title: Synthesis of Five Known Brassinosteroid Analogs from Hyodeoxycholic Acid and Their Activities as Plant-Growth Regulators.
abstract: Brassinosteroids (BRs) are plant hormones that promote growth in different plant organs and tissues. The structural requirements that these compounds should possess to exhibit this biological activity have been studied. In this work, a series of known BR analogs5-15, were synthesized starting from hyodeoxycholic acid4, and maintaining the alkyl side chain as cholic acid or its methyl ester. The growth-promoting effects of brassinolide (1) and synthesized analogs were evaluated by using the rice lamina inclination assay at concentrations ranging from 1 × 10-8-1 × 10-6M. Our results indicate that in this concentration range the induced bending angle of rice seedlings increases with increasing concentration of BRs. Analysis of the activities, determined at the lowest tested concentration, in terms of BR structures shows that the 2α,3α-dihydroxy-7-oxa-6-ketone moiety existing in brassinolide is required for the plant growing activity of these compounds, as it has been proposed by some structure-activity relationship studies. The effect of compound8on cell elongation was assessed by microscopy analysis, and the results indicate that the growth-promoting effect of analog8is mainly due to cell elongation of the adaxial sides, instead of an increase on cell number.
authors.affiliation: Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, Chile. maria.duranp@alumnos.usm.cl.
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Duran
authors.affiliation: Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, Chile. cesar.gonzalez@usm.cl.
authors.forename: Cesar
authors.initials: C
authors.lastname: González
authors.affiliation: Escuela de Ingeniería en Biotecnología, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Quillota 980, Viña del Mar 2520000, Chile. al.acosta@uandresbello.edu.
authors.forename: Alison
authors.initials: A
authors.lastname: Acosta
authors.affiliation: Instituto de Ciencias Químicas Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, Santiago 8910339, Chile. andres.olea@uautonoma.cl.
authors.forename: Andrés F
authors.initials: AF
authors.lastname: Olea
authors.affiliation: Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, Chile. katy.díaz@usm.cl.
authors.forename: Katy
authors.initials: K
authors.lastname: Díaz
authors.affiliation: Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, Chile. luis.espinozac@usm.cl.
authors.forename: Luis
authors.initials: L
authors.lastname: Espinoza
mesh_terms: D060406:Brassinosteroids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D003840:Deoxycholic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D012275:Oryza / Q000187:drug effects / Q000254:growth & development; D010937:Plant Growth Regulators / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development
chemical_list: D060406:Brassinosteroids; D010937:Plant Growth Regulators; D003840:Deoxycholic Acid; C010471:hyodeoxycholic acid
keywords: brassinosteroid analogs; lamina inclination test; plant-growth regulators; synthesis