1. Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography and The Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92037
2. Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 151-747, Korea
3. Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstrausse 25, 79104 Freiburg, Germany
4. Novartis Institute for Biomedical Research, Cambridge, Massachusetts 02139