N9-Substituted N6-[(3-methylbut-2-en-1-yl)amino]purine derivatives and their biological activity in selected cytokinin bioassays

Synthesis of N9-substituted derivatives of N6-[(3-methylbut-2-en-1-yl)amino]purine (iP), their characterization by C, H, N elemental analyses, thin layer chromatography, high performance liquid chromatography, 1H NMR, and CI+ MS spectrometry as well as their cytokinin activity in vitro in three classical cytokinin bioassays (tobacco callus, wheat leaf senescence, and Amaranthus bioassay), and perception by cytokinin receptors CRE1/AHK4, ZmHK1, and ZmHK3a are described.