Solid‐state NMR studies and DFT calculations of flavonoids: baicalein, baicalin and wogonoside

Wolniak, Michał; Oszmiański, Jan; Wawer, Iwona

doi:10.1002/mrc.2165

Cited by 25 publications

(16 citation statements)

References 37 publications

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“…(i) Wolniak and coauthors have recently proven by the use of 2D NMR spectroscopy that, for baicalin in solid state or in DMSO solution, an intramolecular hydrogen bond 5;OH 3 3 3 Od4 exists (25), meaning that the 5-OH in acidic form is stabilized by this specific interaction. (ii) Our quantum chemical calculations show that the DE of 5-OH is ∼28 kJ mol -1 higher than that of 6-OH.…”

Section: Resultsmentioning

confidence: 98%

Baicalin in Radical Scavenging and Its Synergistic Effect with β-Carotene in Antilipoxidation

Ran

Han

et al. 2009

J. Agric. Food Chem.

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The lipophilic flavonoid glycoside baicalin from the traditional oriental herb Scutellaria baicalensis Georgi (logP = 1.27, pK(a1) = 7.6, pK(a2) = 10.1 as determined at 25 degrees C in 0.1 M NaCl) is found to be as reducing (0.39 V vs NHE, reversible two-electron oxidation by CV at pH 7.4) as other catechol flavonoids but a poor radical scavenger (TEAC = 1.12, pH 7.4) and a poor antioxidant against free radical initiated lipid oxidation in liposomes. However, this compound is able to regenerate beta-carotene (beta-Car) from beta-Car(*+) with a second-order rate constant of (5.6 +/- 0.5) x 10(9) L mol(-1) s(-1) in the methanol/chloroform binary solvent (1:9, v/v) and, more importantly, to exhibit a prominent synergistic effect with beta-Car against the lipoxidation induced by AMVN-derived peroxyl radical in liposomal membrane. Thus, baicalin by itself is not an effective antioxidant, but it becomes one via interaction with beta-Car. The radical scavenging and antilipoxidation properties of baicalin are discussed in terms of its physicochemical properties and molecular structures.

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Section: Resultsmentioning

confidence: 98%

Baicalin in Radical Scavenging and Its Synergistic Effect with β-Carotene in Antilipoxidation

Ran

Han

et al. 2009

J. Agric. Food Chem.

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“…This configuration causes a stronger chelation of Fe 2þ by baicalein than by ferrozine and gives baicalein advantage, even compared with other flavonoids (Perez et al 2009;Mladenka et al 2011). The preferred chelation position at C-6 and C-7 is feasible for baicalein but not for baicalin (Wolniak et al 2008). Consequently, the observed activity of baicalin is rather due to its ROS-scavenging properties (Perez et al 2009;Wang et al 2012).…”

mentioning

confidence: 93%

Antiradical and antioxidant activity of flavones fromScutellariae baicalensis radix

Woźniak¹,

Dryś²,

Matkowski³

2014

Natural Product Research

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We evaluated the antioxidant properties of four main flavones from Scutellaria baicalensis: baicalein, wogonin and their glucuronides - baicalin and wogonoside. We used three in vitro assays: free radical scavenging with 2,2'-diphenylpicrylhydrazyl radical, transition metal ions reducing power by phosphomolybdenum assay and inhibition of the hydroxyl radical-induced peroxidation of linoleic acid assay. All flavones have antioxidant capacity, which differs depending on the structure and mechanisms of activity. In all tests, only baicalein - the aglycone with three adjacent hydroxyl groups - exhibited consistent antioxidant effect. Wogonin protected linoleic acid against oxidation. Baicalin displayed less potent antioxidant properties whereas wogonoside did not have significant antioxidant activity.

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“…1), which were identified as compound 1 (baicalein), compound 2 (wogonin), compound 3 (baicalin), and compound 4 (wogonoside) by comparison with the published values (Wolniak et al, 2008). Compound 1-4 were obtained as a yellow powder and 1 H-NMR and 13 C-NMR data were showed the typical aromatic compounds.…”

Section: S Baicalensis Is a Well-known Korean Medicinal Herbmentioning

confidence: 90%

“…Their structures were determined as baicalin, baicalein, wogonoside, and wogonin by spectroscopic methods (Wolniak et al, 2008).…”

Section: Isolation and Structure Elucidation Of Marker Substancesmentioning

confidence: 99%

The Effective Preparation of Flavonoids from Scutellaria baicalensis G_EORGIby Diaion HP-20 Resin

Yu¹

2014

Korean Journal of Plant Resources

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-Scutellaria baicalensis GEORGI (Scutellariae Radix) has been used to clear heat and to dry dampness in the stomach or intestines, which manifests as diarrhea or dysenteric disorder. In this study, we investigated the effective preparation of active components in Scutellariae Radix using the methods of solvent extraction and absorption fractionation for the development of new functional food or pharmaceuticals. The marker substances, baicalin, baicalein, wogonoside, and wogonin were directly isolated from the Scutellariae Radix. There chemical structures were elucidated by spectroscopic analysis. The Scutellariae Radix was extracted with hot water. To enhance yield of flavonoids in Scutellariae Radix, the hot water extract was dissolved in ethanol with concentration dependent manner. The precipitates were separated using centrifugal techniques at 10,000 rpm. Supernatant liquid was applied to the HPLC for quantification of major compounds. Separately, the hot water extract was absorbed on Diaion HP-20 resin. And then, the absorbed fraction was eluted with methanol for HPLC. The contents of baicalin, baicalein, wogonoside and wogonin in different treatment methods were analyzed by HPLC. Total amount of four major components were 16.9% in 50% ethanol extract, 21.7% in 70% ethanol extract, 20.5% in 90% ethanol extract, and 39.3% in absorbed fraction of Diaion HP-20 resin. In these results, we found that resin absorption method is suitable for the extraction of enriched flavonoids from Scutellariae Radix.

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Solid‐state NMR studies and DFT calculations of flavonoids: baicalein, baicalin and wogonoside

Cited by 25 publications

References 37 publications

Baicalin in Radical Scavenging and Its Synergistic Effect with β-Carotene in Antilipoxidation

Baicalin in Radical Scavenging and Its Synergistic Effect with β-Carotene in Antilipoxidation

Antiradical and antioxidant activity of flavones fromScutellariae baicalensis radix

The Effective Preparation of Flavonoids from Scutellaria baicalensis G_EORGIby Diaion HP-20 Resin

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Solid‐state NMR studies and DFT calculations of flavonoids: baicalein, baicalin and wogonoside

Cited by 25 publications

References 37 publications

Baicalin in Radical Scavenging and Its Synergistic Effect with β-Carotene in Antilipoxidation

Baicalin in Radical Scavenging and Its Synergistic Effect with β-Carotene in Antilipoxidation

Antiradical and antioxidant activity of flavones fromScutellariae baicalensis radix

The Effective Preparation of Flavonoids from Scutellaria baicalensis GEORGIby Diaion HP-20 Resin

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Product

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About

The Effective Preparation of Flavonoids from Scutellaria baicalensis G_EORGIby Diaion HP-20 Resin