1- 0-galloyl

Galloyl castalagin (hydrolysable tannin) Genistein (= Genisteol Prunetol Sophoricol 4, 5,7-Trihydroxyisoflavone) (isoflavone)... 

O-Cinnamoyl-1 -0-galloyl-)5-D-glucoside Rhei rhizoma Polygonaceae 74... 

Dithio Diethiocarboxy —s—s— HSSC— Galloyl or 3,4,5-trihy- 3,4,5-(HO)3CgH2—CO—... 

SAR studies were carried out by de Bruyne et al. [92] on a series of dimeric procyanidins, considered as model compounds for antiviral therapies. On the whole, proanthocyanidins containing EC dimers exhibited more pronounced activity against herpes simplex virus (HSV) and human immunodeficiency virus (HIV), while the presence of ortho-trihydroxyl groups in the B-ring appeared to be essential in all proanthocyanidins exhibiting anti-HSV effects. Galloylation and polymerization reinforced the antiviral activities markedly. 

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. 

The organoleptic properties of black tea depend to a considerable extent on the astringency resulting from the interaction of caffeine with the oxidized galloyl ester of the flavanols. The aroma components of black tea also constitute a unique flavor profile that blends well with the taste of the nonvolatile materials. The caffeine provides a moderate level of stimulation, which adds further to the appeal of the beverage, although tea has been shown to provide relaxation as well as revival of character.119... 

Yamabe N, Kang KS, Park CH, Tanaka T, Yokozawa T. (2009) 7-0-galloyl-D-sedoheptulose is a novel therapeutic agent against oxidative stress and advanced glycation endproducts in the diabetic kidney. Biol Pharm Bull 2il 657-664. 

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

Figure 1. Structure of a gallotannin typical of Chinese gallotannin, found, e.g., in galls of Rhus semialata. Note the characteristic meta-depside linkages of the galloyl residues at C-2.

Figure 2. Structure of an ellagitannin, l-0-galloyl-2,3 4,6-di-0-hexahy-droxydiphenoyl-/ -D-glucose (casuarictin).

Figure 4. Chemical synthesis of galloyl coenzyme A thioester (4). (1) 4-0-/3-D-glucosidogallic acid (2) AT-succinimidyl 4-0-/3 -D-glucosidogallate (3)...

In enzymatic studies with cell-free extracts from higher plants, however, no evidence has been found to date for galloyl-CoA s involvement in the biosynthesis of / -glucogallin, or its higher galloylated derivatives an eventual role in the formation of the chemically different meta-depside bonds of gallotannins has not been investigated. 

O-Galloylglucose (/Tglucogallin) 1-O-Galloyl- glucose 1,6-0-Digalloyl- glucose 54... 

Figure 7. Biosynthetic pathway from / -glucogallin to pentagalloylglucose. The galloyl residue introduced in each individual step is marked by an asterisk as indicated by the dashed arrow, the enzyme catalyzing the step from tri- to tetragalloylglucose has not yet been isolated. /3G, / -Glucogallin Glc, glucose.

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