Soman is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the enzyme cholinesterase. It is an inhibitor of both acetylcholinesterase and butyrylcholinesterase. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN Resolution 687. Its production is strictly controlled, and stockpiling is outlawed by the Chemical Weapons Convention of 1993 where it is classified as a Schedule 1 substance. Soman was the third of the so-called G-series nerve agents to be discovered along with GA (tabun), GB (sarin), and GF (cyclosarin).
The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters:
Edrophonium is a readily reversible acetylcholinesterase inhibitor. It prevents breakdown of the neurotransmitter acetylcholine and acts by competitively inhibiting the enzyme acetylcholinesterase, mainly at the neuromuscular junction. It is sold under the trade names Tensilon and Enlon.
In organic chemistry, a carbamate is a category of organic compounds with the general formula R2NC(O)OR and structure >N−C(=O)−O−, which are formally derived from carbamic acid. The term includes organic compounds, formally obtained by replacing one or more of the hydrogen atoms by other organic functional groups; as well as salts with the carbamate anion H2NCOO−.
A parasympathomimetic drug, sometimes called a cholinomimetic drug or cholinergic receptor stimulating agent, is a substance that stimulates the parasympathetic nervous system (PSNS). These chemicals are also called cholinergic drugs because acetylcholine (ACh) is the neurotransmitter used by the PSNS. Chemicals in this family can act either directly by stimulating the nicotinic or muscarinic receptors, or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or other mechanisms. Common uses of parasympathomimetics include glaucoma, Sjögren syndrome and underactive bladder.
Galantamine is an alkaloid extracted from the bulbs and flowers of Galanthus nivalis, Galanthus caucasicus, Galanthus woronowii, and other members of the family Amaryllidaceae, such as Narcissus (daffodil), Leucojum aestivum (snowflake), and Lycoris including Lycoris radiata. It can also be produced synthetically.
Harmaline is a fluorescent indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the partly hydrogenated form of harmine.
Chelidonium majus, the greater celandine, is a perennial herbaceous flowering plant in the poppy family Papaveraceae. One of two species in the genus Chelidonium, it is native to Europe and western Asia and introduced widely in North America.
Huperzine A is a naturally-occurring sesquiterpene alkaloid compound found in the firmoss Huperzia serrata and in varying quantities in other food Huperzia species, including H. elmeri, H. carinat, and H. aqualupian. Huperzine A has been investigated as a treatment for neurological conditions such as Alzheimer's disease, but a 2013 meta-analysis of those studies concluded that they were of poor methodological quality and the findings should be interpreted with caution. Huperzine A inhibits the breakdown of the neurotransmitter acetylcholine (ACh) by the enzyme acetylcholinesterase. It is commonly available over the counter as a nutritional supplement and marketed as a memory and concentration enhancer.
Butyrylcholinesterase, also known asBChE, BuChE, BuChase, pseudocholinesterase, or plasma (cholin)esterase, is a nonspecific cholinesterase enzyme that hydrolyses many different choline-based esters. In humans, it is made in the liver, found mainly in blood plasma, and encoded by the BCHE gene.
Ambenonium is a cholinesterase inhibitor used in the management of myasthenia gravis.
Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters:
Substitution of the heterocycle isoquinoline at the C1 position by a benzyl group provides 1‑benzylisoquinoline, the most widely examined of the numerous benzylisoquinoline structural isomers. The 1-benzylisoquinoline moiety can be identified within numerous compounds of pharmaceutical interest, such as moxaverine; but most notably it is found within the structures of a wide variety of plant natural products, collectively referred to as benzylisoquinoline alkaloids. This class is exemplified in part by the following compounds: papaverine, noscapine, codeine, morphine, apomorphine, berberine, tubocurarine.
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.
Cholinesterase inhibitors (ChEIs), also known as anti-cholinesterase, are chemicals that prevent the breakdown of the neurotransmitter acetylcholine or butyrylcholine. This increases the amount of the acetylcholine or butyrylcholine in the synaptic cleft that can bind to muscarinic receptors, nicotinic receptors and others. This group of inhibitors is divided into two subgroups, acetylcholinesterase inhibitors (AChEIs) and butyrylcholinesterase inhibitors (BChEIs).
Protopine is an alkaloid occurring in opium poppy, Corydalis tubers and other plants of the family papaveraceae, like Fumaria officinalis. Protopine is metabolically derived from the benzylisoquinoline alkaloid (S)-Reticuline through a progressive series of five enzymatic transformations: 1) berberine bridge enzyme to (S)-Scoulerine; 2) (S)-cheilanthifoline synthase/CYP719A25 to (S)-Cheilanthifoline; 3) (S)-stylopine synthase/CYP719A20 to (S)-Stylopine; 4) (S)-tetrahydroprotoberberine N-methyltransferase to (S)-cis-N-Methylstylopine; and ultimately, 5) N-methylstylopine hydroxylase to protopine.
Rivastigmine is a cholinesterase inhibitor used for the treatment of mild to moderate Alzheimer's disease. The drug can be administered orally or via a transdermal patch; the latter form reduces the prevalence of side effects, which typically include nausea and vomiting.
Cymserine is a drug related to physostigmine, which acts as a reversible cholinesterase inhibitor, with moderate selectivity (15×) for the plasma cholinesterase enzyme butyrylcholinesterase, and relatively weaker inhibition of the better-known acetylcholinesterase enzyme. This gives it a much more specific profile of effects that may be useful for treating Alzheimer's disease without producing side effects such as tremors, lacrimation, and salivation that are seen with the older nonselective cholinesterase inhibitors currently used for this application, such as donepezil. A number of cymserine derivatives have been developed with much greater selectivity for butyrylcholinesterase, and both cymserine and several of its analogues have been tested in animals, and found to increase brain acetylcholine levels and produce nootropic effects, as well as reducing levels of amyloid precursor protein and amyloid beta, which are commonly used biomarkers for the development of Alzheimer's disease.
Corydaline is an acetylcholinesterase inhibitor isolated from Corydalis yanhusuo.
The benzylisoquinoline alkaloids are natural products that can be classified as isoquinoline alkaloids and are derived from benzylisoquinoline. They also include the benzyl(tetrahydro)isoquinoline alkaloids.
