Design of nonsteroidal durassinosteroids

采用水稻叶片倾斜试验检测油菜素内酯活性。在根据标准生物测定系统用不同浓度的化合物处理水稻品种后，使用半圆形量角器测量在叶和鞘之间诱导的角度的大小。用不同浓度的化合物处理后诱导的角度相对于浓度作图。在每个测定中，包括用溶剂（DMSO）和高浓度油菜素（10 μ M）的两种处理<-6>分别作为阴性和阳性对照。从各浓度-反应曲线中确定各化合物的50%有效浓度EC_<50>（M），并以EC_（M）的倒数<50>作为活性指标。使用该方法，我们评估了<50>油菜素内酯，Castasterone，和表油菜素内酯的EC_值分别为9.14，8.08和8.28。油菜素甾醇类化合物的活性大小顺序与 ...更多信息 这是以前报告的结果。采用浓度-响应曲线估算50%有效浓度的评价体系的优点是：1）平均值的标准误差小，2）无论实验条件如何，都能确定恒定活性，3）能够评价在测量中未观察到超过标准角（通常为140度）的角度的弱化合物的活性。用这种生物测定系统，昆虫蜕皮激素激动剂，如蜕皮激素和二苯甲酰肼，哺乳动物激素，如己烯雌酚和糖皮质激素，和其他新合成的化合物，如肟和苯基苄基醚化合物进行了筛选，虽然没有测试的化合物是没有活性的。构建了20-羟基蜕皮酮和油菜素内酯的三维结构，并比较了它们之间的差异，这是由于甾体蜕皮酮的C- 17位烷基链与D-环之间的扭转角不同。少

The rice lamina inclination test was used to detect the brassinosteroid activity. After treating the rice cultivar with various concentration of compounds according to the standard bioassay system, the magnitude of the angle induced between the leaf and sheath was measured using semicircular protractor. The angles induced after treatments with various concentration of compounds were plotted against the concentrations. In each assay, both treatments with a solvent (DMSO) and a high concentration of brassinolide (10^<-6> M) were included as the negative and positive control, respectively. From each concentration-response curve, the 50% effective concentration EC_<50> (M) was determined for each compound, and the reciprocal logarithm of EC_<50> was used as the activity index. Using this method, we evaluated reproducible EC_<50> values for brassinolide, castasterone, and epibrassinolide to be 9.14, 8.08, and 8.28, respectively. The order of the activity of brassinosteroids is consistent wi … More th the previously reported results. The advantage of this evaluation system in which the concentration-response curve is adopted to estimate the 50% effective concentration is that 1) the standard error of averaged value is small, 2) the constant activity is able to be determined regardless of the experimental conditions, 3) the activity of weak compounds for which the angle exceeding the standard angle (usually 140 degree) is not observed in the measurement is able to be evaluated. With this bioassay system, insect molting hormone agonists such as ecdysone and dibenzoylhydrazines, mammalian hormones such as diethylstilbestrol and glucocorticoids, and other newly synthesized compounds such as oxime and phenyl benzyl ether compounds were screened, although none of compounds tested was not active. Three-dimensional (3-D) structures of 20-hydroxyecdysone and brassinolide were constructed and compared between them, which were different with respect to the torsion angle between alkyl chain at C- 17 position and D-ring of steroid skelton. Less