Gallocatechin gallate

Gallocatechin gallate (GCG) is the ester of gallocatechin and gallic acid and a type of catechin. It is an epimer of epigallocatechin gallate (EGCG).

Gallocatechin gallate

Names
Other names (-)-Gallocatechin gallate (2S,3R)-2-(3,4,5-Trihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol 3-(3,4,5-trihydroxybenzoate)
Identifiers
CAS Number	5127-64-0^N
3D model (JSmol)	Interactive image
ChEBI	CHEBI:156271
ChemSpider	172662^N
PubChem CID	199472
UNII	0C056HB16M^N
InChI InChI=1S/C22H18O11/c23-10-5-12(24)11-7-18(33-22(31)9-3-15(27)20(30)16(28)4-9)21(32-17(11)6-10)8-1-13(25)19(29)14(26)2-8/h1-6,18,21,23-30H,7H2/t18-,21+/m1/s1^N Key: WMBWREPUVVBILR-NQIIRXRSSA-N^N InChI=1/C22H18O11/c23-10-5-12(24)11-7-18(33-22(31)9-3-15(27)20(30)16(28)4-9)21(32-17(11)6-10)8-1-13(25)19(29)14(26)2-8/h1-6,18,21,23-30H,7H2/t18-,21+/m1/s1 Key: WMBWREPUVVBILR-NQIIRXRSBC
SMILES C1[C@H]([C@@H](OC2=CC(=CC(=C21)O)O)C3=CC(=C(C(=C3)O)O)O)OC(=O)C4=CC(=C(C(=C4)O)O)O
Properties
Chemical formula	C22H18O11
Molar mass	458.372 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is ^YN ?)
Infobox references

In a high temperature environment, an epimerization change is likely to occur, because heating results in the conversion from EGCG to GCG.[1] According to the referenced study the resulting GCG (the epimer of EGCG) results in even lower dietary cholesterol absorption than occurs with EGCG. While this may be a beneficial outcome with respect to cholesterol reduction activity, for those wishing to maximize the EGCG content of green tea infusions, it is still appropriate to use high temperatures, as long as it is taking into account that extreme conditions will lead to small reductions in total EGCG, for example a 12.4% reduction in total EGCG when heated for 30 minutes straight at 100 degrees Celsius.[2]

References

1. Ikeda, Ikuo; Kobayashi, Makoto; Hamada, Tadateru; Tsuda, Koichi; Goto, Hitomi; Imaizumi, Katsumi; Nozawa, Ayumu; Sugimoto, Akio; Kakuda, Takami (2003). "Heat-Epimerized Tea Catechins Rich in Gallocatechin Gallate and Catechin Gallate Are More Effective to Inhibit Cholesterol Absorption than Tea Catechins Rich in Epigallocatechin Gallate and Epicatechin Gallate". Journal of Agricultural and Food Chemistry. 51 (25): 7303–7. doi:10.1021/jf034728l. PMID 14640575.
2. Wang, Rong; Zhou, Weibiao; Jiang, Xiaohui (2008). "Reaction Kinetics of Degradation and Epimerization of Epigallocatechin Gallate (EGCG) in Aqueous System over a Wide Temperature Range". Journal of Agricultural and Food Chemistry. 56 (8): 2694–701. doi:10.1021/jf0730338. PMID 18361498.