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Prenol
Prenol, or 3-methyl-2-buten-1-ol, is a natural alcohol. It is one of the most simple terpenoids. It is a clear colorless oil that is reasonably soluble in water and miscible with most common organic solvents. It has a fruity odor and is used occasionally in perfumery. Prenol occurs naturally in citrus fruits, cranberry, bilberry, currants, grapes, raspberry, blackberry, tomato, white bread, hop oil, coffee, arctic bramble, cloudberry and passion fruit. It is also manufactured industrially by BASF (in Ludwigshafen, Germany) and by Kuraray (in Asia) as an intermediate to pharmaceuticals and aroma compounds. Global production in 2001 was between 6000 and 13,000 tons. Industrial production Prenol is produced industrially by the reaction of formaldehyde with isobutene, followed by the isomerization of the resulting isoprenol (3-methyl-3-buten-1-ol). Polyprenols Prenol is a building block of isoprenoid alcohols, which have the general formula: :H– H2CCH3=CHCH2sub>''n''–OH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prenol Prepn
Prenol, or 3-methyl-2-buten-1-ol, is a natural alcohol. It is one of the most simple terpenoids. It is a clear colorless oil that is reasonably soluble in water and miscible with most common organic solvents. It has a fruity odor and is used occasionally in perfumery. Prenol occurs naturally in citrus fruits, cranberry, bilberry, currants, grapes, raspberry, blackberry, tomato, white bread, hop oil, coffee, arctic bramble, cloudberry and passion fruit. It is also manufactured industrially by BASF (in Ludwigshafen, Germany) and by Kuraray (in Asia) as an intermediate to pharmaceuticals and aroma compounds. Global production in 2001 was between 6000 and 13,000 tons. Industrial production Prenol is produced industrially by the reaction of formaldehyde with isobutene, followed by the isomerization of the resulting isoprenol (3-methyl-3-buten-1-ol). Polyprenols Prenol is a building block of isoprenoid alcohols, which have the general formula: :H– H2CCH3=CHCH2sub>''n''–OH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprenol Prepn
Isoprenol, also known as 3-methylbut-3-en-1-ol, is a hemiterpene alcohol. It is produced industrially as an intermediate to 3-methylbut-2-en-1-ol (prenol): global production in 2001 can be estimated as 6–13 thousand tons.. Major produce in a world is BASF(Germany) and Kuraray(Japan). Isoprenol is produced by the reaction between isobutene (2-methylpropene) and formaldehyde. The thermodynamically preferred prenol with the more substituted double bond cannot be directly formed in the above reaction, but is produced via a subsequent isomerisation: This isomerisation reaction is catalyzed by any species which can form an allyl complex without excessive hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ... of the substrate, for example poisoned palladium catalysts.S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprenol
Isoprenol, also known as 3-methylbut-3-en-1-ol, is a hemiterpene alcohol. It is produced industrially as an intermediate to 3-methylbut-2-en-1-ol (prenol): global production in 2001 can be estimated as 6–13 thousand tons.. Major produce in a world is BASF(Germany) and Kuraray(Japan). Isoprenol is produced by the reaction between isobutene (2-methylpropene) and formaldehyde. The thermodynamically preferred prenol with the more substituted double bond cannot be directly formed in the above reaction, but is produced via a subsequent isomerisation: This isomerisation reaction is catalyzed by any species which can form an allyl complex without excessive hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ... of the substrate, for example poisoned palladium catalysts.S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globally Harmonized System Of Classification And Labelling Of Chemicals
The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is an internationally agreed-upon standard managed by the United Nations that was set up to replace the assortment of hazardous material classification and labelling schemes previously used around the world. Core elements of the GHS include standardized hazard testing criteria, universal warning pictograms, and harmonized safety data sheets which provide users of dangerous goods with a host of information. The system acts as a complement to the UN Numbered system of regulated hazardous material transport. Implementation is managed through the UN Secretariat. Although adoption has taken time, as of 2017, the system has been enacted to significant extents in most major countries of the world. This includes the European Union, which has implemented the United Nations' GHS into EU law as the CLP Regulation, and United States Occupational Safety and Health Administration standards. History Before the Gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydration Reaction
In chemistry, a dehydration reaction is a chemical reaction that involves the loss of water from the reacting molecule or ion. Dehydration reactions are common processes, the reverse of a hydration reaction. Dehydration reactions in organic chemistry Esterification The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester :RCO2H + R′OH RCO2R′ + H2O Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water. Etherification Two monosaccharides, such as glucose and fructose, can be joined together (to form saccharose) using dehydration synthesis. The new molecule, consisting of two monosaccharides, is called a disaccharide. Nitrile formation Nitriles are often prepared by dehydration of primary amides. :RC(O)NH2 → RCN + H2O Ketene formation Ketene is produced by heating acetic acid and trapping the product: :CH3CO2H → CH2=C= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolichol
Dolichol refers to any of a group of long-chain mostly unsaturated organic compounds that are made up of varying numbers of isoprene units terminating in an α-saturated isoprenoid group, containing an alcohol functional group. Functions Dolichols play a role in the co-translational modification of proteins known as ''N''-glycosylation in the form of dolichol phosphate. Dolichols function as a membrane anchor for the formation of the oligosaccharide Glc3-Man9-GlcNAc2 (where Glc is glucose, Man is mannose, and GlcNAc is ''N''-acetylglucosamine). This oligosaccharide is transferred from the dolichol donor onto certain asparagine residues (onto a specific sequence that is "Asn-X-Ser/Thr") of newly forming polypeptide chains. Dolichol is also involved in transfer of the monosaccharides to the forming Glc3-Man9-GlcNAc2-Dolichol carrier. In addition, dolichols can be adducted to proteins as a posttranslational modification, a process in which branched carbohydrate trees are formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Synthesis
As a topic of chemistry, chemical synthesis (or combination) is the artificial execution of chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations usually involving one or more reactions. In modern laboratory uses, the process is reproducible and reliable. A chemical synthesis involves one or more compounds (known as '' reagents'' or ''reactants'') that will experience a transformation when subjected to certain conditions. Various reaction types can be applied to formulate a desired product. This requires mixing the compounds in a reaction vessel, such as a chemical reactor or a simple round-bottom flask. Many reactions require some form of processing (" work-up") or purification procedure to isolate the final product. The amount produced by chemical synthesis is known as the ''reaction yield''. Typically, yields are expressed as a mass in grams (in a laboratory setting) or as a percentage of the total theoretical quantity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysaccharides
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars (monosaccharides, or oligosaccharides). They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as cellulose and chitin. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure, these macromolecules can have distinct properties from their monosaccharide building blocks. They may be amorphous or even insoluble in water. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturated And Unsaturated Compounds
In chemistry, a saturated compound is a chemical compound (or ion) that resists the addition reactions, such as hydrogenation, oxidative addition, and binding of a Lewis base. The term is used in many contexts and for many classes of chemical compounds. Overall, saturated compounds are less reactive than unsaturated compounds. Saturation is derived from the Latin word ''saturare'', meaning 'to fill'. Organic chemistry Unsaturated compounds generally carry out typical addition reactions that are not possible with saturated compounds such as alkanes. A saturated organic compound has only single bonds between carbon atoms. An important class of saturated compounds are the alkanes. Many saturated compounds have functional groups, e.g., alcohols. Unsaturated organic compounds The concept of saturation can be described using various naming systems, formulas, and analytical tests. For instance, IUPAC nomenclature is a system of naming conventions used to describe the type and loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyprenol
Polyprenols are natural long-chain isoprenoid alcohols of the general formula H-(C5H8)n-OH where n is the number of isoprene units. Any prenol with more than 4 isoprene units is a polyprenol. Polyprenols play an important function acting as natural bioregulators and are found in small quantities in various plant tissues. Dolichols, which are found in all living creatures, including humans, are their 2,3-dihydro derivatives. Sources Live trees are known to contain polyprenols. The needles of conifer trees are one of the richest sources of polyprenols. They are also present in shiitake mushrooms in trace amounts. Research Polyprenols have been studied for more than 30 years. Interest has been strongest in Russia, Europe, Japan, India, and the United States. In the early 1930s, a scientific team at the Forest Technical Academy in St Petersburg, Russia led by Fyodor Solodky, the founder of Forest Biochemistry, and Asney Agranet, began research into the composition of conifer tree ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl Group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
