|
Miotine
Miotine is an anticholinesterase drug. Miotine was the first synthetic carbamate that was used clinically. Unlike the miotine analog neostigmine, it doesn't have a quaternary ammonium group to give it a permanent positive charge. It can exist as an uncharged free base which could allow it to cross the blood–brain barrier and cause unwanted central nervous system (CNS) side effects. : See also * Neostigmine * T-1123 *TL-1238 TL-1238 (Substance 3393) is an extremely potent carbamate In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes or ... * TMTFA References Acetylcholinesterase inhibitors Aromatic carbamates Phenol esters {{pharma-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-1123
T-1123 is a carbamate-based acetylcholinesterase inhibitor. It was investigated as a chemical warfare agent starting in 1940. It does not go through the blood-brain barrier due to the charge on quaternary nitrogen. The antidote is atropine. T-1123 is a quaternary ammonium ion. A phenyl carbamate ester is bonded in the meta position to the nitrogen on a diethylmethyl amine. The chloride and methylsulfate salt of T-1123 is TL-1299 and TL-1317, respectively. Synthesis T-1123 can be produced from m-diethylaminophenol, methyl isocyanate and methyl iodide. First, m-diethylaminophenol is reacted with methyl isocyanate to produce a methylcarbamate. The resulting methylcarbamate is then reacted with methyl iodide to produce T-1123. See also *Miotine *Neostigmine *TL-1238 * TMTFA TMTFA is an extremely potent acetylcholinesterase inhibitor. As a transition state analog of acetylcholinesterase, TMTFA is able to inhibit acetylcholinesterase at extremely low concentrations (within the fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TL-1238
TL-1238 (Substance 3393) is an extremely potent carbamate In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formally o ... acetylcholinesterase inhibitor. It has been shown to be more potent than neostigmine. See also * Miotine * Neostigmine * T-1123 * T-1152 * T-1194 * TL-599 References Acetylcholinesterase inhibitors Aromatic carbamates Quaternary ammonium compounds Phenol esters Carbamate nerve agents {{Ester-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholinesterase Inhibitor
Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level and duration of action of acetylcholine in the central nervous system, autonomic ganglia and neuromuscular junctions, which are rich in acetylcholine receptors. Acetylcholinesterase inhibitors are one of two types of cholinesterase inhibitors; the other being butyryl-cholinesterase inhibitors. Acetylcholinesterase is the primary member of the cholinesterase enzyme family. Acetylcholinesterase inhibitors are classified as reversible, irreversible, or quasi-irreversible (also called pseudo-irreversible). Mechanism of action Organophosphates Organophosphates like TEPP and sarin inhibit cholinesterases, enzymes that hydrolyze the neurotransmitter acetylcholine. The active centre of cholinesterases feature two important sites, namely the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbamate
In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formally obtained by replacing one or more of the hydrogen atoms by other organic functional groups; as well as salts with the carbamate anion (e.g. ammonium carbamate). Polymers whose units are joined by carbamate groups are an important family of plastics, the polyurethanes. Properties While carbamic acids are unstable, many carbamate esters or ionic) are stable and well known. Equilibrium with carbonate and bicarbonate In water solutions, the carbamate anion slowly equilibrates with the ammonium cation and the carbonate or bicarbonate anions: : : Calcium carbamate is soluble in water, whereas calcium carbonate is not. Adding a calcium salt to an ammonium carbamate/carbonate solution will precipitate some calcium carbonate immediatel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neostigmine
Neostigmine, sold under the brand name Bloxiverz, among others, is a medication used to treat myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage. It is also used in anaesthesia to end the effects of non-depolarising neuromuscular blocking medication. It is given by injection either into a vein, muscle, or under the skin. After injection effects are generally greatest within 30 minutes and last up to 4 hours. Common side effects include nausea, increased saliva, crampy abdominal pain, and slow heart rate. More severe side effects include low blood pressure, weakness, and allergic reactions. It is unclear if use in pregnancy is safe for the baby. Neostigmine is in the cholinergic family of medications. It works by blocking the action of acetylcholinesterase and therefore increases the levels of acetylcholine. Neostigmine was patented in 1931. It is on the World Health Organization's List of Essential Medicines. The term is from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Group
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (), where one or more hydrogen atoms are replaced by organic groups (indicated by R). Acid–base properties The ammonium ion is generated when ammonia, a weak base, reacts with Brønsted acids (proton donors): :H+ + NH3 -> H4 The ammonium ion is mildly acidic, reacting with Brønsted bases to return to the uncharged ammonia molecule: : H4 + B- -> HB + NH3 Thus, treatment of concentrated solutions of ammonium salts with strong base gives ammonia. When ammonia is dissolved in water, a tiny amount of it converts to ammonium ions: :H2O + NH3 OH- + H4 The degree to which ammonia forms the ammonium ion depends on the pH of the solution. If the pH is low, the equilibrium shifts to the right: more ammonia molecules are conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freebase (chemistry)
Free base (freebase, free-base) is the conjugate base ( deprotonated) form of an amine, as opposed to its conjugate acid ( protonated) form. The amine is often an alkaloid, such as nicotine, cocaine, morphine, and ephedrine, or derivatives thereof. Freebasing is a more efficient method of self-administering alkaloids via the smoking route. Properties Some alkaloids are more stable as ionic salts than as free base. The salts usually exhibit greater water solubility. Common counterions include chloride, bromide, sulfate, phosphate, nitrate, acetate, oxalate, citrate, and tartrate. Ammonium salts formed from the acid-base reaction with hydrochloric acid are known as hydrochlorides. For example, compare the free base hydroxylamine (NH2OH) with the salt hydroxylamine hydrochloride (NH3OH+ Cl−). Freebasing Cocaine hydrochloride ("powder cocaine") cannot be smoked as it decomposes at the high temperatures produced by smoking. Free base cocaine, on the other ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood–brain Barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of the central nervous system where neurons reside. The blood–brain barrier is formed by endothelial cells of the Capillary, capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane. This system allows the passage of some small molecules by passive transport, passive diffusion, as well as the selective and active transport of various nutrients, ions, organic anions, and macromolecules such as glucose and amino acids that are crucial to neural function. The blood–brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and Molecular mass, large or Hydrophile, hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of Hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain (precursor structures exist in onychophorans, gastropods and lancelets). The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal cord are both enclosed in the meninges. The meninges provide a barrier to chemicals dissolv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neostigmine
Neostigmine, sold under the brand name Bloxiverz, among others, is a medication used to treat myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage. It is also used in anaesthesia to end the effects of non-depolarising neuromuscular blocking medication. It is given by injection either into a vein, muscle, or under the skin. After injection effects are generally greatest within 30 minutes and last up to 4 hours. Common side effects include nausea, increased saliva, crampy abdominal pain, and slow heart rate. More severe side effects include low blood pressure, weakness, and allergic reactions. It is unclear if use in pregnancy is safe for the baby. Neostigmine is in the cholinergic family of medications. It works by blocking the action of acetylcholinesterase and therefore increases the levels of acetylcholine. Neostigmine was patented in 1931. It is on the World Health Organization's List of Essential Medicines. The term is from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TMTFA
TMTFA is an extremely potent acetylcholinesterase inhibitor. As a transition state analog of acetylcholinesterase, TMTFA is able to inhibit acetylcholinesterase at extremely low concentrations (within the femtomolar range), making it one of the most potent acetylcholinesterase inhibitors known. Mechanism of action TMTFA has a reactive ketone group that can covalently bind to the serine Serine (symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − form un ... residue in the active site of acetylcholinesterase. This is due to the electron-withdrawing trifluoromethyl group on the carbonyl group. See also * Acetylcholinesterase inhibitor * Methylfluorophosphonylcholine * Transition state analog References Acetylcholinesterase inhibitors Quaternary ammonium compounds Aromatic ketones Trifluoro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
