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Neurotransmitter Precursors
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
-DOPA, also known as levodopa and -3,4-dihydroxyphenylalanine, is an amino acid that is made and used as part of the normal biology of some plants and animals, including humans. Humans, as well as a portion of the other animals that utilize -DOPA, make it via biosynthesis from the amino acid -tyrosine. -DOPA is the precursor to the neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), which are collectively known as catecholamines. Furthermore, -DOPA itself mediates neurotrophic factor release by the brain and CNS. -DOPA can be manufactured and in its pure form is sold as a psychoactive 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. -DOPA has a counterpart with opposite chirality, -DOPA. As is true for many molecules, the human body produces only one of these isomers (the -DOPA form). The ... [...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, su ... [...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 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 selecti ... * Foslevodopa * Melevodopa * Etilevodopa * ''O'',''O''′-Diacetyldopamine * ''O'',''O''′-Dipivaloyldopamine * Neurotransmitter prodrug 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 disconti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melevodopa
Melevodopa (brand name Levomet) is a dopaminergic agent. It is the methyl ester of levodopa. It is used in tablet form as an effervescent prodrug A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug ... with 250 times the water solubility of tablet levodopa. See also * Etilevodopa References Prodrugs Dopamine agonists Catecholamines Carboxylate esters Methyl esters Phenylpropanoids {{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 long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ..., 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 (TV-1203) is a dopaminergic agent which was developed as a treatment for Parkinson's disease. It is the ethyl ester of levodopa -DOPA, also known as levodopa and -3,4-dihydroxyphenylalanine, is an amino acid that is made and used as part of the normal biology of some plants and animals, including humans. Humans, as well as a portion of the other animals that utilize -DOPA .... It was never marketed. See also * Melevodopa References Prodrugs Catecholamines Dopamine agonists Propionate esters Ethyl esters Abandoned drugs {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-hydroxytryptophan
5-Hydroxytryptophan (5-HTP), also known as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin. Uses 5-HTP is sold over the counter in the United States, Canada, Singapore, the Netherlands, and the United Kingdom as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid. It is also marketed in many European countries for the indication of major depression under the trade names Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. A 2002 review concluded that although the data evaluated suggests that 5-HTP is more effective than placebo in the treatment of depression, the evidence was insufficient to be conclusive due to a lack of clinical data meeting the rigorous standards of the day. More and larger studies using current methodologies are needed to determine if 5-HTP is truly effective in treating depression. ... [...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. It is essential in humans, meaning that the body cannot synthesize it and it must be obtained from the diet. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3. 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. Function Amino acids, including tryptophan, are used as building blocks in protein biosynthesis, and proteins are required to sustain lif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin
Melatonin is a natural product found in plants and animals. It is primarily known in animals as a hormone released by the pineal gland in the brain at night, and has long been associated with control of the sleep–wake cycle. In vertebrates, melatonin is involved in synchronizing circadian rhythms, including sleep–wake timing and blood pressure regulation, and in control of seasonal rhythmicity including reproduction, fattening, moulting and hibernation. Many of its effects are through activation of the melatonin receptors, while others are due to its role as an antioxidant. In plants, it functions to defend against oxidative stress. It is also present in various foods. Melatonin was discovered in 1958. In addition to its role as a natural hormone, melatonin is used as a dietary supplement and medication in the treatment of sleep disorders such as insomnia and circadian rhythm sleep disorders; for information on melatonin as a supplement and medication, see the mel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vasoconstriction. Approximately 90% of the serotonin that the body produces is in the intestinal tract. Biochemically, the indoleamine molecule derives from the amino acid tryptophan, via the (rate-limiting) Tryptophan hydroxylase, hydroxylation of the 5 position on the ring (forming the intermediate 5-Hydroxytryptophan, 5-hydroxytryptophan), and then Aromatic L-amino acid decarboxylase, decarboxylation to produce serotonin. Serotonin is primarily found in the enteric nervous system located in the human gastrointestinal tract, gastrointestinal tract (GI tract). However, it is also produced in the central nervous system (CNS), specifically in the raphe nuclei located in the brainstem, Merkel cells located in the skin, Neuroendocrine cell#Pulmo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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