Structure Elucidation of Helioscopinolides D and E from Euphorbia calyptrata Cell Cultures

Diterpenes from Euphorbia piscatoria: Synergistic Interaction of Lathyranes with Doxorubicin on Resistant Cancer Cells

“…The 1 H NMR spectrum of compound 1 displayed three singlets corresponding to tertiary methyls (δ H 1.00, 1.19, 1.22), one vinylic methyl group at δ H 2.19, and three signals of protons at carbons bearing oxygen atoms (δ H 5.15, 4.92, and 3.34). The 13 C NMR and DEPT spectra of piscatolide (1) were consistent with an abietane skeleton [16,17,[23][24][25], showing 20 carbon resonances corresponding to four methyls, five methylenes, four methines (three corresponding to oxymethines at δ C 70.1, 78.7 and 79.1), and seven quaternary carbons (four olefinics at δ C 121.6, 130.4, 137.8, 162.7 and a carbonyl at δ C 176.9). Detailed structure information was obtained from two-dimensional NMR data ( 1 H-1 H COSY, HMQC, and HMBC), which allowed for the clear assignment of all the carbons (l " Table 1) and the location of the functional groups.…”

“…Compound 1, named piscatolide, was isolated as a white powder. The IR absorptions at 1734 and 3385 cm −1 suggested the presence of an α,β-unsaturated γ-lactone and a hydroxyl group [16,23,24]. The molecular formula was deduced as C 20 H 28 O 4 from its ESI-TOF-HRMS spectrum, indicating the presence of seven degrees of unsaturation.…”

“…Diterpenes of the ent-abietane-type are usually found in Euphorbia species as α,β-unsaturated γ-lactones [4,12]. Jolkinolides [13][14][15] and helioscopinolides [16][17][18] constitute representative groups of these compounds. These lactones were identified as having cytotoxicity against various types of tumor cells [4,12].…”

“…1), namely an ent-abietane lactone (1), an uncommon ent-abietane acid (2), and two macro-cyclic diterpenes of the lathyrane type (3 and 4). The known diterpenes 15-acetoxy-5,6-epoxylathyr-12-en-3-ol-14-one (5) [21], ent-13[R]-hydroxy-3,14-dioxo-16-atisene (6) [22], and helioscopinolide E (7) [16] were also isolated and identified by comparison of their spectroscopic data to those reported in the literature. Compound 1, named piscatolide, was isolated as a white powder.…”

Anti-inflammatory principles of Suregada multiflora against nitric oxide and prostaglandin E2 releases

“…Subfraction F6c (327.7 mg) was further purified by CC with acetone-CH 2 Cl 2 (1:9, v/v) to give 1 (22.5 mg). The structures of the isolated compounds were elucidated and compared with the previous literatures (Borghi et al, 1991;Das et al, 1994;Agrawal et al, 1995;Crespi-Perellino et al, 1996;Cheenpracha et al, 2006).…”