From a strain of the fungus Emericella variecolor derived from the marine sponge Haliclona valliculata, two new natural products, evariquinone and isoemericellin, were isolated after HPLC-UV, -MS, and -NMR studies of the extract and their structures were elucidated by mass spectrometry and NMR experiments. Evariquinone showed antiproliferative activity towards KB and NCI-H460 cells at a concentration of 3.16 mug/ml. Furthermore, the fungus was found to produce the known metabolites stromemycin, shamixanthone, and 7-hydroxyemodin. Chemical degradation, NMR decoupling experiments, and spin-system simulation provided evidence for the double bonds in stromemycin to be all E-configured. ROESY experiments established the monosaccharide moiety to be glucose. (C) 2003 Elsevier Science Ltd. All rights reserved.
structural elucidation, Emericella variecolor, Haliclona valliculata, sponge derived fungus, evariquinone, isoemericellin, stromemycin, shamixanthone, 7-hydroxyemodin, HPLC–NMR coupling
NCBI PubMed ID: 12770594Publication DOI: 10.1016/S0031-9422(03)00189-4Journal NLM ID: 0151434Publisher: Elsevier
Correspondence: bringman@chemie.uni-wuerzburg.de
Institutions: Institut für Organische Chemie der Universität, Am Hubland, D-97074 Würzburg, Germany, Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Germany, Zentaris AG, Weismüllerstr. 45, D-60314 Frankfurt am Main, Germany
Methods: 13C NMR, 1H NMR, methylation, IR, FAB-MS, TLC, ESI-MS, chemical methods, methanolysis, HPLC, UV, extraction, CD, cytotoxicity assay
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