Catechin documents

Catechins and proanthocyanidins have a documented antiviral activity. Catechins from an extract of Cocos nucifera husk fibre exhibited a strong inhibitory activity against acyclovir-resistant herpes simplex virus type 1 (HSV-l-ACVr) [62]. The use of 10 to 20ngml of ECG and EGCG has been reported to cause 50% inhibition of human immunodeficiency virus reverse transcriptase [89], while Kara and Nakayama [90] reported that a patented chewing gum containing tea catechins is claimed to prevent viral infections against influenza and to inhibit dissemination of this virus. 

Jam, confectionery, and herb compositional data are presented in Table 4.12. Honey contains low levels of both flavonols and flavones, and the presence of the flavanone naringenin has also been documented. Fruit jams also contain low levels of flavonols and catechins, which generally reflect the flavonoid profile of the whole fruit. 

TMS production involves one specific functional group (-OH, -COOH, =NH, -NH2, or -SH), which loses an activated hydrogen and is replaced by a trimethylsilyl group (Proestos et ah, 2006). To achieve silylation, some authors have used BSTFA (N,0-hA(trimethyl-silyl)trifluoroacetamide) and TMCS (trimethylchlorosilane) successfully in several matrices (e.g. aromatic plants, cranberry fixiit) (Zuo et ah, 2002 Proestos et ah, 2006). Using silylated derivatives is advantageous for several reasons phenols and carboxylic acids are prone to silylation, these compounds can be derivatized in the same part of the process, and the minor products do not impede analysis and are well documented (Little, 1999 Stalikas, 2008). A two-step methylation procedure was used to analyze catechins and tannins in plant extracts. The first step used trimethylsilyl diazomethane (TMS-diazomethane) to pre-methylate the sample, and the second step used thermally assisted hydrolysis and methylation (THM). The pre-methylation step with TMS-diazomethane stabilized the dimer molecule m/z 540) by minimizing isomerization and reducing reactivity. (Shadkami et ah, 2009). 

Further studies are necessary to evaluate and document the observed weight-reducing action of green tea extract, especially in patients with a severe obesity problem. Further studies on the effects of tea catechins on the metabolism of catecholic hormones and their related diseases are warranted. The potential interactions between EGCG and catecholic hormones or drugs should also be considered." Further studies are required to determine the best dosage for tea consumption. Pure components in... 

The American cranberry (Vaccinium macrocarpon Ait (Ericaceae)) was used by North-American Indians to fight urinary tract infections and other bacterial diseases. Proanthocyanidins, present in cranberries as oligomers of catechin and epicatechin, inhibit the docking of bacteria on tissues in vitro an anti-adhesive mechanism of cranberry-proanthocyanidins (Howell et al. 2001). The efficacy of cranberry juice and extracts as a prophylactic agent against recurrent urinary infections is well documented in women (Stothers 2002). The anti-adhesion effect of cranberry-proanthocyandins can also be applied for treatment of other common diseases of bacterial pathogenesis, e.g. Helicobacter py/on-associated gastritis and dental caries/periodontal disease (Nowack 2007). 

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