A new base with the composition C22H26N2O has been isolated from G. pachycarpa and has been called sophorbenzamine. On the basis of UV, IR, mass, and CMR spectra, and also the results of a chemical investigation, sophorbenzamine has been assigned to the quinolizidine alkaloids of the matrine series and a most probable formula has been proposed for it. © 1977 Plenum Publishing Corporation.