Wyniki wyszukiwania - Biblioteka Nauki

1

Validated HPTLC method for quantification of epicatechin in extracts of leaves of Cassia fistula Linn.

100%

Nagore D. H. , Ghosh V. K. , Patil M. J. , Wahile A. M.

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2010

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tom Vol. 22, no. 2

259--265

EN

This paper describes a new, simple, precise, and accurate HPTLC method for quantification of (−)-epicatechin in the leaves of Cassia fistula . The leaves were separately extracted with methanol and water by both maceration and hot extraction (Soxhlet apparatus). Chromatographic separation of the drug was performed on aluminium foil silica gel 60 F 254 plates with toluene-ethyl acetate-formic acid-methanol 20:12:4:4 ( v / v ) as mobile phase. Densitometric evaluation of the separated zone was performed at 280 nm. Epicatechin in the extract was satisfactorily resolved with R F 0.22 ± 0.02. The accuracy and reliability of the method were assessed by evaluation of linearity (200–800 ng per band), precision (method precision RSD 1.42% and instrumental precision RSD 1.12%), accuracy (98.12%), and specificity in accordance with ICH guidelines.

2

Ultrasensitive determination of epicatechin, rutin, and quercetin by capillary electrophoresis chemiluminescence

88%

Wang J. , Wang H. , Han S.

Acta Chromatographica

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2012

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tom Vol. 24, no. 4

679--688

EN

An ultrasensitive and rapid method for the determination of epicatechin, rutin, and quercetin was developed using capillary zone electrophoresis with on-line chemiluminescence detection. Under the optimal conditions, the analytes were baseline separated within 12 min. The limits of detection in turn were 0.60 pg mL-1 for epicatechin, 0.50 pg mL-1 for rutin, and 1.0 pg mL-1 for quercetin. The developed method was an easy and reliable method of determining these analytes concentrations in tea, extract Ginkgo biloba, and rutin tablet, demonstrating the feasibility and reliability of the proposed method.

3

Epicatechin-copper 9II) complexes: Damage of small intestinal epithelium

75%

Stavrescu R. , Kimura T. , Hayakawa F. , Ando T.

Open Chemistry

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2003

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tom 1

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nr 1

35-52

EN

Four epicatechins [(−)-epicatechin (EC), (−)-epicatechin gallate (ECg), (−)-epigallocatechin (EGC), (−)-epigallocatechin gallate (EGCg)] and their corresponding copper complexes were compared with regard to their effect on the viability of Caco-2 colon cancer cells in vitro, measured by 3-(4,5-dimethylthyazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay. The viability of Caco-2 cells exposed to EC (1 mM), ECg (1 mM) or EGC (1mM) respectively, for 30 min, was comparable to that of the saline control group, while EGCg (1 mM) apparently enhanced cellular activity. in contrast, the cells treated with epicatechin-copper complexes were killed. Bivalent copper 91 mM), in similar conditions, did not affect the cells. No cell leakage or other histological differences were observed, implying a rapid cell death. The suggested mechanism of killing is by OH radical attack, produced in the presence of epicatechin-copper complexes, but not in the presence of either of the epicatechins or copper alone. The reaction sites are discussed.

4

The profile of polyphenols and antioxidant properties of selected apple cultivars grown in Poland

63%

Duda-Chodak A. , Tarko T. , Satora P. , Sroka P. , Tuszynski T.

Journal of Fruit and Ornamental Plant Research

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2010

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tom 18

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nr 2

39-50

EN

The aim of the study was to determine the polyphenol profile and antioxidant activity of eleven apple cultivars harvested from an orchard in Garlica Murowana (Poland). 'Antonowka', 'Red Boskoop', and 'Winter Goldparmine' had the highest antioxidant properties of all the cultivars studied. The profile of polyphenols was different in individual cultivars. In all the studied fruits, though, it was shown that (-)epicatechin, procyanidin B2, and chlorogenic acid essentially outnumbered other compounds quantitatively. The apple cultivars recommended for manufacturing apple preserves are presented.

PL

Celem badań było określenie profilu związków fenolowych i właściwo ści prze- ciwutleniających jabłek w zależności od odmiany. Do doświadczeń wybrano jedenaście odmian jab łek uprawianych w Polsce, które zostafy zebrane w jednym sadzie (Garlica Murowana koło Krakowa). Największą aktywność antyoksydacyjną wśród badanych odmian wykazywafy owoce odmian 'Antonówka', 'Red Boskoop' oraz 'Złota Reneta'. Profil związków polifenolowych różnił się w poszczególnych odmianach, jednak cechą wspólną wszystkich badanych odmian była znacząca przewaga ilościowa 3 substancji: (-)epikatechiny, procyjanidyny B2 oraz kwasu chlorogenowe- go. W pracy zasugerowano odmiany rekomendowane do przetwórstwa.

5

Simultaneous determination of gallic acid, protocatechuic acid, catechin, epicatechin, quercetin and kaempferol in Chinese chestnut (Castanea mollissima blume) kernel by high-performance liquid chromatography with diode array detection

63%

Wang T. , Yang Y. D. , Du B. , Yu S. , Hou W. L.

Acta Chromatographica

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2014

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tom Vol. 26, no. 3

539--550

EN

Chestnut exhibits anti-inflammatory, styptic, anti-diarrhea, and analgestic effects as a traditional Chinese medicine. There is increasing evidence that shows that the consumption of chestnuts has become more important in human nutrition due to the health benefits provided by the antioxidants. The phenolic compounds are responsible for major bioactivities, such as anti-tumor and anti-oxidation. A high-performance liquid chromatography (HPLC) method with diode array detection (DAD) was established for the simultaneous determination of six phenolic compounds (gallic acid, GA; protocatechuic acid, PR; catechin, CA; epicatechin, EP; quercetin, QU; kaempferol, KA) in Chinese chestnut (Castanea mollissima blume) kernel. The sample followed by separation on Eclipse XDB-C18 column (150 × 4.6 mm, id., 5 μm) with gradient elution of methanol-1.0% acetate acid solution as a mobile phase, at a temperature of 30°C, under the ratio of 1.2 mL min-1, with 5 μL injection volume, and multi-wavelength synthesis was used with DAD. The correlation coefficients were larger than 0.999, the recoveries were 97.58% for GA, 100.41% for PA, 96.23% for CA, 101.38% for QU, 99.15% for EP, and 98.60% for KA, relative standard deviation (RSD) were 1.04% for GA, 1.21% for PA, 1.09% for CA, 1.19% for QU, 1.06% for EP, and 1.20% for KA. This method was applied for the determination of phenolics in chestnut kernel and was found to be fast, sensitive, and suitable.

6

Radical scavenging capacity of cocoa polyphenols triggers anti-inflammatory properties in human monocytes and allows protective effects on H9c2 cardiomyoblast exposed to oxidative stress

51%

Arlorio M. , Coisson J. D. , Travaglia F. , Locatelli M. , Bordiga M. , Zamperone A. , Pietronave S. , Brunelleschi S. , Prat M.

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tom 61

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nr Suppl.1

7

Procyjanidyny najpopularniejszych w Polsce deserowych odmian jablek

51%

Kosmala M. , Kolodziejczyk K.

Żywność Nauka Technologia Jakość. Suplement

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2006

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tom 13

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nr 2

124-134

PL

W etanolowych ekstraktach 7 deserowych odmian jabłek (Jonagold, Cortland, Lobo, Idared, Gloster, Champion, Elstar) oznaczono zawartość głównych flawan-3-oli jabłek: epikatechiny, procyjanidyn: B1, B2, C i procyjanidyn oligomerycznych. Oznaczenia wykonano metodą RP-HPLC. Przeprowadzono również oznaczenia spektrofotometryczne sumy zawartości: polifenoli metodą Folina-Ciocalteau'a oraz sumy zawartości procyjanidyn metodą testu wanilinowego. Ogólna zawartość procyjanidyn w miąższu jabłek wyniosła od 258 do 631 mg/kg (HPLC) w tym: epikatechina 33-172 mg/kg, procyjanidyna B1 4-47 mg/kg, procyjanidyna B2 64-166 mg/kg, procyjanidyna C 5-73 mg/kg i procyjanidyny oligomeryczne 108-172 mg/kg. W miąższu suma polifenoli wyniosła od 407 do 643 mg/kg. Skórka jabłek zawierała ogółem procyjanidyn od 701 do 1445 mg/kg, w tym: epikatechina 156-400 mg/kg, procyjanidyna B1 14-74 mg/kg, procyjanidyna B2 185-369 mg/kg, procyjanidyna C 97-213 mg/kg i procyjanidyny oligomeryczne 211-459 mg/kg. Suma polifenoli zawartych w skórce wyniosła od 1573 do 2850 mg/kg. Jabłka odmiany Elstar scharakteryzowano jako najbogatsze w procyjanidyny, zarówno w miąższu, jak i w skórce. Wykazano, że skórka bogatsza jest w procyjanidyny w porównaniu z miąższem. Wykazano dobrą korelację między wynikami otrzymanymi metodą testu wanilinowego i metodą HPLC do oznaczania procyjanidyn w miąższu i jadalnych częściach jabłek.

EN

The contents of major flavan-3-ols : epicatechin, procyanidins: B1, B2, C, oligomeric procyanidins in ethanol extracts of 7 dessert apple varieties (Jonagold, Cortland, Lobo, Idared, Gloster, Champion, Elstar) was measured. The measurement was performed by RP-HPLC. Spectrophotomeric measurements of total polyphenols by Folin-Ciocalteau method and total procyanidins by vanillin test method were also performed. The contents of total procyanidins in apple flesh was on level 258-631mg/kg (HPLC), including epicatechin 33-172 mg/kg, procyanidin B1 4-47 mg/kg, procyanidin B2 64-166 mg/kg, procyanidin C1 5-73 mg/kg and oligomeric procyanidins 108-172 mg/kg. For apple flesh the total polyphenols ranged 407-643 mg/kg. For apple peel the total procyanidins ranged 701-1445 mg/kg, including epicatechin 156-400 mg/kg, procyanidin B1 14-74 mg/kg, procyanidin B2 185-369 mg/kg, procyanidin C 97-213 mg/kg and oligomeric procyanidins 211-459 mg/kg. For apple peel the total polyphenols ranged from 1573 to 2850 mg/kg. Elstar variety was characterized as the richest in procyanidins, both in apple flesh and in peel. Apple peel was shown to be richer in procyanidins than apple flesh. Good correlation between vanillin test and HPLC method for quantifying procyanidins in flesh and in edible part of apple was established.

8

Intracellular reduced glutathione content in normal and type 2 diabetic erythrocytes: effect of insulin and (-)epicatechin

51%

Rizvi S. I. , Zaid M. A.

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2001

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tom 52

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nr 3

9

Antioxidant activity of different kinds of commercially available teas – diversity and changes during storage

44%

Duda-Chodak A. , Tarko T. , Sroka P. , Satora P.

Electronic Journal of Polish Agricultural Universities. Series Food Science and Technology

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2008

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tom 11

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nr 4

10

Influence of different rootstocks on basic nutrients, selected minerals, and phenolic compounds of apple cv. ‘Šampion’

38%

Kiczorowski P. , Kiczorowska B. , Krawiec M. , Kaplan M.

Acta Scientiarum Polonorum. Hortorum Cultus

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2018

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tom 17

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nr 4

EN

The research objective was to determine and compare dry matter, crude protein, mineral elements (total), dietary fiber, easily hydrolysable sugars, vitamin C, and minerals (K, Na, Mg, Cu) as well as the content of epicatechin and phenolic acids (homovanillic, chlorogenic, caffeic, coumaric, and ferulic) in the flesh and peel of ‘Šampion’ cv. apples grafted on 4 different rootstocks types: M.26, P2, M.9, and P22 in 2014–2015. The apples from trees grafted on the P22 rootstock had the highest content of dry matter, crude protein, fiber, easily hydrolysable sugars, and vitamin C. The highest mineral compound concentration was exhibited by apples from trees growing on rootstocks P22, P2, and M.9. The highest concentration of phenolic acids was determined in the peel of fruits from trees growing on P22 and M.9. The observations confirm that rootstocks characterized by the lowest growth rate (P22, M.9) ensure the highest accumulation of nutrients in ‘Šampion’ fruits.