Preparation, characterization and biological activity of C8-substituted cytokinins

0476276 - ÚEB 2018 RIV GB eng J - Journal Article
Zahajská, Lenka - Nisler, Jaroslav - Voller, Jiří - Gucký, Tomáš - Pospíšil, Tomáš - Spíchal, Lukáš - Strnad, Miroslav
Preparation, characterization and biological activity of C8-substituted cytokinins.
Phytochemistry. Roč. 135, MAR (2017), s. 115-127. ISSN 0031-9422. E-ISSN 1873-3700
Institutional support: RVO:61389030
Keywords : potential purine antagonists * arabidopsis-thaliana * nucleosides * derivatives * thidiazuron * specificity * receptors * kinetin * Organic synthesis * Cytokinin bioassay * AHK3 and CRE1/AHK4 bacterial receptor assay * C8-substituted cytokinin
OECD category: Organic chemistry
Impact factor: 3.186, year: 2017

Naturally occurring cytokinins are adenine-based plant hormones. Although, the effect of various substituents at positions N1, C2, N3, N-6, N7, or N9 on the biological activity of cytokinins has been studied, the C8-substituted compounds have received little attention. Here, we report the synthesis and in vitro biological testing of thirty-one cytokinin derivatives substituted at the C8 position of the adenine skeleton and twenty-seven compounds which served as their N9-tetrahydropyranyl protected precursors. The cytokinin activity of all the compounds was determined in classical cytokinin biotests (wheat leaf senescence, Amaranthus and tobacco callus assays). With some exceptions, the compounds with a N9-tetrahydropyranyl group were generally less active than their de-protected analogs. The latter were further tested for their ability to activate the Arabidopsis cytokinin receptors AHK3 and CRE1/AHK4 in bacterial receptor activation assays. Using this approach, we identified derivatives bearing short aliphatic chains and retaining high cytokinin activity. Such compounds are suitable candidates for fluorescence labeling or as protein-affinity ligands. We further found that some C8-substituted cytokinins exhibited no or lower cytotoxicity toward tobacco cells when compared to their parent compound. Therefore, we also present and discuss the cytotoxicity of all the compounds against three normal human cell lines.
Permanent Link: http://hdl.handle.net/11104/0272814