1. Department of Pharmaceutical and Biomedical Sciences and Department of Chemistry and Complex Carbohydrate Research Center University of Georgia 250 West Green Street Athens GA 30602 USA
2. Department of Chemistry Wayne State University 5101 Cass Avenue Detroit MI 48202 USA
3. Department of Pharmaceutical Organic Chemistry Faculty of Pharmacy Cairo University Cairo 11562 Egypt
4. Institute of Medical Microbiology University of Zurich Gloriastrasse 28 8006 Zürich Switzerland
5. Organic Chemistry Laboratory ETH Zürich Vladimir-Prelog-Weg 1–5/10 093 Zürich Switzerland