Genus Maytenus (Celastraceae) has proved to be a good source of new bioactive sesquiterpene pyridine alkaloids. Maytenus royleanus is a medicinal plant used in folk medicine for different ailments in a variety of ways around the world. Investigation of the roots of M. royleanus resulted in the isolation of an undescribed antitumor sesquiterpene pyridine alkaloid: Royleanine A (1). Its structure was established by analysis of spectroscopic data and comparison with reported data. Royleanine A (1) was evaluated for its antitumor potential against several cancer cell lines and was was found to be significantly active against OVC-5 cells (ovarian cancer cell line) with half maximal inhibitory concentration (IC50) 28.9 mu g mL(-1), cervical (Hela) IC50 0.064 and prostate (PC-3) cancer lines with 0.034 mu g mL(-1).