1. Contribution from the Department of Pharmaceutical Sciences, Medical University of South Carolina, 171 Ashley Avenue, Charleston, South Carolina 29425-2303, Institut für Pharmazeutische Biologie der Universität Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany, and Center for Coastal Environmental Health and Biomolecular Research, NOAA, National Ocean Service, 219 Fort Johnson Road, Charleston, South Carolina 29412-9110