Synthesis of [ 15 N 4 ] purine labelled cytokinin glycosides derived from zeatins and topolins with 9-β-D, 7-β-D-glucopyranosyl, or 9-β-D-ribofuranosyl group.

Synthesis of [15 N4 ] purine labelled cytokinine glycosides derived from zeatins and topolins containing a 9-β-D, 7-β-D-glucopyranosyl, or 9-β-D-ribofuranosyl group is described. These N6 -substituted adenine derivatives are intended as internal analytic standards for phytohormone analysis. All labelled compounds were prepared from 6-chloro[15 N4 ] purine (1). The equilibrium reaction of 1 with acetobromo-α-D-glucose gave isomeric 7-β-D (3) and 9-β-D (4) chloro glucosyl precursors, which were treated with the corresponding amines to get desired labelled cytokinin 7-β-D (6) and 9-β-D (5) glucopyranosides. Cytokinins containing 9-β-D-ribofuranosyl group (8) were obtained by direct enzymatic transglycosylation reaction of cytokinins (7) prepared from 6-chloro[15 N4 ] purine (1).