Bioactive ent-isopimarane diterpenoids from Euphorbia neriifolia.
Twelve ent-isopimarane diterpenoids, including six undescribed ones, eupnerias J-O, were isolated from the stem barks of Euphorbia neriifolia L. Structurally, eupnerias J-M were the first examples of 18 (or 19)-norditerpenoid with ent-isopimarane skeleton from E. neriifolia. The absolute configuration of eupneria J was established based on the X-ray diffraction analysis and the experimental and calculated electronic circular dichroism (ECD), while the absolute configuration of eupnerias K-N were determined by the experimental and calculated ECD. In addition, the absolute configuration of the known compound, 3β-hydroxysandaracopimaric acid, was determined by comparing its ECD spectrum with eupneria J, and renamed as eupneria P. Furthermore, eupneria J and eurifoloid H showed significant anti-HIV-1 activities with IC50 values of 0.31 and 6.70 μg/mL, respectively, and ent-isopimara-8(14),15-dien-3β,12β-diol possessed obvious anti-influenza virus activity against A/Puerto Rico/8/1934, with an IC50 at 3.86 μg/mL.
Li, Jian-Chun, Wei-Feng Dai, Dan Liu, Ming-Yan Jiang, Zhi-Jun Zhang, Xuan-Qin Chen, Chin-Ho Chen, Rong-Tao Li, and Hong-Mei Li. “Bioactive ent-isopimarane diterpenoids from Euphorbia neriifolia.” Phytochemistry 175 (April 16, 2020): 112373. https://doi.org/10.1016/j.phytochem.2020.112373.