A type proanthocyanidin
Encyclopedia
A type proanthocyanidins are a specific type of proanthocyanidin
, which are a class of flavanoid. Proanthocyanidins fall under a wide range of names in the nutritional and scientific vernacular, including oligomeric proanthocyanidin
s, flavanoids, polyphenol
s, condensed tannins, and OPCs. Proanthocyanidins were first popularized by French scientist Dr. Jacques Masquelier.
) and 2ß→O→7 interflavanoid bonds.
Other A-type proanthocyanidins can be found in cranberries
, in apricot
s, Prunus armeniaca (ent-epiafzelechin-3-O-p-hydroxybenzoate-(4α→8,2α→O→7)-epiafzelechin) and in peanut skins (epicatechin-(2β→O→7, 4β→8)-ent-epicatechin).
An A type proanthocyanidins trimer can be found in Lindera aggregata
(epicatechin-(4β→8,2β→O→7)-entcatechin
-(4β-8)-catechin). This compound shows cytoprotective action against ethanol-induced gastric injury.
In Ecdysanthera utilis
(epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8)-epicatechin and epicatechin-(4β→8)-epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8)-epicatechin) can be found.
dimer) can be converted to A-type procyanidin by radical oxidation.
.
Proanthancyanidins in Ecdysanthera utilis show immunomodulatory effects.
bacteria. E. Coli
use their p type fimbrae
to attach to the wall of the urinary tract. A Type proanthocyanidins have been clinically demonstrated to attach to E. Coli fimbriae, preventing the bacteria from attaching to the urinary tract or bladder
or urinary wall. A Type proanthocyanidins have been demonstrated in vitro
to be more effective than other types of proanthocyanidins at adhering to E. Coli
and preventing urinary tract infections.
The anti-adhesion activity of A Type Proanthocyanidins in cranberry products has been well established by the aforementioned clinical data. But how well does this anti-adhesion activity translate into prevention of urinary tract infections? A Cochrane Collaboration
Review of the body of clinical literature concluded that "there is some evidence to recommend cranberry juice for the prevention of UTIs in women with symptomatic UTIs. The large number of dropouts/withdrawals from some of the trials, however, indicates that cranberry juice may not be acceptable over long periods of time." Another review of cranberry and UTI prevention takes a more skeptical view. The review supports the anti-adhesion of activity of A Type Proanthocyanidins: "evidence suggests that the anthocyanidin/proanthocyanidin moieties are potent antiadhesion compounds" yet asserts that "most clinical trials have had design deficiencies" and points to cranberry products' "adverse events include gastrointestinal intolerance and weight gain (due to the excessive calorie load)." Both reviews agree that the evidence for cranberries (and their anti-adhesion components A Type Proanthocyanidins) and urinary tract infection
prevention can be strengthened by better-designed clinical studies.
Proanthocyanidin
Proanthocyanidins, also known as OPCs or condensed tannins, are a subgroup of the flavonoid class of polyphenols...
, which are a class of flavanoid. Proanthocyanidins fall under a wide range of names in the nutritional and scientific vernacular, including oligomeric proanthocyanidin
Proanthocyanidin
Proanthocyanidins, also known as OPCs or condensed tannins, are a subgroup of the flavonoid class of polyphenols...
s, flavanoids, polyphenol
Polyphenol
Polyphenols are a structural class of natural, synthetic, and semisynthetic organic chemicals characterized by the presence of large multiples of phenol structural units...
s, condensed tannins, and OPCs. Proanthocyanidins were first popularized by French scientist Dr. Jacques Masquelier.
Distribution in plants
A-type linkage is a less common feature in proanthocyanidins with both 4ß→8 (B-typeB type proanthocyanidin
B type proanthocyanidins are a specific type of proanthocyanidin, which are a class of flavanoids. They are oligomers of flavan-3-ols.-Dimeric B type proanthoanthocyanidins :...
) and 2ß→O→7 interflavanoid bonds.
Dimers
- Proanthocyanidin A1Proanthocyanidin A1Proanthocyanidin A1 is a A type proanthocyanidin dimer.It is an epigallocatechin--epicatechin dimer found in Rhododendron spiciferum, in the leaves of Dioclea lasiophylla, in peanut skins and in Ecdysanthera utilis....
is an epigallocatechin-(2β→7,4β→8)-epicatechin dimer. - Proanthocyanidin A2Proanthocyanidin A2Proanthocyanidin 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 dimeric catechin.
Other A-type proanthocyanidins can be found in cranberries
Cranberry
Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus Oxycoccus of the genus Vaccinium. In some methods of classification, Oxycoccus is regarded as a genus in its own right...
, in apricot
Apricot
The apricot, Prunus armeniaca, is a species of Prunus, classified with the plum in the subgenus Prunus. The native range is somewhat uncertain due to its extensive prehistoric cultivation.- Description :...
s, Prunus armeniaca (ent-epiafzelechin-3-O-p-hydroxybenzoate-(4α→8,2α→O→7)-epiafzelechin) and in peanut skins (epicatechin-(2β→O→7, 4β→8)-ent-epicatechin).
Trimers
- Selligueain ASelligueain ASelligueain A is a A type proanthocyanidin trimer.It can be extracted from the rhizome of the fern Selliguea feei collected in Indonesia....
is a natural sweetener - Selligueain B (or (-)-4β-carboxymethyl epiafzelechin (3'-deoxydryopteric acid), epiafzelechin-(4β→8, 2β→O→7)-epiafzelechin-(4β→8)-3'-deoxydryopteric acid methyl ester) can also be isolated from the rhizomes of Selliguea feeiSelliguea feeiSelliguea feei is a plant species belonging to the Selliguea genus. This fern can be collected in Indonesia. The species name feei commemorates the botanist Antoine Laurent Apollinaire Fée.-Biochemistry:...
.
An A type proanthocyanidins trimer can be found in Lindera aggregata
Lindera aggregata
Lindera aggregata is a plant species belonging to the Lindera genus.-Other names:Engl.: evergreen lindera, Japanese evergreen spicebush.TCM: trad.烏樂, simpl. 乌药 or 乌乐, pinyin : wūyào....
(epicatechin-(4β→8,2β→O→7)-entcatechin
-(4β-8)-catechin). This compound shows cytoprotective action against ethanol-induced gastric injury.
In Ecdysanthera utilis
Ecdysanthera utilis
Ecdysanthera utilis is a plant species in the genus Ecdysanthera. It is a shrub found in Taïwan where it is used in folk medicine as an analgesic, antiphlogistic and spasmolytic agent....
(epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8)-epicatechin and epicatechin-(4β→8)-epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8)-epicatechin) can be found.
Chemistry
B-type procyanidin (catechinCatechin
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-ols ....
dimer) can be converted to A-type procyanidin by radical oxidation.
Health Benefits
Proanthocyanidin A1, A2 and epicatechin-(2β→O→7, 4β→8)-ent-epicatechin possess substantial activity against hyaluronidaseHyaluronidase
The hyaluronidases are a family of enzymes that degrade hyaluronic acid.In humans, there are six associated genes, including HYAL1, HYAL2, HYAL3, and PH-20/SPAM1.-Use as a drug:...
.
Proanthancyanidins in Ecdysanthera utilis show immunomodulatory effects.
Urinary Tract Infection Prevention
85-90% of urinary tract infections are caused by E. ColiEscherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
bacteria. E. Coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
use their p type fimbrae
Fimbria (bacteriology)
In bacteriology, a Cilli is a proteinaceous appendage in many Gram-negative and some Gram-positive bacteria that is thinner and shorter than a flagellum. This appendage ranges from 3-10 nanometers in diameter and can be up to several micrometers long...
to attach to the wall of the urinary tract. A Type proanthocyanidins have been clinically demonstrated to attach to E. Coli fimbriae, preventing the bacteria from attaching to the urinary tract or bladder
Bladder
Bladder usually refers to an anatomical hollow organBladder may also refer to:-Biology:* Urinary bladder in humans** Urinary bladder ** Bladder control; see Urinary incontinence** Artificial urinary bladder, in humans...
or urinary wall. A Type proanthocyanidins have been demonstrated in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
to be more effective than other types of proanthocyanidins at adhering to E. Coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
and preventing urinary tract infections.
The anti-adhesion activity of A Type Proanthocyanidins in cranberry products has been well established by the aforementioned clinical data. But how well does this anti-adhesion activity translate into prevention of urinary tract infections? A Cochrane Collaboration
Cochrane Collaboration
The Cochrane Collaboration is a group of over 28,000 volunteers in more than 100 countries who review the effects of health care interventions tested in biomedical randomized controlled trials. A few more recent reviews have also studied the results of non-randomized, observational studies...
Review of the body of clinical literature concluded that "there is some evidence to recommend cranberry juice for the prevention of UTIs in women with symptomatic UTIs. The large number of dropouts/withdrawals from some of the trials, however, indicates that cranberry juice may not be acceptable over long periods of time." Another review of cranberry and UTI prevention takes a more skeptical view. The review supports the anti-adhesion of activity of A Type Proanthocyanidins: "evidence suggests that the anthocyanidin/proanthocyanidin moieties are potent antiadhesion compounds" yet asserts that "most clinical trials have had design deficiencies" and points to cranberry products' "adverse events include gastrointestinal intolerance and weight gain (due to the excessive calorie load)." Both reviews agree that the evidence for cranberries (and their anti-adhesion components A Type Proanthocyanidins) and urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
prevention can be strengthened by better-designed clinical studies.