Chemical Studies on the Mistletoe. IV. The Structure of Isoglucodistylin, a New Flavonoid Glycoside Isolated from <i>Taxillus kaempferi</i>

Sakurai, Atsushi; Okada, Kyoji; Okumura, Yasuaki

doi:10.1246/bcsj.55.3051

Cited by 13 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ESI-MS/MS of the compounds also showed a major fragment at m/z 305.0, which is diagnostic of a flavanone nucleus of the 2,3-dihydroquercetin structure. (Markham & Mabry 1968;Düber et al 1997), 2R,3S-dihydroquercetin-3-O-b-D-glucopyranoside (isoglucodistylin) (2) (Sakurai et al 1982;Düber et al 1997) and 2R,3R-dihydroquercetin-3-O-a-L-arabinopyranoside (3) (Chosson et al 1998) (Figure 1). This is the first report of the isolation of these compounds from this plant species.…”

Section: Resultsmentioning

confidence: 99%

Modulation of intracellular expression of IFNγ and IL-2 in culture of splenic T lymphocytes by some flavonoid glycosides ofAlchornea floribunda

Okoye

Odimegwu

Nworu

et al. 2016

Pharmaceutical Biology

View full text Add to dashboard Cite

Context Alchornea floribunda Mü ll. Arg. (Euphorbiaceae) leaves are widely used in ethnomedicine for the management of rheumatism, arthritis and toothache. Objective In this study, flavonoid glycosides isolated from Alchornea floribunda were screened for their effect on the intracellular expression of interferon-gamma (IFNg) and interleukin-2 (IL-2) type-1 cytokines. Materials and methods Chromatographic purification of the ethyl acetate fraction of the methanol leaf extract led to the isolation of seven flavonoid glycosides (1-7). Their structures were elucidated by 1D and 2D nuclear magnetic resonance and mass spectrometry. Splenocytes were treated with graded concentrations of the compounds (6.25-25 mg/mL) and incubated for 24 h. Thereafter, their effect on the expression of IFNg and IL-2 by CD4 + and CD8 + T-lymphocytes was evaluated using intracellular cytokine staining and FACS analysis. Results Compounds 1-7 (6.25-25 mg/mL) caused the up-regulation of activated CD8 + (57.85-72.45% versus 57.85% for untreated control) and, to a lesser extent, activated CD4 + (3.21-7.21% versus 2.75% for the untreated control) T-lymphocytes that were both largely interferon-gammareleasing in treated mouse T lymphocytes relative to untreated control. FACS data analysis showed that stimulation with all the compounds increased the proportion of CD8 + /IFNg + and CD4 +

show abstract

Section: Resultsmentioning

confidence: 99%

Modulation of intracellular expression of IFNγ and IL-2 in culture of splenic T lymphocytes by some flavonoid glycosides ofAlchornea floribunda

Okoye

Odimegwu

Nworu

et al. 2016

Pharmaceutical Biology

View full text Add to dashboard Cite

show abstract

“…This species is a small herb found in extreme southern regions of South America, including Patagonia, Tierra del Fuego, and the Falkland Islands. To the best of our knowledge, there have been no previous phytochemical studies on the genus Nanodea , but other phytochemical studies of various species belonging to the same family have revealed the presence of saponins, alkaloids, coumarins, flavonoid glycosides, lignans, iridoids, sesquiterpenes, and fatty acids …”

mentioning

confidence: 99%

Acetylenic Acids from the Aerial Parts of Nanodea muscosa

et al. 2003

View full text Add to dashboard Cite

The aerial parts of Nanodea muscosa, collected in Chile, yielded two new acetylenic acids. Their structures were elucidated by spectroscopic analyses, including 2D NMR techniques, as (13E)-octadec-13-en-11-ynoic acid (1) and (2E)-octadec-2-en-4-ynedioic acid (2). Compound 2 constitutes the first example of a conjugated ene-yne fatty diacid isolated from a natural source. Compounds 1 and 2 did not exhibit toxicity toward a panel of DNA damage checkpoint defective yeast mutants or show affinity for the 5-HT(1A), 5-HT(2A), D(2), and H(1) receptors.

show abstract

“…The isomerization of flavanonols at C-2, C-3 is not without precedent, as it was described for taxillusin – the flavanonol glycoside from Taxillus kaempferi (Japanese mistletoe) containing the 3-hydroxy-2,3-dihydro-2-phenylchromen-4-one moiety [ 29 ]. Taxillusin ( 24 , (2 R ,3 R )-taxifolin 3-β-D-glucopyranoside 6''-gallate, Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The proposed mechanism for the isomerization of silybin at C-2, C-3 was inspired by these previous studies, i.e., involving an enolization stage (route II in Scheme 5 ) [ 29 – 34 ]. In EtOAc, the isomerization can occur from 1a or from its acetylated counterpart ( 2a ), since the 23- O -acetylation proceeds in parallel with the isomerization and is substantially faster than the isomerization reaction.…”

Section: Resultsmentioning

confidence: 99%

cis–trans Isomerization of silybins A and B

Novotná

Gažák

Biedermann

et al. 2014

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

SummaryMethods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3∙OEt2) isomerization of silybins A (1a) and B (1b) (trans-isomers). The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis–trans-isomerization of silybin are proposed and supported by quantum mechanical calculations.

show abstract

Chemical Studies on the Mistletoe. IV. The Structure of Isoglucodistylin, a New Flavonoid Glycoside Isolated from Taxillus kaempferi

Abstract: A new flavonoid glycoside, isoglucodistylin was isolated from Taxillus kaempferi, and (2R,3S)-taxifolin 3-β-d-glucopyranoside was assigned to this substance from studies on the hydrolysis products and on the isomerization products, and from analyses of the carbon-13 NMR spectra.

Cited by 13 publications

References 6 publications

Modulation of intracellular expression of IFNγ and IL-2 in culture of splenic T lymphocytes by some flavonoid glycosides ofAlchornea floribunda

Modulation of intracellular expression of IFNγ and IL-2 in culture of splenic T lymphocytes by some flavonoid glycosides ofAlchornea floribunda

Acetylenic Acids from the Aerial Parts of Nanodea muscosa

cis–trans Isomerization of silybins A and B

Contact Info

Product

Resources

About