Epigallocatechin gallate

From Wikipedia, the free encyclopedia
  (Redirected from (-)-Epigallocatechin gallate)
Jump to: navigation, search
Epigallocatechin gallate
Structural formula of epigallocatechin gallate
Space-filling model of the epigallocatechin gallate molecule
Names
IUPAC name
[(2R,3R)-5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)chroman-3-yl] 3,4,5-trihydroxybenzoate
Preferred IUPAC name
(2R,3R)-5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3-yl 3,4,5-trihydroxybenzoate
Other names
(-)-Epigallocatechin gallate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.111.017
MeSH Epigallocatechin+gallate
Properties
C22H18O11
Molar mass 458.372 g/mol
Appearance
soluble (33.3-100 g/L)[vague][1]
Solubility soluble in ethanol, DMSO, dimethyl formamide[1] at about 20 g/l[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin.

EGCG, the most abundant catechin in tea, is a polyphenol under basic research for its potential to affect human health and disease. EGCG is used in many dietary supplements.

Food sources[edit]

Tea[edit]

It is found in high content in the dried leaves of green tea (7380 mg per 100 g), white tea (4245 mg per 100 g), and in smaller quantities, black tea.[3] During black tea production, the catechins are mostly converted to theaflavins and thearubigins via polyphenol oxidases.[which?][4]

Other[edit]

Trace amounts are found in apple skin, plums, onions, hazelnuts, pecans, and carob powder (at 109 mg per 100 g).[3]

Bioavailability[edit]

When taken orally, EGCG has poor absorption even at daily intake equivalent to 8–16 cups of green tea, an amount causing adverse effects such as nausea or heartburn.[5] After consumption, EGCG blood levels peak within 1.7 hours.[6] The absorbed plasma half-life is ~5 hours,[6] but with majority of unchanged EGCG excreted into urine over 0 to 8 hours.[6] Methylated metabolites appear to have longer half-lives and occur at 8-25 times the plasma levels of unmetabolized EGCG.[7]

Research[edit]

Well-studied in basic research, EGCG has various biological effects in laboratory studies.[8][9][10][11]

As of 2014, seventeen clinical trials were ongoing, studying EGCG in numerous clinical conditions.[8] A 2011 analysis by the EFSA found that a cause and effect relationship could not be shown for a link between tea catechins and reduction of LDL.[12]

Regulation[edit]

Over 2008 to 2017, the US Food and Drug Administration issued several warning letters to manufacturers of dietary supplements containing EGCG for violations of the Federal Food, Drug, and Cosmetic Act.[13][14][15][16] The warnings were issued because the products had not been established as safe and effective for their marketed uses and were promoted as "new drugs", without approval as required under the Act.[16]

See also[edit]

References[edit]

  1. ^ a b "(-)-Epigallocatechin gallate". Chemicalland21.com. 
  2. ^ "Product Information: (-)-Epigallocatechin Gallate" (PDF). Cayman Chemical. 4 September 2014. 
  3. ^ a b Bhagwat, Seema; Haytowitz, David B.; Holden, Joanne M. (September 2011). USDA Database for the Flavonoid Content of Selected Foods, Release 3 (PDF) (Report). Agricultural Research Service, U.S. Department of Agriculture. Retrieved 18 May 2015. 
  4. ^ Lorenz, Mario; Urban, Janka; Engelhardt, Ulrich; Baumann, Gert; Stangl, Karl; Stangl, Verena (January 2009). "Green and Black Tea are Equally Potent Stimuli of NO Production and Vasodilation: New Insights into Tea Ingredients Involved". Basic Research in Cardiology. 104 (1): 100–110. doi:10.1007/s00395-008-0759-3. PMID 19101751. (Subscription required (help)). 
  5. ^ Chow, H-H. Sherry; Cai, Yan; Hakim, Iman A.; Crowell, James A.; Shahi, Farah; Brooks, Chris A.; Dorr, Robert T.; Hara, Yukihiko; Alberts, David S. (15 August 2003). "Pharmacokinetics and safety of green tea polyphenols after multiple-dose administration of epigallocatechin gallate and polyphenon E in healthy individuals". Clinical Cancer Research. 9 (9): 3312–3319. PMID 12960117. 
  6. ^ a b c Lee, Mao-Jung; Maliakal, Pius; Chen, Laishun; Meng, Xiaofeng; Bondoc, Flordeliza Y.; Prabhu, Saileta; Lambert, George; Mohr, Sandra; Yang, Chung S. (October 2002). "Pharmacokinetics of tea catechins after ingestion of green tea and (-)-epigallocatechin-3-gallate by humans: formation of different metabolites and individual variability". Cancer Epidemiology, Biomarkers and Prevention. 11 (10 Pt 1): 1025–1032. PMID 12376503. 
  7. ^ Manach, C; Williamson, G; Morand, C; Scalbert, A; Rémésy, C (January 2005). "Bioavailability and bioefficacy of polyphenols in humans. I. Review of 97 bioavailability studies". The American Journal of Clinical Nutrition. 81 (1 Suppl): 230S–242S. PMID 15640486. 
  8. ^ a b Fürst, Robert; Zündorf, Ilse (May 2014). "Plant-derived anti-inflammatory compounds: hopes and disappointments regarding the translation of preclinical knowledge into clinical progress". Mediators of Inflammation. 2014: 1–9. doi:10.1155/2014/146832. PMC 4060065Freely accessible. PMID 24987194. 146832. 
  9. ^ Granja, Andreia; Frias, Iúri; Neves, Ana Rute; Pinheiro, Marina; Reis, Salette (2017). "Therapeutic Potential of Epigallocatechin Gallate Nanodelivery Systems". BioMed Research International. 2017: 1–15. doi:10.1155/2017/5813793. ISSN 2314-6133. 
  10. ^ Wu, Dayong; Wang, Junpeng; Pae, Munkyong; Meydani, Simin Nikbin (2012). "Green tea EGCG, T cells, and T cell-mediated autoimmune diseases". Molecular Aspects of Medicine. 33 (1): 107–118. doi:10.1016/j.mam.2011.10.001. ISSN 0098-2997. 
  11. ^ Riegsecker, Sharayah; Wiczynski, Dustin; Kaplan, Mariana J.; Ahmed, Salahuddin (2013). "Potential benefits of green tea polyphenol EGCG in the prevention and treatment of vascular inflammation in rheumatoid arthritis". Life Sciences. 93 (8): 307–312. PMC 3768132Freely accessible. PMID 23871988. 
  12. ^ EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies) (2011). "Scientific Opinion on the substantiation of health claims related to Camellia sinensis (L.) Kuntze (tea), including catechins in green tea, and improvement of endothelium-dependent vasodilation (ID 1106, 1310), maintenance of normal blood pressure". EFSA Journal. European Food Safety Authority. 9 (4): 2055. doi:10.2903/j.efsa.2011.2055. 
  13. ^ "Sharp Labs Inc: Warning Letter". Inspections, Compliance, Enforcement, and Criminal Investigations. Food and Drug Administration. 9 July 2008. Retrieved 15 September 2015. 
  14. ^ "Fleminger Inc.: Warning Letter". Inspections, Compliance, Enforcement, and Criminal Investigations. Food and Drug Administration. 22 February 2010. Retrieved 6 January 2015. 
  15. ^ "N.V.E. Pharmaceuticals, Inc.: Warning Letter". Inspections, Compliance, Enforcement, and Criminal Investigations. Food and Drug Administration. 22 July 2013. Retrieved 30 September 2017. 
  16. ^ a b "LifeVantage Corporation: Warning Letter". Inspections, Compliance, Enforcement, and Criminal Investigations. Food and Drug Administration. 17 April 2017. Retrieved 30 September 2017.