134308-13-7 Category:
  • # LGM Pharma is a Tolcapone CAS# 134308-13-7 API supplier distributor based in the USA. Inquire about DMF, cGMP, price, availability, samples, sourcing, purity and more.
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Product Details:

  • Product Name: Tolcapone
  • CAS #: 134308-13-7
  • Mode of Action:

    The precise mechanism of action of tolcapone is unknown, but it is believed to be related to its ability to inhibit COMT and alter the plasma pharmacokinetics of levodopa, resulting in an increase in plasma levodopa concentrations. The inhibition of COMT also causes a reduction in circulating 3-OMD as a result of decreased peripheral metabolism of levodopa. This may lead to an increase distribution of levodopa into the CNS through the reduction of its competitive substrate, 3-OMD, for transport mechanisms. Sustained levodopa concentrations presumably result in more consistent dopaminergic stimulation, resulting in greater reduction in the manifestations of parkinsonian syndrome.

  • Pharmacodynamics:

    Tolcapone is a potent, selective, and reversible inhibitor of catechol-O-methyltransferase (COMT). In humans, COMT is distributed throughout various organs. COMT catalyzes the transfer of the methyl group of S-adenosyl-L-methionine to the phenolic group of substrates that contain a catechol structure. Physiological substrates of COMT include dopa, catecholamines (dopamine, norepinephrine, epinephrine) and their hydroxylated metabolites. The function of COMT is the elimination of biologically active catechols and some other hydroxylated metabolites. COMT is responsible for the elimination of biologically active catechols and some other hydroxylated metabolites. In the presence of a decarboxylase inhibitor, COMT becomes the major metabolizing enzyme for levodopa catalyzing it to 3-methoxy-4-hydroxy-L-phenylalanine (3-OMD) in the brain and periphery. When tolcapone is given in conjunction with levodopa and an aromatic amino acid decarboxylase inhibitor, such as carbidopa, plasma levels of levodopa are more sustained than after administration of levodopa and an aromatic amino acid decarboxylase inhibitor alone. It is believed that these sustained plasma levels of levodopa result in more constant dopaminergic stimulation in the brain, leading to greater effects on the signs and symptoms of Parkinson's disease in patients as well as increased levodopa adverse effects, sometimes requiring a decrease in the dose of levodopa.

  • Metabolism:

    The main metabolic pathway of tolcapone is glucuronidation

  • Toxicity:

    LD50 = 1600 mg/kg (Orally in rats)

  • IUPAC: 5-[(4-methylphenyl)carbonyl]-3-nitrobenzene-1, 2-diol
  • ATC: N04BX01
  • PubChem: 4659569
  • DrugBank: DB00323 (APRD00445)
  • Formula: C16H14F3NO3S
  • Molecular Mass: 273.2408
  • SMILES: CC1=CC=C(C=C1)C(=O)C1=CC(=C(O)C(O)=C1)[N+]([O-])=O
  • General Reference:

    1. Guay DR: Tolcapone, a selective catechol-O-methyltransferase inhibitor for treatment of Parkinsonês disease. Pharmacotherapy. 1999 Jan;19(1):6-20. Pubmed
    2. Keating GM, Lyseng-Williamson KA: Tolcapone: a review of its use in the management of Parkinsonês disease. CNS Drugs. 2005;19(2):165-84. Pubmed
    3. Truong DD: Tolcapone: review of its pharmacology and use as adjunctive therapy in patients with Parkinsonês disease. Clin Interv Aging. 2009;4:109-13. Epub 2009 May 14. Pubmed
    4. Forsberg M, Lehtonen M, Heikkinen M, Savolainen J, Jarvinen T, Mannisto PT: Pharmacokinetics and pharmacodynamics of entacapone and tolcapone after acute and repeated administration: a comparative study in the rat. J Pharmacol Exp Ther. 2003 Feb;304(2):498-506. Pubmed
    5. Kaakkola S: Clinical pharmacology, therapeutic use and potential of COMT inhibitors in Parkinsonês disease. Drugs. 2000 Jun;59(6):1233-50. Pubmed

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