The review is devoted to cytokinins — classical plant hormones known for more than six decades. Nevertheless, different aspects of the action of cytokinins are still being investigated. Relevant studies produced interesting, often unexpected, results, which cast doubt on the old paradigms and open new prospects for the use of these phytohormones. Particular attention is given to recent advances in the applications of natural cytokinins and their synthetic analogues in biotechnology, agriculture, medicine and cosmetics. The chemical synthesis, properties and the possible use of artificial cytokinins are considered in detail. The review is aimed at researchers interested in the development and applications of new biologically active compounds with a wide spectrum of action on diverse biological objects, from plants to humans. The bibliography includes 233 references.

No abstract

Natural cytokinines are a promising group of cytoprotective and anti-tumor agents. In this research, we synthesized a set of aryl carbamate, pyridyl urea, and aryl urea cytokinine analogs with alkyl and chlorine substitutions and tested their antiproliferative activity in MDA-MB-231, A-375, and U-87 MG cell lines, and cytoprotective properties in H2O2 and CoCl2 models. Aryl carbamates with the oxamate moiety were selectively anti-proliferative for the cancer cell lines tested, while the aryl ureas were inactive. In the cytoprotection studies, the same aryl carbamates were able to counteract the CoCl2 cytotoxicity by 3–8%. The possible molecular targets of the aryl carbamates during the anti-proliferative action were the adenosine A2 receptor and CDK2. The obtained results are promising for the development of novel anti-cancer therapeutics.

Based on the structure of Octreotide (SMS 201-995) some modified at positions 5 with Dap (diaminopropanoic acid), Dab (diaminobutanoic acid) and Orn new C-amide analogs were synthesized. The Thr6 was replaced by unnatural amino acids Tle (t-leucine). The cytotoxic effects of the novel compounds were tested in vitro against a panel of human tumor cell lines. All investigated compounds exhibited different concentration-dependent antiproliferative effects against the HT-29, MDA-MB-231, HepG2 and HeLa cell lines after 24 h treatment. The compound 2 (D-Phe-c(Cys-Phe-D-Trp- Dap-Tle-Cys)-Thr-NH2) had antiproliferative effects on MDA-MB-231 cells with the IC50 0.03 mM. The HeLa and HepG-2 cells were most sensitive towards tested compounds at various concentrations. Results demonstrated that the peptide analogs 3 (D-Phe-c(Cys-Phe-D-Trp-Lys-Tle-Cys)-Thr-NH2), 4 (D-Phe-c(Cys-Phe-D-Trp-Orn-Tle-Cys)-Thr-NH2) and 5 (RC-102) exert the most pronounced inhibition of the cell vitality up to 77% at higher concentrations and were not toxic to the normal Lep-3 cells.

No abstract