Pepluanols C–D, Two Diterpenoids with Two Skeletons from Euphorbia peplus

Pepluanols C and D (1 and 2), featuring unprecedented 5/5/10 with out,out-[7.2.1]bicylcododecane core and 6/6/7/3 fused-ring skeletons, respectively, were isolated from Euphorbia peplus. Their chemical structures and absolute configurations were determined by a series of extensive spectroscopic methods, and X-ray diffraction analysis. In addition, pepluanols C and D showed 31.6 ± 8.3% and 30.5 ± 2.8% peak current inhibition on the Kv1.3 potassium channel at 30 μM.