Tannin activity ellagic acid

In the same manner, not all ellagitannins are hydrolyzable as those with a C-glycosidic bond will not break down with tannin-active enzymes or hot dilute acids to produce free ellagic acid. 

Black walnut cultivars Rawlins and Thomas had considerably lower gallic acid levels of -1% dw, quite close to that of the pistachio cultivar Kerman (0.5% dw), and in vitro aflatoxin production for the walnut Thomas and pistachio Kerman were also similar at 45 and 40 J,g/plate, respectively [17], The hydrolysable tannin in pistachios has a core of quinic acid, rather than glucose (unpublished results), and its stereochemistry is such that dimerization of gallic acid moieties to hexahy-droxydiphenic esters, and consequent formation of ellagic acid, cannot occur. Any aflatoxin inhibitory activity is, therefore, dependent on either the tannin itself or gallic acid. 

Wine, phenoHc constHuents of. Besides the volatile constituents of wine flavor, alcohols, tartaric acid and tartrates, especially red wines contain phenolic constituents stilbenes, e.g. resveratrol, the vitisins, tannins and other polyphenols like ellagic acid and the viniferins, and other oligomeric stilbenes, e.g. e-viniferin. Mainly to these phenolic compounds, the anti-atherosclerotic and infarction-prophylactic activity is attributed, explaining the so-called French Para-... 

Seeram NP, Adams LS, Henning SM, Niu Y, Zhang Y, Nair MG, Heber D (2005) In vitro antiproliferative, apoptotic and antioxidant activities of punicalagin, ellagic acid and a total pomegranate tannin extract are enhanced in combination with other polyphenols as found in pomegranate juice. J Nutr Biochem 16 360-367... 

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