Adenine phosphoribosyltransferase (APRT) enzyme from Leishmania tarentolae has been proposed as a target for the rational search of new leishmanicidal drugs. In this paper, we describe the evaluation of the inhibitory activity on L. tarentolae APRT enzyme of 46 crude extracts of Meliaceae and Rutaceae plants, besides three furoquinolone alkaloids. The results showed that 21 extracts were able to decrease the APRT enzymatic activity (IA% > or = 50). The methanolic extracts from roots and leaves of Cedrela fissilis and from fruits, branches and leaves of Cipadessa fruticosa have showed strong activities. Therefore, these species could be a promising source of lead compounds for the rational design of new leishmanicidal drugs. The phytochemical investigation of an active fraction from Almeidea rubra afforded the alkaloids isodutaduprine, isoskimmianine and isokokusagine, which showed low to moderate activity on APRT.