Browsing by Author "Jaspars, Marcel"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Hyphenated LC-ICP-MS/ESI-MS identification of halogenated metabolites in South African marine ascidian extracts
    (The South African Chemical Institute, 2018) Bromley, Candice L.; Raab, Andrea; Parker-Nance, Shirley; Beukes, Denzil R.; Jaspars, Marcel; Davies-Coleman, Michael T.
    Extracts of 13 species of marine ascidian collected in Algoa Bay were analyzed by LC-ICP-MS/ESI-MS. This technique allows parallel analysis of the molecular species and the presence of certain elements. The LC-ICP-MS/ESI-MS technique was used to target iodinated metabolites in this study. Three ascidian species afforded the known 3,5–diiodo-4-methoxyphenethylamine (12), which was confirmedby the isolation of this metabolite fromAplidium monile.MS also suggested the presence of theknown 3,5–dibromo-4-methoxyphenethylamine (10) and the new 3-bromo-5–iodo-4-methoxyphenethylamine (11) in the A. monile extract. The presence of the known 3,5-dibromotetramethyltyrosine (21) and the new 3-iodotetramethyltyrosine (23) in extracts of an unidentified Didemnum species was similarly proposed from MS evidence. This is the first report of the occurrence of iodinated metabolites in South African marine invertebrates.
  • Thumbnail Image
    Item
    Novel South African rare actinomycete kribbella speibonae Strain SK5: A prolific producer of hydroxamate siderophores including new dehydroxylated congeners
    (MDPI, 2020) Beukes, Denzil R.; Warner, Digby F.; Jaspars, Marcel
    In this paper, we report on the chemistry of the rare South African Actinomycete Kribbella speibonae strain SK5, a prolific producer of hydroxamate siderophores and their congeners. Two new analogues, dehydroxylated desferrioxamines, speibonoxamine 1 and desoxy-desferrioxamine D1 2, have been isolated, together with four known hydroxamates, desferrioxamine D1 3, desferrioxamine B 4, desoxy-nocardamine 5 and nocardamine 6, and a diketopiperazine (DKP) 7. The structures of 1–7 were characterized by the analysis of HRESIMS and 1D and 2D NMR data, as well as by comparison with the relevant literature.