1. Department of Medicinal Chemistry and Pharmacognosy and UIC/NIH Center for Botanical and Dietary Supplements Research, College of Pharmacy, 833 South Wood Street, University of Illinois at Chicago, Chicago, Illinois 60612, and Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, R. E. Heine Building, 575 Stadium Mall Drive, West Lafayette, Indiana 47907-2091