1. Department of Medicinal Chemistry, School of Pharmacy, Thad Cochran National Center for Natural Products Research, and Department of Chemistry, University of Mississippi, University, Mississippi 38677, Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio), Departamento de Fármacos, Faculdade de Farmácia, UFRJ, RJ, Brazil, 21944-910, and Department of Cellular Molecular Pharmacology, University of California, San Francisco, California 94143-0446