Saudiarabicains A-E, bioactive 19-acetoxyingol diterpenoids from Euphorbia saudiarabica
Date of Original Version
Five new 19-acetoxyingols were isolated from the aerial parts of Euphorbia saudiarabica. They included two uncommon pentacyclic acetoxyingols (1, 2) and two 2,3-diepimers (3, 4), representing the first report of 19-acetoxyingols epimers. Their structures were determined by analysis of extensive 1D and 2D NMR spectroscopic data. The absolute configurations were established by experimental and calculated CD analysis. Compounds 3–5 showed α-glucosidase inhibitory effects superior to the positive control, acarbose (IC50 9.1, 8.0, 1.8 vs 147 µM, respectively). Compounds 1, 2, 4, and 5 showed inhibitory effects on human P-glycoprotein comparable to the positive control, valspodar (IC50 0.1–1.4 vs 0.2 µM, respectively).
Bin Muhsinah, Abdullatif, Alfarius Eko Nugroho, Huifang Li, Sarah Lazzaro, Nicholas A. DaSilva, Dongli Li, Hang Ma, Abdulrhman Alsayari, Hiroshi Morita, Yongqiang Liu, and Navindra P. Seeram. "Saudiarabicains A-E, bioactive 19-acetoxyingol diterpenoids from Euphorbia saudiarabica." Tetrahedron Letters 61, 32 (2020). doi:10.1016/j.tetlet.2020.152203.