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Ethoprop
Ethoprophos (or ethoprop) is an organophosphate ester with the formula C8H19O2PS2. It is a clear yellow to colourless liquid that has a characteristic mercaptan-like odour. It is used as an insecticide and nematicide and it is an acetylcholinesterase inhibitor. Synthesis Ethoprop can be synthesised by reacting phosphoryl chloride with two equivalents of ''n''-propylmercaptan and one equivalent of sodium ethoxide. A second pathway is reacting ''n''-propylmercaptan and sodium ethoxide with phosphorus trichloride to yield ethoxy-bis(propylsulfanyl)phosphane, which can then be oxidized by hydrogen peroxide to yield the product. : : Applications Ethoprop is used as an insecticide against soil insects like wireworms and as a nematicide. It is used on different crops, ranging from potatoes, bananas, and sugarcane to ornamental plants and tobacco. Most of the ethoprop used in the United States is applied to potatoes. In the period of 1987 to 1996, an estimated total of 691,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethoprophos Synthesis 1
Ethoprophos (or ethoprop) is an Organophosphate, organophosphate ester with the formula C8H19O2PS2. It is a clear yellow to colourless liquid that has a characteristic Thiol, mercaptan-like odour. It is used as an insecticide and nematicide and it is an acetylcholinesterase inhibitor. Synthesis Ethoprop can be synthesised by reacting phosphoryl chloride with two equivalents of Propanethiol, ''n''-propylmercaptan and one equivalent of sodium ethoxide. A second pathway is reacting ''n''-propylmercaptan and sodium ethoxide with phosphorus trichloride to yield ethoxy-bis(propylsulfanyl)phosphane, which can then be oxidized by hydrogen peroxide to yield the product. : : Applications Ethoprop is used as an insecticide against soil insects like Click beetle, wireworms and as a nematicide. It is used on different crops, ranging from potatoes, bananas, and sugarcane to ornamental plants and tobacco. Most of the ethoprop used in the United States is applied to potatoes. In the period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insecticide
Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain. Insecticides can be classified into two major groups: systemic insecticides, which have residual or long term activity; and contact insecticides, which have no residual activity. The mode of action describes how the pesticide kills or inactivates a pest. It provides another way of classifying insecticides. Mode of action can be important in understanding whether an insecticide will be toxic to unrelated species, such as fish, birds and mammals. Insecticides may be repe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercaptan
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of Alcohol (chemistry), alcohols (that is, sulfur takes the place of oxygen in the hydroxyl () group of an alcohol), and the word is a blend of "''thio-''" with "alcohol". Many thiols have strong odors resembling that of garlic or rotten eggs. Thiols are used as odorants to assist in the detection of natural gas (which in pure form is odorless), and the "smell of natural gas" is due to the smell of the thiol used as the odorant. Thiols are sometimes referred to as mercaptans () or mercapto compounds, a term introduced in 1832 by William Christopher Zeise and is derived from the Latin ('capturing mercury')''Oxford American Dictionaries'' (Mac OS X Leopard). because the thiolate group ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acetylcholine Receptor
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system. The nicotinic receptors are considered choline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleophile
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. ''Nucleophilic'' describes the affinity of a nucleophile to bond with positively charged atomic nuclei. Nucleophilicity, sometimes referred to as nucleophile strength, refers to a substance's nucleophilic character and is often used to compare the affinity of atoms. Neutral nucleophilic reactions with solvents such as alcohols and water are named solvolysis. Nucleophiles may take part in nucleophilic substitution, whereby a nucleophile becomes attracted to a full or partial positive charge, and nucleophilic addition. Nucleophilicity is closely related to basicity. History The terms ''nucleophile'' and ''electrophile'' were introduced by Christopher Kelk Ingold in 1933, replacing the terms ''anionoid'' and ''cation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pralidoxime
Pralidoxime (2-pyridine aldoxime methyl chloride) or 2-PAM, usually as the chloride or iodide salts, belongs to a family of compounds called oximes that bind to organophosphate-inactivated acetylcholinesterase. It is used to treat organophosphate poisoning in conjunction with atropine and either diazepam or midazolam. It is a white solid. Chemical synthesis Pralidoxime, 2-pyridinaldoxime methylchloride, is prepared by treating pyridine-2-carboxaldehyde with hydroxylamine. The resulting pyridine-2-aldoxime is alkylated with methyl iodide giving pralidoxime as the iodide salt. Mechanism of action Pralidoxime is typically used in cases of organophosphate poisoning. Organophosphates such as sarin bind to the hydroxy component (the site) of the active site of the acetylcholinesterase enzyme, thereby blocking its activity. Pralidoxime binds to the other half (the unblocked, anionic site) of the active site and then displaces the phosphate from the serine residue. The conjoined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscarinic Acetylcholine Receptor
Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor, G protein-coupled receptor complexes in the cell membranes of certain neurons and other Cell (biology), cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system. Muscarinic receptors are so named because they are more sensitive to muscarine than to nicotine. Their counterparts are nicotinic acetylcholine receptors (nAChRs), receptor ion channels that are also important in the autonomic nervous system. Many drugs and other substances (for example pilocarpine and Hyoscine hydrobromide, scopolamine) manipulate these two distinct receptors by acting as selective agonists or receptor antagonist, antagonists. Function acetylcholine, Acetylcholine (ACh) is a neurotransmitter found in the brain, neuromuscular junctions and the autonomic ganglia. Muscarini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miosis
Miosis, or myosis (), is excessive constriction of the pupil. citing: Mosby's Medical Dictionary, 8th ed. The opposite condition, mydriasis, is the dilation of the pupil. Anisocoria is the condition of one pupil being more dilated than the other. Causes Age * Senile miosis (a reduction in the size of a person's pupil in old age)Diseases *[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Blood Cell
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "hollow vessel", with ''-cyte'' translated as "cell" in modern usage), are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries. The cytoplasm of a red blood cell is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esterase
An esterase is a hydrolase enzyme that splits esters into an acid and an alcohol in a chemical reaction with water called hydrolysis. A wide range of different esterases exist that differ in their substrate specificity, their protein structure, and their biological function. EC classification/list of enzymes * ''EC 3.1.1'': Carboxylic ester hydrolases ** Acetylesterase (EC 3.1.1.6), splits off acetyl groups *** Cholinesterase **** Acetylcholinesterase, inactivates the neurotransmitter acetylcholine **** Pseudocholinesterase, broad substrate specificity, found in the blood plasma and in the liver ** Pectinesterase (EC 3.1.1.11), clarifies fruit juices * ''EC 3.1.2'': Thiolester hydrolases ** Thioesterase *** Ubiquitin carboxy-terminal hydrolase L1 * ''EC 3.1.3'': Phosphoric monoester hydrolases ** Phosphatase (EC 3.1.3.x), hydrolyses phosphoric acid monoesters into a phosphate ion and an alcohol *** Alkaline phosphatase, removes phosphate groups from many types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyspnoea
Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger" (the feeling of not enough oxygen). The tripod position is often assumed to be a sign. Dyspnea is a normal symptom of heavy physical exertion but becomes pathological if it occurs in unexpected situations, when resting or during light exertion. In 85% of cases it is due to asthma, pneumonia, cardiac ischemia, interstitial lung disease, congestive heart failu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
