Alternating Dependency of Cytokinin Activity on the Number of Methylene Units in ω-Phenylalkyl Derivatives of Some Purine Cytokinins and 4-Substituted Pyrido[3,4-<i>d</i>]pyrimidine

Nishikawa, Shiro; Kumazawa, Zenzaburo; Kashimura, Naoki; Nishkimi, Yoshio; Uemura, Shoji

doi:10.1080/00021369.1986.10867724

Cited by 7 publications

(9 citation statements)

References 1 publication

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“…The following 6-substituted purine derivatives were obtained according to the previously published protocols: 2-chloro-6-benzylaminopurine (10) (Theiler et al, 1976), 2-amino-6benzylaminopurine (13) (Wang et al, 2013), 6-benzyloxypurine (14), 6-phenylaminopurine (19) (Nishikawa et al, 1986). The initial substrates 2,6dichloropurine, 8-bromo-6-benzylaminopurine, 2-amino-6-chloropurine were obtained according to ref.…”

Section: Generalmentioning

confidence: 99%

Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico

et al. 2018

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Biological effects of hormones in both plants and animals are based on high-affinity interaction with cognate receptors resulting in their activation. The signal of cytokinins, classical plant hormones, is perceived in Arabidopsis by three homologous membrane receptors: AHK2, AHK3, and CRE1/AHK4. To study the cytokinin-receptor interaction, we used 25 derivatives of potent cytokinin N-benzyladenine (BA) with substituents in the purine heterocycle and/or in the side chain. The study was focused primarily on individual cytokinin receptors from Arabidopsis. The main in planta assay system was based on Arabidopsis double mutants retaining only one isoform of cytokinin receptors and harboring cytokinin-sensitive reporter gene. Classical cytokinin biotest with Amaranthus seedlings was used as an additional biotest. In parallel, the binding of ligands to individual cytokinin receptors was assessed in the in vitro test system. Quantitative comparison of results of different assays confirmed the partial similarity of ligand-binding properties of receptor isoforms. Substituents at positions 8 and 9 of adenine moiety, elongated linker up to 4 methylene units, and replacement of N by sulfur or oxygen have resulted in the suppression of cytokinin activity of the derivative toward all receptors. Introduction of a halogen into position 2 of adenine moiety, on the contrary, often increased the ligand activity, especially toward AHK3. Features both common and distinctive of cytokinin receptors in Arabidopsis and Amaranthus were revealed, highlighting species specificity of the cytokinin perception apparatus. Correlations between the extent to which a compound binds to a receptor in vitro and its ability to activate the same receptor in planta were evaluated for each AHK protein. Interaction patterns between individual receptors and ligands were rationalized by structure analysis and molecular docking in sensory modules of AHK receptors. The best correlation between docking scores and specific binding was observed for AHK3. In addition, receptor-specific ligands have been discovered with unique properties to predominantly activate or block distinct cytokinin receptors. These ligands are promising for practical application and as molecular tools in the study of the cytokinin perception by plant cells.

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Section: Generalmentioning

confidence: 99%

Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico

et al. 2018

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“…Compounds 3 [ 19 ], 4 [ 50 ] and 11 [ 51 ] were synthesized as described. Compound 12 was analogously obtained as 11 using 3-phenyl-1-propanol instead of 3-(1,12-dicarba- closo dodecaboran-1-yl)-1-propanol ( Figure 10 ).…”

Section: Resultsmentioning

confidence: 99%

Comparative Study of Carborane- and Phenyl-Modified Adenosine Derivatives as Ligands for the A2A and A3 Adenosine Receptors Based on a Rigid in Silico Docking and Radioligand Replacement Assay

2018

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Adenosine receptors are involved in many physiological processes and pathological conditions and are therefore attractive therapeutic targets. To identify new types of effective ligands for these receptors, a library of adenosine derivatives bearing a boron cluster or phenyl group in the same position was designed. The ligands were screened in silico to determine their calculated affinities for the A2A and A3 adenosine receptors. An virtual screening protocol based on the PatchDock web server was developed. In the first screening phase, the effects of the functional group (organic or inorganic modulator) on the adenosine ligand affinity for the receptors were determined. Then, the lead compounds were identified for each receptor in the second virtual screening phase. Two pairs of the most promising ligands, compounds 3 and 4, and two ligands with lower affinity scores (compounds 11 and 12, one with a boron cluster and one with a phenyl group) were synthesized and tested in a radioligand replacement assay for affinity to the A2A and A3 receptors. A reasonable correlation of in silico and biological assay results was observed. In addition, the effects of a phenyl group and boron cluster, which is new adenosine modifiers, on the adenosine ligand binding were compared.

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“…The following compounds were synthesized as reported previously: la, 3q, 3r (Nishikawa et al, 1986b); 2a, 3d, 6a, 6b, 7a, and 7b (Nishikawa et al, 1986a).…”

Section: Methodsmentioning

confidence: 99%

“…Tobacco Callus Bioassay. This bioassay method has been reported (Nishikawa et al, 1986b). Callus tissues derived from Nicotiana tabacum var.…”

Section: -(Trifluoromethyl)pyridomentioning

confidence: 99%

Preparation and structure-activity relationships of 4-substituted amino-2-methylpyrido[3,4-d]pyrimidines as cytokinin analogs

Nishikawa¹,

Nishikimi²,

Maki³

et al. 1995

J. Agric. Food Chem.

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Alternating Dependency of Cytokinin Activity on the Number of Methylene Units in ω-Phenylalkyl Derivatives of Some Purine Cytokinins and 4-Substituted Pyrido[3,4-d]pyrimidine

Cited by 7 publications

References 1 publication

Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico

Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico

Comparative Study of Carborane- and Phenyl-Modified Adenosine Derivatives as Ligands for the A2A and A3 Adenosine Receptors Based on a Rigid in Silico Docking and Radioligand Replacement Assay

Preparation and structure-activity relationships of 4-substituted amino-2-methylpyrido[3,4-d]pyrimidines as cytokinin analogs

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