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Pyrrolidines
Pyrrolidine, also known as tetrahydropyrrole, is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, also classified as a saturated heterocycle. It is a colourless liquid that is miscible with water and most organic solvents. It has a characteristic odor that has been described as "ammoniacal, fishy, shellfish-like". In addition to pyrrolidine itself, many substituted pyrrolidines are known. Production and synthesis Industrial production Pyrrolidine is prepared industrially by the reaction of 1,4-butanediol and ammonia at a temperature of 165–200 °C and a pressure of 17–21 MPa in the presence of a cobalt- and nickel oxide catalyst, which is supported on alumina. : The reaction is carried out in the liquid phase in a continuous tube- or tube bundle reactor, which is operated in the cycle gas method. The catalyst is arranged as a fixed-bed and the conversion is carried out in the downflow mode. The product is obtained after m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyproline
(2''S'',4''R'')-4-Hydroxyproline, or L-hydroxyproline ( C5 H9 O3 N), is an amino acid, abbreviated as Hyp or O, ''e.g.'', in Protein Data Bank. Structure and discovery In 1902, Hermann Emil Fischer isolated hydroxyproline from hydrolyzed gelatin. In 1905, Hermann Leuchs synthesized a racemic mixture of 4-hydroxyproline. Hydroxyproline differs from proline by the presence of a hydroxyl (OH) group attached to the gamma carbon atom. Production and function Hydroxyproline is produced by hydroxylation of the amino acid proline by the enzyme prolyl 4-hydroxylase following protein synthesis (as a post-translational modification). The enzyme-catalyzed reaction takes place in the lumen of the endoplasmic reticulum. Although it is not directly incorporated into proteins, hydroxyproline comprises roughly 4% of all amino acids found in animal tissue, an amount greater than seven other amino acids that are translationally incorporated. Animals Collagen Hydroxyproline is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proline
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group but is rather a secondary amine. The secondary amine nitrogen is in the protonated form (NH2+) under biological conditions, while the carboxyl group is in the deprotonated −COO− form. The "side chain" from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it as a aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it from the non-essential amino acid L-glutamate. It is encoded by all the codons starting with CC (CCU, CCC, CCA, and CCG). Proline is the only proteinogenic amino acid which is a secondary amine, as the nitrogen atom is attached both to the α-carbon and to a chain of three carbons that together form a five-membered ring. History and etymology Proline was first isolated in 1900 by Richard Willstätter who obtained the amino a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascade Reaction
A cascade reaction, also known as a domino reaction or tandem reaction, is a chemical process that comprises at least two consecutive reactions such that each subsequent reaction occurs only in virtue of the chemical functionality formed in the previous step.Tietze, L. F.; Beifuss, U. ''Angew. Chem. Int. Ed.'' 1993, ''32'', 131–163. In cascade reactions, isolation of intermediates is not required, as each reaction composing the sequence occurs spontaneously. In the strictest definition of the term, the reaction conditions do not change among the consecutive steps of a cascade and no new reagents are added after the initial step.Padwa, A.; Bur, S. K. ''Tetrahedron'' 2007, ''63'', 5341–5378. By contrast, one-pot procedures similarly allow at least two reactions to be carried out consecutively without any isolation of intermediates, but do not preclude the addition of new reagents or the change of conditions after the first reaction. Thus, any cascade reaction is also a one-pot p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotine
Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve drug withdrawal, withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits (nAChRα9 and nAChRα10) where it acts as a receptor antagonist. Nicotine constitutes approximately 0.6–3.0% of the dry weight of tobacco. Nicotine is also present at Parts-per notation, ppb concentrations in edible plants in the family Solanaceae, including potatoes, tomatoes, and eggplants, though sources disagree on whether this has any biological significance to human consumers. It functions as an plant defense against herbivory, antiherbivore toxin; consequently, nicotine was widely used as an insecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups ( alpha- , beta- , gamma- amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type ( aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence. Amino acids are formally named by the IUPAC- IUBMB Joint Commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aniracetam
Aniracetam (brand names Draganon, Sarpul, Ampamet, Memodrin, Referan), also known as ''N''-anisoyl-2-pyrrolidinone, is a racetam which is sold in Europe as a prescription drug. It is not approved by the Food and Drug Administration for use in the United States as a prescription medication or dietary supplement. Despite the FDA's lack of approval, the drug is readily available over-the-counter in misbranded dietary supplements. Medical uses Aniracetam has been used to treat dementia following stroke and in Alzheimer's disease. Results from human clinical trials were published in 1991 (one multi-center placebo-controlled study and a follow-up) and in 2011 (one open-label study). It has undergone a larger number of experiments in rodents; in a 1982 experiment on rats and mice it was found to have a variety of psychoactive effects, improving learning and memory that was otherwise impaired experimentally. It has been identified as a nootropic drug due to these memory effects. A 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piracetam
Piracetam is a drug that has efficacy in cognitive disorders, vertigo, cortical myoclonus, dyslexia, and sickle cell anemia; sources differ on its usefulness for dementia. Piracetam is sold as a medication in many European countries. Piracetam in the United States is not approved for general use. Piracetam is in the racetams group, with chemical name ''2-oxo-1-pyrrolidine acetamide''. It is a cyclic derivative of the neurotransmitter GABA and shares the same 2-oxo-pyrrolidone base structure with pyroglutamic acid. Related drugs include the anticonvulsants levetiracetam and brivaracetam, and the putative nootropics aniracetam and phenylpiracetam. Efficacy Dementia A 2001 Cochrane review concluded that there was not enough evidence to support piracetam for dementia or cognitive problems. A 2005 review found some evidence of benefit in older subjects with cognitive impairment. In 2008, a working group of the British Academy of Medical Sciences noted that many of the trials of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Racetam
Racetams, also sometimes known simply as pyrrolidones, are a class of drugs that share a pyrrolidone nucleus. Many, but not all, specifically have a 2- oxo-1- pyrrolidine acetamide (piracetam) nucleus. Some racetams, such as piracetam, aniracetam, oxiracetam, pramiracetam, and phenylpiracetam, are considered nootropics. Phenylpiracetam is also a stimulant. Others, such as levetiracetam, brivaracetam, and seletracetam, are anticonvulsants. Mechanism There is no universally accepted mechanism of action for racetams. Racetams generally show negligible affinity for common central nervous system receptors, but modulation of central neurotransmitters, including acetylcholine and glutamate, has been reported. Although aniracetam and nebracetam show some affinity for muscarinic acetylcholine receptors, only nefiracetam demonstrates nanomolar interactions with neurotransmitter receptors. Modification of membrane-located mechanisms of central signal transduction is another hypothesis. Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bepridil
Bepridil (trade name Vascor) is an diamine calcium channel blocker once used to treat angina pectoris. It is no longer sold in the United States. It is nonselective. It has been discussed as a possible option in the treatment of atrial fibrillation. It has been implicated in causing ventricular arrhythmia ( torsades de pointes). Ebola research In June 2015 a research paper was published finding bepridil to result in a 100% survival rate for mice exposed to ebola during an experiment searching for potential pharmaceutical ebola treatments; indicating its potential use in future ebola research and therapy. SARS-CoV-2 research A research paper showed that Bepridil inhibited cytopathogenic effects induced by SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic. The virus previously had the Novel coronavirus, provisional nam ... in Ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Procyclidine
Procyclidine is an anticholinergic medication, drug principally used for the treatment of drug-induced parkinsonism, akathisia and acute dystonia, Parkinson's disease, and idiopathic or secondary dystonia. Medical uses It is used in patients with parkinsonism and akathisia, and to reduce the side effects of antipsychotic treatment given for schizophrenia. Procyclidine is also a second-line drug for the treatment of Parkinson's disease. It improves tremor but not rigidity or bradykinesia. Procyclidine is also sometimes used for the treatment of dystonia (but not tardive dyskinesia), a rare disorder that causes abnormal muscle contraction, resulting in twisting postures of limbs, trunk, or face. Side Effects Side effects include nausea, constipation, urinary retention, blurred vision, anxiety, cognitive impairment, confusion, dizziness, gingivitis, hallucination, memory loss, rash and vomiting. Overdose Signs of procyclidine overdose are those of an anticholinergic and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygrine
Hygrine is a pyrrolidine alkaloid, found mainly in coca leaves (0.2%). It was first isolated by Carl Liebermann in 1889 (along with a related compound cuscohygrine) as an alkaloid accompanying cocaine Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ... in coca. Hygrine is extracted as a thick yellow oil, having a pungent taste and odor. See also * Coca alkaloids * Pseudotropine * Troparil References * * * {{cite web, title=USDA, ARS, National Genetic Resources Program. Phytochemical and Ethnobotanical Databases. National Germplasm Resources Laboratory, Beltsville, Maryland. , url=http://sun.ars-grin.gov:8080/npgspub/xsql/duke/chemdisp.xsql?chemical=HYGRINE , archive-url=https://archive.today/20121211210941/http://sun.ars-grin.gov:8080/npgspub/xsql/duke/chemdisp.xsql?che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
