The structure and stereochemistry of two new dihydroflavonol glycosides

Markham, Kenneth R.; Mabry, Tom J.

doi:10.1016/0040-4020(68)88031-7

Cited by 36 publications

(10 citation statements)

References 7 publications

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“…The compounds showed UV maxima typical of flavanone glycosides (Markham & Mabry 1968;Nonaka et al 1987;Sepulveda-Boza et al 1993). 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.…”

Section: Resultsmentioning

confidence: 99%

“…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%

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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

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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 +

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Section: Resultsmentioning

confidence: 99%

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

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“…L-Arabinose was shown by capillary electrophoresis [11] against authentic material. The absolute configuration (2R,3R) was determined due to the typical (+)(−)(+)(+) Cotton effects in the CD spectrum [26,30]. Therefore, compound 5 could be tentatively identified as 2R,3R-taxifolin 3-O-β-L-arabinopyranoside.…”

mentioning

confidence: 99%

“…Signals between δ = 3.3-4.0 ppm gave the typical pattern of an arabinose moiety. The L-configuration of arabinose was determined by capillary electrophoresis against authentic material, the absolute configuration (2R,3R) by CD data in comparison with literature data [26,30]. The presence of β-L-arabinopyranoside was ensured according to the argumentation for compound 5.…”

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confidence: 99%

Phytochemical Characterization ofRhododendron ferrugineumandIn VitroAssessment of an Aqueous Extract on Cell Toxicity

Louis¹,

Petereit²,

Lechtenberg³

et al. 2010

Planta Med

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Within a systematic phytochemical investigation of the leaves of RHODODENDRON FERRUGINEUM L. (Ericaceae), the volatile oil was isolated (0.7 %) and its constituents were characterized. Eleven flavonoids were isolated and characterized, with quercetin 3- O-[6''- O-(2-methyl-1-oxobutyl)]-β- D-glucopyranoside and 2 R,3 R-dihydromyricetin 3- O- β- L-arabinopyranoside as new natural products. Beside monomeric flavan-3-ols (catechin, epicatechin, gallocatechin, epigallocatechin) from the tannin fraction (about 3.5 % calculated as pyrogallol), the dimeric procyanidins B1 to B7 were identified, as well as the trimeric compounds procyanidin C1, epicatechin-(4 β → 8)-epicatechin-(4 β → 8)-catechin and the trimeric A type-linked cinnamtannin B1. Additionally, phloroacetophenon 4- O- β- D-glucopyranoside and chlorogenic acid were isolated. Water-soluble carbohydrates comprised about 13.5 % of the dried leaves, including fructans (3 %), polysaccharides (1 %) (mainly type II arabinogalactans), glucose, fructose, sucrose, stachyose and raffinose. The IN VITRO effects on cellular vitality (MTT test), proliferation (BrdU incorporation) and necrosis (LDH release) of an aqueous extract were investigated. The extract did not exert any toxic effects, while the vitality and the proliferation rates of epithelial HaCaT keratinocytes were significantly increased at 100 µg/mL, indicating that the aqueous extract does not have negative effects against cellular activity.

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“…16 A substância 3 foi identificada como o flavanonol, 3,7,4'-triidroxiflavanona, através da análise dos espectros de RMN 1D e 2D conforme descrito por Nascimento e colaboradores 9 e comparação dos valores divulgados para a aglicona do 3-O-glucopiranosil-garbanzol (lecontina), isolada de Baptisia lecontei (Leguminosae). 17 Desta forma, 3 foi identificada como o garbanzol, isolado anteriormente de várias espécies de Leguminosae como Cicer arietinum, 18 Onobrychis viciifolia, 19 Trifolium subterraneum, 20 Pterocarpus marsupium 21 e de Rhus succedanea L. (Anacardiaceae). 22 Esse é o primeiro registro do isolamento e identificação do garbanzol em Caesalpinoideae.…”

Section: Essas Considerações Permitiram Propor Para 2 a Estrutura Da unclassified

5-desoxiflavonóides e lignana isolados da madeira de Schizolobium parahyba (Vell.) S.F. Blake (guapuruvu)

Carvalho¹,

Nascimento²,

Carvalho³

2008

Quím. Nova

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Recebido em 29/5/07; aceito em 31/1/08; publicado na web em 31/7/08 5-DEOXYFLAVONOIDS AND LIGNAN ISOLATED FROM THE WOOD OF Schizolobium parahyba (Vell.) S.F. Blake (guapuruvu). Four flavonoids, 3,7,4'-trihydroxyflavanone (garbanzol), 7,4'-dihydroxyflavone, 7,4'-dihydroxy-3'-methoxyflavone (geraldone) and 3,4,7,4'-tetrahydroxyflavane (Rel-2R,3S,4S-leucoguibourtinidine, guibourtacacidine) were isolated from the wood of Schizolobium parahyba (Leg., Caesalpinoideae) together with lignan balonofonine, sitosterol, and stigmasterol. The structures were established by IR, NMR and mass spectral data analysis and comparison with literature values.

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The structure and stereochemistry of two new dihydroflavonol glycosides

Cited by 36 publications

References 7 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

Phytochemical Characterization ofRhododendron ferrugineumandIn VitroAssessment of an Aqueous Extract on Cell Toxicity

5-desoxiflavonóides e lignana isolados da madeira de Schizolobium parahyba (Vell.) S.F. Blake (guapuruvu)

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