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Nereistoxin
Nereistoxin is a natural product identified in 1962 as the toxic organic compound ''N'',''N''-dimethyl-1,2-dithiolan-4-amine. It had first been isolated in 1934 from the marine annelid ''Lumbriconereis heteropoda'' and acts by blocking the nicotinic acetylcholine receptor. Researchers at Takeda in Japan investigated it as a possible insecticide. They subsequently developed a number of derivatives that were commercialised, including those with the ISO common names bensultap, cartap, thiocyclam and thiosultap. Structures and synthesis Bensultap.svg, bensultap Thiocyclam neutral.svg, thiocyclam Thiosultap.svg, thiosultap Bensultap (R=SO2Ph) was made by the reaction of the sodium salt of benzenethiolsulfonate (PhSO2SNa) with ''N'',''N''-dimethyl 1,3-dichloro-2-propylamine or ''N'',''N''-dimethyl 2,3-dichloropropylamine in ethanol. : Bensultap can be converted to nereistoxin by treatment with alkali. History Japanese fishermen used the annelid worm ''Lumbriconereis heteropoda'' Maren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bensultap Synthesis
Nereistoxin is a natural product identified in 1962 as the toxic organic compound ''N'',''N''-dimethyl-1,2-dithiolan-4-amine. It had first been isolated in 1934 from the marine annelid ''Lumbriconereis heteropoda'' and acts by blocking the nicotinic acetylcholine receptor. Researchers at Takeda in Japan investigated it as a possible insecticide. They subsequently developed a number of derivatives that were commercialised, including those with the ISO common names bensultap, cartap, thiocyclam and thiosultap. Structures and synthesis Bensultap.svg, bensultap Thiocyclam neutral.svg, thiocyclam Thiosultap.svg, thiosultap Bensultap (R=SO2Ph) was made by the reaction of the sodium salt of benzenethiolsulfonate (PhSO2SNa) with ''N'',''N''-dimethyl 1,3-dichloro-2-propylamine or ''N'',''N''-dimethyl 2,3-dichloropropylamine in ethanol. : Bensultap can be converted to nereistoxin by treatment with alkali. History Japanese fishermen used the annelid worm ''Lumbriconereis heteropoda'' Maren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dithiolane
A dithiolane is a sulfur heterocyclic compound, heterocycle derived from cyclopentane by replacing two methylene bridges (-- units) with thioether groups. The parent compounds are 1,2-dithiolane and 1,3-dithiolane. 1,2-Dithiolanes are cyclic disulfides. Some dithiolanes are natural products that can be found in foods, such as asparagusic acid in asparagus. The 4-dimethylamino derivative nereistoxin was the inspiration for insecticides which act by blocking the nicotinic acetylcholine receptor. Lipoic acid is essential for aerobic metabolism in mammals and also has strong affinity with many metals including gold, molybdenum, and tungsten. Other 1,2-dithiolanes have relevance in nanomaterials such as gold nanoparticles or transition metal dichalcogenide monolayers (TMDs) (MoS2, MoS2 and Tungsten disulfide, WS2). Asparagusic-acid.png, asparagusic acid Nereistoxin.svg, nereistoxin, from which insecticides including cartap and bensultap were derived Lipoic acid.svg, lipoic acid 1,3-Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Product
A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical synthesis (both semisynthesis and total synthesis) and have played a central role in the development of the field of organic chemistry by providing challenging synthetic targets. The term natural product has also been extended for commercial purposes to refer to cosmetics, dietary supplements, and foods produced from natural sources without added artificial ingredients. Within the field of organic chemistry, the definition of natural products is usually restricted to organic compounds isolated from natural sources that are produced by the pathways of primary or secondary metabolism. Within the field of medicinal chemistry, the definition is often further restricted to secondary metabolites. Secondary metabolites (or specialized metabolites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chilo Suppressalis
''Chilo suppressalis'', the Asiatic rice borer or striped rice stemborer, is a moth of the family Crambidae. It is a widespread species, known from Iran, India, Sri Lanka, China, eastern Asia, Japan, Taiwan, Malaysia to the Pacific. It is a serious pest of rice. They are largely responsible for the great reduction in the rice growing in East Asia, India and Indonesia. It was probably introduced in Spain and Hawaii by humans, where it is widely spread towards Northern Territory of Australia. Description The wingspan is 18 mm in male and 18–20 mm in female. In the male, the head and thorax are brown and white. Abdomen pale. Forewings with somewhat acute apex which is ochreous, wholly suffused with brown except a patch in cell and a streak below medial nervure. Inner margin whitish. A sinuous rufous medial line runs with silvery spots on its inner side, also on discocellulars, and below vein 2. A rufous submarginal line, highly angled at vein 6 and with silvery line on i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periplaneta Americana
The american cockroach (''Periplaneta americana'') is the largest species of common cockroach, and often considered a pest. In certain regions of the U.S. it is colloquially known as the waterbug, though it is not a true waterbug since it is not aquatic. It is also known as the ship cockroach, kakerlac, and Bombay canary. It is often misidentified as a palmetto bug. Despite their name, American cockroaches are native to Africa and the Middle East. They are believed to have been introduced to the Americas only from the 17th century AD onward as a result of human commercial patterns, including the Atlantic slave trade The Atlantic slave trade, transatlantic slave trade, or Euro-American slave trade involved the transportation by slave traders of enslaved African people, mainly to the Americas. The slave trade regularly used the triangular trade route and i .... Distribution Despite the name, none of the ''Periplaneta'' species is native to the Americas; ''P. americana'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapses
In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from one neuron to another. Neurons are specialized to pass signals to individual target cells, and synapses are the means by which they do so. At a synapse, the plasma membrane of the signal-passing neuron (the ''presynaptic'' neuron) comes into close apposition with the membrane of the target (''postsynaptic'') cell. Both the presynaptic and postsynaptic sites contain extensive arrays of molecular machinery that link the two membranes together and carry out the signaling process. In many synapses, the presynaptic part is located on an axon and the postsynaptic part is located on a dendrite or soma. Astrocytes also exchange information with the synaptic neurons, responding to synaptic activity and, in turn, regulating neurotransmission. Syna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophysiology
Electrophysiology (from Greek , ''ēlektron'', "amber" etymology of "electron"">Electron#Etymology">etymology of "electron" , ''physis'', "nature, origin"; and , '' -logia'') is the branch of physiology that studies the electrical properties of biological cells and tissues. It involves measurements of voltage changes or electric current or manipulations on a wide variety of scales from single ion channel proteins to whole organs like the heart. In neuroscience, it includes measurements of the electrical activity of neurons, and, in particular, action potential activity. Recordings of large-scale electric signals from the nervous system, such as electroencephalography, may also be referred to as electrophysiological recordings. They are useful for electrodiagnosis and monitoring. Definition and scope Classical electrophysiological techniques Principle and mechanisms Electrophysiology is the branch of physiology that pertains broadly to the flow of ions (ion current) in biologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholinesterase
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 Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ... that catalysis, catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters: : acetylcholine + H2O = choline + acetate It is found at mainly neuromuscular junctions and in chemical synapses of the cholinergic type, where its activity serves to terminate neurotransmission, synaptic transmission. It belongs to the carboxylesterase family of enzymes. It is the primary target of inhibition by organophosphorus compounds such as nerve agents and pesticides. Enzyme structure and mechani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic. Substances that increase or decrease the overall activity of the cholinergic system are called cholinergics and anticholinergics, respectively. Acetylcholine is the neurotransmitter used at the neuromuscular junction—in other words, it is the chemical that motor neurons of the nervous system release in order to activate muscles. This property means that drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions. Acetylcholine is also a neurotransmitter in the autonomic nervous system, both as an internal transmitter for the sympathetic nervous system and as the final product released by the parasymp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkali
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases. Etymology The word "alkali" is derived from Arabic ''al qalīy'' (or ''alkali''), meaning ''the calcined ashes'' (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was mildly basic. After heating this substance with calcium hydroxide (''slaked lime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
