This chapter presents information on celastraceae alkaloids. In 1970, the structures of the nicotinoyl alkaloids maytoline and maytine from Maytenus ovatus Loes (Celastraceae) were reported as prototypes of a new family of alkaloids. Subsequently, the closely related structures or partial structure for 22 further alkaloids from a number of different species in the family Celastraceae has been discussed in the chapter. They all contain either a nicotinate or substituted nicotinate group and are polyesters of hydroxy derivatives of dihydroagarofuran. The other ester groups can include benzoate, acetate, and 3-furoate. Many of these alkaloids had been isolated, and in most cases the presence of a C15 nucleus and a nicotinic acid group had been recognized. A number of closely related nonbasic sesquiterpene polyesters and free polyols have also been explained. The chapter discusses the isolation and chemistry of the nicotinoyl polyester alkaloids reported up to late 1975. The first report of the presence of highly oxygenated C15 compounds in the Celastraceae was during a study in 1938 of the seed oil of Celastrus paniculatus Willd. Hydrolysis of a methanol-soluble fraction yielded formic, acetic, and benzoic acids and a tetraol (C15H26O5). Seven alkaloids have been isolated in which the basic function is a nicotinate group. Similarities in the nuclear magnetic resonance (NMR) spectra have suggested that in each case the nicotinate group is at C-9. © 1977 Academic Press, Inc.