"Chemistry of ascorbic acid Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. It is a mild reducing agent. Ascorbic acid exists as two enantiomers (mirror-image isomers), commonly denoted """" (for ""levo"") and """" (for ""dextro""). The isomer is the one most often ecountered: it occurs naturally in many foods, and is one form (""vitamer"") of vitamin C, an essential nutrient for humans and many animals. Deficiency of vitamin C causes scurvy, formerly a major"
"Vitamin C Vitamin C, also known as ascorbic acid and -ascorbic acid, is a vitamin found in food and used as a dietary supplement. The disease scurvy is prevented and treated with vitamin C-containing foods or dietary supplements. Evidence does not support use in the general population for the prevention of the common cold. There is, however, some evidence that regular use may shorten the length of colds. It is unclear if supplementation affects the risk of cancer, cardiovascular disease, or dementia. It may be taken by mouth or by injection. Vitamin C is generally well tolerated. Large doses may"
"to thousands of people with cancer. In February 2011, the Swiss Post issued a postage stamp bearing a depiction of a model of a molecule of vitamin C to mark the International Year of Chemistry. Vitamin C Vitamin C, also known as ascorbic acid and -ascorbic acid, is a vitamin found in food and used as a dietary supplement. The disease scurvy is prevented and treated with vitamin C-containing foods or dietary supplements. Evidence does not support use in the general population for the prevention of the common cold. There is, however, some evidence that regular use may shorten the"
"It is able to do this by binding to the calcium component found in tartar. Kibbles coated with this compound have been proven to prevent the formation of tartar on all teeth, and not just those involved in the mechanical breakdown of food (mainly the molars). Ascorbic acid, also known as vitamin C, is a useful ingredient for cats whose mouth and gums are already diseased. It is usually added to the coating of kibbles in the form of ascorbyl phosphate. Ascorbic acid is an effective antiseptic used to heal mouth sores and reduce inflammation as tested by Clark (2001)."
"natural vitamin C content of the milk. Scurvy is one of the accompanying diseases of malnutrition (other such micronutrient deficiencies are beriberi or pellagra) and thus is still widespread in areas of the world depending on external food aid. Although rare, there are also documented cases of scurvy due to poor dietary choices by people living in industrialized nations. Vitamins are essential to the production and use of enzymes that are involved in ongoing processes throughout the human body. Ascorbic acid is needed for a variety of biosynthetic pathways, by accelerating hydroxylation and amidation reactions. In the synthesis of collagen,"
"the National Academy of Sciences in 1978 on the basis of that work. Halver carried out research on Vitamin C in its many forms. His research showed that Vitamin C1 (Ascorbic Acid) the active form of C, is required by the body to create new cells and repair cells. His work also showed that C2 though C6 are other forms of C, some of which are stable, and that effectiveness of C1 breaks down when exposed to heat and light. His research showed that animal feeds that use the stable forms of C in their diet formulation can have a"
"as an antioxidant and an acidity regulator. It is approved for use as a food additive in the EU, USA, and Australia and New Zealand. In ""in vitro"" studies, sodium ascorbate has been found to produce cytotoxic effects in various malignant cell lines, which include melanoma cells that are particularly susceptible. Sodium ascorbate is produced by dissolving ascorbic acid in water and adding an equivalent amount of sodium bicarbonate in water. After cessation of effervescence, the sodium ascorbate is precipitated by the addition of isopropanol. Sodium ascorbate Sodium ascorbate is one of a number of mineral salts of ascorbic acid"
"process delays onset of deficiency. Ascorbic acid also converts (reversibly) to dehydroascorbate (DHA) and from that compound non-reversibly to 2,3-diketogluonate and then oxalate. These three compounds are also excreted via urine. Humans are better than guinea pigs at converting DHA back to ascorbate, and thus take much longer to become vitamin C deficient. Ascorbic acid performs numerous physiological functions in the human body. These functions include the synthesis of collagen, carnitine, and neurotransmitters; the synthesis and catabolism of tyrosine; and the metabolism of microsome. During biosynthesis ascorbate acts as a reducing agent, donating electrons and preventing oxidation to keep iron"
"by the human body than the corresponding weakly acidic ascorbic acid. Ascorbates are highly reactive antioxidants used as food preservatives. Examples of mineral ascorbates are: Mineral ascorbates Mineral ascorbates are a group of salts of ascorbic acid (vitamin C). They are composed of a mineral cation bonded to ascorbate (the anion of ascorbic acid). Mineral ascorbates are powders manufactured by reacting ascorbic acid with mineral carbonates in aqueous solutions, venting the carbon dioxide, drying the reaction product, and then milling the dried product to the desired particle size. The choice of the mineral carbonates can be calcium carbonate, potassium carbonate,"
"and do not require it in their diets. Ascorbic acid is required for the conversion of the procollagen to collagen by oxidizing proline residues to hydroxyproline. In other cells, it is maintained in its reduced form by reaction with glutathione, which can be catalysed by protein disulfide isomerase and glutaredoxins. Ascorbic acid is a redox catalyst which can reduce, and thereby neutralize, reactive oxygen species such as hydrogen peroxide. In addition to its direct antioxidant effects, ascorbic acid is also a substrate for the redox enzyme ascorbate peroxidase, a function that is particularly important in stress resistance in plants. Ascorbic"
"term ""vitamin C"" encompasses several vitamers that have vitamin C activity in animals. Ascorbate salts such as sodium ascorbate and calcium ascorbate are used in some dietary supplements. These release ascorbate upon digestion. Ascorbate and ascorbic acid are both naturally present in the body, since the forms interconvert according to pH. Oxidized forms of the molecule such as dehydroascorbic acid are converted back to ascorbic acid by reducing agents. Vitamin C is a cofactor in at least eight enzymatic reactions in animals (and humans) important in many essential functions, including wound healing. In humans, vitamin C deficiency compromises collagen synthesis,"
"in 1928. In 1928 Albert Szent-Györgyi isolated ascorbic acid, and in 1932 proved that it is vitamin C by preventing scurvy. In 1935 he synthesized it, and in 1937 won a Nobel Prize for his efforts. Szent-Györgyi concurrently elucidated much of the citric acid cycle. In the 1930s William Cumming Rose identified essential amino acids, necessary protein components which the body cannot synthesize. In 1935 Eric Underwood and Hedley Marston independently discovered the necessity of cobalt. In 1936 Eugene Floyd Dubois showed that work and school performance relate to caloric intake. In 1938 Erhard Fernholz discovered the chemical structure of"
"and copper atoms in their reduced states. Vitamin C acts as an electron donor for eight enzymes: The name ""vitamin C"" always refers to the -enantiomer of ascorbic acid and its oxidized forms, such as dehydroascorbate (DHA). Therefore, unless written otherwise, ""ascorbate"" and ""ascorbic acid"" refer in the nutritional literature to -ascorbate and -ascorbic acid respectively. Ascorbic acid is a weak sugar acid structurally related to glucose. In biological systems, ascorbic acid can be found only at low pH, but in solutions above pH 5 is predominantly found in the ionized form, ascorbate. All of these molecules have vitamin C"
"mechanisms, so the presence of large quantities of sugar in the intestine can slow absorption. Ascorbic acid is absorbed in the body by both active transport and simple diffusion. Sodium-Dependent Active Transport—Sodium-Ascorbate Co-Transporters (SVCTs) and Hexose transporters (GLUTs)—are the two transporter proteins required for active absorption. SVCT1 and SVCT2 import the reduced form of ascorbate across plasma membranes. GLUT1 and GLUT3 are glucose transporters, and transfer only the dehydroascorbic acid (DHA) form of vitamin C. Although dehydroascorbic acid is absorbed in higher rate than ascorbate, the amount of dehydroascorbic acid found in plasma and tissues under normal conditions is low,"
"in as food. Others may be conditionally essential for certain ages or medical conditions. Essential amino acids may also differ between species. Because of their biological significance, amino acids are important in nutrition and are commonly used in nutritional supplements, fertilizers, feed, and food technology. Industrial uses include the production of drugs, biodegradable plastics, and chiral catalysts. The first few amino acids were discovered in the early 19th century. In 1806, French chemists Louis-Nicolas Vauquelin and Pierre Jean Robiquet isolated a compound in asparagus that was subsequently named asparagine, the first amino acid to be discovered. Cystine was discovered in"
"is responsible for umami, one of the five basic tastes of the human sense of taste. Glutamic acid is often used as a food additive and flavor enhancer in the form of its sodium salt, known as monosodium glutamate (MSG). All meats, poultry, fish, eggs, dairy products, and kombu are excellent sources of glutamic acid. Some protein-rich plant foods also serve as sources. 30% to 35% of gluten (much of the protein in wheat) is glutamic acid. Ninety-five percent of the dietary glutamate is metabolized by intestinal cells in a first pass. Auxigro is a plant growth preparation that contains"
"are necessary for iron absorption. In 1927, Adolf Otto Reinhold Windaus synthesized vitamin D, and was awarded the Nobel Prize in Chemistry in 1928. In 1928, Albert Szent-Györgyi isolated ascorbic acid, and in 1932 proved that it is vitamin C by preventing scurvy. In 1935, he synthesized it, and in 1937, he won a Nobel Prize for his efforts. Szent-Györgyi concurrently elucidated much of the citric acid cycle. In the 1930s, William Cumming Rose identified essential amino acids, necessary protein components that the body cannot synthesize. In 1935, Underwood and Marston independently discovered the necessity of cobalt. In 1936, Eugene"
"change in US meat curing practices resulted in a 69% decrease in average nitrite content. This event preceded the beginning of a dramatic decline in gastric cancer mortality. Around 1970, it was found that ascorbic acid (vitamin C), an antioxidant, inhibits nitrosamine formation. Consequently, the addition of at least 550 ppm of ascorbic acid is required in meats manufactured in the United States. Manufacturers sometimes instead use erythorbic acid, a cheaper but equally effective isomer of ascorbic acid. Additionally, manufacturers may include α-tocopherol (vitamin E) to further inhibit nitrosamine production. α-Tocopherol, ascorbic acid, and erythorbic acid all inhibit nitrosamine production"
"also added to some fruit juices and juice drinks. Tablet and capsule content ranges from 25 mg to 1500 mg per serving. The most commonly used supplement compounds are ascorbic acid, sodium ascorbate and calcium ascorbate. Vitamin C molecules can also be bound to the fatty acid palmitate, creating ascorbyl palmitate, or else incorporated into liposomes. In 2014, the Canadian Food Inspection Agency evaluated the effect of fortification of foods with ascorbate in the guidance document, ""Foods to Which Vitamins, Mineral Nutrients and Amino Acids May or Must be Added"". Voluntary and mandatory fortification was described for various classes of"
"as cells rapidly reduce dehydroascorbic acid to ascorbate. SVCTs appear to be the predominant system for vitamin C transport in the body, the notable exception being red blood cells, which lose SVCT proteins during maturation. In both vitamin C synthesizers (example: rat) and non-synthesizers (example: human) cells with few exceptions maintain ascorbic acid concentrations much higher than the approximately 50 micromoles/liter (µmol/L) found in plasma. For example, the ascorbic acid content of pituitary and adrenal glands can exceed 2,000 µmol/L, and muscle is at 200-300 µmol/L. The known coenzymatic functions of ascorbic acid do not require such high concentrations, so"
"Based on that study, the American Burn Association (ABA) considers high-dose ascorbic acid an option to be considered for adjuvant therapy in addition to the more accepted standard treatments. Atrial fibrillation (AF) is a common cardiac rhythm disturbance and it is associated with oxidative stress. Four meta-analyses have concluded that there is strong evidence that 1-2 g/day of vitamin C before and after cardiac operations can decrease the risk of post-operative AF. However, five randomized studies did not find benefit in the USA, so that the benefit was restricted to less wealthy countries. Exercise-induced bronchoconstriction (EIB) indicates acute narrowing of"
"Niacin Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It has the formula and belongs to the group of the pyridinecarboxylic acid. Niacin is obtained in the diet from a variety of whole and processed foods, with highest contents in fortified packaged foods, tuna, some vegetable and other animal sources. Some countries require its addition to grains. Medication and supplemental niacin are primarily used to treat high blood cholesterol and pellagra (niacin deficiency). Insufficient niacin in the diet can cause nausea, skin and mouth lesions, anemia, headaches, and"
"much of the basis of the controversy on current recommended dietary allowances. It is countered by arguments that humans are very good at conserving dietary vitamin C, and are able to maintain blood levels of vitamin C comparable with simians on a far smaller dietary intake, perhaps by recycling oxidized vitamin C. There are many different biosynthesis pathways for ascorbic acid in plants. Most of these pathways are derived from products found in glycolysis and other pathways. For example, one pathway goes through the plant cell wall polymers. The plant ascorbic acid biosynthesis pathway most principal seems to be -galactose."
"fresh cabbage or lemon juice. Their findings were published in 1907 in the ""Journal of Hygiene"", but were unpopular within the scientific community as the concepts of nutritional deficiencies was unheard of at the time (the concept and word ""vitamine"" did not arrive until 1912, and was in part based upon Holst and Frølich's work). However, in the later work which led up to the isolation of vitamin C as the antiscorbutic factor in 1932-33, Holst and Frølich's guinea pig model of scurvy proved to be the key biological assay which allowed identification of the chemical substance (hexuronic acid, later"
"a compound he called ""hexuronic acid"". Szent-Györgyi suspected hexuronic acid, which he had isolated from adrenal glands, to be the antiscorbutic agent, but he could not prove it without an animal-deficiency model. In 1932, the connection between hexuronic acid and scurvy was finally proven by American researcher Charles Glen King of the University of Pittsburgh. King's laboratory was given some hexuronic acid by Szent-Györgyi and soon established that it was the sought-after anti-scorbutic agent. Because of this, hexuronic acid was subsequently renamed ""ascorbic acid."" Rates of scurvy in most of the world are low. Those most commonly affected are malnourished"
"from animal adrenal glands. In 1932 Charles Glen King confirmed that it was indeed the antiscorbutic factor. In 1933, sugar chemist Walter Norman Haworth, working with samples of ""hexuronic acid"" that Szent-Györgyi had isolated from paprika and sent him in the previous year, deduced the correct structure and optical-isomeric nature of the compound, and in 1934 reported its first synthesis. In reference to the compound's antiscorbutic properties, Haworth and Szent-Györgyi proposed to rename it ""a-scorbic acid"" for the compound, and later specifically -ascorbic acid. Because of their work, in 1937 the Nobel Prizes for chemistry and medicine were awarded to"
"the skin than in the flesh. They also contain moderate levels of carotenoids and ascorbic acid. Peaches and nectarines are orange and yellow in color which can be attributed to the carotenoids present. Ascorbic acid is important in hydroxylation reactions, such as collagen synthesis and de novo synthesis of bone and cartilage, and wound healing. Ascorbic acid is also a precursor of Vitamin C, which is essential for repairing tissues and absorbing iron. Various ""Prunus"" species are winter hosts of the Damson-hop aphid, ""Phorodon humuli"", which is destructive to hops ""Humulus lupulus"" just at the time of their maturity, so"
"of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host. Different types of organism have different essential nutrients. Ascorbic acid (vitamin C) is essential, meaning it must be consumed in sufficient amounts, to humans and some other animal species, but not to all animals and not to plants, which are able to synthesize it. Nutrients may be organic or inorganic:"
"foods. Among foods classified for mandatory fortification with vitamin C were fruit-flavored drinks, mixes, and concentrates, foods for a low-energy diet, meal replacement products, and evaporated milk. Ascorbic acid and some of its salts and esters are common additives added to various foods, mostly to retard oxidation. The relevant European food additive E numbers are: From the U.S. National Institutes of Health: [In humans] ""Approximately 70%–90% of vitamin C is absorbed at moderate intakes of 30–180 mg/day. However, at doses above 1,000 mg/day, absorption falls to less than 50%."" It is transported through the intestine via both glucose-sensitive and glucose-insensitive"
"derived from acetic acid, is fundamental to all forms of life. When bound to coenzyme A, it is central to the metabolism of carbohydrates and fats. The global demand for acetic acid is about 6.5 million metric tons per year (Mt/a), of which approximately 1.5 Mt/a is met by recycling; the remainder is manufactured from methanol. Vinegar is mostly dilute acetic acid, often produced by fermentation and subsequent oxidation of ethanol. The trivial name ""acetic acid"" is the most commonly used and preferred IUPAC name. The systematic name ""ethanoic acid"", a valid IUPAC name, is constructed according to the substitutive"
"in 1758. (However, ""G. morhua callarias"", a low-salinity, nonmigratory race restricted to parts of the Baltic, was originally described as ""Gadus callarias"" by Linnaeus.) Cod is popular as a food with a mild flavour and a dense, flaky, white flesh. Cod livers are processed to make cod liver oil, an important source of vitamin A, vitamin D, vitamin E, and omega-3 fatty acids (EPA and DHA). Young Atlantic cod or haddock prepared in strips for cooking is called scrod. In the United Kingdom, Atlantic cod is one of the most common ingredients in fish and chips, along with haddock and"
"called ""hexuronic acid"", from adrenal gland tissue. He accepted a position at the University of Szeged in 1930. There, Szent-Györgyi and his research fellow Joseph Svirbely found that ""hexuronic acid"" was actually the thus far unidentified antiscorbutic factor, known as vitamin C. After Walter Norman Haworth had determined the structure of vitamin C, and in honour of its antiscorbutic properties, it was given the formal chemical name of L-ascorbic acid. In some experiments they used paprika as the source for their vitamin C. Also during this time, Szent-Györgyi continued his work on cellular respiration, identifying fumaric acid and other steps"
"disease of sailors in long sea voyages. It is used in as a food additive and a dietary supplement for its antioxidant properties. The """" form can be made via chemical synthesis but has no significant biological role. The antiscorbutic properties of certain foods were demonstrated in the 18th century by James Lind. In 1907, Axel Holst and Theodor Frølich discovered that the antiscorbutic factor was a water-soluble chemical substance, distinct from the one that prevented beriberi. Between 1928 to 1932, Albert Szent-Györgyi isolated a candidate for this substance, which he called it ""hexuronic acid"", first from plants and later"