Design, synthesis and perception of fluorescently labeled isoprenoid cytokinins

C2- and N9-substituted 6-[(3-methylbut-2-en-1-yl)amino]purine fluorescent derivatives were prepared using 2-carbon or 6-carbon linkers. Derivatives labeled with RhoB, FC and NBD were able to bind cytokinin receptor CRE1/AHK4. NBD-labeled compound 28 and its fluorescent negative control 29 were used for in planta staining experiments in Arabidopsis thaliana cell suspension culture using live cell confocal microscopy.372