505 2,3,4,4',6-Pentachlorobiphenyl 2,3,4,4',6-Pentachlorobiphenyl (C12H5Cl5) is an exogenous organic compound with an average molecular weight of 326.43 g/mol. It exists as a solid at room temperature. 2,3,4,4',6-Pentachlorobiphenyl belongs to the biphenyls and derivatives, a subclass of benzene and substituted derivatives within the organic compounds. This compound interacts with seven recorded protein targets. It is believed to cause decreased dopamine synthesis by inhibiting tyrosine 3-monooxygenase (TH) and aromatic-L-amino-acid decarboxylase (DDC). As a dioxin-like PCB, it binds to the aryl hydrocarbon receptor (AHR), which alters gene transcription and disrupts cell function, primarily by inducing the expression of hepatic Phase II and Phase I enzymes, specifically the cytochrome P450 family. It causes endocrine disruption in humans by binding to and inhibiting estrogen receptor beta (ESR2) and estrogen receptor (ESR1). Additionally, it can bind to estrogen sulfotransferase (SULT1E1), which may produce estrogenic effects such as reproductive dysfunction and stimulate the growth of certain cancer cells. Finally, 2,3,4,4',6-Pentachlorobiphenyl will bioaccumulate by binding to receptor proteins such as uteroglobin (SCGB1A1). 74472-38-1 91720 C12H5Cl5 323.883390 Oily liquids or solids that are colorless to light yellow. 3.66e-06 mg/mL at 25°C [PATIL,GS (1991)] Oral (L4) ; inhalation (L4) ; dermal (L4) The mechanism of action varies with the specific PCB. Dioxin-like PCBs bind to the aryl hydrocarbon receptor, which disrupts cell function by altering the transcription of genes, mainly be inducing the expression of hepatic Phase I and Phase II enzymes, especially of the cytochrome P450 family. Most of the toxic effects of PCBs are believed to be results of Ah receptor binding. Other PBCs are believed to interfere with calcium channels and/or change brain dopamine levels. PCBs can also cause endocrine disurption by altering the production of thyroid hormones and binding to estrogen receptors, which can stimulate the growth of certain cancer cells and produce other estrogenic effects, such as reproductive dysfunction. They will bioaccumulate by binding to receptor proteins such as uteroglobin. (A3, A4, A30, A66) PCBs are absorbed via inhalation, oral, and dermal routes of exposure. They are trasported in the blood, often bound to albumin. Due to their lipophilic nature they tend to accumulate in lipid-rich tissues, such as the liver, adipose, and skin. Metabolism of PCBs is very slow and varies based on the degree and position of chlorination. PCBs are metabolized by the microsomal monooxygenase system catalyzed by cytochrome P-450 enzymes to polar metabolites that can undergo conjugation with glutathione and glucuronic acid. The major metabolites are hydroxylated products which are excreted in the bile and faeces. The slow metabolism of PCBs means they tend to accumulate in body tissues. (L4, T6) LD50: 1010 mg/kg (Oral, Rat) (T14) LD50: 880 mg/kg (Intraperitoneal, Mouse) (T14) 1, carcinogenic to humans. (L135) PCBs were used as coolants and lubricants in transformers, capacitors, and other electrical devices (such as fluorescent lights and refridgerators) produced before 1977. PCBs may contaminate the air and water near hazardous waste sites. In addition, PCBs bioaccumulate in the environment and may be found in fish, meat, and dairy products. (L4) Intermediate Oral: 0.03 ug/kg/day (L134) The most common health effects of PCBs are skin conditions such as chloracne and rashes. Chronic PCB exposure has also been shown to cause liver, stomach and kidney, damage, jaundice, edema, anemia, changes in the immune system, behavioral alterations, and impaired reproduction. (L4) Chronic PCB exposure results in symptoms such as abdominal pain, nausea, vomiting, diarrhea, headache, dizziness, depression, nervousness, dermal and ocular lesions, fatigue, irregular menstrual cycles and a lowered immune response. (A3) There are no specific treatments for PCB poisoning, since it is not usually recognized until after substantial chronic exposure. Only preventing further exposure and treating the observed symptoms can be done. Acute inhalation can be treated by administering oxygen. (L4) 2009-03-06T18:58:57Z 2026-08-18T21:13:44Z Cytochrome P450 1A1 (P04798) Cytochrome P450 1A2 (P05177) Cytochrome P450 2B6 (P20813) Serum albumin (P02768) (L4) CPD-946 2,3,4,4',6-Pentachlorobiphenyl true Cytochrome P450 1A1 (P04798) Cytochrome P450 1A2 (P05177) Cytochrome P450 2B6 (P20813) (L4) Serum albumin (P02768) (L4) ClC1=CC=C(C=C1)C1=C(Cl)C=C(Cl)C(Cl)=C1Cl C12H5Cl5 InChI=1S/C12H5Cl5/c13-7-3-1-6(2-4-7)10-8(14)5-9(15)11(16)12(10)17/h1-5H IOVARPVVZDOPGQ-UHFFFAOYSA-N 326.433 323.883388695 Exogenous Solid 6.6 82820 CHEM000446 DTXSID4074227 NS00077043 1,2,3,5-tetrachloro-4-(4-chlorophenyl)benzene 0 75.2182 28.937461839743467 1 0 0 0 2 6.76 -7.65 7.35e-06 g/l Organic compounds Benzenoids Benzene and substituted derivatives Biphenyls and derivatives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 776t3gAAAAAQAAAAAwAAAAAAAAARAAAAEgAAAIABEQAgAAAAAQZAKAAAAAME BkBoAAAAAwMBBkBoAAAAAwMBBkAoAAAAAwQGQGgAAAADAwEGQGgAAAADAwEG QCgAAAADBAZAKAAAAAMEEQAgAAAAAQZAaAAAAAMDAQZAKAAAAAMEEQAgAAAA AQZAKAAAAAMEEQAgAAAAAQZAKAAAAAMEEQAgAAAAAQsAAQABAmgMAgNoDAME aAwEBWgMBQZoDAQHIAcIaAwICQAICmgMCgtoDAsMAAsNaAwNDgAND2gMDxAA BgFoDA8HaAxCAgAAAAYBBgUEAwIGCAoLDQ8HFwQAAAAAAAAAFg== 2026-09-19T03:59:42Z