New N9-substituted cytokinin derivatives for affinity chromatography and proteomic analyses

Cytokinins belong to a class of plant hormones that play a crucial role during the cell division cycle. They influence numerous developmental processes such as shoot growth and branching, apical dominance and leaf senescence [1]. The natural cytokinins are adenine derivatives classified according to the side-chain attached at the N⁶ atom of adenine moiety into isoprenoid, e.g. N⁶-isopentenyladenine (iP), trans-zeatin (t-Z) and cis-zeatin (c-Z), and aromatic cytokinins, e.g. N⁶-benzyladenine (BA), kinetin (K). These cytokinins and their derivatives can be also used for affinity chromatography based on covalent immobilization of cytokinin to a solid matrix. This approach is very promising for purification, separation and identification of a range of binding proteins present in plant tissues at various stage of their development [2]. Targeted design of N⁹-substituted derivatives of iP was made with the aim to prepare suitable affinity ligands of this cytokinin. The N⁹-substituents had selected from a group containing a saturated alkyl chains with two, three or four carbon atoms terminated by various functional groups such as -Cl, -Br, -NH₂, -N₃, -CN, -OH, -COOH or –COOEt, which are usable to form a natural spacer-arm. All of the prepared compounds were characterized by available physico-chemical methods (¹H, ¹³C NMR, MS/MS, HPLC) and tested in numerous cytokinin bioassays (e.g. senescence, Amaranthus, callus, receptor) routinely provided in our laboratory to evaluate appropriate biological activity.

Acknowledgements: The work was supported by the grant of the Ministry of Education, Youth, and Sports of the Czech Republic No. MSM 6198959216.

References: 1. Davies, P.J. (2004) Plant Hormones, Biosynthesis, Signal Transduction, Action! Kluwer Academic Publishers. Dordrecht, The Netherlands.

2. Hermanson G. et al. (1992) Immobilized Affinity Ligand Techniques. Academia Press. San Diego, USA.