1. Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
2. Department of Chemistry, University of the Free State, PO Box 339, 9300 Bloemfontein, South Africa
3. Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
4. Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria
5. Institute of Medical Microbiology, Section Experimental Virology, Jena University Hospital, Hans-Knöll-Straße 2, 07745 Jena, Germany