Three novel nicotinoyl sesquiterpene alkaloids, maytoline (1, C29H37NO13), maytine (2, C29H37NO12), and maytolidine (4, C36H41NO14), have been isolated from the fruit of Maytenus serrata (Hochst., ex A. Rich.) R. Wilczek. The structure of 1 was determined by x-ray crystallography of its methiodide and is the prototype of a new class of alkaloids found in the Celastraceae. The structures of 2 and 4 were shown to be 3-deoxymaytoline and 3-acetyl-6-deacetyl-6-benzoylmaytoline, respectively, by a study of the physical properties, in particular mass and NMR spectroscopy.