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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 Th ... [...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] |
Geranylgeraniol
Geranylgeraniol is a diterpenoid alcohol. It is a colorless waxy solid. Geranylgeraniol is an important intermediate in the biosynthesis of other diterpenes, of vitamins E, and of K. It also used in the post-translational modification known as geranylgeranylation. Geranylgeraniol is a pheromone for bumblebees and a variety of other insects. Geranylgeraniol is a potent inhibitor of ''Mycobacterium tuberculosis'' ''in vitro''. See also * Geranylgeranyl pyrophosphate Geranylgeranyl pyrophosphate is an intermediate in the biosynthesis of diterpenes and diterpenoids. It is also the precursor to carotenoids, gibberellins, tocopherols, and chlorophylls. It is also a precursor to geranylgeranylated proteins, whi ... References {{reflist Diterpenes Fatty alcohols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin E
Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitamin E, can cause Neurological disorder, nerve problems. Vitamin E is a fat-soluble antioxidant which may help protect cell membranes from reactive oxygen species. Worldwide, government organizations recommend adults consume in the range of 3 to 15 mg per day. As of 2016, consumption was below recommendations according to a worldwide summary of more than one hundred studies that reported a median dietary intake of 6.2 mg per day for alpha-tocopherol. Population studies suggested that people who consumed foods with more vitamin E, or who chose on their own to consume a vitamin E dietary supplement, had lower incidence of cardiovascular diseases, cancer, dementia, and other diseases. However, placebo-controlled clinical trials using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin A
Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably beta-carotene -carotene. Vitamin A has multiple functions: it is essential for embryo development and growth, for maintenance of the immune system, and for vision, where it combines with the protein opsin to form rhodopsin the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision. Vitamin A occurs as two principal forms in foods: A) retinol, found in animal-sourced foods, either as retinol or bound to a fatty acid to become a retinyl ester, and B) the carotenoids alpha-carotene, β-carotene, gamma-carotene, and the xanthophyll beta-cryptoxanthin (all of which contain β-ionone rings) that function as provitamin A in herbivore and omnivore animals which possess the enzymes that cleave and convert provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotenoid
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, maize, corn, tomatoes, Domestic Canary, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Carotenoids can be produced from Lipid, fats and other basic organic metabolic building blocks by all these organisms. It is also produced by Endosymbiont, endosymbiotic bacteria in Whitefly, whiteflies. Carotenoids from the diet are stored in the fatty tissues of animals, and exclusively Carnivore, carnivorous animals obtain the compounds from animal fat. In the human diet, Small intestine#Absorption, absorption of carotenoids is improved when consumed with fat in a meal. Cooking carotenoid-containing vegetables in oil and shredding the vegetable both increase carotenoid bioavailability. There are over 1,100 known c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues ... [...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 func ... [...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] |
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] |
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] |
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] |
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 that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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