Hönig Martin, Plíhalová Lucie, Spíchal Lukáš, Grúz Jiří, Kadlecová Alena, Voller Jiří, Svobodová Alena Rajnochová, Vostálová Jitka, Ulrichová Jitka, Doležal Karel, Strnad Miroslav
Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71, Olomouc, Czech Republic; Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71, Olomouc, Czech Republic.
Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71, Olomouc, Czech Republic; Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71, Olomouc, Czech Republic.
Eur J Med Chem. 2018 Apr 25;150:946-957. doi: 10.1016/j.ejmech.2018.03.043. Epub 2018 Mar 21.
Eleven 6-furfurylaminopurine (kinetin, Kin) derivatives were synthesized to obtain biologically active compounds. The prepared compounds were characterized using H NMR, mass spectrometry combined with HPLC purity determination and elemental C, H, N analyses. The biological activity of new derivatives was tested on plant cells and tissues in cytokinin bioassays, such as tobacco callus, detached wheat leaf chlorophyll retention bioassay and Amaranthus bioassay. The selected compounds were subsequently tested on normal human dermal fibroblasts (NHDF) and keratinocyte cell lines (HaCaT) to exclude possible phototoxic effects and, on the other hand, to reveal possible UVA and UVB photoprotective activity. The protective antioxidant activity of the prepared cytokinin derivatives was further studied and compared to previously prepared antisenescent compound 6-furfurylamino-9-(tetrahydrofuran-2-yl)purine (Kin-THF) using induced oxidative stress (OS) on nematode Caenorhabditis elegans damaged by 5-hydroxy-1,4-naphthoquinone (juglone), a generator of reactive oxygen species. The observed biological activity was interpreted in relation to the structure of the prepared derivatives. The most potent oxidative stress protection of all the prepared compounds was shown by 6-(thiophen-2-ylmethylamino)-9-(tetrahydrofuran-2-yl)purine (6) and 2-chloro-6-furfurylamino-9-(tetrahydrofuran-2-yl)purine (9) derivatives and the results were comparable to Kin-THF. Compounds 6 and 9 were able to significantly protect human skin cells against UV radiation in vitro. Both the derivatives 6 and 9 showed higher protective activity in comparison to previously known structurally similar compounds Kin and Kin-THF. The obtained results are surprising due to the fact that the prepared compounds showed to be inactive in the ORAC assay which proved that the compounds did not act as direct antioxidants as they were unable to directly scavenge oxygen radicals.
合成了11种6-糠基氨基嘌呤（激动素，Kin）衍生物以获得具有生物活性的化合物。使用核磁共振氢谱、结合高效液相色谱纯度测定的质谱以及元素碳、氢、氮分析对所制备的化合物进行了表征。在细胞分裂素生物测定中，如烟草愈伤组织、离体小麦叶片叶绿素保留生物测定和苋属生物测定，对新衍生物的生物活性进行了测试。随后，对选定的化合物在正常人皮肤成纤维细胞（NHDF）和角质形成细胞系（HaCaT）上进行测试，以排除可能的光毒性作用，另一方面，揭示可能的UVA和UVB光保护活性。进一步研究了所制备的细胞分裂素衍生物的保护性抗氧化活性，并与先前制备的抗衰老化合物6-糠基氨基-9-（四氢呋喃-2-基）嘌呤（Kin-THF）进行比较，使用对被5-羟基-1,4-萘醌（胡桃醌，一种活性氧生成剂）损伤的秀丽隐杆线虫诱导氧化应激（OS）。根据所制备衍生物的结构对观察到的生物活性进行了解释。所制备的所有化合物中，6-（噻吩-2-基甲基氨基）-9-（四氢呋喃-2-基）嘌呤（6）和2-氯-6-糠基氨基-9-（四氢呋喃-2-基）嘌呤（9）衍生物表现出最有效的氧化应激保护作用，结果与Kin-THF相当。化合物6和9能够在体外显著保护人类皮肤细胞免受紫外线辐射。与先前已知的结构相似的化合物激动素和Kin-THF相比，衍生物6和9均表现出更高的保护活性。由于所制备的化合物在氧自由基吸收能力（ORAC）测定中显示无活性，这证明这些化合物不作为直接抗氧化剂起作用，因为它们无法直接清除氧自由基，所以获得的结果令人惊讶。
