough, North Carolina 27278, United States.
authors.forename: Cedric J
authors.initials: CJ
authors.lastname: Pearce
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Oberlies
mesh_terms: D001688:Biological Products / Q000737:chemistry*; D002845:Chromatography; D016208:Databases, Factual; D005658:Fungi / Q000737:chemistry* / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001688:Biological Products