Cyclomyrsinane and premyrsinane diterpenes from Euphorbia falcata modulate resistance of cancer cells to doxorubicin

Diterpenes from European Euphorbia Species Serving as Prototypes for Natural‐Product‐Based Drug Discovery

“…In 2011, four new premyrsinane‐type diterpenes ( 56 – 59 , Figure 8) were isolated from the methanol extract of the whole, undried plant of Euphorbia falcata , together with two new and one known cyclomyrsinane‐type diterpenes ( 53 – 55 ) 67,68. The compounds are di‐, tetra‐, penta‐, hexa‐ and heptaesters of diterpene polyols, esterified with acetic, benzoic, propanoic, isobutanoic, n ‐hexanoic, 2‐methylbutanoic and benzoic acids.…”

Cytotoxic diterpenoids from Jatropha curcas cv. nigroviensrugosus CY Yang Roots

“…The 1D NMR spectroscopic data of 5 were analogous to those of diterpene B (Sulyok et al, 2011;Vasas et al, 2012;Appendino et al, 1999;Ahmad and Jassbi, 1998); however, the oxygenated methine at C-7 in diterpene B was replaced by a methylene in 5, which was proved by the HMBC correlations from H 3 -17 to C-5 (d C 117.3, d), C-6 (d C 146.7, s), and C-7 (d C 36.9, t). The structure of 5 was further supported by the HMBC and 1 H-1 H COSY spectra (see Fig.…”

Structurally diversified diterpenoids from Euphorbia dracunculoides

“…All of the above evidences suggested that 7 shared a cyclomyrsinane-type diterpene skeleton, based on the cyclomyrsinane diterpenes reported from the genus Euphorbia. 12,14,[28][29][30] Five acyl groups including one benzoyl and four acetyl groups were also unambiguous in the 1D NMR spectra of 7. Further 2D NMR experiments ( , and , respectively, demonstrated the presence of three acetoxy groups and one benzoyloxy group at C-3, C-5, C-14 and C-8, respectively.…”

“…18,19 Meanwhile, the typical signal of a quaternary carbon at δ C 25.1 indicated the presence of a gem-dimethylcyclopropane unit [δ H 1.51 (1H, dd, J = 12.0, 8.4 Hz), 1.17 (3H, s), 1. 15 (1H,dt,J = 12.0,4.2 Hz), and 1.05 (3H, s); δ C 35.2 (d), 30.0 (d), 29.2 (q), 25.1(s), and 16.4 (q)], which were present frequently in diterpenes from the genus Euphorbia. 20, 21 Above evidences indicated that compound 1 was presumably a lathyrane diterpene glucoside.…”

“…All of the above data confirmed 10 as a premyrsinane esters. 13,[28][29][30][31] were conducted to assure the accurate structure of 10. The HMBC correlations of the proton signals at δ H 5.…”