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Neurotransmitter Precursor
A neurotransmitter prodrug, or neurotransmitter precursor, is a drug that acts as a prodrug of a neurotransmitter. A variety of neurotransmitter prodrugs have been developed and used in medicine. They can be useful when the neurotransmitter itself is not suitable for use as a pharmaceutical drug owing to unfavorable pharmacokinetic or physicochemical properties, for instance high susceptibility to metabolism, short elimination half-life, or lack of blood–brain barrier drug permeability, permeability. Besides their use in medicine, neurotransmitter prodrugs have also been used as recreational drugs in some cases. Monoamine prodrugs Monoamine precursor, Monoamine neurotransmitter prodrugs include the catecholamine precursors and prodrugs phenylalanine, L-phenylalanine, tyrosine, L-tyrosine, levodopa, L-DOPA (levodopa), droxidopa, L-DOPS (droxidopa), dipivefrine (''O'',''O'''-dipivalylepinephrine), and dibutepinephrine, as well as the serotonin and melatonin precursors and prodr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levodopa
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 (PD) 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 (as foslevodopa). Side effects of levodopa include nausea, the wearing-off phenomenon, dopamine dysregulation syndrome, and levodopa-induced dyskinesia, among others. The drug is a centrally permeable monoamine precursor and prodrug of dopamine and hence acts as a dopamine receptor agonist. Chemically, levodopa is an amino acid, a phenethylamine, and a catecholamine. The major reason for enhanced risks for levodopa induced dyskinesia (LID) and OFF phases durin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DA-Phen
DA-Phen, also known as dopamine–phenylalanine conjugate, is a synthetic dopamine prodrug which is under preclinical evaluation. Dopamine itself is hydrophilic and is unable to cross the blood–brain barrier, thus showing peripheral selectivity. DA-Phen was developed as a dopamine prodrug that would allow for entry into the central nervous system via passive diffusion and/or active transport. DA-Phen is a conjugate of dopamine and the amino acid phenylalanine (Phe or Phen). It is slowly cleaved by brain enzymes ( t½ = 460minutes) to yield free dopamine but is also rapidly hydrolyzed in human blood plasma (t½ = 28minutes). The drug was intended as a prodrug but may also directly interact with the dopamine D1-like and/or D2-like receptors. DA-Phen has shown centrally mediated effects in animals, including increased cognitive flexibility, improved spatial learning and memory, antidepressant- and anxiolytic-like effects, and decreased ethanol intake. Other analogues, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DopAmide
DopAmide, or L-DopAmide, is a synthetic levodopa (L-DOPA) analogue that can serve as a levodopa and dopamine prodrug and is of potential interest in the treatment of Parkinson's disease. DopAmide has an amide rather than the carboxyl group of L-DOPA, which imparts greater water solubility. The amide is hydrolyzed back to the acid by aminopeptidase enzymes. See also * DA-Phen * Foslevodopa * Melevodopa * Etilevodopa * ''O'',''O''′-Diacetyldopamine * ''O'',''O''′-Dipivaloyldopamine * Neurotransmitter prodrug A neurotransmitter prodrug, or neurotransmitter precursor, is a drug that acts as a prodrug of a neurotransmitter. A variety of neurotransmitter prodrugs have been developed and used in medicine. They can be useful when the neurotransmitter itse ... References Antiparkinsonian agents Catecholamines Dopamine agonists Experimental drugs Monoamine precursors Prodrugs Amides {{Nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XP-21279
XP-21279 is a sustained-release levodopa (L-DOPA) prodrug and hence a dopamine precursor and non-selective dopamine receptor agonist which was under development for the treatment of Parkinson's disease. It is taken by mouth. Pharmacology The drug is said to add a five-carbon ester conjugate to levodopa that allows it to be actively transported by high-capacity nutrient transporters throughout the entire gastrointestinal tract. Subsequently, it is rapidly converted into levodopa by carboxylesterases. Levodopa itself can only be transported by a short section of the small intestine and hence XP-21279 allows more time for levodopa to be absorbed, in turn resulting in an increased duration and possibly reduced fluctuations in dopamine levels between levodopa doses. Clinical studies As of June 2015, XP-21279 was in phase 2 clinical trials. As of May 2022, there have been no further developmental updates. It was reported in 2018 that development of the drug had been discon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melevodopa
Melevodopa, also known as levodopa methyl ester (LDME) and sold under the brand name Levomet, is a dopaminergic agent. It is the methyl ester of levodopa. It is used in oral tablet form as an effervescent prodrug with 250times the water solubility of tablet levodopa. In combination with carbidopa, as melevodopa/carbidopa (brand name Sirio), it is approved for use in the treatment of Parkinson's disease. See also * Etilevodopa * Foslevodopa * XP-21279 XP-21279 is a sustained-release levodopa (L-DOPA) prodrug and hence a dopamine precursor and non-selective dopamine receptor agonist which was under development for the treatment of Parkinson's disease. It is taken by mouth. Pharmacology Th ... References Antiparkinsonian agents Carboxylate esters Catecholamines Dopamine agonists Methyl esters Monoamine precursors Phenylpropanoids Prodrugs {{Nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foslevodopa
Foslevodopa is a medication which acts as a prodrug for levodopa, originally invented in the 1980s but not developed for medical use at that time. It is approved for use in a subcutaneous infusion as a fixed-dose combination with foscarbidopa for the treatment of Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ..., under the brand name Vyalev. References {{Authority control Amino acids Antiparkinsonian agents Catecholamines Dopamine agonists Monoamine precursors Organophosphates Prodrugs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etilevodopa
Etilevodopa (developmental code name TV-1203) is a dopaminergic agent which was developed as a treatment for Parkinson's disease. It is the ethyl ester of levodopa 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 (PD) and certain other conditions like dopamine-responsive dystonia and restless legs syndrome. .... It was never marketed. See also * Melevodopa * Foslevodopa * XP-21279 References Abandoned drugs Antiparkinsonian agents Catecholamines Dopamine agonists Ethyl esters Monoamine precursors Prodrugs Propionate esters {{Nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-hydroxytryptophan
5-Hydroxytryptophan (5-HTP), used medically as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin. 5-HTP can be manufactured and used as a drug and supplement with the ''oxitriptan''. Brand names include Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. As a drug, it is used in the treatment of depression and for certain other indications. Production 5-HTP is produced from the amino acid tryptophan through the action of the enzyme tryptophan hydroxylase. Tryptophan hydroxylase is one of the biopterin-dependent aromatic amino acid hydroxylases. Production of 5-HTP is the rate-limiting step in 5-HT (serotonin) synthesis. 5-HTP is normally rapidly converted to 5-HT by amino acid decarboxylase. Metabolism 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase with the help of vita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptophan
Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic beta carbon substituent. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3 (niacin). It is encoded by the codon UGG. Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO−; pKa = 2.38). Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid. Tryptophan is named after the digestive enzymes trypsin, which were used in its first isolation from casein proteins. It was assigned the one-letter symbol W based on the double ring being visually suggestive to the bulky letter. Function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin
Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cows that could induce skin lightening in common frogs. This compound was later identified as a hormone secreted in the brain during the night, playing a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm, in vertebrates. In vertebrates, melatonin's functions extend to Entrainment (chronobiology), synchronizing sleep-wake cycles, encompassing sleep-wake timing and blood pressure regulation, as well as controlling seasonal rhythmicity (circannual cycle), which includes reproduction, fattening, molting, and hibernation. Its effects are mediated through the activation of melatonin receptors and its role as an antioxidant. In plants and bacteria, melatonin primarily serves as a defense mechanism against oxidative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin
Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, memory, and physiological processes such as vomiting and vasoconstriction. In the CNS, serotonin regulates mood, appetite, and sleep. Most of the body's serotonin—about 90%—is synthesized in the gastrointestinal tract by enterochromaffin cells, where it regulates intestinal movements. It is also produced in smaller amounts in the brainstem's raphe nuclei, the skin's Merkel cells, pulmonary neuroendocrine cells, and taste receptor cells of the tongue. Once secreted, serotonin is taken up by platelets in the blood, which release it during clotting to promote vasoconstriction and platelet aggregation. Around 8% of the body's serotonin is stored in platelets, and 1–2% is found in the CNS. Serotonin acts as both a vasoconstrictor and vas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
