Mass Spectrometric Analysis of Cytokinins in Plant Tissues

The cytokinin complex of Datura innoxia Mill. crown gall tissue was purified by ion exchange, Sephadex LH-20 chromatography and reversed-phase high performance liquid chromatography. By gas chromatography-mass spectrometry using (2)H-labeled compounds, the following cytokinins were identified in the basic fraction eluting from a cation exchange column: zeatin, zeatin riboside, dihydrozeatin, dihydrozeatin riboside, their corresponding O-glucosides, 7- and 9-glucosides of zeatin, 9-glucoside of dihydrozeatin, isopentenyladenine, and isopentenyladenosine. Zeatin riboside 5'-monophosphate was the major cytokinin nucleotide in the tissue. In addition, dihydrozeatin riboside and isopentenyladenosine were identified in the nucleotide fraction following enymic degradation.