1. Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico 00931-3346, Florida State University−Panamá, Cell and Molecular Biology of Pathogens Unit, Institute for Tropical Medicine and Health Sciences, P.O. Box 6-4794, La Boca 1034, Balboa, Ancón, Panamá, and Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Ancón, Panamá