School of Pharmacy, Lanzhou University, Lanzhou 730000, People's Republic of China.
Org Biomol Chem. 2018 Mar 7;16(10):1745-1750. doi: 10.1039/c7ob02991h.
A novel C tetranorditerpenoid, norcrassin A (1), and an unusual dimeric labdane-type diterpenoid, bicrotonol A (2), were isolated from the roots of Croton crassifolius. Norcrassin A (1) featured a new carbon skeleton with an unprecedented 5/5/5/6 tetracyclic system. Bicrotonol A (2) possessed an unusual tetrahydroxypyran ring linkage connecting two labdane diterpenoid monomers. The structures of all compounds, including the absolute configuration, were elucidated by the interpretation of their NMR spectroscopic data, high resolution mass spectrometry, and single-crystal X-ray diffraction. A plausible biosynthetic pathway of 1 is proposed. The anti-Alzheimer's Disease (AD) activities of 1 and 2 are also evaluated using the AD pathological model.
从巴豆根中分离得到了一种新型的 C 四环二萜诺卡瑞辛 A（1）和一种不寻常的二聚型贝壳杉烷型二萜，比克罗通醇 A（2）。诺卡瑞辛 A（1）具有一个全新的碳骨架，具有前所未有的 5/5/5/6 四环系统。比克罗通醇 A（2）具有一个不寻常的四羟基吡喃环连接两个贝壳杉烷二萜单体。所有化合物的结构，包括绝对构型，都是通过它们的 NMR 波谱数据、高分辨率质谱和单晶 X 射线衍射的解释来阐明的。提出了 1 的可能生物合成途径。还使用 AD 病理模型评估了 1 和 2 的抗阿尔茨海默病（AD）活性。
