Abstract
Mass spectrographic and chemical studies of the permethyl and trimethylsilyl ethers of two new cytokinins isolated from Vinca rosea crown gall callus cultures by Peterson and Miller (Plant Physiol 59: 1026-1028) indicate that they are 6-(4-0-β-d-glucopyranosyl-3-methyl-trans-but-2-enylamino) purine (glucosyl zeatin) and 9-β-d-ribofuranosyl-6 (4-0-β-d-glucopyranosyl-3-methyl-trans-but-2-enylamino) purine (glucosyl ribosylzeatin). The nature of the mass spectra of the permethylated cytokinins suggests that these derivatives may have considerable utility in the detection of low levels of cytokinins in plant material.