L-Pyroglutamic acid

129.11400

129.11

202-700-3

760414|11742|9966

DTXSID6046260

2933790090

66.40000

-0.8

White fine crystals

1.38 g/cm3

184.7 °C

453.1ºC at 760 mmHg

227.8ºC

-10 ° (C=5, H2O)

H2O: 10-15 g/100 mL (20 ºC)

Store at RT.

130.6 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with Agilent tune mix (Agilent)]|121 Ų [M+H]+ [CCS Type: TW, Method: calibrated with polyalanine]|130.3 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|130.1 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|124.1 Ų [M-H]- [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|124.6 Ų [M-H]-

NONH for all modes of transport

3

R36/37/38

S26-S36

TW3710000

Xi

Stable. Incompatible with bases, acids, strong oxidizing agents.

P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501

H315

|Danger|H315 (54.74%): Causes skin irritation [Warning Skin corrosion/irritation]|P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, and P501|Aggregated GHS information provided by 142 companies from 15 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

High levels of pidolic acid in the blood can lead to 5-Oxoprolinuria, which can ultimately result in severe metabolic acidosis, hemolytic anaemia, or even central nervous system dysfunction.

Readily available data regarding the protein binding of pidolic acid is not available.

There is currently no clinically approved and/or marketed medicine that relies upon pidolic acid as an active ingredient for any formal therapeutic indication. Although pidolic acid may be sold in a variety of non-prescription, over-the-counter dietary supplement products for cognitive or memory enhancement, there are many studies that suggest that such products or such supplementation do not elicit any kind of cognitive benefit to users. In fact, the general suggestion for any such pidolic acid product is to exercise caution in their recommendation as much more research is necessary. Pidolic acid and sodium pidolic acid are, however, used to some extent in skin and hair conditioning agents owing to their humectant characteristics.

Pidolic acid is a naturally occurring but little-studied amino acid derivative that can be formed enzymatically or non-enzymatically and participates as a biological intermediate in various chemical pathways. Elevations of the acid in blood levels may be associated with problems of glutamine or glutathione metabolism. Pidolic acid, in general, is found in large quantities in brain tissue and other tissues in bound form, like skin. Moreover, pidolic acid in high enough levels can act as an acidogen capable of inducing acidosis and a metabotoxin that can result in adverse health effects. Chronically elevated levels of pidolic acid are associated with at least five inborn errors of metabolism including 5-oxoprolinuria (where 5-oxoproline is otherwise known as pidolic acid), 5-oxoprolinase deficiency, glutathione synthetase deficiency, hawkinsinuria, and propionic acidemia. In particular, abnormally high levels of organic acids like pidolic acid in the blood, urine, brain, and/or other tissues results in general metabolic acidosis. Such acidosis generally occurs when arterial pH falls below 7.35. In infants, the initial symptoms of acidosis consist of poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy. Eventually, acidosis and the symptoms of acidosis can lead to heart, liver, and kidney abnormalities, seizures, coma, and possibly even death. Many children who are afflicted with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures. High levels of pidolic acid in the blood have also been demonstrated following acetaminophen overdose, causing an increased level of acidity called a high anion gap metabolic acidosis.

In skin conditioning agents, it has been observed that the percutaneous absorption of 5, 10, and 20% sodium pidolic acid through human skin was 5.97, 6.78, and 5.89%, respectively.|In the dog animal model, it was determined that 30% of an absorbed oral administration of pidolic acid was excreted unchanged in the urine and the remainder converted to urea.|Readily available data regarding the volume of distribution of pidolic acid is not available.|Readily available data regarding the clearance of pidolic acid is not available.

In living cells, various metabolic pathways involving pidolic acid exist: (a) glutamyl/glutaminyl (amino acid) n is converted to pyroglutamyl- (amino acid) n by glutaminyl cyclase, pyroglutamyl- (amino acid) n is then metabolised to pyroglutamic acid (pidolic acid) by pyroglutamyl peptidase; (b) via the gamma-Glutamyl cycle, gamma-Glutamyl transpeptidase generates gamma-Glutamyl amino acid which is metabolised to pyroglutamic acid via gamma-Glutamyl cyclotransferase; (c) glutamate via gamma-Glutamylcysteine synthetase or Glutamine synthetase or Glutamate 5-kinase metabolism generates gamma-Glutamyl phosphate which itself can be converted to pyroglutamic acid; and (d) glutamate or glutamine can be non-enzymatically converted to pyroglutamic acid. Finally, pyroglutamic acid (or pidolic acid) itself is metabolized to glutamate via the 5-Oxoprolinase enzyme.

Some studies have determined that the specific half-life of the N-terminal glutamic acid is about 9 months in a pH 4.1 buffer at 45 degrees Celsius.

Pidolic acid is an endogenous amino acid derivative where the free amino group of glutamic acid or glutamine cyclizes to generate a lactam. Subsequently it is also a metabolite in the glutathione cycle that is converted to glutamate by the enzyme 5-oxoprolinase. Moreover, N-terminal glutamic acid and glutamine residues can either spontaneously cyclize to become pidolic acid, or be enzymatically transformed by glutaminyl cyclases. In particular, this is ultimately a form of N-termini that is a challenge for N-terminal sequencing using Edman chemistry, which necessitates a free primary amino group that is not present in pidolic acid. Pyroglutamate aminopeptidase can restore a free N-terminus by cleaving off the pyroglutamate residue, however. Additionally, pidolic acid and certain pidolic acid salts like calcium, magnesium, and potassium pidolic acid are sometimes used as skin or hair conditioning agents because of their humectant effects. In such humectant formulations, hydrophilic amine, hydroxyl, or even carboxyl groups possess high affinities for forming hydrogen bonds with molecules of water, allowing the hygroscopic formulations to attract and retain moisture in the air nearby through absorption, therefore drawing the water vapor into the formulation.

5-Ketoproline

Agriculture, forestry, fishing and hunting|L-Proline, 5-oxo-: ACTIVE

Cosmetics -> Humectant; Moisturising