The complex of O-glucosylzeatin derivatives formed in Populus species

When zeatin was supplied to excised leaves of Populus alba, the principal metabolites formed were adenosine, O-β-d-glucopyranosyl-cis-zeatin (derived from cis-zeatin in the commercial zeatin used), O-β-d-glucopyranosylzeatin, and two new metabolites, namely, O-β-d-glucopyranosyldihydrozeatin and O-β-d-glycopyranosyl-9-β-d-ribofuranosyldihydrozeatin, the structures of which were confirmed by unambiguous synthesis. Chromatographic studies indicated that adenosine 5′-phosphate, zeatin 7-glucopyranoside, zeatin 9-glucopyranoside, dihydrozeatin and zeatin 9-riboside were minor metabolites. The principal metabolites of zeatin 9-riboside in P. nigra leaves were the new metabolites O-β-d-glucopyranosyl-9-β-d-ribofuranosylzeatin (synthesized chemically) and O-β-d-glucopyranosl-9-β-d-ribofuranosyldihydrozeatin.