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Piperine
Piperine, possibly along with its isomer chavicine, is the compound responsible for the pungency of black pepper and long pepper via activation of TRPV1. It has been used in some forms of traditional medicine. Preparation Extraction Due to its poor solubility in water, piperine is typically extracted from black pepper by using organic solvents like dichloromethane or ethanol. The amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers. Piperine can also be prepared by treating the solvent-free residue from a concentrated alcoholic extract of black pepper with a solution of potassium hydroxide to remove resin (said to contain chavicine, an isomer of piperine). The solution is decanted from the insoluble residue and left to stand overnight in alcohol. During this period, the alkaloid slowly crystallizes from the solution. Chemical synthesis Piperine has been synthesized by the action of piperonoyl chloride on piperidine. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chavicine
Chavicine is a possibly pungent compound found in black pepper and other species of the genus ''Piper''. It is one of the four geometric isomers of piperine Piperine, possibly along with its isomer chavicine, is the compound responsible for the pungency of black pepper and long pepper via activation of TRPV1. It has been used in some forms of traditional medicine. Preparation Extraction Due t .... In light, especially ultra-violet light, chavicine is formed from its isomer piperine. Its flavor has been reported as flavorless Chavicine will also re-isomerise back to piperine. See also * Guineesine References Benzodioxoles Piperidine alkaloids Carboxamides Alkene derivatives {{alkaloid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piperic Acid
Piperic acid is a chemical often obtained by the base-hydrolysis of the alkaloid piperine from black pepper, followed by acidification of the corresponding salt. Piperic acid is an intermediate in the synthesis of other compounds such as piperonal, and as-such may be used to produce fragrances, perfumes flavorants and drugs as well as other useful compounds. Preparation Piperic acid can be prepared from the commercially available alkaloid piperine, a cyclic amide containing a piperidine group, by reacting it with a hydroxide such as potassium hydroxide, then acidifying the formed piperate salt with hydrochloric acid or another acid. The toxic compound piperidine is given off during the base-hydrolysis of piperine and as-such, safety precautions should be taken. : Reactions Reaction of piperic acid with strong oxidizers such as potassium permanganate or ozone, or a halogen such as bromine followed by sodium hydroxide causes oxidative cleavage of the double-bonds, yielding piperon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piperidine
Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic amine consists of a six-membered ring containing five methylene bridges (–CH2–) and one amine bridge (–NH–). It is a colorless liquid with an odor described as objectionable, typical of amines. The name comes from the genus name '' Piper'', which is the Latin word for pepper. Although piperidine is a common organic compound, it is best known as a representative structure element within many pharmaceuticals and alkaloids, such as natural-occurring solenopsins. Production Piperidine was first reported in 1850 by the Scottish chemist Thomas Anderson and again, independently, in 1852 by the French chemist Auguste Cahours, who named it. Both of them obtained piperidine by reacting piperine with nitric acid. Industrially, piperidine is produced by the hydrogenation of pyridine, usually over a molybdenum disulfide catalyst: : C5H5N + 3 H2 → C5H10NH Pyridine can also be reduce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting Point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state of matter, state from solid to liquid. At the melting point the solid and liquid phase (matter), phase exist in Thermodynamic equilibrium, equilibrium. The melting point of a substance depends on pressure and is usually specified at a Standard temperature and pressure, standard pressure such as 1 Atmosphere (unit), atmosphere or 100 Pascal (unit), kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to Supercooling, supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact, the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the #Melting point measurements, melting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplatinic Acid
Chloroplatinic acid (also known as hexachloroplatinic acid) is an inorganic compound with the formula 3Osub>2 tCl6H2O)''x'' (0 ≤ ''x'' ≤ 6). A red solid, it is an important commercial source of platinum, usually as an aqueous solution. Although often written in shorthand as H2PtCl6, it is the hydronium (H3O+) salt of the hexachloroplatinate anion (). Hexachloroplatinic acid is highly hygroscopic. Production Hexachloroplatinic acid may be produced via a variety of methods. The most common of these methods involves dissolution of platinum in aqua regia. Other methods include exposing an aqueous suspension of platinum particles to chlorine gas, or via electrolysis. When produced by the aqua regia route, hexachloroplatinic acid is thought to arise by the following equation: The resulting orange/red solution can be evaporated to produce brownish red crystals. Some authors suggest that hexachloroplatinic acid produced using this method is contaminated with nitrosonium hexac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine
Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek , meaning 'violet'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to organic compounds, it has also found favour as a non-toxic radiocontrast material. Because of the spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Iodide
Potassium iodide is a chemical compound, medication, and dietary supplement. It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are used. It is also used for treating skin sporotrichosis and phycomycosis. It is a supplement used by people with low dietary intake of iodine. It is administered orally. Common side effects include vomiting, diarrhea, abdominal pain, rash, and swelling of the salivary glands. Other side effects include allergic reactions, headache, goitre, and depression. While use during pregnancy may harm the baby, its use is still recommended in radiation emergencies. Potassium iodide has the chemical formula K I. Commercially it is made by mixing potassium hydroxide with iodine. Potassium iodide has been used medically since at least 1820. It is on the World Health Organization's List of Essential Medicines. Potassium iodide is available as a g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochloric Acid
Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical. Etymology Because it was produced from halite, rock salt according to the methods of Johann Rudolph Glauber, hydrochloric acid was historically called by European alchemists ''spirits of salt'' or ''acidum salis'' (salt acid). Both names are still used, especially in other languages, such as , , , , , , , , , , (''ensan''), zh, 盐酸 (''yánsuān''), and (''yeomsan''). Gaseous HCl was called ''marine acid air''. The name ''muriatic acid'' has the same origin (''muriatic'' means "pertaining to brine or salt", hence ''muriate'' means hydrochloride), and this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the existence or possibility of isomers. Isomers do not necessarily share similar chemical property, chemical or physical property, physical properties. Two main forms of isomerism are structural isomerism, structural (or constitutional) isomerism, in which ''chemical bond, bonds'' between the atoms differ; and stereoisomerism (or spatial isomerism), in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different Isotopologue, isotopologues. The depth of analy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BAHD Acyltransferase
{{technical, date=September 2015 General Information The BAHD acyltransferases are a super family of enzymes found primarily in plants, algae and bacteria. They are CoA-dependent enzymes that transfer acylated moieties (RC(O)R’) of an acyl-activated CoA thioester donor to an acceptor molecule (D’Auria, 2006). Members of this enzyme family typically share two conserved amino acid motifs. The first motif, or string of consecutive amino acids, is HXXXD (Histidine, Any, Any, Any, Aspartic acid) and it is typically found in the central region of the protein. The Histidine in this motif has also been shown to act as a catalytic residue in many BAHD enzymes. The second conserved motif is DFGWG (Aspartic acid, Phenylalanine, Glycine, Tryptophan, Glycine) and it is typically found near the carboxyl terminus of the protein and is thought to participate in CoA binding (D'Auria, 2006). Additionally, further information such as currently discovered structures, sequences and gene architectu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet Light
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. These int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Christian Ørsted
Hans Christian Ørsted (; 14 August 1777 – 9 March 1851), sometimes Transliteration, transliterated as Oersted ( ), was a Danish chemist and physicist who discovered that electric currents create magnetic fields. This phenomenon is known as Oersted's law. He also discovered aluminium, a chemical element. A leader of the Danish Golden Age, Ørsted was a close friend of Hans Christian Andersen and the brother of politician and jurist Anders Sandøe Ørsted, who served as Prime Minister of Denmark from 1853 to 1854. Early life and studies Ørsted was born in Rudkøbing in 1777. As a young boy he developed an interest in science while working for his father, who was a pharmacist in the Rudkøbing Pharmacy, town's pharmacy. He and his brother Anders Sandøe Ørsted, Anders received most of their early education through self-study at home, going to Copenhagen in 1793 to take entrance exams for the University of Copenhagen, where both brothers excelled academically. By 1796, Ørst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
