Cytokinin-Active Ribonucleosides in Phaseolus RNA

Abstract
The cytokinin-active ribonucleosides present in tRNA from etiolated P. vulgaris L. seedlings were isolated and identified as cis-ribosylzeatin, 2-methylthio-ribosylzeatin and N6-(.DELTA.2-isopentenyl)-adenosine. The structures of the compounds were established on the basis of their chromatographic properties and the mass spectra of their permethylated and perdeuteromethylated derivatives. Cis-ribosylzeatin was the major cytokinin-active constituent of tRNA from this source.