Description |
D(+)-glucose ,a short form of dextrorotatory glucose, is a stereoisomer of glucose molecule, which is biologically active and whose bottom chiral carbon has its hydroxyl group (OH) located spatially to the right. Its molecule can exist in an open-chain (acyclic) and ring (cyclic) form and has two isomers α- and β-. It is the main source of energy in the form of ATP for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. In animals, it arises from the breakdown of glycogen in a process known as glycogenolysis. D-(+)-Glucose has been used as a standard for the estimation of total sugar in hydrolyzed starch by phenol-sulfuric acid method. It has also been used in the preparation of the liquid media for culturing some yeast cells. In addition, it is used therapeutically in fluid and nutrient replacement, such as glucose syrup and glucose powder. It can be obtained by enzymatic cleavage of starch, so there are multiple sources like sugar cane, sugar beet, corn (corn syrup), potatoes and wheat. Today, large-scale starch hydrolysis is used to produce glucose. |
Description |
Glucose is one of the most important biological compounds found in nature. It is a main product in photosynthesis and is oxidized in cellular respiration. Glucose polymerizes to form several important classes of biomolecules including cellulose, starch, and glycogen. It also combines with other compounds to produce common sugars such as sucrose and lactose. The form of glucose displayed above is D-glucose. The "D" designation indicates the configuration of the molecule. The "D" configuration specifies that the hydroxyl group on the number 5 carbon is on the right side of the molecule. The mirror image of D-glucose produces another form of glucose called L-glucose.
Glucose is the most common form of a large class of molecules called carbohydrates. Carbohydrates are the predominant type of organic compounds found in organisms and include sugar, starches, and fats. Carbohydrates, as the name implies, derive their name from glucose,C6H12O6, which was considered a hydrate of carbon with the general formula of Cn(H2O)n, where n is a positive integer. Although the idea of water bonded to carbon to form a hydrate of carbon was wrong, the term carbohydrate persisted. Carbohydrates consist of carbon, hydrogen, and oxygen atoms, with the carbon atoms generally forming long unbranched chains. Carbohydrates are also known as saccharides derived from the Latin word for sugar, saccharon. |
Chemical Properties |
White or almost white, crystalline powder. |
History |
D-Glucose is the most important and predominant monosaccharide found in nature. It was isolated from raisins by Andreas Sigismund Marggraf (1709-1782) in 1747, and in 1838, Jean-Baptiste-André Dumas (1800-1884) adopted the name glucose from the Greek word glycos meaning sweet. Emil Fischer (1852-1919) determined the structure of glucose in the late 19th century. Glucose also goes by the names dextrose (from its ability to rotate polarized light to the right), grape sugar, and blood sugar. The term blood sugar indicates that glucose is the primary sugar dissolved in blood. Glucose's abundant hydroxyl groups enable extensive hydrogen bonding, and so glucose is highly soluble in water. |
Uses |
Glucose is the primary fuel for biological respiration. During digestion, complex sugarsand starches are broken down into glucose (as well as fructose and galactose) in the small intestine.Glucose then moves into the bloodstream and is transported to the liver where glucoseis metabolized through a series of biochemical reactions, collectively referred to as glycolysis.Glycolysis, the breakdown of glucose, occurs in most organisms. In glycolysis, the final productis pyruvate. The fate of pyruvate depends on the type of organism and cellular conditions.In animals, pyruvate is oxidized under aerobic conditions producing carbon dioxide. Underanaerobic conditions in animals, lactate is produced. This occurs in the muscle of humansand other animals. During strenuous conditions the accumulation of lactate causes musclefatigue and soreness. Certain microorganisms, such as yeast, under anaerobic conditions convertpyruvate to carbonic dioxide and ethanol. This is the basis of the production of alcohol.Glycolysis also results in the production of various intermediates used in the synthesis of otherbiomolecules. Depending on the organism, glycolysis takes various forms, with numerousproducts and intermediates possible. |
Uses |
glucose has moisture-binding properties and provides the skin with a soothing effect. It is a sugar that is generally obtained by the hydrolysis of starch. |
Uses |
Glucose is a corn sweetener that is commercially made from starch by the action of heat and acids or enzymes, resulting in the complete hydrolysis of the cornstarch. There are two types of refined commercially available: hydrate, which contains 9% by weight water of crystallization and is the most often used, and anhydrous glucose, which contains less than 0.5% water. is a reducing sugar and produces a high-temperature browning effect in baked goods. It is used in ice cream, bakery products, and confections. It is also termed corn sugar. |
Uses |
Dextrose(D-glucose), a simple sugar (monosaccharide), is an important carbohydrate in biology |
Uses |
Labelled D-Glucose is a simple sugar that is present in plants. A monosaccharide that may exist in open chain or cyclic conformation if in solution. It plays a vital role in photosynthesis and fuels the energy required for cellular respiration. D-Glucose is used in various metabolic processes including enzymic synthesis of cyclohexyl-α and β-D-glucosides. Can also be used as a diagnostic tool in detection of type 2 diabetes mellitus and potentially Huntington's disease through analysis of blood-glucose in type 1 diabetes mellitus. |
Uses |
A primary source of energy for living organisms |
Definition |
ChEBI: The open chain form of D-glucose. |
Definition |
Naturally occurring GLUCOSE belongs to the stereochemical series D and is dextrorotatory, indicated by the symbol (+). Thus the term dextrose is used to indicate D-(+)-glucose. As other stereochemical forms of glucose have no significance in biological systems the term 'glucose' is often used interchangeably with dextrose in biology. |
Brand name |
Cartose (Sterling Winthrop) Dextrose. |
Biotechnological Production |
The D-configuration of D-isoascorbic acid at C5 allows a short biosynthetic pathway from D-glucose, i.e., its 1,5-glucopyranoside, which is oxidized to D-glucono-1,5-lactone by glucose oxidase followed by oxidation at C2 by D-gluconolactone oxidase. The immediate oxidation product of D-glucono-1,5-lactone by gluconolactone oxidase already has reducing activity on, e.g., 2,6-dichlorphenolindophenol. It is rather stable at pH 4. Upon pH shift, this compound spontaneously converts to D-isoascorbic acid. The unidentified immediate oxidation product could be 2-keto-D-glucono-1,5-lactone, which rearranges via a reversible transesterification reaction to the 1,4-lactone followed by an irreversible enolization to D-isoascorbic acid. The formation of 2-keto-D-gluconic acid as the result of 2-keto-D-glucono-1,5-lactone hydrolysis was not reported. The oxidation of the 1,4-lactone by D-gluconolactone oxidase might also occur to some extent, since D-glucono-1,5-lactone shows a tendency to slowly rearrange to the 1,4-lactone at pH[4and the D-gluconolactone oxidase of Penicillium cyaneofulvum accepts both D-glucono-1,5-lactone and the corresponding 1,4-lactone . This reaction would directly deliver the keto-isomer of D-isoascorbic acid. The sequence of the reactions from D-glucose to D-isoascorbic acid, first oxidation at C1, then oxidation at C2 (C1, C2), is similar to the naturally evolved Asc biosynthesis from L-galactose or L-gulose.
Oxidation of D-gluconolactone at C2 is also afforded by pyranose-2-oxidase from Polyporus obtusus. In this reaction both D-isoascorbic acid and 2-keto- D-gluconic acid were obtained in a roughly 1:1 ratio. Obviously, following the natural C1, C2 oxidation sequence, transesterification and (iso)ascorbic acid formation are preferred over hydrolysis and 2-keto sugar acid formation or are at least possible to a significant extent.
If the sequence of oxidation reactions is reversed (C2, C1), i.e., D-glucopyranose is first oxidized by pyranose-2-oxidase to D-glucosone followed by glucose oxidase treatment, 2-keto-D-gluconate was reported as the only oxidation product. Though not explicitly reported, it is safe to assume that the later oxidation occurs with 2-keto-D-gluco-1,5-pyranose and delivers as the immediate reaction product 2-keto-D-glucono-1,5-lactone, which hydrolyzes affording 2-keto-D-gluconate. It is unclear why the spontaneous follow-up reaction of 2-keto-D-glucono-1,5-lactone delivers, at least to some extent, D-isoascorbic acid if obtained according to the C1, C2 reaction sequence, but only 2-keto-D-gluconate if obtained by the C2, C1 oxidation sequence. |
General Description |
Watery odorless colorless liquid. Denser than water and soluble in water. Hence sinks in and mixes with water. |
Air & Water Reactions |
Water soluble. |
Reactivity Profile |
A weak reducing agent. |
Health Hazard |
No toxicity |
Safety Profile |
Mildly toxic by ingest ion. An experimental teratogen. Experi mental reproductive effects. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. Potentially explosive reaction with potassium nitrate + sodium peroxide when heated in a sealed container. Uxtures with alkali release carbon monoxide when heated. When heated to decomposition it emits acrid smoke and irritating fumes. |
Purification Methods |
Crystallise -D-glucose from hot glacial acetic acid or pyridine. Traces of solvent are removed by drying in a vacuum oven at 75o for >3hours. [Gottfried Adv Carbohydr Chem 5 127 1950, Kjaer & Lindberg Acta Chem Scand 1 3 1713 1959, Whistler & Miller Methods in Carbohydrate Chemistry I 1301962, Academic Press, Beilstein 1 IV 4306.] [For equilibrium forms see Angyal Adv Carbohydr Chem 42 15 1984, Angyal & Pickles Aust J Chem 25 1711 1972.] |