Dereplication of Microbial Natural Products by LC-DAD-TOFMS

Kristian Fog Nielsen, Maria Månsson, Christian Rank, Jens Christian Frisvad, Thomas Ostenfeld Larsen

    Research output: Contribution to journalJournal articleResearchpeer-review


    Dereplication, the rapid identification of known compounds present in a mixture, is crucial to the fast discovery of novel natural products. Determining the elemental composition of compounds in mixtures and tentatively identifying natural products using MS/MS and UV/vis spectra is becoming easier with advances in analytical equipment and better compound databases. Here we demonstrate the use of LC-UV/vis-MS-based dereplication using data from UV/vis diode array detection and ESI+/ESI– time-of-flight MS for assignment of 719 microbial natural product and mycotoxin reference standards. ESI+ was the most versatile ionization method, detecting 93% of the compounds, although with 12% ionizing poorly. Using ESI+ alone, 56.1% of the compounds could be unambiguously assigned based on characteristic patterns of multiple adduct ions. Using ESI–, 36.4% of the compounds could have their molecular mass assigned unambiguously using multiple adduct ions, while a further 41% of the compounds were detected only as [M – H]−. The most reliable interpretations of conflicting ESI+ and ESI– data on a chromatographic peak were from the ionization polarity with the most intense ionization. Poor ionization was most common with small molecules (
    Original languageEnglish
    JournalJournal of Natural Products
    Issue number11
    Pages (from-to)2338-2348
    Publication statusPublished - 2011

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