Duran María Isabel, González Cesar, Acosta Alison, Olea Andrés F, Díaz Katy, Espinoza Luis
Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2340000, Chile.
Escuela de Ingeniería en Biotecnología, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Quillota 980, Viña del Mar 2520000, Chile.
Int J Mol Sci. 2017 Mar 8;18(3):516. doi: 10.3390/ijms18030516.
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 analogs -, were synthesized starting from hyodeoxycholic acid , and maintaining the alkyl side chain as cholic acid or its methyl ester. The growth-promoting effects of brassinolide () and synthesized analogs were evaluated by using the rice lamina inclination assay at concentrations ranging from 1 × 10-1 × 10 M. 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 compound on cell elongation was assessed by microscopy analysis, and the results indicate that the growth-promoting effect of analog is mainly due to cell elongation of the adaxial sides, instead of an increase on cell number.
油菜素甾醇（BRs）是促进不同植物器官和组织生长的植物激素。人们已经研究了这些化合物展现这种生物活性应具备的结构要求。在这项工作中，从猪去氧胆酸开始合成了一系列已知的BR类似物，并保持胆酸或其甲酯作为烷基侧链。通过水稻叶片倾斜试验，在1×10⁻¹×10⁻⁶M的浓度范围内评估了油菜素内酯（）和合成类似物的促生长作用。我们的结果表明，在此浓度范围内，水稻幼苗的诱导弯曲角度随BRs浓度的增加而增加。根据BR结构，在最低测试浓度下测定活性的分析表明，如一些构效关系研究所提出的，油菜素内酯中存在的2α,3α - 二羟基 - 7 - 氧杂 - 6 - 酮部分是这些化合物植物生长活性所必需的。通过显微镜分析评估了化合物对细胞伸长的影响，结果表明类似物的促生长作用主要归因于近轴侧细胞的伸长，而非细胞数量的增加。
