ECGEpicatechin-3-O-gallate

Formula

C₂₂H₁₈O₁₀

Molar mass

442.40 g·mol⁻¹

CAS

1257-08-5

PubChem CID

107905

Origin

A natural constituent of tea leaves, where it accompanies epigallocatechin gallate and epigallocatechin among the major catechins. It is also present in other tannin-rich plants. It is extracted from tea and produced as a research reagent and as a food supplement ingredient.

InChIKey

LSHVYAFMTMFKBA-TZIWHRDSSA-N

Editorial estimate, not clinical.

Epicatechin-3-O-gallate is one of the major catechins of tea, alongside epigallocatechin gallate and epigallocatechin. Korte and colleagues asked in 2010 whether the anti-inflammatory, neuroprotective and appetite-reducing activity attributed to catechins could pass through a cannabimimetic action, and measured by radioligand competition the affinity of five of them for recombinant human cannabinoid receptors. Three proved to be ligands of the CB1 receptor of moderate affinity: epigallocatechin gallate with an inhibition constant of 33.6 micromolar, epigallocatechin with 35.7 micromolar, and epicatechin gallate with 47.3 micromolar. Binding to the CB2 receptor proved weaker, with constants above 50 micromolar. The epimers lacking galloylation, catechin and epicatechin, proved of negligible affinity, which designates the gallic ester and the number of hydroxyls of the B ring as the determinants of recognition. Reading those figures calls for restraint. An inhibition constant of several tens of micromolar is three to four orders of magnitude above that of the classical cannabinoid ligands, and the plasma concentrations attained after drinking tea are counted in nanomolar or submicromolar. The authors themselves conclude that the peripheral route is unlikely to contribute in vivo. This entry therefore describes a real and measured interaction, not a dietary mechanism of action.

An esterified flavan-3-ol. The phenylpropanoid route leads first to the flavanone naringenin, then to the dihydroflavonols and finally to the flavan-3-ols by reduction. The product obtained is then esterified on the hydroxyl at position 3 by gallic acid, a galloylation reaction that characterises this subfamily and appreciably increases the mass and the number of phenolic functions. The route is proper to plants and unrelated to that of the cannabinoids.

Sources: EUR-Lex, UNODC, CND, ANSM, IUPHAR/BPS, ChEBI, EUDA. Our method.

Class

ECS modulator (research)

Origin

A natural constituent of tea leaves, where it accompanies epigallocatechin gallate and epigallocatechin among the major catechins. It is also present in other tannin-rich plants. It is extracted from tea and produced as a research reagent and as a food supplement ingredient.

Status

Unscheduled

1. 1.Korte et coll. 2010 : affinité des catéchines du thé pour les récepteurs cannabinoïdes humainsPMID 19897346