CHAPTER 2 Alkaloids with Antiprotozoal Activity Edison J. Osorio 1,à , Sara M. Robledo 2 and Jaume Bastida 3 Contents I. Introduction 113 II. Tropical Diseases Caused by Protozoan Parasites 115 A. Leishmaniasis 115 B. Chagas’ Disease 118 C. African Trypanosomiasis (Sleeping Sickness) 119 D. Malaria 120 III. Alkaloids with Antiprotozoal Activity 122 A. Quinoline and Isoquinoline Alkaloids 122 B. Indole Alkaloids 149 C. Steroidal and Diterpenoid Alkaloids 160 D. Alkaloid Marine Natural Products 164 E. Other Alkaloids 168 IV. Current Strategies and Recent Developments 171 V. Conclusions and Future Directions 178 Acknowledgments 179 References 179 I. INTRODUCTION Protozoan parasites are among the most common chronic infections that occur primarily in rural and poor urban areas of tropical and subtropical regions E-mail address: josorio48@yahoo.com (E.J. Osorio). 1 Grupo de Investigacio ´n en Sustancias Bioactivas, Facultad de Quı´mica-Farmace ´ utica, Universidad de Antioquia, A. A. 1226, Medellı´n, Colombia 2 Programa de Estudio y Control de Enfermedades Tropicales, Facultad de Medicina, Universidad de Antioquia, Medellı´n, Colombia 3 Departament de Productes Naturals, Biologia Vegetal i Edafologia, Facultat de Farma ` cia, Universitat de Barcelona, 08028 Barcelona, Spain à Corresponding author. The Alkaloids, Volume 66 r 2008 Elsevier Inc. ISSN: 1099-4831, DOI 10.1016/S1099-4831(08)00202-2 All rights reserved 113