|Preferred IUPAC name
|Molar mass||458.37 g·mol−1|
|soluble (33.3-100 g/L)[vague]|
|Solubility||soluble in ethanol, DMSO, dimethyl formamide at about 20 g/l|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
It is found in high content in the dried leaves of white tea (4245 mg per 100 g), green tea (7380 mg per 100 g) and, in smaller quantities, black tea. During black tea production, the catechins are mostly converted to theaflavins and thearubigins. via polyphenol oxidases.[which?]
Research on potential therapeutic uses
|This section is outdated. (January 2015)|
EGCG has been the subject of a number of basic research studies investigating its potential use as a therapeutic for a broad range of disorders. As of January 2015, however, these effects remain unsubstantiated in humans and there are no approved health claims for EGCG in the United States or Europe. The US Food and Drug Administration has issued warning letters against marketers of products claiming that EGCG provides anti-disease effects or overall health benefits.
A large amount of research has been conducted investigating the benefit of EGCG from green tea in the treatment of HIV infection, where EGCG has been shown to reduce plaques related to AIDS-related dementia in the laboratory, as well as block gp120. However, these effects have yet to be confirmed in live human trials, and it does not imply that green tea will cure or block HIV infection. The concentrations of EGCG used in the studies could not be reached by drinking green tea.
There is evidence from rodent and in vitro studies that EGCG may be useful in preventing or treating various gastrointestinal, prostate, and other cancers. However, the dose needed for effectiveness is high, (far higher than is obtainable through drinking tea) and so companies and academic groups have focused on developing novel analogs or combinations to improve the potential for EGCG to be useful in treating or preventing cancer.
In vitro research
In preliminary laboratory research, EGCG is an inhibitor of various enzymes:
- Histone acetyltransferase
- DNA methyltransferase
- Fatty acid synthase
- Glutamate dehydrogenase
- Topoisomerase I and II
- Aromatic L-amino acid decarboxylase
In a high temperature environment[quantify], an epimerization change is more likely to occur[further explanation needed]; however as exposure to boiling water for 30 straight minutes leads to only a 12.4% reduction in the total amount of EGCG, the amount lost in a brief exposure is insignificant. In fact, even when special conditions were used to create temperatures well above that of boiling water, the amount lost increased only slightly.
A study using mouse models at the University of Southern California showed that EGCG binds with the anti-cancer drug Velcade, significantly reducing its bioavailability and thereby rendering it therapeutically useless. Schönthal, who headed the study, suggests that consumption of green tea and GTE products be strongly contraindicated for patients undergoing treatment for multiple myeloma and mantle cell lymphoma. EGCG may reduce the bioavailability of the drug sunitinib when they are taken together. EGCG was also found to induce apoptosis in endometrial carcinoma cell line (Ishikawa cells and human primary endometrial carcinoma cells) via ROS generation and p-38 activation.2012 Manohar et al., J Nutr Biochem. 2012 Sep 5 [Epub ahead of print]
EGCG may have carcinogenic potential. EGCG was, among other tea polyphenols, found to be a strong topoisomerase inhibitor, similar to some chemotherapeutic anticancer drugs, for example, etoposide and doxorubicin. This property might be responsible for observed anticarcinogenic effects; however, there is also a carcinogenic potential. High intake of polyphenolic compounds during pregnancy is suspected to increase risk of neonatal leukemia. Bioflavonoid supplements should not be used by pregnant women. Maternal consumption of tea or coffee during pregnancy may elevate the risk of childhood malignant central nervous system (CNS) tumours through unknown mechanisms.
A study in mice found that a high dose of EGCG raises ALT levels considerably.
|Retention time||34.5 min (C18 RP, Acetonitrile 80%)|
|Lambda-max||274 and 240 nm (see picture)|
|Major absorption bands||cm−1|
|Other NMR data|
|ESI-MS [M+H]+ m/z : 459|
- Proteasome inhibitor
- Health benefits of tea
- Phenolic content in tea
- Green tea extract
- List of phytochemicals in food
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