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(2,5-Dihydroxyphenyl)essigsure
2,5-DIHYDROXYPHENYLACETIC ACID · 2-(2,5-dihydroxyphenyl)acetic acid · alcapton · Melanic acid · homogentisicaci · Homogentisic acid · Homogentisinic acid · HOMOGENTISIC ACID(RG)
Identifikatoren & physikalische Daten
| CAS No. | 451-13-8 |
|---|---|
| Summenformel | C8H8O4 |
| Durchschnittliche Molmasse | 168,15 g/mol |
| Monoisotopische Masse | 168,04225874 g/mol |
| SMILES | O=C(O)Cc1cc(O)ccc1O |
| InChIKey | IGMNYECMUMZDDF-UHFFFAOYSA-N |
| PubChem CID | 780 |
| ChEBI | CHEBI:44747 |
| EC No. | 207-192-7 |
| DTXSID | DTXSID1060005 |
| Lokaler Name | (2,5-Dihydroxyphenyl)essigsure |
Chemische & physikalische Eigenschaften
| XLogP | 0,5 |
|---|---|
| Polarare Oberfläche (TPSA) | 77,8 |
| H-Brücken-Donoren | 3 |
| H-Brücken-Akzeptoren | 4 |
| Frei drehbare Bindungen | 2 |
| Schwere Atome | 12 |
| Formalladung | 0 |
| Komplexität | 168 |
| Stoffklassen | Other Classes -> Organic Acids |
| Arzneimittel | Pharmaceuticals -> Metabolite of DiclofenacPharmaceuticals -> Listed in ZINC15 |
| LogP (Verteilungskoeffizient) | 0.86 |
| Löslichkeit | 850 mg/mL at 25 °CSoluble in methanol.very faint turbidity |
| Schmelzpunkt | 153 °C150-152 °C (lit.) |
| Dampfdruck | 0.00000082 [mmHg] |
| Physical Description | Beige crystalline solid[Sigma-Aldrich MSDS] |
| Collision Cross Section | 132.4 Ų [M-H]- [CCS Type: DTMethod: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]135.9 Ų [M+H-H2O]+ [CCS Type: DTMethod: single field calibrated with Agilent tune mix (Agilent)]132.7 Ų [M-H]- |
| Siedepunkt | 257.07°C (rough estimate) |
| Dichte | 1.3037 (rough estimate) |
| Brechungsindex | 1.5090 (estimate) |
| Lagerbedingungen | 2-8°C |
| pKa (Säurekonstante) | 4.4(at 25℃) |
| Aggregatzustand | crystalline |
| Farbe | off-white to tan |
| Merck | 14,4737 |
| BRN | 2692860 |
| Hauptanwendungen | food and beverages |
| InChI | 1S/C8H8O4/c9-6-1-2-7(10)5(3-6)4-8(11)12/h1-3,9-10H,4H2,(H,11,12) |
| InChIKey | IGMNYECMUMZDDF-UHFFFAOYSA-N |
| SMILES | OC(=O)Cc1cc(O)ccc1O |
| LogP (Verteilungskoeffizient) | 0.860 |
| CAS Datenbank | 451-13-8(CAS DataBase Reference) |
| EPA chemische Informationen | Benzeneacetic acid, 2,5-dihydroxy- (451-13-8) |
Sicherheit & Vorschriften
| GHS-Einstufung | WarningH315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)Aggregated GHS information provided per 40 reports by companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies. |
|---|---|
| Gefahrenübersicht | Causes changes in urine composition in 5-day intermittent intraperitoneal studies of rats[RTECS] A skin and strong eye irritant[Sigma-Aldrich MSDS] |
| Hazard Classes and Categories | Skin Irrit. 2 (100%) |
| Treatment | Apart from treatment of the complications (such as pain relief using NSAIDs and joint replacement for the cartilage damage), vitamin C has been used to reduce the ochronosis and lowering of the homogentisic acid levels may be attempted with a low-protein diet. Recently the drug nitisinone has been found to suppress homogentisic acid production. Nitrisinone inhibits the enzyme, 4-hydroxyphenylpyruvate dioxygenase, responsible for converting tyrosine to homogentisic acid, thereby blocking the production and accumulation of homogentisic acid. Nitisinone treatment has been shown to cause a 95% reduction in plasma and urinary homogentisic acid. |
| Gesundheitliche Auswirkungen | Homogentisic acid is only toxic under chronic exposure. One of the first symptoms of alkaptonuria is darkening of urine on standing (due to the oxidation of homogentisic acid). In most pediatric patients, darkening of urine is the only feature suggesting alkaptonuria. Most patients are usually asymptomatic until age 30. Scleral pigmentation usually starts around age 30. Skin pigmentation becomes obvious by the time patients reach age 40. One of the first sites to be affected is the ear cartilage. There may be discoloration of the forehead, cheeks, axilla, genitalia, palms, nails and soles. Ochronotic arthropathy starts around the 4th decade. Weight-bearing joints like the knees and the intervertebral joints in the spine, as well as the shoulder joints, are involved, with narrowing of joint spaces and disc calcifications. Arthritis is the only disabling effect of this condition and occurs in almost all patients as age advances. Ochronotic arthropathy can be so severe as to require total joint replacement. Pigment deposits can be seen in the larynx, tonsils, esophagus, dura mater, eardrums, trachea, and bronchi. Aortic or mitral valvulitis, calcification of coronary arteries and atherosclerotic plaques are seen after the age of 50 years. |
| Toxizitätsübersicht | Extremely high levels of homogentisic acid are found in patients with the inborn error of metabolism (IEM) called Alkaptonuria. Homogentisic acid spontaneously undergoes oxidation into benzoquinone acetic acid (BQA), which polymerizes forming plasma soluble melanins (PSM). The PSM darkens many tissues (ochronosis - as the tissue looks like ochre), and produces widespread degenerative changes in cartilage and other connective tissues, joints, blood vessels, heart valves and the kidneys. Ochronotic tissue is stiff and unusually brittle. The accumulation of PSM in chondrocytes (the cells that form cartilage) leads to profound alterations in the levels of proteins involved in cell defense, protein folding, and cell organization. An increased post-translational oxidation of proteins, which also involved high molecular weight protein aggregates, has been found to be particularly evident in chondrocytes from patients with alkaptonuria. |
| Carcinogen Classification | No indication of carcinogenicity to humans (not listed by IARC). |
| Wassergefährdungsklasse (WGK) | 3 |
| TSCA-Inventar-Status | TSCA listed |
| Zollcode | 29182900 |
| RTECS-Nr. | AH0589000 |
| R-Sätze (R) | 36/37/38 |
| Gefahrensymbole | Xi |
| Sicherheitshinweise (S) | 26-36 |
| Lagerklasse | 13 - Non Combustible Solids |
Anwendungen & Verwendung
Verwenden
Homogentisic acid may be used as an analytical reference standard for the quantification of the analyte in the following:Urine matrices using reversed-phase liquid chromatography tandem mass spectrometry (LC-MS/MS).Strawberry tree honey samples using reversed phase-high performance liquid chromatography (RP-HPLC) and ion chromatography (IC).It may also be used as an internal standard for the determination of ascorbic acid (AA) and uric acid (UA) in human plasma samples using high-pressure liquid chromatography–electrochemical detection (HPLC–ECD).