diabetestalk.net

# Beta D Glucose

## 31-beta-d-cellobiosyl-glucose Oligosaccharide - Megazyme

Fermentation of -glucan fractions from barley [average molecular mass (MM), of 243, 172, and 137 kDa] and oats (average MM of 230 and 150 kDa) by the human faecal microbiota was investigated. Fractions were supplemented to pH-controlled anaerobic batch culture fermenters inoculated with human faecal samples from three donors, in triplicate, for each substrate. Microbiota changes were monitored by fluorescent in situ hybridization; groups enumerated were: Bifidobacterium genus, Bacteroides and Prevotella group, Clostridium histolyticum subgroup, Ruminococcus-Eubacterium-Clostridium (REC) cluster, Lactobacillus-Enterococcus group, Atopobium cluster, and clostridial cluster IX. Short-chain fatty acids and lactic acid were measured by HPLC. The C. histolyticum subgroup increased significantly in all vessels and clostridial cluster IX maintained high populations with all fractions. The Bacteroides-Prevotella group increased with all but the 243-kDa barley and 230-kDa oat substrates. In general -glucans displayed no apparent prebiotic potential. The SCFA profile (51 : 32 : 17; acetate : propionate : butyrate) was considered propionate-rich. In a further study a -glucan oligosaccharide fraction was produced with a degree of polymerization of 3-4. This fraction was supplemented to small-scale faecal batch cultures and gave significant increases in the Lactobacillus-Enterococcus group; however, the prebiotic potential of this fraction was marginal compared with that of inulin. Versatile high resolution oligosaccharide microarrays for plant glycobiology and cell wall research. Pedersen, H. L., Fangel, J. U., McCleary, B., Ruzanski, C., Rydahl, M. G., Ralet, M. C., Farkas, V., Von Schantz, L., Marcus, S. E., Andersen, M.C. F., Field, R., Ohlin, M., Knox, J. P., Clausen, M. H. & W Continue reading >>

## Enzymic Synthesis Of Indole-3-acetyl-1-o--d-glucose

Enzymic Synthesis of Indole-3-Acetyl-1-O--d-Glucose II. Metabolic Characteristics of the Enzyme 1988 American Society of Plant Biologists The synthesis of indole-3-acetyl-1-O--d-glucose from indole-3-acetic acid (IAA) and uridine diphosphoglucose (UDPG) has been shown to be a reversible reaction with the equilibrium away from ester formation and toward formation of IAA. The enzyme occurs primarily in the liquid endosperm of the corn kernel but some activity occurs in the embryo. It is relatively specific showing no glucose ester formation with oxindole-3-acetic acid or 7-hydroxy-oxindole-3-acetic acid, and low activity with phenylpropene acids, such as -coumaric acid. The enzyme is also specific for the nucleotide sugar showing no activity with UDPGalactose or UDPXylose. The enzyme is inhibited by inorganic pyrophosphate, by phosphate esters and by phospholipids, particularly phosphatidyl ethanolamine. The enzyme is inhibited by zeatin, by 2,4-dichlorophenoxy-acetic acid, by IAA-myo-inositol and IAA-glucan, but not by zeatin riboside, and only weakly by gibberellic acid, abscisic acid, and kinetin. The reaction is slightly stimulated by both calcium and calmodulin and, in some cases, by thiol compounds. The role of this enzyme in the homeostatic control of indole-3-acetic acid levels in Zea mays is discussed. Continue reading >>

## Beta-d-glucose - Drugbank

A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. (2R,3R,4S,5S,6R)-6-(hydroxymethyl)oxane-2,3,4,5-tetrol OC[ [emailprotected] ]1O[ [emailprotected] @H](O)[ [emailprotected] ](O)[ [emailprotected] @H](O)[ [emailprotected] @H]1O U Malto-oligosyltrehalose trehalohydrolase Deinococcus radiodurans (strain ATCC 13939 / DSM 20539 / JCM 16871 / LMG 4051 / NBRC 15346 / NCIMB 9279 / R1 / VKM B-1422) Chen Gong, "Method for preparation of 2'-deoxy-2', 2'-difluoro-beta-cytidine or pharmaceutically acceptable salts thereof by using 1,6-anhydro-beta-D-glucose as raw material." U.S. Patent US20060003963, issued January 05, 2006. This compound belongs to the class of organic compounds known as hexoses. These are monosaccharides in which the sugar unit is a is a six-carbon containing moeity. Hexose monosaccharide / Oxane / Secondary alcohol / Hemiacetal / Oxacycle / Organoheterocyclic compound / Polyol / Hydrocarbon derivative / Primary alcohol / Alcohol DNA contains the instructions needed for an organism to develop, survive and reproduce. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [ PubMed:17139284 ] Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. [ PubMed:17016423 ] Pedobacter heparinus (strain ATCC 13125 / DSM 2366 / NCIB 9290) Cleaves the glycosaminoglycan, dermatan sulfate. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [ PubMed:17139284 ] Imming P, Sinning C, Meyer A: Drugs, their targets and the Continue reading >>

## Mutarotation Master Organic Chemistry

In our recent post on ring-chain tautomerism , we said that there are two isomers of D-glucose in its 6-membered ring (pyranose) form. These two diastereomers which, to make matters more confusing, are called anomers in the context of sugar chemistry differ in the orientation of the hydroxyl group on C-1. (Note that C-1 is a hemiacetal . ) In the alpha () anomer, the OH group on C-1 is on theopposite side of the ring as the chain on C-5. In the beta () anomer, the OH group on C-1 is on the sameside of the ring as the C-5 substituent. Each of these two forms can be synthesized and isolated as pure compounds. The alpha () anomer of D-glucose has a specific rotation of +112 degrees in water. The beta () anomer of D-glucose has a specific rotation of +19 degrees. (18.7 actually, but rounding up to 19). Heres the interesting thing.When either anomer is dissolved in water, the value of the specific rotation changes over time, eventually reaching the same value of +52.5. The specific rotation of -D-glucopyranose decreases from +112 to +52.5. The specific rotation of-D-glucopyranose increases from +19 to +52.5. This behaviour is calledmutarotation(literally, change in rotation). Hold on. Isnt specific rotation of a molecule supposed to remain the same? Yes if it is indeed the same molecule! And therein lies the answer to the puzzle. For when the solutions whose specific rotations have changed to +52.5 are analyzed, they are found to no longer consist of 100% alpha () or 100% beta ()anomers, but instead a ratio of alpha () (36%) and beta () (64% ) isomers. Wait. What happened here? How did the alpha convert to the beta, and vice-versa? You may recall how we said in the last post on ring-chain tautomerism that the cyclic hemiacetal forms of sugars are in equilibrium with the str Continue reading >>

## Glucose

This article is about the naturally occurring D-form of glucose. For the L-form, see L-Glucose. Glucose is a simple sugar with the molecular formula C6H12O6, which means that it is a molecule that is made of six carbon atoms, twelve hydrogen atoms, and six oxygen atoms. Glucose circulates in the blood of animals as blood sugar. It is made during photosynthesis from water and carbon dioxide, using energy from sunlight. It is the most important source of energy for cellular respiration. Glucose is stored as a polymer, in plants as starch and in animals as glycogen. With six carbon atoms, it is classed as a hexose, a subcategory of the monosaccharides. D-Glucose is one of the sixteen aldohexose stereoisomers. The D-isomer, D-glucose, also known as dextrose, occurs widely in nature, but the L-isomer, L-glucose, does not. Glucose can be obtained by hydrolysis of carbohydrates such as milk sugar (lactose), cane sugar (sucrose), maltose, cellulose, glycogen, etc. It is commonly commercially manufactured from cornstarch by hydrolysis via pressurized steaming at controlled pH in a jet followed by further enzymatic depolymerization.[3] In 1747, Andreas Marggraf was the first to isolate glucose.[4] Glucose is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.[5] The name glucose derives through the French from the Greek γλυκός, which means "sweet," in reference to must, the sweet, first press of grapes in the making of wine.[6][7] The suffix "-ose" is a chemical classifier, denoting a carbohydrate. Function in biology Glucose is the most widely used aldohexose in living organisms. One possible explanation for this is that glucose has a lower tendency than other aldohexoses to react nonspecific Continue reading >>

## 1-thio--d-glucose Tetraacetate (2,3,4,6-tetra-o-acetyl-1-thioglucopyranose) (ab143717)

1-Thio--D-glucose tetraacetate (2,3,4,6-tetra-O-acetyl-1-thioglucopyranose) Maillard reaction inhibitor between glucose and glycine Maillard reaction inhibitor between glucose and glycine. Reduces advanced glycation end-products. Potential preventive agent against vascular stiffening, atherosclerosis, osteoarthritis, inflammatory arthritis and cataracts. Store at Room Temperature. The product can be stored for up to 12 months. Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour. Need more advice on solubility, usage and handling? Please visit our frequently asked questions (FAQ) page for more details. CC(=O)OCC1C(C(C(C(O1)S)OC(=O)C)OC(=O)C)OC(=O)C Continue reading >>

## Sucrose

Another disaccharide of particular importance is sucrose. It is a disaccharide that can be made from the combinations of the two monosaccharides, glucose and fructose. In particular, it involves the use of the alpha form of D-glucose and the beta form ofD-fructose. In the diagrams below, note that the a-D-glucose isin the conventional orientation (the #6C is up). The b-D-fructose,however, is shown in two orientations. In the standard orientation the #6C is up on theleft side and the b-2-OH is up on the right. Because it will bethe b-2-OH group that bond to the -1-OH of the a-D-glucose, the b-D-fructose moleculemust be inverted. Take a moment to study the diagrams and identify the location of thenumbered carbon atoms in each diagram. (Similar diagrams are shown in Example 27 of yourworkbook for reference. The carbon atoms are numbered in those diagrams.) As you look at these diagrams in the equation below (and in your workbook), be sure tonote the numbering for fructose is opposite from the conventional orientation, and that isjust because we want the two reacting OH's to be next to one another. When these two OH'sreact by an enzyme-catalyzed dehydration reaction, the resulting product is sucrose. The glycosidic bond for the sucrose is sometimes referred to as an a-b-1-2 bond, because there's an alpha-OHfrom the glucose bonding to a beta-OH from the sucrose, and we're going from the #1 carbonon the glucose to the #2 carbon on the fructose. There are a few other ways of indicatingthis designation, (a-1)(b-2) is probably the most descriptive, but they all try tosay the same kind of thing, that we're dealing with the #1-OH in the alpha position bondedto the #2-OH in the beta position. Sucrose is an unusual disaccharide in that it is a nonreducing sugar. This is becauseboth Continue reading >>

## Is Alpha (d+) Glucose Same As Beta (d-) Glucose?

Is alpha (D+) glucose same as beta (D-) glucose? No. In the name D(+) Glucose, D represents the orientation of the hydroxyl group at the chiral carbon that is farthest from the highest oxidised carbon (Aldehyde group in this case) with respect to glyceraldehyde. D says that the hydroxyl group is on the right side (In fischer projection). L says the opposite. Where as (+) and (-) represent the direction of rotation of plane polarised light {Optical rotation} (Determined experimentally) by the solution as a whole. When a water molecule adds to the glucose molecule, the aldehyde group turns into hemiacetal (Ring is formed between 1st and 5th carbon), making the first carbon (previously aldehyde) chiral. Alpha and Beta represent the orientation of hydroxide group (R and S) at that new chiral carbon (Anomeric carbon). Hence those forms are called anomers. Pure Alpha glucose has a positive optical rotation and the Beta form has the opposite rotation (but of different magnitude). The compounds which you have mentioned in the question are pure alpha and pure beta forms of glucose. If you get some random D glucose from somewhere and you some how determined that it has a positive optical rotation,it doesnt mean that it is alpha D glucose. It may also contain beta D glucose each cancelling the effect of other and ultimately resulting a positive optical rotation (Overall dominated by alpha D glucose). Continue reading >>

## Bf638r_0830 - 4-o-beta-d-mannosyl-d-glucose Phosphorylase - Bacteroides Fragilis (strain 638r) - Bf638r_0830 Gene & Protein

The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome.More...-Protein inferred from homologyiThis indicates the type of evidence that supports the existence of the protein. Note that the protein existence evidence does not give information on the accuracy or correctness of the sequence(s) displayed.More... Select a section on the left to see content. This section provides any useful information about the protein, mostly biological knowledge.More...Functioni Converts 4-O-beta-D-mannopyranosyl-D-glucopyranose (Man-Glc) to mannose 1-phosphate (Man1P) and glucose.UniRule annotation Information which has been generated by the UniProtKB automatic annotation system, without manual validation. More Automatic assertion according to rulesi This subsection of the Function section describes the catalytic activity of an enzyme, i.e. the chemical reaction it catalyzes. This information usually correlates with the presence of an EC (Enzyme Commission) number in the Names and taxonomy section.More...Catalytic activityi 4-O-beta-D-mannopyranosyl-D-glucopyranose + phosphate = D-glucose + alpha-D-mannose 1-phosphate.UniRule annotation Information which has been generated by the UniProtKB automatic annotation system, without manual validation. More Automatic assertion according to rulesi This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.More...Names & Taxonomyi This subsection of the Names and taxonomy section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.More...Protein namesi 4-O-beta-D-mannosyl-D-glucose phosphorylaseUniRule annotation Informat Continue reading >>

## 24.3: Anomers Of Simple Sugars: Mutarotation Of Glucose

24.3: Anomers of Simple Sugars: Mutarotation of Glucose Define what is meant by anomers and describe how they are formed. So far we have represented monosaccharides as linear molecules, but many of them also adopt cyclic structures. This conversion occurs because of the ability of aldehydes and ketones to react with alcohols: In some cases, OH and carbonyl groups on the same molecule are able to react with one another in an intramolecular reaction. Thus, monosaccharides larger than tetroses exist mainly as cyclic compounds (Figure $$\PageIndex{1}$$). You might wonder why the aldehyde reacts with the OH group on the fifth carbon atom rather than the OH group on the second carbon atom next to it. Recall that cyclic alkanes containing five or six carbon atoms in the ring are the most stable. The same is true for monosaccharides that form cyclic structures: rings consisting of five or six carbon atoms are the most stable. Figure $$\PageIndex{1}$$: Cyclization of D-Glucose. D-Glucose can be represented with a Fischer projection (a) or three dimensionally (b). By reacting the OH group on the fifth carbon atom with the aldehyde group, the cyclic monosaccharide (c) is produced. When a straight-chain monosaccharide, such as any of the structures shown in Figure $$\PageIndex{1}$$, forms a cyclic structure, the carbonyl oxygen atom may be pushed either up or down, giving rise to two stereoisomers, as shown in Figure $$\PageIndex{2}$$. The structure shown on the left side of Figure $$\PageIndex{2}$$, with the OH group on the first carbon atom projected downward, represent what is called the alpha () form. The structures on the right side, with the OH group on the first carbon atom pointed upward, is the beta () form. These two stereoisomers of a cyclic monosaccharide are known as Continue reading >>

## Animation: Interconversion Between Glucose Isomers

In this animation, you can see D-glucose switch between its different forms (or isomers): -glucose to the open chain form to -glucose, back to the open chain form, and then back to -glucose (and on and on and on...) To help make this easier to see, we've used a short-cut way of drawing molecules that doesn't show some of the carbons and hydrogens. Click here for more info about drawing molecules like this. When the ring opens up, watch the red O and the blue H rotate around. So, when the ring closes again, that red O can be either out or down. In the -glucose, that red O is pointed down. In -glucose, it's pointed out. Watch the green carbon - in each structure it always has four bonds. If D-glucose molecules are dissolved in water, some molecules will be in each one of these forms. Most of them will be in the -glucose form, though, because that's the most stable. It turns out that in a ring like this, when all the -OH groups are sticking out, the molecule is the most comfortable, that is, it has the most amount of "elbow room", or, the least amount of "clutter", so to speak. (O.k., do ya want the big cheesy science talk?! Here it is! -D-glucose has less 1,3-diaxial interactions and less steric hindrance than -D-glucose. Phew!) Note: (O.k, now this is a disclaimer to all the folks who want to know exactly how the ring opens and closes...) There's more to the mechanism of ring opening and closing that's really not shown here; this animation is intended to illustrate what happens as opposed to exactly how it happens. Continue reading >>

## The Suitability Of -d-glucose Pentaacetate For Food Use: I. The Subacute Toxicity Of -d-glucose Pentaacetate

Volume 2, Issue 3 , May 1960, Pages 270-280 The suitability of -d-glucose pentaacetate for food use: I. The subacute toxicity of -d-glucose pentaacetate Author links open overlay panel B.R.Zeitlin R.ThiessenJr. C.L.Long Get rights and content The presence of GPA in diets of young growing rats at levels as high as 10% for a period of 90 days (10% of life span) does not alter their normal growth and food efficiency patterns. The mortality among test rats was not increased; organ weights were not significantly altered from those of controls; no significant histopathologic trends were discerned, nor was there shown to be any alteration in the physiological function studied as determined by the urine analysis, renal function studies, blood chemistry, or hematologic findings. On the other hand, the presence of GPA in the diets appears to bring about a more efficient food utilization, probably by providing for an increase in caloric content of the food. Continue reading >>

## Motd Glucose

(R)-D- and (S)-L-glyceraldehyde serve as reference points for the assignment of relative configuration to all other carbohydrates such as glucose. The reference point is the chiral center farthest from the carbonyl group. A D-carbohydrate has the same configuration at its farthest chiral center as D-glyceraldehyde (its -OH is on the right when written as a Fischer projection); an L-carbohydrate has the same configuration at its farthest chiral center as L-glyceraldehyde (its -OH is on the left). D-Glucose is the stereoisomer found in living systems. Note that the other chiral centers in D-glucose define it as a glucose and not another sugar such as mannose or galactose (different carbohydrate stereoisomers), yet only the last chiral center is relevant to defining a carbohydrate as being D or L. Most students find this definition hard to understand, so you might want to make sure you understand this before moving on. Hemiacetals are generally unstable and are only minor components of an equilibrium mixture of an aldehyde or ketone in water, except in one very important type of compound. When a hydroxyl group is part of the same molecule that contains the carbonyl group, and a five- or six-membered ring can form, the compound exists almost entirely in the cyclic hemiacetal form. Recall that five- and six-membered rings have relatively little ring strain. Carbohydrates like glucose exist in solution as cyclic hemiacetals. Because carbohydrates have several alcohol groups, they could potentially form rings of different sizes. Generally, only the most stable (strain free) cyclic structures are produced to an appreciable extent for a given carbohydrate. The new stereocenter created in a carbohydrate cyclic hemiacetal structure can have either stereochemical configuration, an Continue reading >>

## What's The Difference Between Alpha-glucose And Beta-glucose?

What's the difference between alpha-glucose and beta-glucose? beta D-glucose units makes up the structure of cellulose polysaccharides while alpha D-glucose units makes up the structure of polysaccharides starch. user9873 Nov 18 '14 at 14:12 $\alpha$-D-glucose and $\beta$-D-glucose are stereoisomers - they differ in the 3-dimensional configuration of atoms/groups at one or more positions. Note that the structures are almost identical, except that in the $\alpha$ form, the $\ce{OH}$ group on the far right is down, and, in the $\beta$ form, the $\ce{OH}$ group on the far right is up. More specifically, they are a class of stereoisomer called an anomer . Anomers are capable of interconverting in solution. All cyclic structures of monosaccharides exhibit anomeric $\alpha$ (down) and $\beta$ (up) versions. These differences occur at the anomeric acetal carbon (the only carbon with two $\ce{C-O}$ bonds. These two forms exist because all monosaccharides also have an open-chain form with one fewer stereocenter. When the chain closes to the cyclic structure, the aldehyde or ketone carbon becomes a stereocenter , and it can do so in either configuration. One configuration is preferred ($\beta$), but both exist. In the presence of acid or base (although water can fulfill this role if need be), the two anomers interconvert through the open form until dynamic equilibrium is established. The mechanism below starts with $\alpha$ in the upper left and finishes with $\beta$ in the lower right. The open-chain form is in the middle. Just to add, in the L-configuration, the situation is reversed, since you draw the CH2OH below the ring in the Haworth projection. In both cases, the structure is when the relevant groups are on the same side of the ring, and when they're on opposite sides. H Continue reading >>