Five new diterpene polyesters, 1-5, with jatrophane skeletons were isolated from the fresh whole plants of Euphorbia serrulata. The structure elucidation was performed by means of UV/VIS spectroscopy, HR-ESI-MS, and advanced two-dimensional NMR methods, including 1H-NMR, JMOD, 1H,1H-COSY, NOESY, HMQC, and HMBC experiments. The relative configurations of 1-5 and their conformations in solution were analyzed on the basis of NOESY measurements. As a result of detailed NMR studies, complete 1H and 13C chemical-shift assignments of the compounds were possible. The isolated compounds differ stereochemically and do not comprise a uniform series regarding the configurations at C(2), C(6), and C(13). Compound 5 possesses the new structural feature of a double bond with (Z)-configuration in the macrocyclic ring of the jatrophane skeleton, while compound 2 has a C=C bond in the five-membered ring, this being the first observation of this structural feature in the type of macrocyclic Euphorbiaceae diterpenes.
ASJC Scopus subject areas
- Drug Discovery
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry