Isolation and Structure Determination of New Jatrophane Diterpenoids from Euphorbia platyphyllos L.

Three new, highly functionalized jatrophane diterpenes ( 1 – 3 ) have been isolated from the whole, dried plants of Euphorbia platyphyllos L., together with one known jatrophane polyester ( 4 ). The structures were established by UV/VIS spectroscopy, HR‐ESI‐MS, and advanced two‐dimensional NMR, including ¹H‐NMR, JMOD, ¹H,¹H‐COSY, HMQC, and HMBC experiments. Stereochemical studies and conformational analyses were performed by means of NOESY experiments. Interestingly, compounds 1 – 4 do not represent a stereochemically uniform series because they differ in the orientations of the Me groups at C(2), C(6), and C(13). A similar observation was reported earlier for Euphorbia serrulata, whose diterpenes are related to the compounds obtained from E. platyphyllos. This chemical relationship is of taxonomic importance and supports the botanical similarity of the two species.