[Isolation of cytostatically active proteins from seeds of Ricinus communis, Abrus praecatorius and Canavalia ensiformis (author's transl)].

The extraction and isolation of, as yet, uninvestigated antitumor active protein mixtures from the seeds of Abrus praecatorius, Canavalia ensiformis and especially Ricinus communis is reported. By means of membrane ultrafiltration of crude ricin a low-molecular weight protein mixture, Ro 413, could be obtained, which showed, in comparison to ricin-toxin, a reduced toxicity but with the same cytostatic action. An almost complete separation of Ro 413 into the individual components was achieved using preparative disc electrophoresis. Using the same procedures it was also possible to isolate a low-molecular weight protein mixture from the crude extract of Abrus praecatorius beans and to concentrate their various individual components. The characterization, toxicity and cytostatic action of these proteinaceous plant materials are reported.