Discussion

The Wadden Sea forms a unique habitat since it underlies permanent changes due to the tidal influence. Fungi living in such an environment presumably need a high metabolic versatility in order to survive. As metabolic versatility may also relate to natural product biosynthesis, fungal strains isolated from the German Wadden Sea were investigated with regard to metabolite production. The 109 strains isolated from sediments were grown under varying culture conditions, in shaken or static cultures and in different media. Cultures were extracted applying liquid-liquid extraction, and extracts were analysed by HPLC-DAD/MS. One of the fungal strains showed exceptionally attractive metabolite profiles and was selected for detailed investigations. The structures of the purified compounds of this strain were elucidated by NMR spectroscopy. Beside the known substances tricinonoic acid (Bashyal and Gunatilaka, 2010), 6-hydroxymellein, 6-methoxymellein (Dunn et al. 1979), orbuticin, 32-hydroxyorbuticin, antibiotic 15G256α-2, 15G256β-2, and 15G256π (Schlingmann et al. 2002), six new compounds were identified. These substances exhibited strong inhibitory properties in bioactivity assays and hence have a potential in biotechnological applications.


Johanna Silber, Birgit Ohlendorf, Arlette Erhard, Antje Labes, Johannes F. Imhoff
Kiel Centre for marine natural products, Am Kiel-Kanal 44, D-24106 Kiel