From Glycosmis pentaphylla (Retz.) DC., three different alkaloids have been isolated: skimtnianine, m.p. 175-176°, C 14 H 13 O 4 N; glyeosminine, m.p. 225-227° and glycosine, m.p. 155-156°, C 16 H 14 N 2 O. A complete assignment of the structure for the alkaloid glycosine as 2-benzylidene-1-methyl-4-quinazolone has been possible from studies of its infrared and ultraviolet absorption spectra, from the hydrolysis characteristics of the base and its ozonolysis and from the oxidation experiments of the alkaloid with periodic acid as well as with neutral potassium permanganate in acetone. © 1954, American Chemical Society. All rights reserved.