Department of Biological Sciences, University of Exeter, Exeter EX4 4QG, United Kingdom.
Plant Physiol. 1981 Oct;68(4):872-5. doi: 10.1104/pp.68.4.872.
Sterol levels in dandelion (Taraxacum officinale Weber) leaves were monitored over a period of 19 months. Sitosterol was the most abundant free sterol, followed by stigmasterol, then campesterol. Cholesterol could not be detected. With the exception of stigmasterol and campesterol, esters were present in greater quantities than were free forms, with 4,4-dimethyl sterol esters being the most abundant type. Glycosides occurred only sporadically. Free 4-demethyl sterols were maximal during the winter months; levels correlated negatively with sunshine and temperature, but proportions did not alter significantly. Sitosterol ester and cycloartenol ester (but not others) showed the opposite response, with levels correlating positively with sunshine and temperature. Relative amounts of 4-demethyl sterol esters remained reasonably constant, but those of cycloartenol ester and 24-methylene cycloartanol ester varied on an annual basis and were negatively correlated with each other.
蒲公英（蒲公英属）叶中的甾醇水平在 19 个月的时间里得到了监测。豆甾醇是最丰富的游离甾醇，其次是谷甾醇，然后是菜油甾醇。胆固醇无法被检测到。除了谷甾醇和菜油甾醇外，酯的含量高于游离形式，其中 4,4-二甲基甾醇酯是最丰富的类型。糖苷只零星出现。游离 4-去甲基甾醇在冬季达到最大值；其水平与阳光和温度呈负相关，但比例没有明显变化。甾醇酯和环阿屯醇酯（但不是其他的）表现出相反的反应，其水平与阳光和温度呈正相关。4-去甲基甾醇酯的相对含量保持相当稳定，但环阿屯醇酯和 24-亚甲基环阿屯醇酯的含量则在年度间变化，并相互呈负相关。
