The metabolism of brassinosteroid leads to structural modifications in the ring skeleton or the side alkyl chain. The esterification and glycosylation at C-3 are the most common metabolic pathways, and it has been suggested that conjugate brassinosteroids are less active or inactive. In this way, plants regulate the content of active brassinosteroids. In this work, the synthesis of brassinosteroid 24-norcholane type analogs conjugated at C-3 with benzoate groups, carrying electron donor and electron attractant substituents on the aromatic ring, is described. Additionally, their growth-promoting activities were evaluated using the Rice Lamina Inclination Test (RLIT) and compared with that exhibited by brassinolide (used as positive control) and non-conjugated analogs. The results indicate that at the lowest tested concentrations (10-8-10-7 M), all analogs conjugated at C-3 exhibit similar or higher activities than brassinolide, and the diasteroisomers with S configuration at C-22 are the more active ones. Increasing concentration (10-6 M) reduces the biological activities of analogs as compared to brassinolide.

• Klíčová slova
• 24-norcholane, Rice Lamina Inclination Test, analogs, benzoate esters, brassinosteroids, conjugated in C-3, synthesis,
• MeSH
• benzoáty chemie   farmakologie   MeSH
• brassinosteroidy chemická syntéza   chemie   farmakologie   MeSH
• molekulární konformace MeSH
• regulátory růstu rostlin chemická syntéza   chemie   farmakologie   MeSH
• rýže (rod) účinky léků   metabolismus   MeSH
• stereoizomerie MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• benzoáty MeSH
• brassinosteroidy MeSH
• regulátory růstu rostlin MeSH

Brassinosteroids are a class of plant hormones that regulate a broad range of physiological processes such as plant growth, development and immunity, including the suppression of biotic and abiotic stresses. In this paper, we report the synthesis of new brassinosteroid analogues with a nitrogen-containing side chain and their biological activity on Arabidopis thaliana. Based on molecular docking experiments, two groups of brassinosteroid analogues were prepared with short and long side chains in order to study the impact of side chain length on plants. The derivatives with a short side chain were prepared with amide, amine and ammonium functional groups. The derivatives with a long side chain were synthesized using amide and ammonium functional groups. A total of 25 new brassinosteroid analogues were prepared. All 25 compounds were tested in an Arabidopsis root sensitivity bioassay and cytotoxicity screening. The synthesized substances showed no significant inhibitory activity compared to natural 24-epibrassinolide. In contrast, in low concentration, several compounds (8a, 8b, 8e, 16e, 22a and 22e) showed interesting growth-promoting activity. The cytotoxicity assay showed no toxicity of the prepared compounds on cancer and normal cell lines.

• Klíčová slova
• brassinosteroid, cytotoxicity, nitrogen-containing steroid, organic synthesis, plant bioassay,
• MeSH
• Arabidopsis účinky léků   růst a vývoj   MeSH
• brassinosteroidy chemická syntéza   chemie   farmakologie   MeSH
• dusík chemie   MeSH
• molekulární struktura MeSH
• techniky syntetické chemie * MeSH
• vývoj rostlin účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• brassinosteroidy MeSH
• dusík MeSH