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T3D0058 - 3-Xylene
| Record Information | |
|---|---|
| Version | 1.0 |
| Creation Date | 2009-03-06 18:58:00 UTC |
| Update Date | 2013-04-25 08:32:39 UTC |
| Accession Number | T3D0058 |
| Identification | |
| Common Name | 3-Xylene |
| Description | Xylene refers to the mixture of its three aromatic hydrocarbon isomers: meta-xylene, ortho-xylene, and para-xylene. It occurs naturally in petroleum and coal tar, and is major component of gasoline and fuel oil. Xylene is used mainly as a solvent and in the printing, rubber, and leather industries. (R029, R319) |
| Compound Type |
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| Chemical Structure |
|
| Synonyms |
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| Chemical Formula | Not Available |
| Average Molecular Weight | Not Available |
| Monoisotopic Molecular Weight | Not Available |
| Chemical IUPAC Name | Not Available |
| CAS Registry Number | 1330-20-7 |
| SMILES | Not Available |
| InChI Identifier | Not Available |
| InChI Key | Not Available |
| Chemical Taxonomy | |
| Kingdom | Not Available |
| Super Class | Not Available |
| Class | Not Available |
| Sub Class | Not Available |
| Direct Parent | Not Available |
| Alternative Parents | Not Available |
| Molecular Framework | Not Available |
| Substituents | Not Available |
| External Descriptors | Not Available |
| External Links | |
| DrugBank ID | Not Available |
| PubChem Compound ID | 7929  |
| KEGG ID | Not Available |
| UniProt ID | Not Available |
| OMIM ID | Not Available |
| ChEBI ID | 27338 |
| BioCyc ID | CPD-1125 |
| CTD ID | Not Available |
| Stitch ID | Xylene |
| PDB ID | Not Available |
| ACToR ID | 1479 |
| Wikipedia Link | Not Available |
| Physical Properties | |
| Appearance | Colorless liquid. |
| Melting Point | Boiling Pt : 138.5 C |
| Solubility | 0.106 mg/mL at 25 °C [YALKOWSKY,SH & DANNENFELSER,RM (1992)] |
| Predicted LogP | Not Available |
| Toxicity Profile | |
| Route of Exposure | Oral (R319) ; inhalation (R319) ; dermal (R319) |
| Mechanism of Action | In the blood, xylene is bound to serum proteins and accumulates primarily in the adipose tissue. The lipophilic effects of xylene, which dissolve lipid membranes, is responsible for the irritant effects on eyes, mucous membranes and skin. In addition, the lipophilicity of xylene is responsible for its narcotic and anaesthetic properties, which are similar for the three isomers. The mechanism of is anesthetic function probably relates to intercalation of the chemical into neuronal cell membranes, changing membrane properties that affect transmission of nerve impulses. The mechanism could be either by a disruption of the lipid environment in which membrane proteins function or by direct interaction with the hydrophobic/hydrophilic conformation of proteins in the neuronal membrane. Acute-duration oral or intermediate-duration inhalation exposures to high concentrations of xylene may result in death of cochlear hair cells and hearing loss. Experiments suggest that renal toxicity of xylene may be related to its metabolism by CYP2E1, which generates the production of oxidative intermediates and subsequent necrosis. Nephrotoxicity from xylene may involve induction of apoptosis through the activation of mitochondrial caspase-9 and caspase-3. (R319) |
| Metabolism | Xylenes are well absorbed by the inhalation and oral routes. Approximately 60% of inspired xylene is retained and approximately 90% of ingested xylene is absorbed. Absorption also occurs by the dermal route, but to a much lesser extent than by the inhalation and oral routes. Following absorption, xylene is rapidly distributed throughout the body by way of the systemic circulation. In the blood, it is primarily bound to serum proteins and accumulates primarily in adipose tissue. Xylene is primarily metabolized by oxidation of a methyl group and conjugation with glycine to yield the methylhippuric acid, whicih is the primary metabolite excreted in urine. Aromatic hydroxylation of xylene to xylenol occurs to only a limited extent in humans. Less than 2% of an absorbed dose is excreted in the urine as xylenol. Other minor metabolites found in urine include methylbenzyl alcohol and glucuronic acid conjugates of the oxidized xylene. In humans, hepatic microsomal CYP2E1 is the primary enzyme involved with the metabolism of xylene to methylbenzylalcohol, the dominant pathway leading to the formation of methylhippuric acid isomers. Unmetabolized xylene can be exhalated or also excreted in urine. (R319) |
| Toxicity Values | LD50: 1590 mg/kg (Oral, Rat) (R276) LC50: 6350 ppm over 4 hours (Inhalation, Rat) (R286) LD50: 1548 mg/kg (Intraperitoneal, Mouse) (R293) LD50: 1700 mg/kg (Subcutaneous, Rat) (R293) |
| Lethal Dose | 50 and 500 mg/kg for an adult human. (R521) |
| Carcinogenicity (IARC Classification) | 3, not classifiable as to its carcinogenicity to humans. (R264) |
| Uses/Sources | Xylene mainly affects the nervous system. Exposure may cause delayed reaction time, impaired short-term memory, and changes in one’s sense of balance. High levels of exposure can result in coma, respiratory depression and death from cerebral anoxia. Xylene may also damage the liver, kidney, and lungs. Effects on fetal body weight and delay of skeletal ossification can occur in pregnant women. (R319, R319, R320) |
| Minimum Risk Level | Acute Inhalation: 2 ppm (R260) Intermediate Inhalation: 0.6 ppm (R260) Chronic Inhalation: 0.05 ppm (R260) Acute Oral: 1 mg/kg/day (R260) Intermediate Oral: 0.4 mg/kg/day (R260) Chronic Oral: 0.2 mg/kg/day (R260) |
| Health Effects | Xylene mainly affects the nervous system. Exposure may cause delayed reaction time, impaired short-term memory, and changes in one’s sense of balance. High levels of exposure can result in coma, respiratory depression and death from cerebral anoxia. Xylene may also damage the liver, kidney, and lungs. Effects on fetal body weight and delay of skeletal ossification can occur in pregnant women. (R319, R319, R320) |
| Symptoms | Dizziness, drowsiness, headache, and nausea can follow ihnalation and ingestion exposure. Burning sensations and abdominal pain can also result from ingestion. Dry skin, redness, and pain can result from dermal and eye exposure depending on the route of exposure. Conjunctivitis, dermatitis, irritation to respiratory tract, dyspnea, anorexia, vomiting, fatigue, vertigo, incoordination, irritation, gangrene and anemia can also follow xylene poisoning. (N010) |
| Treatment | Gastric lavage is generally NOT indicated following oral exposure, as it is likely to increase the risk of aspiration. Activated charcoal may induce vomiting and increase pulmonary aspiration risk, and is generally NOT indicated. It should be limited to rare situations when there is a toxic coingestant. Following inhalation exposure, move patient to fresh air. Monitor for respiratory distress, if cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with inhaled beta2 agonist and oral or parenteral corticosteroids. The development of pulmonary edema from extreme vapour inhalation may be delayed up to 72 hours. If symptomatic, obtain chest x-ray, if severe, monitor arterial blood gases or pulse oximetry. Supplemental oxygen, PEEP, or CPAP may be necessary. Do not administer excessive fluids. Irrigate exposed eyes with copious amounts of room temperature water for at least 15 minutes in case of eye exposure. Following dermal exposure, remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician may need to examine the area if irritation or pain persists. (R264) |
| References | |
| General References |
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Targets
1. Cytochrome P450 2E1
Metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Inactivates a number of drugs and xenobiotics and also bioactivates many xenobiotic substrates to their hepatotoxic or carcinogenic forms.
Certain metabolites of xylene have been shown to inhibit pulmonary mixed-function oxidases. (R322)UniProt ID: P05181
Gene: CYP2E1
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report
References:
- R322 — Foy JW, Silverman DM, Schatz RA: Low-level m-Xylene inhalation alters pulmonary and hepatic cytochrome P-450 activity in the rat. J Toxicol Environ Health. 1996 Feb 9;47(2):135-44.
[8598570 ]
2. Cytochrome P450 4B1
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics.
Certain metabolites of xylene have been shown to inhibit pulmonary mixed-function oxidases. (R322)UniProt ID: P13584
Gene: CYP4B1
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report
References:
- R322 — Foy JW, Silverman DM, Schatz RA: Low-level m-Xylene inhalation alters pulmonary and hepatic cytochrome P-450 activity in the rat. J Toxicol Environ Health. 1996 Feb 9;47(2):135-44.
[8598570 ]