|
Allyl Cyanide
Allyl cyanide is an organic compound with the formula CH2CHCH2CN. Like other small alkyl nitriles, allyl cyanide is colorless and soluble in organic solvents. Allyl cyanide occurs naturally as an antifeedant and is used as a cross-linking agent in some polymers. Synthesis Allyl cyanide is obtained by the reaction of allyl acetate with hydrogen cyanide. A laboratory route to allyl cyanide involves treating allyl bromide with copper(I) cyanide. :CH2=CHCH2Br + CuCN → CH2=CHCH2CN + CuBr Other allyl halides may be used for this reaction including allyl iodide as done by A. Rinne and B. Tollens in 1871 where iodide is a better leaving group than its bromide equivalent and therefore increases the yield. Natural occurrences Allyl cyanide was discovered in 1863 by H. Will and W. Koerner in 1863, they found the compound to be present in mustard oil. The first synthesis of allyl cyanide was reported by A. Claus in 1864. Allyl cyanide is produced in cruciferous vegetables by myrosinas ... [...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] |
Antifeedant
Antifeedants are organic compounds produced by plants to inhibit attack by insects and grazing animals. These chemical compounds are typically classified as secondary metabolites in that they are not essential for the metabolism of the plant, but instead confer longevity. Antifeedants exhibit a wide range of activities and chemical structures as biopesticides. Examples include rosin, which inhibits attack on trees, and many alkaloids, which are highly toxic to specific insect species. History "Plant-derived insecticides (e.g., rotenone, veratridines, pyrethrins, and nicotine) have been used for insect control since antiquity." The active ingredients in these plants have been purified and modified. For example, variations on pyrethrin has spawned a large number of synthetic insecticides call pyrethroids. Culinary implications In addition to their role defending the plant, antifeedants often confer taste or odors, enhancing the flavor of certain plants. Examples are provided by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allyl Acetate
Allyl acetate is an organic compound with formula C3H5OC(O)CH3. This colourless liquid is a precursor to especially allyl alcohol, which is a useful industrial intermediate. It is the acetate ester of allyl alcohol. Preparation Allyl acetate is produced industrially by the gas phase reaction of propene in the presence of acetic acid using a palladium catalyst: :C3H6 + CH3COOH + ½ O2 → CH2=CHCH2OCOCH3 + H2O This method is advantageous because propene is inexpensive and "green." Allyl alcohol is also produced primarily from allyl chloride, but production via the hydrolysis of allyl acetate route avoids the use of chlorine, and so is increasing in use. Vinyl acetate is produced similarly, using ethylene in place of propene. These reactions are examples of acetoxylation. The palladium center is then re-oxidized by the O2 present. The mechanism for the acetoxylation follows a similar pathway, with propene forming a π-allyl bond on the palladium. : Reactions and applicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allyl Bromide
Allyl bromide (3-bromopropene) is an organic halide. It is an alkylating agent used in synthesis of polymers, pharmaceuticals, synthetic perfumes and other organic compounds. Physically, allyl bromide is a colorless liquid with an irritating and persistent smell, however, commercial samples are yellow or brown. Allyl bromide is more reactive but more expensive than allyl chloride, and these considerations guide its use. Preparation Allyl bromide is produced commercially from allyl alcohol and hydrobromic acid: :CH2=CHCH2OH + HBr → CH2=CHCH2Br + H2O It can also be prepared by the halogen-exchange reaction between allyl chloride and hydrobromic acid or by the allylic bromination of propene. Reactions and uses Electrophilic properties Allyl bromide is an electrophilic alkylating agent. It reacts with nucleophiles, such as amines, carbanions, alkoxides, etc., to introduce the allyl group: :CH2=CHCH2Br + Nu− → CH2=CHCH2Nu + Br− (Nu− is a nucleophile) It is used in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(I) Cyanide
Copper(I) cyanide is an inorganic compound with the formula CuCN. This off-white solid occurs in two polymorphs; impure samples can be green due to the presence of Cu(II) impurities. The compound is useful as a catalyst, in electroplating copper, and as a reagent in the preparation of nitriles.H. Wayne Richardson "Copper Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. Structure Copper cyanide is a coordination polymer. It exists in two polymorphs both of which contain - u-CN chains made from linear copper(I) centres linked by cyanide bridges. In the high-temperature polymorph, HT-CuCN, which is isostructural with AgCN, the linear chains pack on a hexagonal lattice and adjacent chains are off set by +/- 1/3 ''c'', Figure 1. In the low-temperature polymorph, LT-CuCN, the chains deviate from linearity and pack into rippled layers which pack in an AB fashion with chains in adjacent layers rotated by 49 °, Figure 2. File:Structure of HT-C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mustard Oil
Mustard oil can mean either the pressed oil used for cooking, or a pungent essential oil also known as volatile oil of mustard. The essential oil results from grinding mustard seed, mixing the grounds with water, and extracting the resulting volatile oil by distillation. It can also be produced by dry distillation of the seed. Pressed mustard oil is used as cooking oil in some cultures, but sale is restricted in some countries due to high levels of erucic acid. Varieties of mustard seed also exist that are low in erucic acid. Pressed oil Oil makes up about 30% of mustard seeds. It can be produced from black mustard (''Brassica nigra''), brown mustard ('' B. juncea''), and white mustard ('' B. alba''). Having a distinctive pungent taste, the oil is used for cooking in India, Pakistan, Nepal and Bangladesh. Its pungent flavor is due to allyl isothiocyanate, a phytochemical of plants in the mustard family, Brassicaceae (for example, cabbage, horseradish or wasabi). Mustard oil ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cruciferous Vegetables
Cruciferous vegetables are vegetables of the family Brassicaceae (also called Cruciferae) with many genera, species, and cultivars being raised for food production such as cauliflower, cabbage, kale, garden cress, bok choy, broccoli, Brussels sprouts, mustard plant and similar green leaf vegetables. The family takes its alternative name (Cruciferae, New Latin for "cross-bearing") from the shape of their flowers, whose four petals resemble a cross. Ten of the most common cruciferous vegetables eaten by people, known colloquially in North America as cole crops and in the UK, Ireland and Australia as brassicas, are in a single species (''Brassica oleracea''); they are not distinguished from one another Taxonomy (biology), taxonomically, only by horticultural category of cultivar groups. Numerous other genus, genera and species in the family are also edible. Cruciferous vegetables are one of the dominant food crops worldwide. They are high in vitamin C and dietary fiber, soluble fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myrosinase
Myrosinase (, ''thioglucoside glucohydrolase'', ''sinigrinase'', and ''sinigrase'') is a family of enzymes involved in plant defense against herbivores, specifically the mustard oil bomb. The three-dimensional structure has been elucidated and is available in the PDB (see links in the infobox). A member of the glycoside hydrolase family, myrosinase possesses several similarities with the more ubiquitous O-glycosidases. However, myrosinase is the only known enzyme found in nature that can cleave a thio-linked glucose. Its known biological function is to catalyze the hydrolysis of a class of compounds called glucosinolates. Myrosinase activity Myrosinase is regarded as a defense-related enzyme and is capable of hydrolyzing glucosinolates into various compounds, some of which are toxic. Mechanism Myrosinase catalyzes the chemical reaction :a thioglucoside + H2O \rightleftharpoons a sugar + a thiol Thus, the two substrates of this enzyme are thioglucoside and H2O, whereas it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucosinolates
Glucosinolates are natural components of many pungency, pungent plants such as mustard plant, mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. These natural chemicals most likely contribute to plant defence against pests and Plant disease resistance, diseases, and impart a characteristic bitter (taste), bitter flavor property to cruciferous vegetables. Plants with glucosinolates Glucosinolates occur as secondary metabolites of almost all plants of the order (biology), order Brassicales. Ordered in the Brassicales are for example the economically important family Brassicaceae as well as Capparaceae and Caricaceae. Outside of the Brassicales, the genus, genera ''Drypetes'' and ''Putranjiva'' in the family Putranjivaceae, are the only other known occurrence of glucosinolates. Glucosinolates occur in various edible plants such as cabbage (white cabbage, Chines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants and the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. The rumen's microbial favoring environment allows it to serve as the primary site for microbial fermentation of ingested feed. The smaller part of the reticulorumen is the reticulum, which is fully continuous with the rumen, but differs from it with regard to the texture of its lining. Brief anatomy The rumen is composed of several muscular sacs, the cranial sac, ventral sac, ventral blindsac, and reticulum. The lining of the rumen wall is covered in small fingerlike projections called papillae, which are flattened, approximately 5mm in length and 3mm wide in cattle. The reticulum is lined with ridges that form a hexagonal honeycomb pattern. The ridges are approximately 0.1–0.2mm wide and are raised 5mm above the reticulum wall. The hexagons in the reticulum are approximately 2â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitriles
In organic chemistry, a nitrile is any organic compound that has a functional group. The prefix ''cyano-'' is used interchangeably with the term ''nitrile'' in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons. Inorganic compounds containing the group are not called nitriles, but cyanides instead. Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic. Structure and basic properties The N−C−C geometry is linear in nitriles, reflecting the sp hybridization of the triply bonded carbon. The C−N distance is short at 1.16 Å, consistent with a triple bond. Nitriles a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
