Valdez, Juan; Cedillo, Roberto; Hernandez-Campos, Alicia; Yepez, Lilian; Hernandez-Luis, Francisco; Navarrete-Vazquez, Gabriel; Tapia, Amparo; Cortes, Rafael; Hernandez, Manuel; Castillo, Rafael Bioorganic and medicinal chemistry letters, 2002 , vol. 12, # 16 p. 2221 - 2224