Structure of helioscopinolide A, C20H28O3, a novel diterpene

Ohba, Shigeru; Ito, Mayumi; Saito, Y.; Shizuri, Yoshikazu; Kosemura, Seiji; Yamamura, Shosuke

doi:10.1107/s0108270183007684

Cited by 7 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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.…”

mentioning

confidence: 73%

See 1 more Smart Citation

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

et al. 2014

View full text Add to dashboard Cite

Four new diterpenes were isolated from the methanolic extract of Euphorbia piscatoria, two ent-abietanes (1, 2) and two lathyrane-type macrocyclic diterpenes (3, 4), along with three known diterpenes (5-7). Their structures were characterized by spectroscopic methods, mainly 1D and 2D NMR ((1)H, (13)C, DEPT, COSY, HMBC, HMQC, and NOESY) experiments. Compound 2, with an unusual structure, might be considered intermediate in the biosynthesis of ent-abietane α,β-unsaturated lactones, commonly found in Euphorbia species. Therefore, a possible biogenetic pathway is proposed. The MDR reversal potential of macrocyclic diterpenes 3-5 was evaluated through a drug combination assay, using the L5178Y mouse T lymphoma cell line transfected with the human MDR1 gene. Compounds 3-5 were able to enhance, synergistically, the antiproliferative activity of doxorubicin (combination indexes < 0.5). Moreover, compounds 1-6 were also assessed for their antiproliferative activity on human MDR cancer cell models, namely gastric, pancreatic, and colon. Weak antiproliferative activity was observed for compounds 1 (IC50 = 66.02 ± 7.10 µM) and 4 (IC50 = 39.51 ± 3.82 µM) on the MDR gastric cell line.

show abstract

mentioning

confidence: 73%

“…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].…”

mentioning

confidence: 99%

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

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Euphorbia helioscopia , and Euphorbia jolkini produce diterpenes as secondary metabolites named helioscopinolides and jolkinolides, respectively. These diterpenes, characterized by an α,β-unsaturated γ-lactone with a conjugated double bond at the β position, have the same carbon skeleton but different oxidation patterns.…”

mentioning

confidence: 99%

Identification of New Diterpenoids from Euphorbia calyptrata Cell Cultures

et al. 1996

View full text Add to dashboard Cite

show abstract

“…Because from a preliminary inspection of nmr data the unknown compound 1 was recognized to have the same carbon skeleton as compounds 2-4, it was decided to perform the main body of spectroscopic work on product 3, which was obtained in satisfactory amounts and purity, although its crystal structure data had already been published (3).…”

Section: Resultsmentioning

confidence: 99%