Robert J R Jaeger, Marc Lamshöft, Sebastian Gottfried, Michael Spiteller, Peter Spiteller
Institut für Organische und Analytische Chemie, Universität Bremen, Leobener Straße NW2C, Bremen, Germany.
Journal of natural products 2013 Feb 22Fruiting bodies of Mycena metata were screened for the presence of new secondary metabolites by means of HPLC-UV, LC-HR-ESIMS, and high-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (HR-MALDI-MS imaging). Thus, a new β-carboline alkaloid, 6-hydroxymetatacarboline D (1d), was isolated from fruiting bodies of M. metata. 6-Hydroxymetatacarboline D consists of a highly substituted β-carboline skeleton, which is likely to be derived biosynthetically from l-tryptophan, 2-oxoglutaric acid, l-threonine, and l-proline. The structure of the alkaloid was established by 2D NMR spectroscopic methods and HR-ESIMS. Moreover, by extensive application of LC-HR-ESIMS, LC-HR-ESIMS/MS, and LC-HR-ESIMS(3) techniques we were able to elucidate the structures of a number of accompanying β-carboline alkaloids, 1a-1c, 1e-1i, and 2a-2g, structurally closely related to 6-hydroxymetatacarboline D, which are present in M. metata in minor amounts. The absolute configuration of the stereogenic centers of the β-carboline alkaloids was determined by GC-MS comparison with authentic synthetic samples after hydrolytic cleavage and derivatization of the resulting amino acids.
Robert J R Jaeger, Marc Lamshöft, Sebastian Gottfried, Michael Spiteller, Peter Spiteller. HR-MALDI-MS imaging assisted screening of β-carboline alkaloids discovered from Mycena metata. Journal of natural products. 2013 Feb 22;76(2):127-34
PMID: 23330951
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