151
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Wu LC, Lu YW. Electrophoretic method for the identification of a haze-active protein in grape seeds. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:3130-3135. [PMID: 15137864 DOI: 10.1021/jf0352982] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A simple, fast, and more selective approach is presented in this study for the identification of haze-active proteins. Grape seed proteins were unfolded by 1% SDS and then interacted with different amounts of tannin at 4 degrees C, followed by gel electrophoresis. It was found that the intensity of the band at 45 kDa was decreased as tannins increased. The amino acid composition of this isolated 45-kDa protein was higher in proline (9.49%) than the average proline content of total grape seed proteins (4.85%). To verify the selectivity of the proposed method, a globular protein (bovine serum albumin, BSA) and a proline-rich protein (gelatin) were selected and used in the model system. As expected, gelatin was removed as it reacted with the increasing added tannins, whereas BSA did not. These results showed that it is possible to identify haze-active proteins by modulating the accessibility of protein to tannins, suggesting this new method can be used by the beverage industry to trouble-shoot haze problems and for quality control.
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Affiliation(s)
- Li-Chen Wu
- Department of Applied Chemistry, National Chi-Nan University, Puli, Nantou, 545 Taiwan.
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152
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Viljanen K, Kivikari R, Heinonen M. Protein-lipid interactions during liposome oxidation with added anthocyanin and other phenolic compounds. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:1104-1111. [PMID: 14995106 DOI: 10.1021/jf034785e] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Oxidation of bovine serum albumin, casein, and lactalbumin and the effect of different procyanidins, anthocyanins, and their aglycons (10 and 20 microM) on lactalbumin oxidation were investigated in a liposome system. Samples were incubated in the dark at 37 degrees C with copper, and the extent of oxidation was measured by determining the loss of tryptophan fluorescence and the formation of protein carbonyls, conjugated diene hydroperoxides, and hexanal. The correlation between different protein and lipid oxidation measurements was good and statistically significant. Casein was the most stable protein in the liposome model, and it was also the best inhibitor of liposome oxidation. All tested anthocyanins and other phenolic compounds inhibited both lipid and protein oxidation. There were no systematic differences with anthocyanins and their aglycons in relation to the concentrations used or glycosylation with either glucose or rutinose. Procyanidins B1 and B2 and ellagic acid were potentially better antioxidants than anthocyanins due to their several hydroxyl groups as measured by both protein and lipid oxidation. In conclusion, oxidative deterioration of liposomes due to protein-lipid interaction is inhibited by anthocyanins, procyanidins, and ellagitannin present, for example, in berries.
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Affiliation(s)
- Kaarina Viljanen
- Department of Applied Chemistry and Microbiology, Division of Food Chemistry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland.
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153
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Skrabanja V, Kreft I, Golob T, Modic M, Ikeda S, Ikeda K, Kreft S, Bonafaccia G, Knapp M, Kosmelj K. Nutrient Content in Buckwheat Milling Fractions. Cereal Chem 2004. [DOI: 10.1094/cchem.2004.81.2.172] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Vida Skrabanja
- Biotechnical Faculty, University of Ljubljana, P.O. Box 2995, SI-1001 Ljubljana, Slovenia
| | - Ivan Kreft
- Biotechnical Faculty, University of Ljubljana, P.O. Box 2995, SI-1001 Ljubljana, Slovenia
- Corresponding author. Phone: +386 1 423 1161. Fax: +386 1 517 1488. E-mail:
| | - Terezija Golob
- Biotechnical Faculty, University of Ljubljana, P.O. Box 2995, SI-1001 Ljubljana, Slovenia
| | - Mateja Modic
- Zito, d.d., Smartinska c. 154, SI-1529 Ljubljana, Slovenia
| | - Sayoko Ikeda
- Faculty of Nutrition, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Kiyokazu Ikeda
- Faculty of Nutrition, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Samo Kreft
- Faculty of Pharmacy, University of Ljubljana, Askerceva 7, SI-1000 Ljubljana, Slovenia
| | | | - Martina Knapp
- Biotechnical Faculty, University of Ljubljana, P.O. Box 2995, SI-1001 Ljubljana, Slovenia
| | - Katarina Kosmelj
- Biotechnical Faculty, University of Ljubljana, P.O. Box 2995, SI-1001 Ljubljana, Slovenia
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154
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155
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156
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Wu YT, Huang WY, Lin TC, Sheu SJ. Determination of moutan tannins by high-performance liquid chromatography and capillary electrophoresis. J Sep Sci 2003. [DOI: 10.1002/jssc.200301587] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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157
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Takebayashi J, Tai A, Yamamoto I. pH-dependent long-term radical scavenging activity of AA-2G and 6-Octa-AA-2G against 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation. Biol Pharm Bull 2003; 26:1368-70. [PMID: 12951491 DOI: 10.1248/bpb.26.1368] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS (radical +)) decolorization assay was applied to evaluate the stoichiometric radical scavenging activity of ascorbic acid (AA) and two AA derivatives, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and 2-O-alpha-D-glucopyranosyl-6-O-octanoyl-L-ascorbic acid (6-Octa-AA-2G). AA rapidly reacted with ABTS (radical +), and the reaction was completed within 10 min. In contrast, AA-2G and 6-Octa-AA-2G continuously reacted with ABTS (radical +), and the reaction was not completed after 2 h. The radical scavenging activity of AA-2G and 6-Octa-AA-2G in aqueous solutions at pH 4.0 and above was higher than that at pH 3.0, whereas AA showed no difference in the pH range 3 to 6. The amounts of ABTS (radical +) scavenged by one molecule of AA, AA-2G and 6-Octa-AA-2G after 2 h of reaction at pH 6.0 were approximately 2.0, 3.4 or 3.9 molecules, respectively. This study demonstrates that the quantity of ABTS (radical +) quenched by AA-2G and 6-Octa-AA-2G is superior to that of AA in a long-term reaction.
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Affiliation(s)
- Jun Takebayashi
- Department of Immunochemistry, Faculty of Pharmaceutical Sciences, Okayama University, Okayama, Japan
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158
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Frazier RA, Papadopoulou A, Mueller-Harvey I, Kissoon D, Green RJ. Probing protein-tannin interactions by isothermal titration microcalorimetry. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003; 51:5189-5195. [PMID: 12926857 DOI: 10.1021/jf021179v] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Isothermal titration microcalorimetry (ITC) has been applied to investigate protein-tannin interactions. Two hydrolyzable tannins were studied, namely myrabolan and tara tannins, for their interaction with bovine serum albumin (BSA), a model globular protein, and gelatin, a model proline-rich random coil protein. Calorimetry data indicate that protein-tannin interaction mechanisms are dependent upon the nature of the protein involved. Tannins apparently interact nonspecifically with the globular BSA, leading to binding saturation at estimated tannin/BSA molar ratios of 48:1 for tara- and 178:1 for myrabolan tannins. Tannins bind to the random coil protein gelatin by a two-stage mechanism. The energetics of the first stage show evidence for cooperative binding of tannins to the protein, while the second stage indicates gradual saturation of binding sites as observed for interaction with BSA. The structure and flexibility of the tannins themselves alters the stoichiometry of the interaction, but does not appear to have any significant affect on the overall binding mechanism observed. This study demonstrates the potential of ITC for providing an insight into the nature of protein-tannin interactions.
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Affiliation(s)
- Richard A Frazier
- School of Food Biosciences, The University of Reading, P.O. Box 226, Whiteknights, Reading RG6 6AP, United Kingdom.
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159
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Ignatowicz E, Balana B, Vulimiri SV, Szaefer H, Baer-Dubowska W. The effect of plant phenolics on the formation of 7,12-dimethylbenz[a]anthracene-DNA adducts and TPA-stimulated polymorphonuclear neutrophils chemiluminescence in vitro. Toxicology 2003; 189:199-209. [PMID: 12832153 DOI: 10.1016/s0300-483x(03)00148-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Phenolics, common plant constituents, form up an important part of human diet and are considered potential chemopreventive agents. In the present study, structurally diverse phenolics, such as tannic acid, protocatechuic acid, chlorogenic acid and resveratrol, were investigated for their inhibitory effects on covalent binding of 7,12-dimethylbenz[a]anthracene (DMBA) to DNA in vitro and the suppression of oxidative burst in 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated human polymorphonuclear neutrophils (PMNs). 32P-postlabeling analysis of DNA incubated with DMBA in the presence of 3-methylcholanthrene (3-MC)-induced microsomes produced three major adducts derived from anti-, syn- and anti-dihydrodiol epoxides through reactions with dGuo and dAdo, respectively. Phenolic compounds at the concentration of 150 microM reduced the levels of all DMBA-DNA adducts by 55-98%. The most dramatic effect was observed in case of tannic acid, which completely inhibited the formation of DMBA-dAdo adducts. Chlorogenic acid was the least effective inhibitor of DMBA-DNA adducts formation particularly syn-DMBADE-dAdo (20%). Human neutrophils showed a significant dose-related decrease of TPA-induced chemiluminescence after pretreatment with phenolic compounds. The most effective inhibitors were tannic acid and resveratrol with IC(50)=5.19 and 5.76 microM, respectively. These results suggest that the suppression of reactive oxygen species (ROS) and carcinogen-DNA adducts formation may be important for anticarcinogenic activity of the examined phenolics.
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Affiliation(s)
- Ewa Ignatowicz
- Department of Pharmaceutical Biochemistry, Karol Marcinkowski University of Medical Sciences, Grunwaldzka 6, Poznan 60-780, Poland
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160
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Hatano T, Hori M, Hemingway RW, Yoshida T. Size exclusion chromatographic analysis of polyphenol-serum albumin complexes. PHYTOCHEMISTRY 2003; 63:817-823. [PMID: 12877923 DOI: 10.1016/s0031-9422(03)00340-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Formation of water-soluble polyphenol-protein complexes was investigated by size-exclusion chromatography (SEC). The combination of (-)-epigallocatechin gallate (EGCG) and bovine serum albumin (BSA), which did not form a precipitate after the solutions were mixed, showed an SEC peak due to complex formation 2-24 h after mixing. Peak size of the complex varied with time, suggesting slow change of the conformation of the protein accompanied by complexation. Formation of the complex was substantiated by ultrafiltration of the mixture; the complex did not pass through a membrane with a 100,000 nominal molecular weight limit (NMWL). The SEC profile varied with the combination of compounds. The peaks due to the complexes showed that the apparent value of the number average molecular weight (M(n)) of the EGCG-BSA complex was 2.8x10(5), while that of a pentagalloylglucose (PGG)-BSA complex was 9.5x10(5) under the conditions used. Dimeric hydrolyzable tannins, oenothein B and cornusiin A, also caused changes in the SEC profile of BSA, although the combinations did not show peaks attributable to formation of such large complexes observed for EGCG and PGG. Procyanidin B3 and (+)-catechin did not cause changes in the SEC profile of BSA. With cytochrome c, EGCG did not show any chromatographic changes.
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Affiliation(s)
- Tsutomu Hatano
- Faculty of Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
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161
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Hagerman AE, Dean RT, Davies MJ. Radical chemistry of epigallocatechin gallate and its relevance to protein damage. Arch Biochem Biophys 2003; 414:115-20. [PMID: 12745262 DOI: 10.1016/s0003-9861(03)00158-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The radical chemistry of the plant polyphenolics epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were investigated using electron paramagnetic resonance spectroscopy. Radical species formed spontaneously in aqueous solutions at low pH without external oxidant and were spin stabilized with Zn(II). The spectra were assigned to the gallyl radical and the anion gallyl radical, with only 10% of the signal assigned to a radical from the galloyl ester. Spectral simulations were used to establish a pK(a) of 4.8 for the EGCG radical and a pK(a) of 4.4 for the EGC radical. The electrochemical redox potentials of EGCG and EGC varied from 1000 mV at pH 3 to 400 mV at pH 8. The polyphenolics did not produce hydroxyl radicals unless reduced metal ions such as iron(II) were added to the system. Zinc(II)-stabilized EGCG radicals were more effective protein-precipitating agents than unoxidized EGCG and produced irreversibly complexed protein. EGCG and other naturally occurring polyphenolics are effective radical scavengers but their radical products have the potential to damage biological molecules such as proteins.
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Affiliation(s)
- Ann E Hagerman
- Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA.
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162
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Gertsch J, Güttinger M, Sticher O, Heilmann J. Relative quantification of mRNA levels in Jurkat T cells with RT-real time-PCR (RT-rt-PCR): new possibilities for the screening of anti-inflammatory and cytotoxic compounds. Pharm Res 2003; 19:1236-43. [PMID: 12240952 DOI: 10.1023/a:1019818814336] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Quantification of the pro-inflammatory action of mitogens on mRNA levels of growth-related genes, transcription factors, and cytokines in T cells as markers for the screening of compounds with immunomodulatory, anti-inflammatory or cytotoxic potential. METHOD A reverse transcription-real time-polymerase chain reaction assay with TaqMan probes was developed. Jurkat T cells were treated with cyclosporin A, hypericin, capsaicin, and catechin before phorbol 12-myristate 13-acetate stimulation, and their effects on the relative mRNA levels were determined. A cell viability assay was performed in parallel. RESULTS Cyclosporin A and capsaicin were potent inhibitors of PMA-induced cytokine transcription. Cyclosporin A further targeted cyclin D1 transcription. Capsaicin exhibited no effects on the cell viability at low concentrations, whereas cyclosporin A did. Hypericin down-regulated nearly all investigated mRNAs, resulting in a strong time-dependent cytotoxicity. Catechin showed no effects on mRNA levels and cell viability. CONCLUSIONS The inhibition of the up-regulation of mRNA levels of cytokines points to a specific anti-inflammatory potential of capsaicin. Hypericin showed no specific effects on the mRNA expression. The overall decrease of mRNA levels is probably an early indication of the strong cytotoxic effect observed after 48 h. Therefore, quantification of mRNA levels by reverse transcription-real time-polymerase chain reaction is, in combination with the monitoring of cell viability, a valuable tool to distinguish between specific immunomodulatory and cytotoxic effects in vitro.
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Affiliation(s)
- Jürg Gertsch
- Swiss Federal Institute of Technology (ETH) Zurich, Institute of Pharmaceutical Sciences
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163
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Goupy P, Dufour C, Loonis M, Dangles O. Quantitative kinetic analysis of hydrogen transfer reactions from dietary polyphenols to the DPPH radical. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003; 51:615-22. [PMID: 12537431 DOI: 10.1021/jf025938l] [Citation(s) in RCA: 215] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Diphenylpicrylhydrazyl (DPPH) is widely used for quickly assessing the ability of polyphenols to transfer labile H atoms to radicals, a likely mechanism of antioxidant protection. This popular test generally pays no attention to the kinetics of H atom transfer, which however could be even more important than the total H-atom-donating capacities (stoichiometry, EC50) typically evaluated. In the present work, a series of dietary polyphenols belonging to the most representative families (flavonols from onion, flavanol monomers and oligomers from barley, and caffeic acid and caffeoyl esters from artichoke and endive) are characterized not only by their total stoichiometries (n(tot)) but also by their rate constants of first H atom abstraction by DPPH (k(1)), deduced from the kinetic analysis of the decay of the DPPH visible band following addition of the antioxidant. The mildly reactive DPPH radical allows a good discrimation between polyphenols, as demonstrated by the relatively large ranges of k(1) (ca. 400-5000 M(-)(1) s(-)(1)) and n(tot) (ca. 1-5) values typically measured with antioxidants having a single polyphenolic nucleus. With antioxidants displaying more than one polyphenolic nucleus (procyanidin oligomers, dicaffeoyl esters), the kinetic analysis makes it possible to demonstrate significant differences in reactivity between the subunits (two distinct k(1) values whose ratio lies in the range 3-10) and nonadditive stoichiometries.
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Affiliation(s)
- Pascale Goupy
- UMR A 408 INRA-Université d'Avignon, Site Agroparc, Domaine St-Paul, 84914 Avignon Cedex 9, France
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