Three new leucothane-type (1–3), two new micrathane-type (4, 5), eight new grayanane-type diterpenoids (6–13), and four known compounds were obtained from the ethanol extract of the leaves and twigs of Rhododendron decorum. The structures were determined based on NMR spectra, quantum chemical calculations, and X-ray crystallography. The antinociceptive activities of compounds 1, 3, 4, 6, 8, 10–13, and 15–17 were evaluated via the acetic acid-induced writhing test. Compounds 1, 8, 11–13, and 15 exhibited significant antinociceptive activities. In particular, 12 and 15 were found to be effective at doses of 0.8 and 0.08 mg/kg, respectively.

中文翻译：

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杜鹃花叶和嫩枝的抗伤害性二萜类化合物

三个新的leucothane型（13），两个新micrathane型（4，5），八个新grayanane型二萜（6 - 13），以及四个已知化合物从叶和枝条的乙醇提取物得到杜鹃杜鹃。结构是根据NMR光谱，量子化学计算和X射线晶体学确定的。化合物的抗伤害活性1，3，4，6，8，10 - 13，和15 - 17通过乙酸诱导的扭曲测试评估。化合物1，8，11 - 13，和15显示出显著镇痛活性。特别地，发现12和15分别在0.8和0.08mg / kg的剂量下是有效的。