1. Leibniz-Institute for Natural Products Research and Infection Biology, Hans-Knöll-Institute, Beutenbergstrasse 11a, D-07745 Jena, Germany, Fachhochschule Ostfriesland (FHO), Constantiaplatz 4, D-26723 Emden, Germany, BRAIN Biotechnology Research and Information Network AG, Darmstädter Strasse 34, D-64673 Zwingenberg, Germany, and Alfred-Wegener-Institut für Polar- und Meeresforschung (AWI), Am Handelshafen 12, D-27570 Bremerhaven, Germany