Catechin
Encyclopedia
Catechin is a natural phenol
antioxidant
plant
secondary metabolite
. The term catechins is also commonly used to refer to the related family of flavonoids and the subgroup flavan-3-ol
s (or simply flavanols).
The name of the catechin chemical family derives from catechu
, which is the juice or boiled extract of Mimosa catechu (Acacia catechu
L.f)
moiety while the B ring is similar to a catechol moiety. There are two chiral
centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in trans configuration and are called catechin and the other two are in cis configuration and are called epicatechin.
The most common catechin isomer is the (+)-catechin. The other stereoisomer is (-)-catechin or ent-catechin. The most common epicatechin isomer is (-)-epicatechin (also known under the names L-epicatechin, epicatechol, (-)-epicatechol, l-acacatechin, l-epicatechol, epi-catechin, 2,3-cis-epicatechin or (2R,3R)-(-)-epicatechin).
The different epimers can be distinguished using chiral column chromatography
.
Making reference to no particular isomer, the molecule can just be called catechin. Mixtures of the different enantiomers can be called (+/-)-catechin or DL-catechin and (+/-)-epicatechin or DL-epicatechin.
Moreover, the flexibility of the C-ring allows for two conformation isomers
, putting the B ring either in a pseudoequatorial position (E conformer) or in a pseudoaxial position (A conformer). Studies confirmed that (+)-catechin adopts a mixture of A- and E-conformers in aqueous solution and their conformational equilibrium has been evaluated to be 33:67.
Regarding the antioxidant activity, (+)-catechin has been found to be the most powerful scavenger between different members of the different classes of flavonoids. The ability to quench singlet oxygen seems to be in relation with the chemical structure of catechin, with the presence of the catechol moiety on ring B and the presence of a hydroxyl group activating the double bond on ring C.
Catechin exists in the form of a glycoside
. Antioxidant properties can also be provided using a catechin associated with a sugar. In 1975-76, a group of USSR scientists of Kaz ssr discovered first the catechin rhamnoside using the plants of Filipendula
that grow in that region. Pioneer and head of the discovery was PhD N. D. Storozhenko born in 1944. Though not thoroughly studied, the rhamnoside
of catechin can enter the blood cell without breaking the outer layer.
groups and the oxidation is pH-dependent. The oxidation of the catechol 3′,4′-dihydroxyl electron-donating groups occurs first, at very low positive potentials, and is a reversible reaction. The hydroxyl groups of the resorcinol moiety oxidised afterwards were shown to undergo an irreversible oxidation reaction.
. Potentilla fragarioides
, also used in traditional Chinese medicine, contains D-catechin.
A racemic mixture of (+)-catechin and (-)-catechin is released from the roots of the invasive weed, Centaurea maculosa
, the spotted knapweed. It acts as an herbicide to inhibit competition by a wide range of other plant species. This phytotoxic compound inhibits seed germination and growth.
, a related species, contains epicatechin and D-catechin. Açaí oil
, obtained from the fruit of tha açaí palm (Euterpe oleracea), is rich in (+)-catechin (66.7 +/- 4.8 mg/kg).
, nor exactly bitter. It is envisaged to encapsulate catechin in cyclodextrin
s to mask its taste to use it as an additive
.
to produce (+)-catechin and is the first enzyme in the proanthocyanidins (PA)-specific pathway. Its activity has been measured in leaves, flowers, and seeds of the legumes Medicago sativa, Lotus japonicus
, Lotus uliginosus
, Hedysarum sulfurescens, and Robinia pseudoacacia. The enzyme is also present in Vitis vinifera
(grape).
Among bacteria, degradation of (+)-catechin can be achieved by Acinetobacter calcoaceticus
. Catechin is metabolized to protocatechuic acid
(PCA) and phloroglucinol carboxylic acid
(PGCA). It is also degraded by Bradyrhizobium japonicum
. Phloroglucinol carboxylic acid is further decarboxylated to phloroglucinol
, which is dehydroxylated to resorcinol
. Resorcinol is hydroxylated to hydroxyquinol
. Protocatechuic acid and hydroxyquinol undergo intradiol
cleavage through protocatechuate 3,4-dioxygenase
and hydroxyquinol 1,2-dioxygenase
to form β-carboxy cis, cis-muconic acid and maleyl acetate.
Among fungi, degradation of catechin can be achieve by Chaetomium cupreum
.
In rats, all plasma catechin metabolites are present as conjugated forms and mainly constituted by glucuronidated
derivatives. In the liver, the concentrations of catechin derivatives are lower than in plasma, and no accumulation is observed when the rats are adapted for 14 days to the supplemented diets. The hepatic metabolites are intensively methylated (90–95%), but in contrast to plasma, some free aglycones can be detected. Rats fed with (+)-catechin and (-)-epicatechin exhibit (+)-catechin 5-O-β-glucuronide and (-)-epicatechin 5-O-β-glucuronide in their body fluids. The primary metabolite of (+)-catechin in plasma is glucuronide in the nonmethylated form. In contrast, the primary metabolites of (-)-epicatechin in plasma are glucuronide and sulfoglucuronide in nonmethylated forms, and sulfate in the 3'-O-methylated forms (3'OMC). Catechin is absorbed into intestinal cells and metabolized extensively because no native catechin can be detected in plasma from the mesenteric vein. Mesenteric plasma contains glucuronide conjugates of catechin and 3'-O-methyl catechin, indicating the intestinal origin of these conjugates. Additional methylation and sulfation occur in the liver, and glucuronide or sulfate conjugates of 3'OMC are excreted extensively in bile. Circulating forms are mainly glucuronide conjugates of catechin and 3'OMC. Another study shows that catechin undergoes enzymatic oxidation by tyrosinase
in the presence of glutathione
(GSH) to form mono-, bi-, and tri-glutathione conjugates of catechin and mono- and bi-glutathione conjugates of a catechin dimer.
In the crab eating macaque
Macaca iris, (+)-catechin administered orally or intraperitonally leads to the formation of 10 metabolites and notably to m-hydroxyphenylhydracrylic acid excreted in the urine.
In man, (+)-catechin absorbed orally is metabolized largely within 24 hours with the production of eleven metabolites detected in the urine.
by a two-step oxidation can be achieved by Burkholderia
sp.
The laccase
/ABTS
system oxidizes (+)-catechin to oligomeric products of which proanthocyanidin A2
is a dimer.
(+)-Catechin and (-)-epicatechin are transformed by the endophytic filamentous fungus Diaporthe
sp. into the 3,4-cis-dihydroxyflavan derivatives, (+)-(2R,3S,4S)-3,4,5,7,3',4'-hexahydroxyflavan (leucocyanidin) and (-)-(2R,3R,4R)-3,4,5,7,3',4'-hexahydroxyflavan, respectively, whereas (-)-catechin and (+)-epicatechin with a 2S-phenyl group resisted the biooxidation.
Leucoanthocyanidin reductase
(LAR) uses (2R,3S)-catechin, NADP+ and H2O to produce 2,3-trans-3,4-cis-leucocyanidin
, NADPH, and H+. Its gene expression has been studied in developing grape berries and grapevine leaves.
Catechin and epicatechin are the building blocks of the proanthocyanidin
s, a type of condensed tannin.
in the nematode worm Caenorhabditis elegans
. Transcriptomic studies shows that catechin reduces atherosclerotic
lesion development in apo E
-deficient mice
. (+)- and (−)-catechin seem to have stereospecific opposite effects on glycogen
metabolism in isolated rat hepatocyte
s. (+)-Catechin inhibits intestinal tumor formation in mice.
(+)-Catechin inhibits the oxidation of low density lipoprotein
.
(-)-Catechin suppresses expression of Kruppel-like factor 7
.
Catechin shows an enhancement of the antifungal effect of amphotericin B
against Candida albicans
.
Incubation experiments with (+)-catechin show a prevention of human plasma oxidation.
, IL1B
, CAT
, CYP1A1
, SOD
, BAX
, CASP3, MAPK1
, MAPK3
and S100B
human genes.
PTGS2 (aka COX-2 for cyclooxygenase-2) is a dioxygenase
. The presence of catechin seems to increase its expression.
IL1B induces the formation of cyclooxygenase-2 (PTGS2/COX2). Catechin increases its expression.
CAT is a catalase. Catechin decreases its expression.
CYP1A1 (Cytochrome P450, family 1, member A1) is an enzyme implied in the metabolism of xenobiotic
s. Catechin decreases its expression.
SOD (Superoxide dismutase) is an enzyme that catalyzes the dismutation of superoxide into oxygen and hydrogen peroxide. Catechin increases its expression.
BAX (Bcl-2–associated X protein) is a protein of the Bcl-2 gene family. It promotes apoptosis by competing with Bcl-2 proper. Catechin increases its expression.
CASP3 (Caspase 3) is a protein that plays a central role in the execution-phase of cell apoptosis. Catechin increases its expression.
MAPK1 (Mitogen-activated protein kinase 1) and MAPK3 (Mitogen-activated protein kinase 3) are enzymes that are extracellular signal-regulated kinases (ERKs) and act as an integration point for multiple biochemical signals, involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation, and development. Catechin seems to increase their expression.
S100B (S100 calcium binding protein B) is an pro-inflammatory enzyme specific of mature astrocytes that ensheath the blood vessels. Catechin decreases the expression of the gene and could regulate S100B-activated oxidant stress-sensitive pathways through blocking p47phox protein expression. Treatment with catechin could eliminate reactive oxygen species (ROS) to reduce oxidative stress stimulated by S100B. Catechin decreases its expression.
Experiments on human Caco-2
cells show changes in the expression of genes like STAT1
, MAPKK1, MRP1 and FTH1
genes, which are involved in the cellular response to oxidative stress, are in agreement with the antioxidant properties of catechin. In addition, the changes in the expression of genes like C/EBPG, topoisomerase 1, MLF2 and XRCC1
suggest novel mechanisms of action at the molecular level.
Detail for all tested genes :
(dec : decreased expression, inc : increased expression, = : does not affect the activity, expression assayed in human if not specified otherwise)
ABCG2
: (-)-catechin decreases the expression of ABCG2
ACE
(in Rattus norvegicus) : (+)-catechin or (-)-epicatechin do not affect the activity of the angiotensin-converting enzyme
ACTB (in Rattus norvegicus) decrease
AKT1
decrease
ANXA2 increase
ARHGAP4
decrease
ATF4
increase
BAT2
increase
BAX
(rattus norvegicus) increase
BCL2 decrease
BRCC3
decrease
BTG1
increase
CASP3 increase
CAT
(mus musculus) decrease
CCL2
increase
CCND1 decrease
CD81
increase
CD9
increase
CEBPG
increase
CXCL10
increase
CYP19A1 (rattus norvegicus) increase
CYP1A1
decrease
CYP1A2
=
DEK
decrease
DFFA
(mus musculus) decrease
DNMT1
decrease
EWSR1 increase
FLT3LG
decrease
FTH1
increase
GRN
increase
HCFC1 increase
HEAB decrease
HMOX1
increase
HOXD3
increase
HSPD1 decrease
ICAM1 increase
IL10
increase
IL1B
increase
IL2RA
decrease
IL32 decrease
IRF4
decrease
ITGAL increase
ITGB2 increase
LYN
decrease
MAP2K1
decrease ?
MAPK1
increase ?
MAPK3
increase ?
MIF
decrease
NCF1
?
NFE2L2
increase
NFKBIA decrease
NOS2 (mus musculus) increase
NOTCH1
increase
NPM1
decrease
PARP1
(mus musculus) increase
PECAM1 increase
PLAT
increase
PLAU
increase
PON1
=
PTGS2
increase?
RAC1
decrease
RARB
decrease
RELA
decrease
RPL6
increase
S100B
decrease
SERPINE1 decrease
SF1
decrease
SLC20A1
increase
SOD
(Drosophila melanogaster) increase
SOD2
(Drosophila melanogaster) increase
STAT1
decrease
STAT5B
increase
STAT6
increase
SULT1A1
increase : sulfation of catechin
TCF7
increase
TK1
decrease
TNF
increase
TNFRSF8 decrease
TOP1 decrease
TOP2A
decrease
TRP53 increase
XCR1
decrease
ZNF593
increase
While most treatments against stroke in humans have to be given within a two- to three-hour time window to be effective, epicatechin appeared to limit further neuronal damage when given to mice 3.5 hours after a stroke. Given six hours after a stroke, however, the compound offered no protection to brain cells.
inhibitor. Thus, it inhibits the conversion of histidine to histamine, and, so, is thought to be beneficial through reduction of potentially damaging, histamine-related local immune response(s).
s (MAOIs) of type MAO-B
. They could be used as part of the treatment of Parkinson's and Alzheimer's patients.
It is released into the ground by some plants to hinder the growth of their neighbors, a form of allelopathy
. Centaurea maculosa
, the spotted knapweed, is the most studied plant showing this behaviour, catechin isomers, both released into the ground through its root exudates, have effects ranging from antibiotic
to herbicide
. It causes a reactive oxygen species
wave through the target plant's root starting in the apical meristem
rapidly followed by a Ca2+ spike that kills the root cells through apoptosis. Most plants in the European ecosystem have defenses against catechin, but few plants are protected against it in the North-American ecosystem where Centaurea maculosa
has been introduced causing uncontrolled growth of this weed.
(+)-Catechin acts as an infection-inhibiting factor in strawberry leaf. Epicatechin and catechin may prevent coffee berry disease by inhibition of appressorial
melanization of Colletotrichum kahawae
.
s to air conditioners or to air purifier
s.
Natural phenol
Natural phenols, bioavailable phenols, plant phenolics, low molecular weight phenols or phenoloids are a class of natural products. They are small molecules containing one or more phenolic group. These molecules are smaller in size than polyphenols, containing less than 12 phenolic groups...
antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
secondary metabolite
Secondary metabolite
Secondary metabolites are organic compounds that are not directly involved in the normal growth, development, or reproduction of an organism. Unlike primary metabolites, absence of secondary metabolities does not result in immediate death, but rather in long-term impairment of the organism's...
. The term catechins is also commonly used to refer to the related family of flavonoids and the subgroup flavan-3-ol
Flavan-3-ol
Flavan-3-ols are a class of flavonoids that use the 2-phenyl-3,4-dihydro-2H-chromen-3-ol skeleton. These compounds include the catechins and the catechin gallates....
s (or simply flavanols).
The name of the catechin chemical family derives from catechu
Catechu
For the region in India, see Kutch District.Catechu is an extract of any of several species of Acacia—but especially Acacia catechu—produced by boiling the wood in water and evaporating the resulting brew....
, which is the juice or boiled extract of Mimosa catechu (Acacia catechu
Acacia catechu
Acacia catechu also commonly called Mimosa catechu, is a deciduous, thorny tree which grows up to in height. The plant is called khair in Hindi, and kachu in Malay, hence the name was Latinized to "catechu" in Linnaean taxonomy, as the type-species from which the extracts cutch and catechu are...
L.f)
Chemistry
Catechin possesses two benzene rings (called the A- and B-rings) and a dihydropyran heterocycle (the C-ring) with a hydroxyl group on carbon 3. The A ring is similar to a resorcinolResorcinol
Resorcinol is a dihydroxy benzene. It is the 1,3-isomer of benzenediol with the formula C6H42.-Nomenclature:Benzene-1,3-diol is the name recommended by the International Union of Pure and Applied Chemistry in its 1993 Recommendations for the Nomenclature of Organic Chemistry.-Production:It is...
moiety while the B ring is similar to a catechol moiety. There are two chiral
Chirality (chemistry)
A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom....
centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in trans configuration and are called catechin and the other two are in cis configuration and are called epicatechin.
The most common catechin isomer is the (+)-catechin. The other stereoisomer is (-)-catechin or ent-catechin. The most common epicatechin isomer is (-)-epicatechin (also known under the names L-epicatechin, epicatechol, (-)-epicatechol, l-acacatechin, l-epicatechol, epi-catechin, 2,3-cis-epicatechin or (2R,3R)-(-)-epicatechin).
The different epimers can be distinguished using chiral column chromatography
Chiral column chromatography
Chiral column chromatography is a variant of column chromatography in which the stationary phase contains a single enantiomer of a chiral compound rather than being achiral...
.
Making reference to no particular isomer, the molecule can just be called catechin. Mixtures of the different enantiomers can be called (+/-)-catechin or DL-catechin and (+/-)-epicatechin or DL-epicatechin.
Moreover, the flexibility of the C-ring allows for two conformation isomers
Conformational isomerism
In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted exclusively by rotations about formally single bonds...
, putting the B ring either in a pseudoequatorial position (E conformer) or in a pseudoaxial position (A conformer). Studies confirmed that (+)-catechin adopts a mixture of A- and E-conformers in aqueous solution and their conformational equilibrium has been evaluated to be 33:67.
Regarding the antioxidant activity, (+)-catechin has been found to be the most powerful scavenger between different members of the different classes of flavonoids. The ability to quench singlet oxygen seems to be in relation with the chemical structure of catechin, with the presence of the catechol moiety on ring B and the presence of a hydroxyl group activating the double bond on ring C.
Catechin exists in the form of a glycoside
Glycoside
In chemistry, a glycoside is a molecule in which a sugar is bound to a non-carbohydrate moiety, usually a small organic molecule. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme...
. Antioxidant properties can also be provided using a catechin associated with a sugar. In 1975-76, a group of USSR scientists of Kaz ssr discovered first the catechin rhamnoside using the plants of Filipendula
Filipendula
Filipendula is a genus of 12 species of perennial herbaceous flowering plants in the family Rosaceae, native to the temperate regions of the Northern Hemisphere. Well-known species include Meadowsweet and Dropwort , both native to Europe, and Queen-of-the-forest and Queen-of-the-prairie...
that grow in that region. Pioneer and head of the discovery was PhD N. D. Storozhenko born in 1944. Though not thoroughly studied, the rhamnoside
Rhamnose
Rhamnose is a naturally occurring deoxy sugar. It can be classified as either a methyl-pentose or a 6-deoxy-hexose. Rhamnose occurs in nature in its L-form as L-rhamnose . This is unusual, since most of the naturally occurring sugars are in D-form...
of catechin can enter the blood cell without breaking the outer layer.
Oxidation
Electrochemical experiments show that (+)-catechin oxidation mechanism proceeds in sequential steps, related with the catechol and resorcinolResorcinol
Resorcinol is a dihydroxy benzene. It is the 1,3-isomer of benzenediol with the formula C6H42.-Nomenclature:Benzene-1,3-diol is the name recommended by the International Union of Pure and Applied Chemistry in its 1993 Recommendations for the Nomenclature of Organic Chemistry.-Production:It is...
groups and the oxidation is pH-dependent. The oxidation of the catechol 3′,4′-dihydroxyl electron-donating groups occurs first, at very low positive potentials, and is a reversible reaction. The hydroxyl groups of the resorcinol moiety oxidised afterwards were shown to undergo an irreversible oxidation reaction.
Spectral Data
| UV-Vis | |
|---|---|
| Lambda-max: | 276 nm Nanometre A nanometre is a unit of length in the metric system, equal to one billionth of a metre. The name combines the SI prefix nano- with the parent unit name metre .The nanometre is often used to express dimensions on the atomic scale: the diameter... |
| Extinction coefficient Molar absorptivity The molar absorption coefficient, molar extinction coefficient, or molar absorptivity, is a measurement of how strongly a chemical species absorbs light at a given wavelength... (log ε) |
4.01 |
| IR Infrared Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm... |
|
| Major absorption bands | 1600 cm−1(benzene rings) |
| NMR NMR spectroscopy Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained... |
|
| Proton NMR Proton NMR Proton NMR is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. In samples where natural hydrogen is used, practically all of the hydrogen consists of the... (500 MHz, CD3OD): Reference d : doublet, dd : doublet of doublets, m : multiplet, s : singlet |
δ Chemical shift In nuclear magnetic resonance spectroscopy, the chemical shift is the resonant frequency of a nucleus relative to a standard. Often the position and number of chemical shifts are diagnostic of the structure of a molecule... : 2.49 (1H, dd, J = 16.0, 8.6 Hz, H-4a), 2.82 (1H, dd, J = 16.0, 1.6 Hz, H-4b), 3.97 (1H, m, H-3), 4.56 (1H, d, J = 7.8 Hz, H-2), 5.86 (1H, d, J = 2.1 Hz, H-6), 5.92 (1H, d, J = 2.1 Hz, H-8), 6.70 (1H, dd, J = 8.1, 1.8 Hz, H-6′), 6.75 (1H, d, J = 8.1 Hz, H-5′), 6.83 (1H, d, J = 1.8 Hz, H-2′) |
| Carbon-13 NMR Carbon-13 NMR Carbon-13 NMR is the application of nuclear magnetic resonance spectroscopy to carbon. It is analogous to proton NMR and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms... |
|
| Other NMR data | |
| MS Mass spectrometry Mass spectrometry is an analytical technique that measures the mass-to-charge ratio of charged particles.It is used for determining masses of particles, for determining the elemental composition of a sample or molecule, and for elucidating the chemical structures of molecules, such as peptides and... |
|
| Masses of main fragments |
ESI-MS [M+H]+ m/z : 291.0 273 water loss 139 Retro Diels Alder 123 165 147 |
Sources
(+)-catechin and (-)-epicatechin are found in the traditional Chinese medicine plant Uncaria rhynchophyllaUncaria rhynchophylla
Uncaria rhynchophylla or the cat's claw herb is a plant species used in traditional Chinese medicine.-Catechin and -epicatechin are found in the plant as well as the alkaloid rhynchophylline....
. Potentilla fragarioides
Potentilla fragarioides
Potentilla fragarioides is a member of the Rosaceae family that is native to Asia.It is native to China, Japan, Korea, Mongolia, and Russia.-Ethnomedical uses:The stem is boiled for use as a hemostatic in Traditional Chinese Medicine ....
, also used in traditional Chinese medicine, contains D-catechin.
A racemic mixture of (+)-catechin and (-)-catechin is released from the roots of the invasive weed, Centaurea maculosa
Centaurea maculosa
Centaurea maculosa, the spotted knapweed, is a species of Centaurea native to eastern Europe.It has been introduced to North America, where it is considered an invasive plant species in much of the western United States and Canada. In 2000, C. maculosa occupied more than in the US.Knapweed is a...
, the spotted knapweed. It acts as an herbicide to inhibit competition by a wide range of other plant species. This phytotoxic compound inhibits seed germination and growth.
In food
l-Epicatechin can be found in cacao beans and was first called kakaool. The different other enantiomers can as well be found in chocolate where the different processes of fabrication can lead to epimerisation by heating. The kola nutKola nut
Kola Nut is the nut of the kola tree, a genus of trees native to the tropical rainforests of Africa, classified in the family Malvaceae, subfamily Sterculioideae . It is related to the South American genus Theobroma, or cocoa...
, a related species, contains epicatechin and D-catechin. Açaí oil
Acai oil
Açaí oil is obtained from the fruit of Euterpe oleracea , which grows in the Amazon Rainforest. The oil is rich in phenolic compounds similar in profile to the pulp itself, such as vanillic acid, syringic acid, p-hydroxybenzoic acid, protocatechuic acid and ferulic acid as well as -catechin and...
, obtained from the fruit of tha açaí palm (Euterpe oleracea), is rich in (+)-catechin (66.7 +/- 4.8 mg/kg).
- see also : List of phytochemicals in food, List of micronutrients and List of antioxidants in food
Taste
The taste associated with monomeric (+)-catechin or (-)-epicatechin is described as not exactly astringentAstringent
An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...
, nor exactly bitter. It is envisaged to encapsulate catechin in cyclodextrin
Cyclodextrin
Cyclodextrins are a family of compounds made up of sugar molecules bound together in a ring ....
s to mask its taste to use it as an additive
Food additive
Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...
.
Biosynthesis
Leucocyanidin reductase (LCR) uses 2,3-trans-3,4-cis-leucocyanidinLeucocyanidin
Leucocyanidin is a colorless chemical compound related to leucoanthocyanidins. Leucoyanidin can be found in Aesculus hippocastanum , Anacardium occidentale , Arachis hypogaea , Areca catechu , Asimina triloba , Cerasus vulgaris , Cinnamomum camphora , Erythroxylon...
to produce (+)-catechin and is the first enzyme in the proanthocyanidins (PA)-specific pathway. Its activity has been measured in leaves, flowers, and seeds of the legumes Medicago sativa, Lotus japonicus
Lotus japonicus
Lotus japonicus is a wild legume that belongs to family Fabaceae. Members of this family are very diverse, constituting about 20,000 species. They are of significant agricultural and biological importance as many of the legume species are rich sources of protein and oil and can also fix atmospheric...
, Lotus uliginosus
Lotus uliginosus
Lotus pedunculatus , Greater Bird's-foot Trefoil or Marsh Bird's-foot Trefoil is a member of the pea family ....
, Hedysarum sulfurescens, and Robinia pseudoacacia. The enzyme is also present in Vitis vinifera
Vitis vinifera
Vitis vinifera is a species of Vitis, native to the Mediterranean region, central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran....
(grape).
Biodegradation
Catechin oxygenase, a key enzyme in the degradation of catechin, is present in fungi and bacteria.Among bacteria, degradation of (+)-catechin can be achieved by Acinetobacter calcoaceticus
Acinetobacter calcoaceticus
Acinetobacter calcoaceticus is a species of bacteria part of the Human body normal flora.Phloroglucinol carboxylic acid is a degradation product excreted by A. calcoaceticus grown on -catechin as sole source of carbon.-External links:*...
. Catechin is metabolized to protocatechuic acid
Protocatechuic acid
Protocatechuic acid is a dihydroxybenzoic acid, a type of phenolic acid. It has mixed effects on normal and cancer cells in in vitro and in vivo studies.-Biological effects:...
(PCA) and phloroglucinol carboxylic acid
Phloroglucinol carboxylic acid
Phloroglucinol carboxylic acid is a trihydroxybenzoic acid, a type of phenolic acid. It is a catechin degradation product excreted by the bacterium Acinetobacter calcoaceticus ,a species of bacteria part of the Human body normal flora, grown on catechin as sole source of carbon. It is also found in...
(PGCA). It is also degraded by Bradyrhizobium japonicum
Bradyrhizobium japonicum
Bradyrhizobium japonicum is a species of legume-root nodulating, microsymbiotic nitrogen-fixing bacterium species. B. japonicum is identified as a DNA homology group .B...
. Phloroglucinol carboxylic acid is further decarboxylated to phloroglucinol
Phloroglucinol
Phloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione , which has ketone-like character. These two...
, which is dehydroxylated to resorcinol
Resorcinol
Resorcinol is a dihydroxy benzene. It is the 1,3-isomer of benzenediol with the formula C6H42.-Nomenclature:Benzene-1,3-diol is the name recommended by the International Union of Pure and Applied Chemistry in its 1993 Recommendations for the Nomenclature of Organic Chemistry.-Production:It is...
. Resorcinol is hydroxylated to hydroxyquinol
Hydroxyquinol
Hydroxyquinol is a benzenetriol.It is a catechin biodegradation product formed by Bradyrhizobium japonicum.Hydroxyquinol 1,2-dioxygenase is an enzyme that uses hydroxyquinol and O2 to produce 3-hydroxy-cis,cis-muconate....
. Protocatechuic acid and hydroxyquinol undergo intradiol
Diol
A diol or glycol is a chemical compound containing two hydroxyl groups A geminal diol has two hydroxyl groups bonded to the same atom...
cleavage through protocatechuate 3,4-dioxygenase
Protocatechuate 3,4-dioxygenase
In enzymology, a protocatechuate 3,4-dioxygenase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are 3,4-dihydroxybenzoate and O2, whereas its product is 3-carboxy-cis,cis-muconate....
and hydroxyquinol 1,2-dioxygenase
Hydroxyquinol 1,2-dioxygenase
In enzymology, a hydroxyquinol 1,2-dioxygenase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are benzene-1,2,4-triol and O2, whereas its product is 3-hydroxy-cis,cis-muconate....
to form β-carboxy cis, cis-muconic acid and maleyl acetate.
Among fungi, degradation of catechin can be achieve by Chaetomium cupreum
Chaetomium cupreum
Chaetomium cupreum is a fungus species in the Chaetomium genus.C. cupreum is able to achieve the degradation of catechin....
.
In rats, all plasma catechin metabolites are present as conjugated forms and mainly constituted by glucuronidated
Glucuronic acid
Glucuronic acid is a carboxylic acid. Its structure is similar to that of glucose. However, glucuronic acid's sixth carbon is oxidized to a carboxylic acid...
derivatives. In the liver, the concentrations of catechin derivatives are lower than in plasma, and no accumulation is observed when the rats are adapted for 14 days to the supplemented diets. The hepatic metabolites are intensively methylated (90–95%), but in contrast to plasma, some free aglycones can be detected. Rats fed with (+)-catechin and (-)-epicatechin exhibit (+)-catechin 5-O-β-glucuronide and (-)-epicatechin 5-O-β-glucuronide in their body fluids. The primary metabolite of (+)-catechin in plasma is glucuronide in the nonmethylated form. In contrast, the primary metabolites of (-)-epicatechin in plasma are glucuronide and sulfoglucuronide in nonmethylated forms, and sulfate in the 3'-O-methylated forms (3'OMC). Catechin is absorbed into intestinal cells and metabolized extensively because no native catechin can be detected in plasma from the mesenteric vein. Mesenteric plasma contains glucuronide conjugates of catechin and 3'-O-methyl catechin, indicating the intestinal origin of these conjugates. Additional methylation and sulfation occur in the liver, and glucuronide or sulfate conjugates of 3'OMC are excreted extensively in bile. Circulating forms are mainly glucuronide conjugates of catechin and 3'OMC. Another study shows that catechin undergoes enzymatic oxidation by tyrosinase
Tyrosinase
Tyrosinase also known as monophenol monooxygenase is an enzyme that catalyses the oxidation of phenols and is widespread in plants and animals...
in the presence of glutathione
Glutathione
Glutathione is a tripeptide that contains an unusual peptide linkage between the amine group of cysteine and the carboxyl group of the glutamate side-chain...
(GSH) to form mono-, bi-, and tri-glutathione conjugates of catechin and mono- and bi-glutathione conjugates of a catechin dimer.
In the crab eating macaque
Crab-eating Macaque
The Crab-eating macaque is a cercopithecine primate native to Southeast Asia. It is also called the "long-tailed macaque", and is referred to as the "cynomolgus monkey" in laboratories.-Etymology:...
Macaca iris, (+)-catechin administered orally or intraperitonally leads to the formation of 10 metabolites and notably to m-hydroxyphenylhydracrylic acid excreted in the urine.
In man, (+)-catechin absorbed orally is metabolized largely within 24 hours with the production of eleven metabolites detected in the urine.
Biotransformation
Biotransformation of (+)-catechin into taxifolinTaxifolin
Taxifolin is a flavanonol, a type of flavonoid. It can be found in the açaí palm, in the Siberian larch in Russia and in the silymarin extract from the milk thistle seeds. It's also found in small quantities in red onion.-Pharmacology:...
by a two-step oxidation can be achieved by Burkholderia
Burkholderia
Burkholderia is a genus of proteobacteria probably best known for its pathogenic members:Burkholderia mallei, responsible for glanders, a disease that occurs mostly in horses and related animals;...
sp.
The laccase
Laccase
Laccases are copper-containing oxidase enzymes that are found in many plants, fungi, and microorganisms. The copper is bound in several sites; Type 1, Type 2, and/or Type 3. The ensemble of types 2 and 3 copper is called a trinuclear cluster . Type 1 copper is available to action of solvents,...
/ABTS
ABTS
In biochemistry, 2,2'-azino-bis or ABTS is chemical compound used to observe the reaction kinetics of specific enzymes...
system oxidizes (+)-catechin to oligomeric products of which proanthocyanidin A2
Proanthocyanidin A2
Proanthocyanidin A2 is a A type proanthocyanidin.It can be found in horse chestnut ., in cranberry juice concentrate, in peanut skins in Cinchona Cinchona and Cinchona pubescens rind, bark and cortex, in Cinnamomum verum rind, bark and cortex, in the fruit of Persea americana , in Urvillea...
is a dimer.
(+)-Catechin and (-)-epicatechin are transformed by the endophytic filamentous fungus Diaporthe
Diaporthe
Diaporthe is a genus of endophytic filamentous fungus plant pathogens.Diaporthe species have been shown to transform the infection-inhibiting factors -catechin and -epicatechin into the 3,4-cis-dihydroxyflavan derivatives...
sp. into the 3,4-cis-dihydroxyflavan derivatives, (+)-(2R,3S,4S)-3,4,5,7,3',4'-hexahydroxyflavan (leucocyanidin) and (-)-(2R,3R,4R)-3,4,5,7,3',4'-hexahydroxyflavan, respectively, whereas (-)-catechin and (+)-epicatechin with a 2S-phenyl group resisted the biooxidation.
Leucoanthocyanidin reductase
Leucoanthocyanidin reductase
In enzymology, a leucoanthocyanidin reductase is an enzyme that catalyzes the chemical reaction-catechin + NADP+ + H2O \rightleftharpoons 2,3-trans-3,4-cis-leucocyanidin + NADPH + H+...
(LAR) uses (2R,3S)-catechin, NADP+ and H2O to produce 2,3-trans-3,4-cis-leucocyanidin
Leucocyanidin
Leucocyanidin is a colorless chemical compound related to leucoanthocyanidins. Leucoyanidin can be found in Aesculus hippocastanum , Anacardium occidentale , Arachis hypogaea , Areca catechu , Asimina triloba , Cerasus vulgaris , Cinnamomum camphora , Erythroxylon...
, NADPH, and H+. Its gene expression has been studied in developing grape berries and grapevine leaves.
Catechin and epicatechin are the building blocks of the proanthocyanidin
Proanthocyanidin
Proanthocyanidins, also known as OPCs or condensed tannins, are a subgroup of the flavonoid class of polyphenols...
s, a type of condensed tannin.
Bioactivity studies
Catechin is reported to induce longevityLongevity
The word "longevity" is sometimes used as a synonym for "life expectancy" in demography or known as "long life", especially when it concerns someone or something lasting longer than expected ....
in the nematode worm Caenorhabditis elegans
Caenorhabditis elegans
Caenorhabditis elegans is a free-living, transparent nematode , about 1 mm in length, which lives in temperate soil environments. Research into the molecular and developmental biology of C. elegans was begun in 1974 by Sydney Brenner and it has since been used extensively as a model...
. Transcriptomic studies shows that catechin reduces atherosclerotic
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
lesion development in apo E
Apolipoprotein E
Apolipoprotein E is a class of apolipoprotein found in the chylomicron and IDLs that binds to a specific receptor on liver cells and peripheral cells. It is essential for the normal catabolism of triglyceride-rich lipoprotein constituents.-Function:...
-deficient mice
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
. (+)- and (−)-catechin seem to have stereospecific opposite effects on glycogen
Glycogen
Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...
metabolism in isolated rat hepatocyte
Hepatocyte
A hepatocyte is a cell of the main tissue of the liver. Hepatocytes make up 70-80% of the liver's cytoplasmic mass.These cells are involved in:* Protein synthesis* Protein storage* Transformation of carbohydrates...
s. (+)-Catechin inhibits intestinal tumor formation in mice.
(+)-Catechin inhibits the oxidation of low density lipoprotein
Low density lipoprotein
Low-density lipoprotein is one of the five major groups of lipoproteins, which in order of size, largest to smallest, are chylomicrons, VLDL, IDL, LDL, and HDL, that enable transport of cholesterol within the water-based bloodstream...
.
(-)-Catechin suppresses expression of Kruppel-like factor 7
KLF7
Kruppel-like factor 7 , also known as KLF7, is a protein which in humans is encoded by the KLF7 gene.This protein is a member of the Kruppel-like family of transcription factors....
.
Catechin shows an enhancement of the antifungal effect of amphotericin B
Amphotericin B
Amphotericin B is a polyene antifungal drug, often used intravenously for systemic fungal infections...
against Candida albicans
Candida albicans
Candida albicans is a diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans. Systemic fungal infections including those by C...
.
Incubation experiments with (+)-catechin show a prevention of human plasma oxidation.
Interactions with human genes
Catechin interacts the most with the PTGS2PTGS2
Prostaglandin-endoperoxide synthase 2, also known as cyclooxygenase-2 or simply COX-2, is an enzyme that in humans is encoded by the PTGS2 gene.- History :...
, IL1B
IL1B
Interleukin-1 beta also known as catabolin, is a cytokine protein that in humans is encoded by the IL1B gene. IL-1β precursor is cleaved by caspase 1 . Cytosolic thiol protease cleaves the product to form mature IL-1β.- Function :Interleukin 1 was discovered by Gery in 1972...
, CAT
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...
, CYP1A1
CYP1A1
Cytochrome P450, family 1, subfamily A, polypeptide 1 is a protein that in humans is encoded by the CYP1A1 gene. The protein is a member of the cytochrome P450 superfamily of enzymes.-Function:...
, SOD
Superoxide dismutase
Superoxide dismutases are a class of enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. As such, they are an important antioxidant defense in nearly all cells exposed to oxygen...
, BAX
Bcl-2-associated X protein
The Bcl-2–associated X protein, or Bax is a protein of the Bcl-2 gene family. It promotes apoptosis by competing with Bcl-2 proper.The BAX gene was the first identified pro-apoptotic member of the Bcl-2 protein family....
, CASP3, MAPK1
MAPK1
Mitogen-activated protein kinase 1, also known as MAPK1, p42MAPK, and ERK2, is an enzyme that in humans is encoded by the MAPK1 gene.- Function :The protein encoded by this gene is a member of the MAP kinase family...
, MAPK3
MAPK3
Mitogen-activated protein kinase 3 is an enzyme that in humans is encoded by the MAPK3 gene.-Interactions:MAPK3 has been shown to interact with PTPN7, SPIB, GTF2I, DUSP3, HDAC4, RPS6KA2, MAP2K1, DUSP6 and MAP2K2.-Further reading:...
and S100B
S100B
S100 calcium binding protein B or S100B is a protein of the S-100 protein family.S100 proteins are localized in the cytoplasm and nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation...
human genes.
PTGS2 (aka COX-2 for cyclooxygenase-2) is a dioxygenase
Dioxygenase
In molecular biology, a dioxygenase is an enzyme which catalyses the incorporation of both atoms of molecular oxygen into substrates using a variety of reaction mechanisms. Cleavage of aromatic rings is one of the most important functions of dioxygenases, which play key roles in the degradation of...
. The presence of catechin seems to increase its expression.
IL1B induces the formation of cyclooxygenase-2 (PTGS2/COX2). Catechin increases its expression.
CAT is a catalase. Catechin decreases its expression.
CYP1A1 (Cytochrome P450, family 1, member A1) is an enzyme implied in the metabolism of xenobiotic
Xenobiotic
A xenobiotic is a chemical which is found in an organism but which is not normally produced or expected to be present in it. It can also cover substances which are present in much higher concentrations than are usual...
s. Catechin decreases its expression.
SOD (Superoxide dismutase) is an enzyme that catalyzes the dismutation of superoxide into oxygen and hydrogen peroxide. Catechin increases its expression.
BAX (Bcl-2–associated X protein) is a protein of the Bcl-2 gene family. It promotes apoptosis by competing with Bcl-2 proper. Catechin increases its expression.
CASP3 (Caspase 3) is a protein that plays a central role in the execution-phase of cell apoptosis. Catechin increases its expression.
MAPK1 (Mitogen-activated protein kinase 1) and MAPK3 (Mitogen-activated protein kinase 3) are enzymes that are extracellular signal-regulated kinases (ERKs) and act as an integration point for multiple biochemical signals, involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation, and development. Catechin seems to increase their expression.
S100B (S100 calcium binding protein B) is an pro-inflammatory enzyme specific of mature astrocytes that ensheath the blood vessels. Catechin decreases the expression of the gene and could regulate S100B-activated oxidant stress-sensitive pathways through blocking p47phox protein expression. Treatment with catechin could eliminate reactive oxygen species (ROS) to reduce oxidative stress stimulated by S100B. Catechin decreases its expression.
Experiments on human Caco-2
Caco-2
The Caco-2 cell line is a continuous line of heterogeneous human epithelial colorectal adenocarcinoma cells, developed by the Sloan-Kettering Institute for Cancer Research through research conducted by Dr...
cells show changes in the expression of genes like STAT1
STAT1
STAT1 is a member of the Signal Transducers and Activators of Transcription family of transcription factors. STAT1 is involved in upregulating genes due to a signal by either type I, type II or type III interferons...
, MAPKK1, MRP1 and FTH1
FTH1
Ferritin heavy chain is a ferroxidase enzyme that in humans is encoded by the FTH1 gene.- Function :This gene encodes the heavy subunit of ferritin, the major intracellular iron storage protein in prokaryotes and eukaryotes. It is composed of 24 subunits of the heavy and light ferritin chains...
genes, which are involved in the cellular response to oxidative stress, are in agreement with the antioxidant properties of catechin. In addition, the changes in the expression of genes like C/EBPG, topoisomerase 1, MLF2 and XRCC1
XRCC1
XRCC1 is a DNA repair protein.It complexes with DNA ligase III.-Interactions:XRCC1 has been shown to interact with PARP2, DNA polymerase beta, Aprataxin, Oxoguanine glycosylase, PCNA, APEX1, PNKP and PARP1.-Further reading:-External links:...
suggest novel mechanisms of action at the molecular level.
Detail for all tested genes :
(dec : decreased expression, inc : increased expression, = : does not affect the activity, expression assayed in human if not specified otherwise)
ABCG2
ABCG2
ATP-binding cassette sub-family G member 2 is a protein that in humans is encoded by the ABCG2 gene. ABCG2 has also been designated as CDw338 . - External links :...
: (-)-catechin decreases the expression of ABCG2
ACE
Angiotensin-converting enzyme
Angiotensin I-converting enzyme , an exopeptidase, is a circulating enzyme that participates in the body's renin-angiotensin system , which mediates extracellular volume , and arterial vasoconstriction...
(in Rattus norvegicus) : (+)-catechin or (-)-epicatechin do not affect the activity of the angiotensin-converting enzyme
ACTB (in Rattus norvegicus) decrease
AKT1
AKT1
RAC-alpha serine/threonine-protein kinase is an enzyme that in humans is encoded by the AKT1 gene. Multiple alternatively spliced transcript variants have been found for this gene.- Function :...
decrease
ANXA2 increase
ARHGAP4
ARHGAP4
Rho GTPase-activating protein 4 is an enzyme that in humans is encoded by the ARHGAP4 gene. It has been shown to regulate cell motility and axonal outgrowth in vitro.-Further reading:...
decrease
ATF4
ATF4
Activating transcription factor 4 , also known as ATF4, is a protein that in humans is encoded by the ATF4 gene.- Function :...
increase
BAT2
BAT2
Large proline-rich protein BAT2 is a protein that in humans is encoded by the BAT2 gene.-Interactions:BAT2 has been shown to interact with IFT88, C1QBP, EIF3S6, IMMT, UBAP2L and Heterogeneous nuclear ribonucleoprotein A1.-Further reading:...
increase
BAX
Bcl-2-associated X protein
The Bcl-2–associated X protein, or Bax is a protein of the Bcl-2 gene family. It promotes apoptosis by competing with Bcl-2 proper.The BAX gene was the first identified pro-apoptotic member of the Bcl-2 protein family....
(rattus norvegicus) increase
BCL2 decrease
BRCC3
BRCC3
Lys-63-specific deubiquitinase BRCC36 is an enzyme that in humans is encoded by the BRCC3 gene.-Interactions:BRCC3 has been shown to interact with BRE, BRCA2, RAD51, BRCA1, P53 and BARD1.-Further reading:...
decrease
BTG1
BTG1
Protein BTG1 is a protein that in humans is encoded by the BTG1 gene.-Interactions:BTG1 has been shown to interact with CNOT7, HOXB9, PRMT1 and CNOT8.-Further reading:...
increase
CASP3 increase
CAT
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...
(mus musculus) decrease
CCL2
CCL2
For the ICAO airport code see Candle Lake Airpark, for the diradical compound see Dichlorocarbene.Chemokine ligand 2 also known as monocyte chemotactic protein-1 or small inducible cytokine A2 is a protein that in humans is encoded by the CCL2 gene. CCL2 is a small cytokine belonging to the CC...
increase
CCND1 decrease
CD81
CD81
CD81 molecule, also known as CD81 , is a protein which in humans is encoded by the CD81 gene...
increase
CD9
CD9
CD9 antigen is a protein that in humans is encoded by the CD9 gene.-Interactions:CD9 has been shown to interact with TSPAN4, PTGFRN, CD81, CD117, CD46, CD29 and CD49c.-Further reading:...
increase
CEBPG
CEBPG
CCAAT/enhancer-binding protein gamma is a protein that in humans is encoded by the CEBPG gene....
increase
CXCL10
CXCL10
C-X-C motif chemokine 10 also known as Interferon gamma-induced protein 10 or small-inducible cytokine B10 is an 8.7 kDa protein that in humans is encoded by the CXCL10 gene...
increase
CYP19A1 (rattus norvegicus) increase
CYP1A1
CYP1A1
Cytochrome P450, family 1, subfamily A, polypeptide 1 is a protein that in humans is encoded by the CYP1A1 gene. The protein is a member of the cytochrome P450 superfamily of enzymes.-Function:...
decrease
CYP1A2
CYP1A2
Cytochrome P450 1A2 , a member of the cytochrome P450 mixed-function oxidase system, is involved in the metabolism of xenobiotics in the body...
=
DEK
DEK (gene)
Protein DEK is a protein that in humans is encoded by the DEK gene.-Interactions:DEK has been shown to interact with TFAP2A.-Further reading:...
decrease
DFFA
DFFA
The C-terminal domain of DFFA consists of four alpha-helices, which are folded in a helix-packing arrangement, with alpha-2 and alpha-3 packing against a long C-terminal helix . The main function of this domain is the inhibition of DFFB by binding to its C-terminal catalytic domain through ionic...
(mus musculus) decrease
DNMT1
DNMT1
DNA -methyltransferase 1 is an enzyme that in humans is encoded by the DNMT1 gene.-Interactions:DNMT1 has been shown to interact with Histone deacetylase 2, DMAP1, PCNA, Retinoblastoma protein, DNMT3A and DNMT3B.-Further reading:...
decrease
EWSR1 increase
FLT3LG
FLT3LG
Fms-related tyrosine kinase 3 ligand is a protein which in humans is encoded by the FLT3LG gene.Flt3 ligand is a hematopoietic four helical bundle cytokine. It is structurally homologous to stem cell factor and colony stimulating facor 1...
decrease
FTH1
FTH1
Ferritin heavy chain is a ferroxidase enzyme that in humans is encoded by the FTH1 gene.- Function :This gene encodes the heavy subunit of ferritin, the major intracellular iron storage protein in prokaryotes and eukaryotes. It is composed of 24 subunits of the heavy and light ferritin chains...
increase
GRN
Granulin
Granulin is a protein that in humans is encoded by the GRN gene.- Structure :Granulins are a family of secreted, glycosylated peptides that are cleaved from a single precursor protein with 7.5 repeats of a highly conserved 12-cysteine granulin/epithelin motif. The 88 kDa precursor protein,...
increase
HCFC1 increase
HEAB decrease
HMOX1
HMOX1
HMOX1 is a human gene that encodes for the enzyme heme oxygenase 1 . Heme oxygenase is an essential enzyme in heme catabolism, it cleaves heme to form biliverdin....
increase
HOXD3
HOXD3
Homeobox protein Hox-D3 is a protein that in humans is encoded by the HOXD3 gene.- External links :...
increase
HSPD1 decrease
ICAM1 increase
IL10
IL10
Il-10 may refer to:* Ilyushin Il-10, a Soviet aircraft of World War II* Interleukin 10, an anti-inflammatory cytokine* Illinois' 10th congressional district* Illinois Route 10...
increase
IL1B
IL1B
Interleukin-1 beta also known as catabolin, is a cytokine protein that in humans is encoded by the IL1B gene. IL-1β precursor is cleaved by caspase 1 . Cytosolic thiol protease cleaves the product to form mature IL-1β.- Function :Interleukin 1 was discovered by Gery in 1972...
increase
IL2RA
IL2RA
Interleukin-2 receptor alpha chain is a protein that in humans is encoded by the IL2RA gene.Infection by the protozoan Trypanosoma cruzi causes Chagas disease, characterized by a reduction in the amount of IL2RA expressed on the surface of immune cells...
decrease
IL32 decrease
IRF4
IRF4
Interferon regulatory factor 4 is a protein that in humans is encoded by the IRF4 gene, also known as MUM1. In melanocytic cells the IRF4 gene may be regulated by MITF.-Interactions:IRF4 has been shown to interact with STAT6, NFATC2, BCL6 and SPI1....
decrease
ITGAL increase
ITGB2 increase
LYN
LYN
Tyrosine-protein kinase Lyn is a protein that in humans is encoded in humans by the LYN gene.Lyn is a member of the Src family of protein tyrosine kinases, which is mainly expressed in hematopoietic cells, in neural tissues liver, and adipose tissue. In various hematopoietic cells, Lyn has emerged...
decrease
MAP2K1
MAP2K1
Dual specificity mitogen-activated protein kinase kinase 1 is an enzyme that in humans is encoded by the MAP2K1 gene.- Function :The protein encoded by this gene is a member of the dual specificity protein kinase family, which acts as a mitogen-activated protein kinase kinase...
decrease ?
MAPK1
MAPK1
Mitogen-activated protein kinase 1, also known as MAPK1, p42MAPK, and ERK2, is an enzyme that in humans is encoded by the MAPK1 gene.- Function :The protein encoded by this gene is a member of the MAP kinase family...
increase ?
MAPK3
MAPK3
Mitogen-activated protein kinase 3 is an enzyme that in humans is encoded by the MAPK3 gene.-Interactions:MAPK3 has been shown to interact with PTPN7, SPIB, GTF2I, DUSP3, HDAC4, RPS6KA2, MAP2K1, DUSP6 and MAP2K2.-Further reading:...
increase ?
MIF
Macrophage migration inhibitory factor
Macrophage migration inhibitory factor also known as glycosylation-inhibiting factor , L-dopachrome isomerase, or phenylpyruvate tautomerase is a protein that in humans is encoded by the MIF gene.- Structure :...
decrease
NCF1
NCF1
Neutrophil cytosol factor 1 is a protein that in humans is encoded by the NCF1 gene.p47 is vital to the activation of NADPH oxidase. P47 becomes heavily phosphorylated-Interactions:...
?
NFE2L2
NFE2L2
Nuclear factor -like 2, also known as NFE2L2 or Nrf2, is a transcription factor that in humans is encoded by the NFE2L2 gene. NFE2L2 induces the expression of various genes including those that encode for several antioxidant enzymes, and it may play a physiological role in the regulation of...
increase
NFKBIA decrease
NOS2 (mus musculus) increase
NOTCH1
NOTCH1
Notch homolog 1, translocation-associated , also known as NOTCH1, is a human gene encoding a single-pass transmembrane receptor.A deficiency can be associated with bicuspid aortic valve....
increase
NPM1
NPM1
Nucleophosmin , also known as nucleolar phosphoprotein B23 or numatrin, is a protein that in humans is encoded by the NPM1 gene.- Function :...
decrease
PARP1
PARP1
Poly [ADP-ribose] polymerase 1 also known as NAD+ ADP-ribosyltransferase 1 or poly[ADP-ribose] synthase 1 is an enzyme that in humans is encoded by the PARP1 gene.- Function :PARP1 works:...
(mus musculus) increase
PECAM1 increase
PLAT
Tissue plasminogen activator
Tissue plasminogen activator is a protein involved in the breakdown of blood clots. It is a serine protease found on endothelial cells, the cells that line the blood vessels. As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown...
increase
PLAU
PLAU
Urokinase-type plasminogen activator is an enzyme that in humans is encoded by the PLAU gene.-Interactions:PLAU has been shown to interact with Protein C inhibitor.-Further reading:...
increase
PON1
PON1
Paraoxonase 1 is a protein-coding gene. The protein encoded by this gene has esterase activity.-Function:PON1 is responsible for hydrolyising organophosphate pesticides and nerve gasses....
=
PTGS2
PTGS2
Prostaglandin-endoperoxide synthase 2, also known as cyclooxygenase-2 or simply COX-2, is an enzyme that in humans is encoded by the PTGS2 gene.- History :...
increase?
RAC1
RAC1
Ras-related C3 botulinum toxin substrate 1 also known as Rac1 is a protein that in humans is encoded by the RAC1 gene. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined.- Function :Rac1 is...
decrease
RARB
Retinoic acid receptor beta
Retinoic acid receptor beta , also known as NR1B2 is a nuclear receptor that in humans is encoded by the RARB gene.- Function :...
decrease
RELA
RELA
Transcription factor p65 is a protein that in humans is encoded by the RELA gene.-Interactions:RELA has been shown to interact with NFKBIB, ETHE1, NFKBIE, RFC1, TRIB3, CREB binding protein, Neutrophil cytosolic factor 1, Glucocorticoid receptor, MTPN, BRCA1, C-Fos, POU2F1, BTRC, TATA-binding...
decrease
RPL6
RPL6
60S ribosomal protein L6 is a protein that in humans is encoded by the RPL6 gene.-Interactions:RPL6 has been shown to interact with Basic fibroblast growth factor.-Further reading:...
increase
S100B
S100B
S100 calcium binding protein B or S100B is a protein of the S-100 protein family.S100 proteins are localized in the cytoplasm and nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation...
decrease
SERPINE1 decrease
SF1
SF1 (gene)
Splicing factor 1 also known as zinc finger protein 162 is a protein that in humans is encoded by the SF1 gene.Splicing factor SF1 is involved in the ATP-dependent formation of the spliceosome complex.-Interactions:...
decrease
SLC20A1
SLC20A1
Sodium-dependent phosphate transporter 1 is a protein that in humans is encoded by the SLC20A1 gene.-Further reading:...
increase
SOD
Superoxide dismutase
Superoxide dismutases are a class of enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. As such, they are an important antioxidant defense in nearly all cells exposed to oxygen...
(Drosophila melanogaster) increase
SOD2
SOD2
Superoxide dismutase 2, mitochondrial, also known as SOD2, is an enzyme which in humans is encoded by the SOD2 gene.- Function :This gene is a member of the iron/manganese superoxide dismutase family. It encodes a mitochondrial matrix protein that forms a homotetramer and binds one manganese ion...
(Drosophila melanogaster) increase
STAT1
STAT1
STAT1 is a member of the Signal Transducers and Activators of Transcription family of transcription factors. STAT1 is involved in upregulating genes due to a signal by either type I, type II or type III interferons...
decrease
STAT5B
STAT5B
Signal transducer and activator of transcription 5B is a protein that in humans is encoded by the STAT5B gene. STAT5B orthologs have been identified in most placentals for which complete genome data are available.-Interactions:...
increase
STAT6
STAT6
STAT6 is a human gene. The protein encoded by this gene is a member of the STAT family of transcription factors.In response to cytokines and growth factors, STAT family members are phosphorylated by the receptor associated kinases, and then form homo- or heterodimers that translocate to the cell...
increase
SULT1A1
SULT1A1
Sulfotransferase 1A1 is an enzyme that in humans is encoded by the SULT1A1 gene.-Further reading:...
increase : sulfation of catechin
TCF7
TCF7
Transcription factor 7 is a protein that in humans is encoded by the TCF7 gene.-Further reading:...
increase
TK1
Thymidine kinase 1
Thymidine kinase 1, soluble , is a human thymidine kinase.Two forms of this protein have been identified in animal cells, one in cytosol and one in mitochondria...
decrease
TNF
Tumor necrosis factors
Tumor necrosis factors refers to a group of cytokines family that can cause cell death . The first two members of the family to be identified were:...
increase
TNFRSF8 decrease
TOP1 decrease
TOP2A
TOP2A
DNA topoisomerase 2-alpha is an enzyme that in humans is encoded by the TOP2A gene.-Interactions:TOP2A has been shown to interact with HDAC1, CDC5L, Small ubiquitin-related modifier 1 and P53.-Further reading:...
decrease
TRP53 increase
XCR1
XCR1
The "C" sub-family of chemokine receptors contains only one member: XCR1, the receptor for XCL1 and XCL2 .XCR1 is also known as GPR5.-External links:...
decrease
ZNF593
ZNF593
Zinc finger protein 593 is a protein that in humans is encoded by the ZNF593 gene.-Further reading:...
increase
Protection of the mouse brain after a stroke
Ninety minutes after feeding mice a single modest dose of epicatechin, a compound found naturally in dark chocolate, the scientists induced an ischemic stroke by, in essence, cutting off blood supply to the animals' brains. They found that the animals that had preventively ingested the epicatechin suffered significantly less brain damage than the ones that had not been given the compound.While most treatments against stroke in humans have to be given within a two- to three-hour time window to be effective, epicatechin appeared to limit further neuronal damage when given to mice 3.5 hours after a stroke. Given six hours after a stroke, however, the compound offered no protection to brain cells.
Histidine decarboxylase inhibitor
(+)-Catechin is a histidine decarboxylaseHistidine decarboxylase
Histidine decarboxylase is the enzyme that catalyzes the reaction that produces histamine from histidine with the help of vitamin B6 as follows:C6H9N3O2 → C5H9N3 + CO2...
inhibitor. Thus, it inhibits the conversion of histidine to histamine, and, so, is thought to be beneficial through reduction of potentially damaging, histamine-related local immune response(s).
Monoamine oxidase inhibitor
(+)-Catechin and (-)-epicatechin are also selective monoamine oxidase inhibitorMonoamine oxidase inhibitor
Monoamine oxidase inhibitors are a class of antidepressant drugs prescribed for the treatment of depression. They are particularly effective in treating atypical depression....
s (MAOIs) of type MAO-B
Monoamine oxidase B
Monoamine oxidase B, also known as MAOB, is a protein that in humans is encoded by the MAOB gene.The protein encoded by this gene belongs to the flavin monoamine oxidase family. It is an enzyme located in the mitochondrial outer membrane...
. They could be used as part of the treatment of Parkinson's and Alzheimer's patients.
Ecological effects
Catechin also has ecological functions.It is released into the ground by some plants to hinder the growth of their neighbors, a form of allelopathy
Allelopathy
Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms...
. Centaurea maculosa
Centaurea maculosa
Centaurea maculosa, the spotted knapweed, is a species of Centaurea native to eastern Europe.It has been introduced to North America, where it is considered an invasive plant species in much of the western United States and Canada. In 2000, C. maculosa occupied more than in the US.Knapweed is a...
, the spotted knapweed, is the most studied plant showing this behaviour, catechin isomers, both released into the ground through its root exudates, have effects ranging from antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
to herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
. It causes a reactive oxygen species
Reactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
wave through the target plant's root starting in the apical meristem
Meristem
A meristem is the tissue in most plants consisting of undifferentiated cells , found in zones of the plant where growth can take place....
rapidly followed by a Ca2+ spike that kills the root cells through apoptosis. Most plants in the European ecosystem have defenses against catechin, but few plants are protected against it in the North-American ecosystem where Centaurea maculosa
Centaurea maculosa
Centaurea maculosa, the spotted knapweed, is a species of Centaurea native to eastern Europe.It has been introduced to North America, where it is considered an invasive plant species in much of the western United States and Canada. In 2000, C. maculosa occupied more than in the US.Knapweed is a...
has been introduced causing uncontrolled growth of this weed.
(+)-Catechin acts as an infection-inhibiting factor in strawberry leaf. Epicatechin and catechin may prevent coffee berry disease by inhibition of appressorial
Appressorium
An appressorium is a flattened, hyphal "pressing" organ, from which a minute infection peg grows and enters the host, using turgor pressure capable of punching through even Mylar....
melanization of Colletotrichum kahawae
Colletotrichum kahawae
Colletotrichum kahawae is a plant pathogen associated with Coffee berry disease.- External links :* *...
.
Other uses
It has been suggested that (+)-catechin could be used as a scavenger for indoor air pollutents such as volatile organic compounds (VOC) to adapt for instance as filterAir filter
A particulate air filter is a device composed of fibrous materials which removes solid particulates such as dust, pollen, mold, and bacteria from the air. A chemical air filter consists of an absorbent or catalyst for the removal of airborne molecular contaminants such as volatile organic compounds...
s to air conditioners or to air purifier
Air purifier
An air purifier is a device which removes contaminants from the air. These devices are commonly marketed as being beneficial to allergy sufferers and asthmatics, and at reducing or eliminating second-hand tobacco smoke...
s.