Four new spermidine alkaloids, celacinnine (1), celallocinnine (2), celafurine (3), and celabenzine (4), have been isolated in studies of Maytenus serrata (Hochst., ex A. Rich.) R. Wilczek and Tripterygium wilfordii Hook. The 13-membered macrocyclic structures of the alkaloids were elucidated by chemical degradation and by a study of the spectral properties of the alkaloids and their derivatives. © 1977, American Chemical Society. All rights reserved.