Four brassinolide analogs were synthesized starting from cholesterol, stigmasterol or pregnenolone. An analog possessing a hydroxyl group at C-17 instead of the steroidal side chain was only 0.001% as active as brassinolide upon lamina-inclination testing with rice seedlings, while other analogs were 1-2% as active as brassinolide. This indicates the indispensable role of the side chain for the plant growth-promoting activity of brassino-steroids.
从
胆固醇、
豆甾醇或
孕烯醇酮出发,合成了四种黄
铜内酯类似物。在对
水稻秧苗进行片层倾斜试验时,一种在 C-17 处具有羟基而不是甾体侧链的类似物的活性只有黄
铜内酯的 0.001%,而其他类似物的活性是黄
铜内酯的 1-2%。这表明侧链对黄
铜内酯的植物生长促进活性起着不可或缺的作用。