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Extracts from tissue cultures of crown-gall from Parthenocissus tricuspidata (Sieb. and Zucc.) Planch. exhibited cell division activity in the soybean cytokinin assay. The chromatographic migration of one component, responsible for most of the activity, is similar to that of zeatin ribonucleoside. In addition, acid hydrolysis of the active region taken from chromatograms and of an eluate from a cation-exchange resin column resulted in the production of an active free-base-like derivative. Since the derivative and the parent compound lose activity after KMnO(4) treatment, they are believed to possess an unsaturated constituent essential for biological activity. The major active factor present in crown-gall from Parthenocissus tricuspidata is therefore distinct from the nicotinamide derivative reported to be present in Vinca rosea L. tumor cells.

Extracts from various parts of Phaseolus vulgaris L. var. Pinto plants were found to exhibit cytokinin activity with the highest levels present in extracts of the fruit tissue. To separate the cytokinins present in the fruit, extracts were chromatographed in several solvent systems. Bioassays of chromatograms indicated the presence of active factors in those regions of migration associated with several known N-6-substituted aminopurines.Ultraviolet and mass spectral studies confirm the presence of a mixture of N-6-substituted aminopurines in the active material isolated by cation exchange resin chromatography. The evidence strongly supports the conclusions that dihydrozeatin is naturally occurring as the free base and possibly as a ribonucleoside. Further, zeatin appears to occur mainly as a glycosidic compound which is altered by KMnO(4) treatment and is hydrolyzed under acid conditions.