1. Department of Clinical Biochemistry, Glostrup Hospital, Nordre Ringvej 57, DK-2600 Glostrup, Denmark, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark, Center for Biological Sequence Analysis, BioCentrum-DTU, Technical University of Denmark, Anker Engelunds Vej 1, DK-2800 Kgs. Lyngby, Denmark, and Department of Medicinal Chemistry, Division of Pharmacognosy, Uppsala University, BMC, 751 23 Uppsala, Sweden