The isolation and structural elucidation of ten new alkaloids from the "additional weak bases" fraction of Buxus sempervirens L. are reported. A structural feature common to eight of the new alkaloids is the presence of a secondary benzamide function at the C-3 position. Evidence is presented for assignment of structures for N-benzoylcycloxobuxine-F (I), N-benzoylcycloxobuxidine-F (Xa), N-benzoyldihydrocyclomicrophylline-F (XII), N-benzoylcycloxobuxoline-F (XF), N-benzoyl-O-acetylcycloxobuxoline-F (XVI), N-benzoylbuxidienine-F (XIX), N-benzoylcycloprotobuxoline-D (XXIIIa), N-benzoylcycloprotobuxoline-C (XXXIIIb), tigloycyclovirobuxeine-B (XXIXb), and N-acetylcyclopropotobuxine-D (XXXc). © 1967.