Representative condensed and hydrolyzable tannins related simple phenolics were evaluated as biological antioxidants using cyclic voltammetry, the metmyoglobin assay, deoxyribose assay. The redox potentials of similar to those structurally phenolics. However, 15−30 times more effective at quenching peroxyl radicals than or Trolox. One tannins, polygalloyl glucose, reacted an order magnitude quickly with hydroxyl radical mannitol. These results suggest that which are found in many plant-based...

The proanthocyanidins or condensed tannins, phenolic polymers which are synthesized by many plants, characteristically bind and precipitate proteins. specificity of the interaction was investigated using a competitive binding assay to compare directly affinities various proteins synthetic for tannin obtained from Sorghum bicolor (Lin.) Moench. At pH 4.9, relative range over more than 4 orders magnitude, indicating that this proanthocyanidin interacts quite selectively with protein...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProtein precipitation method for the quantitative determination of tanninsAnn E. Hagerman and Larry G. ButlerCite this: J. Agric. Food Chem. 1978, 26, 4, 809–812Publication Date (Print):July 1, 1978Publication History Published online1 May 2002Published inissue 1 July 1978https://doi.org/10.1021/jf60218a027RIGHTS & PERMISSIONSArticle Views4817Altmetric-Citations631LEARN ABOUT THESE METRICSArticle Views are COUNTER-compliant sum full text article...

We tested the hypothesis that tannins defend plants against large herbivores by decreasing protein availability. Digestion trials were conducted with mule deer (Odocoileus hemionus) and results from previous white—tailed (O. virginianus), moose (Alces alces), caribou/reindeer (Rangifer tarandus), elk (Cervus elaphus) summarized to evaluate dietary factors affecting The digestibility of plant in feeds minimal tannins, such as grasses agriculturally produced legumes grains, was a highly...

Polyphenolic allelochemicals, such as tannins, are widely thought to reduce the digestibility of plants consumed by herbivores binding digestive enzymes and dietary proteins. While apparent protein and, therefore, cell solubles is reduced in mule deer (Odocoileus hemionus) white-tailed (O. virginianus) consuming tanniferous forages, digestion plant wall not beyond that predicted from its content lignin, cutin, silica. The lack a tannin effect on contrast studies with domestic sheep numerous...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTContinuous spectrophotometric assay for plant pectin methyl esteraseAnn E. Hagerman and Paul J. AustinCite this: Agric. Food Chem. 1986, 34, 3, 440–444Publication Date (Print):May 1, 1986Publication History Published online1 May 2002Published inissue 1 1986https://pubs.acs.org/doi/10.1021/jf00069a015https://doi.org/10.1021/jf00069a015research-articleACS PublicationsRequest reuse permissionsArticle Views2745Altmetric-Citations326LEARN ABOUT THESE...

ALESSIO, H. M., A. E. HAGERMAN, B. K. FULKERSON, J. AMBROSE, R. RICE, and L. WILEY. Generation of reactive oxygen species after exhaustive aerobic isometric exercise. Med. Sci. Sports Exerc., Vol. 32, No. 9, pp. 1576–1581, 2000. Many studies have implicated elevated consumption (V̇O2) associated with exercise as contributing to oxidative stress. Only a few investigated nonaerobic its relation pro-oxidant antioxidant activities. Purpose The purpose this study was compare biomarkers stress:...

The precipitates that form when purified pentagalloylglucose or a procyanidin [epicatechin16 (4→8) catechin; EC16-C] are mixed with bovine serum albumin were quantitatively analyzed. EC16-C is more efficient protein precipitating agent than on molar mass basis. independently of temperature and presence organic solvent. Precipitation by increases as increased decreases alcohols present. When tannin in excess, up to 40 mol bound per mole precipitated, but only 20 precipitated. data support...

Tannins are a diverse group of compounds which precipitate protein.The impact tannins on herbivory has been difficult to assess because diversity in tannin chemistry and animal physiology.We have evaluated the effects large ruminants (deer, sheep) using artificial diets containing well-defhred tannins, compared results those obtained with natural forages.The different condensed gallotannins herbivores related chemical stability tannins.Commercial tannic acid does not same as...

A widely used method for analyzing hydrolyzable tannins afer reaction with KIO3 has been modified to include a methanolysis step followed by oxidation KIO3. In the new method, (gallotannins and ellagitannins) are reacted at 85 °C 20 h in methanol/sulfuric acid quantitatively release methyl gallate. Dried plant samples can be methanolyzed under same conditions convert Oxidation of gallate pH 5.5, 30 °C, forms chromophore λmax 525 nm, which is determined spectrophotometrically. The detection...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCondensed tannin purification and characterization of tannin-associated proteinsAnn E. Hagerman Larry G. ButlerCite this: J. Agric. Food Chem. 1980, 28, 5, 947–952Publication Date (Print):May 1, 1980Publication History Published online1 May 2002Published inissue 1 1980https://pubs.acs.org/doi/10.1021/jf60231a011https://doi.org/10.1021/jf60231a011research-articleACS PublicationsRequest reuse permissionsArticle Views1657Altmetric-Citations208LEARN...

Mule deer ( Odocoileus hemionus ), domestic sheep Ovis aries and American black bears Ursus americanus ) were fed quebracho Schinopsis sp.) tannin to determine the contribution of salivary proteins nitrogen- fiber-digestive efficiencies metabolism. These values compared previously published for laboratory rats Rattus rattus prairie voles Microtus ochrogaster ). deer, bears, consuming this condensed produced tannin-binding that reduced fecal-nitrogen losses per unit ingested metabolism...

The 2,2'-azinobis(3-ethylbenzothiazoline 6-sulfonic acid) radical cation (ABTS•+) decolorization assay has been used to determine the antioxidant activity of polyphenol epicatechin16 (4 → 8) catechin (procyanidin, PC) alone or in complex with model proteins bovine serum albumin (BSA) gelatin. PC had a molar capacity approximately 54, 92, 108 radicals at pH values 3.0, 4.9, 7.4, respectively. Radical scavenging occurred via rapid step followed by slow step. Interaction gelatin reduced rate...

Over the last 20 years, information about diverse compounds classified as "tannins" has rapidly accumulated. Structural studies have revealed that belong to one of three groups compounds: proanthocyanidins, gallotannins or ellagitannins. Each types tannin interacts strongly with protein, and a variety approaches been used probe this characteristic reaction. The interaction is influenced by characteristics protein (including size, amino acid composition, pI, extent posttranslational...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTannin content of cowpeas, chickpeas, pigeon peas, and mung beansMartin L. Price, Ann E. Hagerman, Larry G. ButlerCite this: J. Agric. Food Chem. 1980, 28, 2, 459–461Publication Date (Print):March 1, 1980Publication History Published online1 May 2002Published inissue 1 March 1980https://pubs.acs.org/doi/10.1021/jf60228a047https://doi.org/10.1021/jf60228a047research-articleACS PublicationsRequest reuse permissionsArticle...

Feeding of sorghum with a high level tannin (high-tannin sorghum) to rats caused changes in gene expression parotid glands similar isoproterenol treatment. Within 3 days the were enlarged about 3-fold and series proline-rich proteins increased 12-fold. Unlike treatment, no observed submandibular glands, Mr 220,000 glycoprotein was not induced. Amino acid analyses, electrophoretic patterns, cell-free translations mRNAs all confirmed that induced by feeding high-tannin identical those Binding...