Bioactive Myrsinol Diterpenoids from the Roots of Euphorbia prolifera

Abstract

Ten myrsinol diterpenes, euphorbiaproliferins A-J (1-10), along with nine known analogues (11-19) were isolated from the roots of Euphorbia prolifera. Their structures were elucidated by spectroscopic data analysis (IR, ESIMS, HRESIMS, 1D and 2D NMR), and the structure of 1 was confirmed by X-ray crystallography. The diterpenes showed neuroprotective effects against MPP+-induced neuronal cell death in SH-SY5Y cells.

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.…”

“…These assignments were in accordance with the configurations of reported cyclomyrsinane diterpenes. 12,14,28,29 Moreover, as shown in Fig. 4, a single-crystal X-ray crystallographic analysis using Mo Kα radiation was carried out to confirm the above assignments and the relative configuration.…”

“…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.…”

Myrsinane, Premyrsinane, and Cyclomyrsinane Diterpenes from Euphorbia falcata as Potassium Ion Channel Inhibitors with Selective G Protein-Activated Inwardly Rectifying Ion Channel (GIRK) Blocking Effects

“…The characteristic cyclobutane ring, which is built with incorporation of one of the geminal dimethyl groups (C-19) besides C-9, C-10, and C-11 of the myrsinane skeleton, can be characterized by two methines [δ C 29.8−30.7 (C-9), 41.1−41.5 (C-11)], one methylene [δ C 34.6−37.1 (C-19)], and one Osubstituted quaternary carbon [δ C 77.5−77.8 (C-10)], due to the connection of an ester and a methyl group (C-18) in this position. 25,28,29 The substitution pattern of compound 7 was determined using HMBC and NOESY experiments. The HMBC correlations of H-3, H-5, H-8, and H-14 to the corresponding carbonyl carbons revealed that the two acetoxy and two benzoyloxy groups are attached at C-3, C-5 and C-8, C-14, respectively.…”

Isolation, Structural Elucidation, and Neuroprotective Effects of Iridoids fromValeriana jatamansi

“…1,2) Previous phytochemical investigations on this species have revealed iridoids to be the characteristic constituents of V. jatamansi. [3][4][5][6] In our continuous search for new natural products or bioactive substances from medicinal plants, [7][8][9] with focus on minor compounds, we investigated the chemical constituents of the roots of V. jatamansi. Two new iridoids, named jatadoids A (1) and B (2), and two known compounds (3 and 4) (Fig.…”