Pidolic acid   中文名称: L-焦谷氨酸

Absorption, Distribution and Excretion
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.

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Metabolism / Metabolites
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.
5-Oxoproline is part of the glutathione metabolism pathway. Degradation of glutathione is initiated by γ-glutamyl transpeptidase, which catalyses the transfer of its γ-glutamyl-group to acceptors. The γ-glutamyl residues are substrates of the γ-glutamyl-cyclotransferase, which converts them to 5-oxoproline and the corresponding amino acids. Conversion of 5-oxoproline to glutamate is catalysed by 5-oxoprolinase. (T527)

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Biological Half-Life
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.

Toxicity Summary
5-Oxoprolinuria develops in moderate to severe cases of glutathione synthetase deficiency. The deficiency in glutathione synthetase leads to the accumulation of γ-glutamylcysteine, which is converted into 5-oxoproline by the action of γ-glutamyl cyclotransferase. The excessive formation of 5-oxoproline exceeds the capacity of 5-oxoprolinase, leading to accumulation of 5-oxoproline in body fluids causing metabolic acidosis and 5-oxoprolinuria. 5-Oxoproline accumulation is thought to be the cause of metabolic acidosis in Hawkinsinuria. 5-Oxoprolinase deficiency also leads to decreased conversion of 5-oxoproline to glutamate, resulting in elevated levels of 5-oxoproline in body fluids. 5-Oxoprolinuria has also been described in patients with urea cycle defects, such as ornithine transcarbamoylase deficiency or homocystinuria. In nephropathic cystinosis 5-oxoprolinuria may occur because of secondary impairment of the γ-glutamyl cycle resulting from decreased availability of free cysteine and can be corrected through cysteamine therapy. Transient 5-oxoprolinuria of unknown cause has been reported in very preterm infants. Limited availability of glycine in malnutrition and pregnancy as well as increased turnover of collagen, fibrinogen and other proteins containing considerable amounts of 5-oxoproline in patients with severe burns or Stevens-Johnson syndrome may lead to 5-oxoprolinuria. In addition, certain drugs, such as paracetamol, vigabatrin or some antibiotics (flucloxacillin, netimicin), are known to induce 5-oxoprolinuria, probably through interaction with the γ-glutamyl cycle. Particular infant formulas and tomato juice may contain modified proteins with increased content of 5-oxoproline. (T527)

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

Pharmacodynamics
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.

C5H7NO3

129.11

129.042

98-79-3

7405

White to light yellow solid powder

1.6±0.1 g/cm3

382.4±52.0 °C at 760 mmHg

160-163 °C(lit.)

185.1±30.7 °C

0.0±2.0 mmHg at 25°C

1.627

-1.95

66.4

2

3

1

9

154

1

C1CC(=O)N[C@@H]1C(=O)O

ODHCTXKNWHHXJC-VKHMYHEASA-N

InChI=1S/C5H7NO3/c7-4-2-1-3(6-4)5(8)9/h3H,1-2H2,(H,6,7)(H,8,9)/t3-/m0/s1

(2S)-5-oxopyrrolidine-2-carboxylic acid

EINECS 202-700-3; Glutimic acid; Pidolic acid; NSC-9966; NSC143034; NSC 9966; NSC9966;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~774.53 mM)
H2O : ~100 mg/mL (~774.53 mM)

配方 1 中的溶解度: ≥ 2.5 mg/mL (19.36 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 25.0 mg/mL澄清DMSO储备液加入到400 μL PEG300中，混匀；然后向上述溶液中加入50 μL Tween-80，混匀；加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: ≥ 2.5 mg/mL (19.36 mM) (饱和度未知) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL澄清DMSO储备液加入900 μL 20% SBE-β-CD生理盐水溶液中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

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配方 3 中的溶解度: ≥ 2.5 mg/mL (19.36 mM) (饱和度未知) in 10% DMSO + 90% Corn Oil (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL 澄清 DMSO 储备液加入到 900 μL 玉米油中并混合均匀。

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配方 4 中的溶解度: 140 mg/mL (1084.35 mM) in PBS (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶.

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。