Skeletal formula of L-DOPA | |
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Names | |
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IUPAC name (S)-2-Amino-3-(3,4-dihydroxyphenyl)propanoic acid | |
Other names l-3,4-Dihydroxyphenylalanine; Levodopa | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.000.405 |
EC Number |
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KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C9H11NO4 | |
Molar mass | 197.19 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
l-DOPA, also known as l-3,4-dihydroxyphenylalanine and used medically as levodopa, is made and used as part of the normal biology of some plants [2] and animals, including humans. Humans, as well as a portion of the other animals that utilize l-DOPA, make it via biosynthesis from the amino acid l-tyrosine.
l-DOPA is the precursor to the neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), which are collectively known as catecholamines. Furthermore, l-DOPA itself mediates neurotrophic factor release by the brain and CNS. [3] [4] In some plant families (of the order Caryophyllales), l-DOPA is the central precursor of a biosynthetic pathway that produces a class of pigments called betalains. [5]
l-DOPA can be manufactured and in its pure form is sold as a drug with the INN levodopa . Trade names include Sinemet, Pharmacopa, Atamet, and Stalevo. As a drug, it is used in the clinical treatment of Parkinson's disease and dopamine-responsive dystonia.
l-DOPA has a counterpart with opposite chirality, d-DOPA. As is true for many molecules, the human body produces only one of these isomers (the l-DOPA form). The enantiomeric purity of l-DOPA may be analyzed by determination of the optical rotation or by chiral thin-layer chromatography. [6]
l-DOPA is produced from the amino acid l-tyrosine by the enzyme tyrosine hydroxylase. l-DOPA can act as an l-tyrosine mimetic and be incorporated into proteins by mammalian cells in place of l-tyrosine, generating protease-resistant and aggregate-prone proteins in vitro and may contribute to neurotoxicity with chronic l-DOPA administration. [10] It is also the precursor for the monoamine or catecholamine neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline). Dopamine is formed by the decarboxylation of l-DOPA by aromatic l-amino acid decarboxylase (AADC).
l-DOPA can be directly metabolized by catechol-O-methyl transferase to 3-O-methyldopa, and then further to vanillactic acid. This metabolic pathway is nonexistent in the healthy body, but becomes important after peripheral l-DOPA administration in patients with Parkinson's disease or in the rare cases of patients with AADC enzyme deficiency. [11]
l-Phenylalanine, l-tyrosine, and l-DOPA are all precursors to the biological pigment melanin. The enzyme tyrosinase catalyzes the oxidation of l-DOPA to the reactive intermediate dopaquinone, which reacts further, eventually leading to melanin oligomers. In addition, tyrosinase can convert tyrosine directly to l-DOPA in the presence of a reducing agent such as ascorbic acid. [12]
l-dopa was first islolated from the seeds of the Vicia faba or broad bean plant in 1913 by Swiss biochemist Markus Guggenheim. [13]
The 2001 Nobel Prize in Chemistry was also related to l-DOPA: the Nobel Committee awarded one-quarter of the prize to William S. Knowles for his work on chirally catalysed hydrogenation reactions, the most noted example of which was used for the synthesis of l-DOPA. [14] [15] [16]
l-DOPA is a key compound in the formation of marine adhesive proteins, such as those found in mussels. [17] [18] It is believed to be responsible for the water-resistance and rapid curing abilities of these proteins. l-DOPA may also be used to prevent surfaces from fouling by bonding antifouling polymers to a susceptible substrate. [19] The versatile chemistry of l-DOPA can be exploited in nanotechnology. [20] For example, DOPA-containing self-assembling peptides were found to form functional nanostructures, adhesives and gels. [21] [22] [23] [24]
In plants, L-DOPA functions as an allelochemical which inhibits the growth of certain species, and is produced and secreted by a few legume species such as the broad bean Vicia faba and the velvet bean Mucuna pruriens . [25] Its effect is strongly dependent on the pH and the reactivity of iron in the soil. [26]
L-DOPA is used medically under the name levodopa in the treatment of Parkinson's disease and certain other medical conditions. It is usually used in combination with a peripherally selective aromatic L-amino acid decarboxylase (AAAD) inhibitor such as carbidopa or benserazide. These agents increase the strength and duration of levodopa. Combination formulations include levodopa/carbidopa and levodopa/benserazide, as well as levodopa/carbidopa/entacapone.
L-DOPA is found in high amounts in Mucuna pruriens (velvet bean) and is available and used over-the-counter as a supplement.
L-Tyrosine or tyrosine or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is from the Greek tyrós, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese. It is called tyrosyl when referred to as a functional group or side chain. While tyrosine is generally classified as a hydrophobic amino acid, it is more hydrophilic than phenylalanine. It is encoded by the codons UAC and UAU in messenger RNA.
Dopamine is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical, L-DOPA, which is synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons to send signals to other nerve cells. Neurotransmitters are synthesized in specific regions of the brain but affect many regions systemically. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many addictive drugs increase dopamine release or block its reuptake into neurons following release. Other brain dopamine pathways are involved in motor control and in controlling the release of various hormones. These pathways and cell groups form a dopamine system which is neuromodulatory.
A catecholamine is a monoamine neurotransmitter, an organic compound that has a catechol and a side-chain amine.
Aromatic L-amino acid decarboxylase, also known as DOPA decarboxylase (DDC), tryptophan decarboxylase, and 5-hydroxytryptophan decarboxylase, is a lyase enzyme, located in region 7p12.2-p12.1.
Carbidopa (Lodosyn) is a drug given to people with Parkinson's disease in order to inhibit peripheral metabolism of levodopa. This property is significant in that it allows a greater proportion of administered levodopa to cross the blood–brain barrier for central nervous system effect, instead of being peripherally metabolised into substances unable to cross said barrier.
Benserazide is a peripherally acting aromatic L-amino acid decarboxylase or DOPA decarboxylase inhibitor, which is unable to cross the blood–brain barrier.
Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper–Mason pathway. Firstly, the hydroxylation of a monophenol and secondly, the conversion of an o-diphenol to the corresponding o-quinone. o-Quinone undergoes several reactions to eventually form melanin. Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation. It is found inside melanosomes which are synthesized in the skin melanocytes. In humans, the tyrosinase enzyme is encoded by the TYR gene.
Carbidopa/levodopa, also known as levocarb and co-careldopa, is the combination of the two medications carbidopa and levodopa. It is primarily used to manage the symptoms of Parkinson's disease, but it does not slow down the disease or stop it from getting worse. It is taken by mouth. It can take two to three weeks of treatment before benefits are seen. Each dose then begins working in about ten minutes to two hours with a duration of effect of about five hours.
Dopaminergic means "related to dopamine", a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain.
Mucuna pruriens is a tropical legume native to Africa and tropical Asia and widely naturalized and cultivated. Its English common names include monkey tamarind, velvet bean, Bengal velvet bean, Florida velvet bean, Mauritius velvet bean, Yokohama velvet bean, cowage, cowitch, lacuna bean, and Lyon bean. The Tshivenda/Venda language name is Vhulada.
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA). It does so using molecular oxygen (O2), as well as iron (Fe2+) and tetrahydrobiopterin as cofactors. L-DOPA is a precursor for dopamine, which, in turn, is a precursor for the important neurotransmitters norepinephrine (noradrenaline) and epinephrine (adrenaline). Tyrosine hydroxylase catalyzes the rate limiting step in this synthesis of catecholamines. In humans, tyrosine hydroxylase is encoded by the TH gene, and the enzyme is present in the central nervous system (CNS), peripheral sympathetic neurons and the adrenal medulla. Tyrosine hydroxylase, phenylalanine hydroxylase and tryptophan hydroxylase together make up the family of aromatic amino acid hydroxylases (AAAHs).
A catechol-O-methyltransferase inhibitor is a drug that inhibits the enzyme catechol-O-methyltransferase. This enzyme methylates catecholamines such as dopamine, norepinephrine and epinephrine. It also methylates levodopa. COMT inhibitors are indicated for the treatment of Parkinson's disease in combination with levodopa and an aromatic L-amino acid decarboxylase inhibitor. The therapeutic benefit of using a COMT inhibitor is based on its ability to prevent the methylation of levodopa to 3-O-methyldopa, thus increasing the bioavailability of levodopa. COMT inhibitors significantly decrease off time in people with Parkinson's disease also taking carbidopa/levodopa.
Bioadhesives are natural polymeric materials that act as adhesives. The term is sometimes used more loosely to describe a glue formed synthetically from biological monomers such as sugars, or to mean a synthetic material designed to adhere to biological tissue.
Droxidopa, also known as L-threo-dihydroxyphenylserine (L-DOPS) and sold under the brand names Northera and Dops among others, is sympathomimetic medication which is used in the treatment of hypotension and for other indications. It is taken by mouth.
Levodopa, also known as L-DOPA and sold under many brand names, is a dopaminergic medication which is used in the treatment of Parkinson's disease and certain other conditions like dopamine-responsive dystonia and restless legs syndrome. The drug is usually used and formulated in combination with a peripherally selective aromatic L-amino acid decarboxylase (AAAD) inhibitor like carbidopa or benserazide. Levodopa is taken by mouth, by inhalation, through an intestinal tube, or by administration into fat.
An aromatic L-amino acid decarboxylase inhibitor (synonyms: DOPA decarboxylase inhibitor, extracerebral decarboxylase inhibitor, DDCI and AAADI) is a medication of type enzyme inhibitor which inhibits the synthesis of dopamine by the enzyme aromatic L-amino acid decarboxylase (AADC, AAAD, or DOPA decarboxylase). It is used to inhibit the decarboxylation of L-DOPA to dopamine outside the brain, i.e. in the blood. This is primarily co-administered with L-DOPA to combat Parkinson's disease. Administration can prevent common side-effects, such as nausea and vomiting, as a result of interaction with D2 receptors in the vomiting center (or cheomoreceptor trigger zone) located outside the blood–brain barrier.
α-Difluoromethyl-3,4-dihydroxyphenylalanine is a DOPA decarboxylase inhibitor.
3-O-Methyldopa (3-OMD) is one of the most important metabolites of L-DOPA, a drug used in the treatment of the Parkinson's disease.
Monoamine precursors are precursors of monoamines and monoamine neurotransmitters in the body. The amino acids L-tryptophan and L-5-hydroxytryptophan are precursors of serotonin and melatonin, while the amino acids L-phenylalanine, L-tyrosine, and L-DOPA (levodopa) are precursors of dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).
Melevodopa/carbidopa, sold under the brand name Sirio, is a combination of melevodopa, a prodrug of the dopamine precursor and hence non-selective dopamine receptor agonist levodopa (L-DOPA), and carbidopa, a peripherally selective aromatic L-amino acid decarboxylase (AAAD) inhibitor, which is used in the treatment of Parkinson's disease in Italy. It is taken orally in the form of tablets.