Synthesis of [¹⁵N₄] purine labeled cytokinin glycosides derived from zeatins and topolins with 9‐β‐d, 7‐β‐d‐glucopyranosyl, or 9‐β‐d‐ribofuranosyl group

Abstract

Synthesis of [ 15 N 4 ] purine labeled cytokinine glycosides derived from zeatinsand topolins containing a 9-β-D, 7-β-D-glucopyranosyl, or 9-β-D-ribofuranosyl group is described. These N 6 -substituted adenine derivatives are intended as internal analytic standards for phytohormone analysis. All labeled compounds were prepared from 6-chloro[ 15 N 4 ]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 labeled 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 N 4 ] purine (1).

Study of the N7 Regioselective Glycosylation of 6-Chloropurine and 2,6-Dichloropurine with Tin and Titanium Tetrachloride

“…In the most promising report in the literature, peracetylated 6-chloro-7-(β- d -glucopyranosyl)­purine ( 3a ) was isolated in 60% yield by the modified Vorbrüggen method . However, we found that the NMR data they reported for the prepared compound corresponded to N 9 -isomer 4a and thus were consistent with the spectra of the N 9 -isomer in other reports where the NMR spectra of both isomers were provided. ,, Additionally, analogous N 7 -galactosyl 3d and mannosyl 3e derivatives were incorrectly described in this paper, which was verified experimentally in our work.…”

“…Generally, the N 7 position of the glucosyl group in prepared 6chloro-7-(β-D-glucopyranosyl)purine 3a was confirmed by comparison of 1 H and 13 C NMR data with identical compounds prepared in two different ways. 18,33 Moreover, the regioselectivity of the glycosyl group in the purine skeleton of prepared compounds 3 and 5 was also solved after assigning 1 H and 13 C signals to the corresponding atoms in the molecule. The chemical shifts of the single 13 C atoms across all of the prepared N 7 -nucleosides (3 and 5) of 6-chloropurine and 2,6-dichloropurine correlated and were essentially preserved.…”

“…One method is based on the alkylation of purine derivatives with protected 1-halogen glycosyl derivatives (e.g., 6-chloropurine − ) under basic conditions. These direct glycosylations usually lead to a mixture of N 7 / N 9 -nucleoside derivatives and are suitable when both isomers are of interest; the two isomers are obtained after precise chromatographic separation (Scheme , eq 1).…”

Salinity Management in Glycine Max L. Using Cytokinin from Rhizobacteria Isolated from Mines and Dump Sites

“…The extracted cytokinin sample in the lane had the same Rf value as the cytokinin reference standard (Kinetin). The findings are consistent with prior findings from our lab and other authors [17,24,30].…”