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Thymol
Thymol (also known as 2-isopropyl-5-methylphenol, IPMP), , is a natural monoterpenoid phenol derivative of ''p''-Cymene, isomeric with carvacrol, found in oil of thyme, and extracted from ''Thymus vulgaris'' (common thyme), ajwain, and various other plants as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. Thymol also provides the distinctive, strong flavor of the culinary herb thyme, also produced from ''T. vulgaris''. Thymol is only slightly soluble in water at neutral pH, but it is extremely soluble in alcohols and other organic solvents. It is also soluble in strongly alkaline aqueous solutions due to deprotonation of the phenol. Its dissociation constant ( p''K''a) is . Thymol absorbs maximum UV radiation at 274 nm. Chemical synthesis Thymol is produced by the alkylation of ''m''-cresol and propene: : History Ancient Egyptians used thyme for embalming. The ancient Greeks used it in their baths and burned it as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carvacrol
Carvacrol, or cymophenol, C6H3(CH3)(OH)C3H7, is a monoterpenoid phenol. It has a characteristic pungent, warm odor of oregano. Natural occurrence Carvacrol is present in the essential oil of ''Origanum vulgare'' (oregano), oil of thyme, oil obtained from pepperwort, and wild bergamot. The essential oil of thyme subspecies contains between 5% and 75% of carvacrol, while ''Satureja'' (savory) subspecies have a content between 1% and 45%. ''Origanum majorana'' (marjoram) and Dittany of Crete are rich in carvacrol, 50% and 60–80% respectively. It is also found in tequila and ''Lippia graveolens'' (Mexican oregano) in the verbena family. Sources * ''Monarda didyma'' * ''Nigella sativa'' * '' Origanum compactum'' * ''Origanum dictamnus'' * '' Origanum microphyllum'' * ''Origanum onites'' * '' Origanum scabrum'' * '' Origanum syriacum'' * ''Origanum vulgare'' * '' Plectranthus amboinicus'' * '' Thymus glandulosus'' * ''Lavandula multifida'' * '' Origanum minutiflorum'' * ''Satur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ajwain
Ajwain, ajowan (), or ''Trachyspermum ammi''—also known as ajowancaraway, omam (in Tamil), thymol seeds, bishop's weed, or carom—is an annual herb in the family Apiaceae. Both the leaves and the seed‑like fruit (often mistakenly called seeds) of the plant are consumed by humans. The name " bishop's weed" also is a common name for other plants. The "seed" (i.e., the fruit) is often confused with lovage "seed". Description Ajwain's small, oval-shaped, seed-like fruits are pale brown schizocarps, which resemble the seeds of other plants in the family Apiaceae such as caraway, cumin and fennel. They have a bitter and pungent taste, with a flavor similar to anise and oregano. They smell almost exactly like thyme because they also contain thymol, but they are more aromatic and less subtle in taste, as well as being somewhat bitter and pungent. Even a small number of fruits tends to dominate the flavor of a dish. Cultivation and production Ajwain tends to grow in reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoterpene
Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen functionality or missing a methyl group, are called monoterpenoids. Monoterpenes and monoterpenoids are diverse. They have relevance to the pharmaceutical, cosmetic, agricultural, and food industries. Biosynthesis Monoterpenes are derived biosynthetically from units of isopentenyl pyrophosphate, which is formed from acetyl-CoA via the intermediacy of mevalonic acid in the HMG-CoA reductase pathway. An alternative, unrelated biosynthesis pathway of IPP is known in some bacterial groups and the plastids of plants, the so-called MEP-(2-methyl-D-erythritol-4-phosphate) pathway, which is initiated from C5 sugars. In both pathways, IPP is isomerized to DMAPP by the enzyme isopentenyl pyrophosphate isomerase. Geranyl pyrophosphate is the precu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyme
Thyme () is the herb (dried aerial parts) of some members of the genus '' Thymus'' of aromatic perennial evergreen herbs in the mint family Lamiaceae. Thymes are relatives of the oregano genus ''Origanum'', with both plants being mostly indigenous to the Mediterranean region. Thymes have culinary, medicinal, and ornamental uses, and the species most commonly cultivated and used for culinary purposes is ''Thymus vulgaris''. History Thyme is indigenous to the Mediterranean region. Wild thyme grows in the Levant, where it might have been first cultivated. Ancient Egyptians used thyme for embalming. The ancient Greeks used it in their baths and burnt it as incense in their temples, believing it was a source of courage. The spread of thyme throughout Europe was thought to be due to the Romans, as they used it to purify their rooms and to "give an aromatic flavour to cheese and liqueurs". In the European Middle Ages, the herb was placed beneath pillows to aid sleep and ward of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-Cresol
''meta''-Cresol, also 3-methylphenol, is an organic compound with the formula CH3C6H4(OH). It is a colourless, viscous liquid that is used as an intermediate in the production of other chemicals. It is a derivative of phenol and is an isomer of ''p''-cresol and ''o''-cresol. Production Together with many other compounds, ''m''-cresol is traditionally extracted from coal tar, the volatile materials obtained in the production of coke from (bituminous) coal. This residue contains a few percent by weight of phenol and isomeric cresols. In the cymene–cresol process, toluene is alkylated with propylene to give isomers of cymene, which can be oxidatively dealkylated analogous to the cumene process. Another method, involves carbonylation of a mixture of methallyl chloride and acetylene in the presence of nickel carbonyl. Applications ''m''-Cresol is a precursor to numerous compounds. Important applications include: * pesticides such as fenitrothion and fenthion * synthetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs. Properties Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), 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 and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkylation
Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents. Nucleophilic alkylating agents Nucleophilic alkylating agents deliver the equivalent of an alkyl anion ( carbanion). The formal "alkyl anion" attacks an electrophile, forming a new coval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propene
Propylene, also known as propene, is an unsaturated organic compound with the chemical formula CH3CH=CH2. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor. Production Steam cracking The dominant technology for producing propylene is steam cracking. The same technology is applied to ethane to ethylene. These two conversions are the #2 and #1 processes in the chemical industry, as judged by their scale. In this process, propane undergoes dehydrogenation. The by-product is hydrogen: :CH3CH2CH3 → CH3CH=CH2 + H2 The yield of propene is about 85 m%. By-products are usually used as fuel for the propane dehydrogenation reaction. Steam cracking is one of the most energy-intensive industrial processes. The feedstock is naphtha or propane, especially in the Middle East, where there is an abundance of propane from oil/gas operations. Propene can be separated by fractional di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, China and in Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deprotonation
Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H+) from a Brønsted–Lowry acid in an acid–base reaction.Henry Jakubowski, Biochemistry Online Chapter 2A3, https://employees.csbsju.edu/hjakubowski/classes/ch331/protstructure/PS_2A3_AA_Charges.html, accessed 12/2/2020 The species formed is the conjugate base of that acid. The complementary process, when a proton is added (transferred) to a Brønsted–Lowry base, is protonation (or hydronation). The species formed is the conjugate acid of that base. A species that can either accept or donate a proton is referred to as amphiprotic. An example is the H2O (water) molecule, which can gain a proton to form the hydronium ion, H3O+, or lose a proton, leaving the hydroxide ion, OH−. The relative ability of a molecule to give up a proton is measured by its p''K''a value. A low p''K''a value indicates that the compound is acidic and will easily give up its proton to a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
