<i>In Vitro</i> Hypoglycemic Diterpenoids from the Roots of <i>Croton yunnanensis</i>

Fifteen compounds including nine new diterpenes were isolated from the roots of Croton yunnanensis. By HRESIMS, NMR, ECD data, and X-ray diffraction analysis, the new compounds were characterized as eight neo-clerodane diterpenes (compounds 1–8) and one 15,16-dinor-ent-pimarane diterpene (9). All diterpenes were assayed for their hypoglycemic activities. Compounds 1–4, 6, 7, and 10 promoted glucose uptake activity in insulin-resistant 3T3-L1 adipocytes. Compounds 1 and 6 showed insulin sensitizing activity, potentiating conspicuously their glucose uptake activity at a concentration of 20 μM when treated synergistically with low-concentration insulin at 1 nM.本研究从云南巴豆（Croton yunnanensis）的根部分离得到15个化合物，其中包含9个新二萜类化合物。通过高分辨电喷雾电离质谱（HRESIMS）、核磁共振波谱（NMR）、圆二色谱（ECD）数据及X射线衍射分析，确定了新化合物的结构：其中8个为新克罗烷型二萜（化合物1~8），1个为15,16-断-对映-海松烷型二萜（化合物9）。对所有二萜类化合物开展降血糖活性评价。结果显示，化合物1~4、6、7及10可促进胰岛素抵抗3T3-L1脂肪细胞的葡萄糖摄取。其中，化合物1和6表现出显著的胰岛素增敏活性：在与1 nM低浓度胰岛素协同处理时，于20 μM浓度下可显著增强葡萄糖摄取能力。