Catechin galloylated

Malan, E. Piennar, D.H. (1987). (+)-Catechin-galloyl esters liom the bark of Acacia gerrardii. Phytochemistry, 26,2049-2051. 

The initial oxidation of the flavanol components of fresh leaf to quinone structures through the mediation of tea polyphenol oxidase is the essential driving force in the production of black tea. While each of the catechins is oxidizable by this route, epigallocatechin and its galloyl ester are preferentially oxidized.68 Subsequent reactions of the flavonoid substances are largely nonenzymic. 

Building blocks Gallic acid, galloyl ester, ester-linked with glucose Flavanoid units (Procyanidins), catechin... 

Tuckmantel, W., Kozikowski, A.P., and Romanczyk, L.J. Jr., Studies in polyphenol chemistry and bioactivity. 1. Preparation of building blocks from (+)-catechin. Procyanidin formation. Synthesis of the cancer cell growth inhibitor, 3-0-galloyl-(2R,3R)-epicatechin-4(3,8-[3,0-galloyl-(2R,3R)-epicatechin], J. Am. Chem. Soc., 121, 12073, 1999. 

Diffusion of aglycone Into blood. Small amounts of Isoflavone aglycones and larger amounts of galloylated catechins are found In plasma, suggesting that some aglycone diffuses across the basolateral membrane Into the blood. 

A proportion of some flavonoids escapes intestinal conjugation. Evidence for this is derived from the presence of unconjugated flavonoids in the plasma. However, this has been shown only for galloylated catechins and isoflavones under certain conditions and is dose and time dependent, whereas unconjugated catechin and quercetin are not found in plasma in significant amounts. - " ... 

The LC/MS does not allow separation and identification of oligomers higher than pentamers because the number of diastereoisomers is large and their separation is not possible. By having positive-ion MALDI-TOF in the reflectron mode, determination of (+)-catechin, (-)-epicatechin oligomers, and their galloylated derivatives up to a heptamer in grape seed extracts as sodium adducts [M+Na]+ is possible... 

MW of the terminal catechin unit, c degree of polymerization, g number of galloyl ester, 23 Na atomic mass (Krueger et al., 2000). 

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