DOCSLIB.ORG

Chem 352 - Lecture 7 Carbohydrates

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chem 352 - Lecture 7 Carbohydrates 1 Chem 352 - Lecture 7 Carbohydrates Question for the Day: Unlike amino acids, which owe their diversity to a diverse array of functional groups, monosaccharides feature primarily two functional groups, hydroxyl groups and either a ketone or aldehyde group. What, then, do monosaccharides owe their diversity to? Introduction to Carbohydrates 2 Carbohydrates are one of the four major classes of biological molecules, which include, ✦ Proteins ✦ Nucleic acids ✦ Carbohydrates ✦ Lipids Chem 352, Lecture 7 - Carbohydrates X Introduction to Carbohydrates 3 ✦ Carbohydrates represent a major source of energy for living organisms. ✦ They also play major structural, protective and communication roles. glucose Chem 352, Lecture 7 - Carbohydrates X Introduction to Carbohydrates 4 Carbohydrates are chemically simple, but can be structurally complex ✦ The simple sugars have the basis stoichiometric empirical formula(CH2O)n, where n = 3 to 7 Like amino acid, simple sugars (monosaccharides) can combine to form polymers. ✦ monosaccharides (monomer) ✦ oligosaccharides (several monomers linked together) ✦ polysaccharides (many monomers linked together Chem 352, Lecture 7 - Carbohydrates X 5 9.1 Monosaccharides Monosaccharides 6 Question: Monosaccharides are What is the name ending that is ✦ either Aldoses typically used to designate a carbohydrate? • polyhydroxylaldehydes A. -ase ✦ or Ketoses • polyhydroxylketones B. -ose Classes based on number of carbonsC. -ol ✦ triose (3) D. -al ✦ tetrose (4) E. -amine ✦ pentose (5) ✦ hexose (6) ✦ heptose (7) Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 7 Trioses ✦ L and D Glyceraldehyde • Contains a chiral carbon • Fischer projections ✦ Dihydroxyacetone Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 8 There are different ways to designate the stereochemistry of a chiral center: ✦ R vs S • Rectus versus Sinister - based on the atomic mass of the substituents ✦ d (+) vs l (-) • dextrorotatory versus levorotatory - based on the bending of plane polarized light ✦ D vs L • Based on how glyceraldehyde bends plane polarized light Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 9 Trioses ✦ L and D Glyceraldehyde enantiomers • Contains a chiral carbon • Fischer projections ✦ Dihydroxyacetone Chem 352, Lecture 7 - Carbohydrates X These are FischerMonosaccharides 10 Clicker Question:Projections Aldohexoses•Aldoses contain 4 chiral carbons. Therefore, how many different stereoisomers are members of this group of ✦ Trioses through hexoses monosaccharides? A. 4 B. 16 C. 8 D. 12 E. 32 Chem 352, Lecture 7 - Carbohydrates X 11 L-enantiomersMonosaccharides Trioses through hexoses ✦ This figure shows only the D–enantantiomers ✦ The L-enantiomers are mirror images of the D- enantiomers. ✦ Members of an enantiomeric pair are are distinguished using the chirial carbon that is furthest from the carbonyl group. ✦ Most of the monosaccharides that we will encounter are the D-enantiomers. L D D L L D L D Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 12 Question:Question:•Types of optical isomers WhatWhich is the of relationshipfollowing monosaccharides between D-glucose is an and epimer D-mannose? of glucose: ✦ Enantiomers are stereoisomers that are mirror images A. Enantiomersof one another B. Epimers✦ Epimer are stereoisomers having more than one chiral carbon that differ from one another at just one chiral C. Diastereomerscarbon. D. Not stereoisomers A.✦ DiastereomersB. are stereoisomersC. havingD. more than one chiral carbon that differ from one another at multiple chiral carbons. Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 13 Ketoses ✦ Trioses through hexoses Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 14 •The ones to remember ✦ Aldoses • triose ✦ D-glyceraldehyde • tetrose ‣ D-erythrose • pentoses ✦ D-ribose • hexoses ✦ D-glucose ✦ D-mannose ✦ D-galactose Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 15 •The ones to remember ✦ Ketoses • trisoes ✦ dihydroxyacetone • pentoses ✦ D-ribulose ✦ D-xylulose • hexoses ✦ D-fructose Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 16 •Cyclization of aldoses and ketoses ✦ An aldehyde can react spontaneously with an alcohol to form a hemiacetal. ✦ A ketone can react spontaneously with an alcohol to form a hemiketal. ✦ Both of these reactions are addition reactions that lead to the formation of a new chiral carbon. Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 17 •Cyclization of aldoses and ketoses ✦ For aldoses and ketoses, this reaction occurs intramolecularly and leads to a cyclic molecule. ✦ The chiral hemiacetal or hemiketal carbon is called the anomeric carbon. ≈≈ 0% 0% • The new stereoisomers are designated α (-OH down) and β anomers (-OH up). ✦ Haworth projections are used to represent the cyclic 21.5% 58.5% 6.5% 13.5% form of monosaccharides.36%36% 64%64% Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 18 •Cyclization of aldoses and ketoses ✦ The six-member rings are called pyranose rings ✦ The five-member rings are called furanose rings. Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 19 •Cyclization of aldoses and ketoses ✦ pyranose rings • D-glucopyranose (aldohexose) • D-mannopyranose (aldohexose) • D-galactopyranose (aldohexose) ✦ furanose rings • D-fructofuranose (ketohexose) • D-ribofuranose (aldopentose) Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 20 Clicker Question: •Conformations of Monosaccharides Which of following conformations for β-D-glucosopyranose is predicted✦ Monosaccharides to be more stable: can have different conformations. A. B. Chem 352, Lecture 7 - Carbohydrates X 21 9.2 Derivatives of the Monosaccharides Monosaccharides 22 Derivatives of monosaccharides are produced by chemical modifications. ✦ Phosphate esters ✦ Deoxy sugars also called sialic acid • One of the hydroxyl groups is replaced with a hydrogen ✦ Amino sugars • One of the hydroxyl groups is replaced with an amino group. Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 23 Sugar alcohols ✦ The aldehyde or ketone group is reduced to an alcohol. ✦ Some are used as natural artificial sweeteners. erythritol xylitol Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 24 Sugar acids ✦ The aldehyde can be oxidized to an acid to produce aldonic acids. • Which in turn can cyclize to form lactones. ✦ The 6-hydroxyl group on aldohexoses can also be oxidized to an acid to produce uronic acids . Chem 352, Lecture 7 - Carbohydrates X Glycosides 25 The hemiacetal or hemiketal carbon can go on to react with the hydroxyl group from another molecule to form an acetal or ketal. ✦ The bond formed is called a glycosidic bond. ✦ Glycosidic bonds are used to connect one monosaccharide to another. Chem 352, Lecture 7 - Carbohydrates X Glycosides 26 ✦ Unlike hemiacetals and hemiketals, acetals and ketals cannot open and close dynamically, • The glycosidic bond blocks a pyranose or furanose ring from reopening again. ✦ In cells, glycosidic bond formation is enzyme catalyzed and requires a source of free energy. Chem 352, Lecture 7 - Carbohydrates X Monosaccharides 27 Cyclized aldoses and ketoses tend to get locked into the following ring configurations ✦ pyranose rings • 21.5%D-glucopyranose58.5% (aldohexose)6.5% 13.5% • D-mannopyranose (aldohexose) • D-galactopyranose (aldohexose) ✦ furanose rings • D-fructofuranose (ketohexose) • D-ribofuranose (aldopentose) Chem 352, Lecture 7 - Carbohydrates X 28 9.3 Oligosaccharides Disaccharides 29 The glycosidic bond can be used to connect two monosaccharides together to form disaccharides. Important disaccharides include: ✦ Maltose (obtained from starch) α(1-4) glycosidic bond β-anonomer Chem 352, Lecture 7 - Carbohydrates 3 Disaccharides 30 TheClickerQuestion: glycosidic Question: bond can be used to connect two monosacchridesWhichWhat typeanomer of glycosidicof togetherlactose bond is shown?to does form lactose a disaccharides. have? ImportantA. α (1-4) disaccharides include: • B.Lactoseβ(1-6) C. β(1-4) (milk sugar) (1-4) glycosidic bond D. α(1-5) β α-anonomer Chem 352, Lecture 7 - Carbohydrates 4 Disaccharides 31 The glycosidic bond can be used to connect two monosaccharides together to form disaccharides. Important disaccharides include: • Cellobiose (obtained from cellulose) Chem 352, Lecture 7 - Carbohydrates 5 Disaccharides 32 The glycosidic bond can be used to connect two monosaccharides together to form disaccharides. Important disaccharides include: • Sucrose (table sugar) α1-β2 glycosidic bond Chem 352, Lecture 7 - Carbohydrates 6 Disaccharides 33 Question: Because a hemiacetal or hemiketal can easily open to expose Whicheither anend aldehyde of the disaccharideor α-hydroxy maltose ketone, isthey the can reducing still serve end? as reducing agents for the Cu2+ ions found in Fehling’s and Benedict’s reagents. A. B. O O R C H + Cu2+ R C OH + Cu+ CuSO4(aq) Cu2O(s) clear blue red ppt. ‣ This reaction is used to distinguish the two monosaccharides in a disaccharide as the reducing and the nonreducing ends. Chem 352, Lecture 7 - Carbohydrates 7 Disaccharides 34 Not all disaccharides have a reducing end ✦ For example, the disaccharide sucrose contains both and acetal and a ketal, but no hemiacetal or hemiketal. Chem 352, Lecture 7 - Carbohydrates 8 Glycosides 35 Monosaccharides also form glycosidic bonds to non- sugar. ✦ For example, nucleotides, such as • ATP • UDP-glucose • NAD and NADP • FMN and FAD ✦ And sterols, such as Adenosine triphosphate • Ouabain Flavin mononucleotide (FMN) Flavin adenine dinucleotide (FAD) Chem 352, Lecture 7 - Carbohydrates 9 Glycosides 36 Ribitol
Load more

Recommended publications
  • The Role of Biocatalysis in the Asymmetric Synthesis of Alkaloids – an Update Cite This: RSC Adv.,2021,11, 28223 Emmanuel Cigan, † Bettina Eggbauer, † Joerg H
    RSC Advances REVIEW View Article Online View Journal | View Issue The role of biocatalysis in the asymmetric synthesis of alkaloids – an update Cite this: RSC Adv.,2021,11, 28223 Emmanuel Cigan, † Bettina Eggbauer, † Joerg H. Schrittwieser * and Wolfgang Kroutil Alkaloids are a group of natural products with interesting pharmacological properties and a long history of medicinal application. Their complex molecular structures have fascinated chemists for decades, and their total synthesis still poses a considerable challenge. In a previous review, we have illustrated how biocatalysis can make valuable contributions to the asymmetric synthesis of alkaloids. The chemo-enzymatic strategies discussed therein have been further explored and improved in recent years, and advances in amine Received 29th May 2021 biocatalysis have vastly expanded the opportunities for incorporating enzymes into synthetic routes Accepted 30th July 2021 towards these important natural products. The present review summarises modern developments in DOI: 10.1039/d1ra04181a chemo-enzymatic alkaloid synthesis since 2013, in which the biocatalytic transformations continue to rsc.li/rsc-advances take an increasingly ‘central’ role. Creative Commons Attribution 3.0 Unported Licence. 1 Introduction originally derived – but also amides, nitro, and nitroso compounds, while excluding primary metabolites such as The alkaloids are a large and structurally diverse group of amino acids, proteins, and porphyrins.1a,d Between 25 000 and nitrogen-containing secondary metabolites that
    [Show full text]
  • Structures of Monosaccharides Hemiacetals
    Structures of Monosaccharides Hemiacetals • Although, the open chain structures of monosaccharides are consistent with the chemistry of carbohydrates, in reality they are oversimplifications of the true structure of carbohydrates. • It is common knowledge that aldehydes react with alcohols to form hemiacetals. In cases where a molecule is a hydroxyaldehyde such as 4- hydroxybutanal or 5-hydroxypentanal, cyclic hemiacetals result. 9:47 AM 1 Structures of Monosaccharides Hemiacetals • Aldoses often contain an aldehyde group and several hydroxyl groups as part of the same molecule; they have a greater tendency of forming cyclic hemiacetals. In fact, in aqueous solution carbohydrates exist almost exclusively in the ring-closed form At equilibrium, the linear aldehyde or ketone structure represents less than 1% of the sugar present. • Five and six-membered rings are thermodynamically more stable than their corresponding four and seven membered rings, since they are less strained. • Five- (furanoses) and six-membered cyclic hemiacetals (pyranoses) are often more stable than their open-chain forms. In particular the six-membered rings which can adopt a chair conformation are 9:47 AM 2 essentially free from all types of strains. Structures of Monosaccharides Evidence for Existence of Monosacharides as Hemiacetals What physical, chemical and spectroscopic evidence support the existence of monosaccharide sugars as cyclic hemi-acetals. (a) Two anomers of glucose capable of existing independently with different physical (melting points and specific optical rotation) and chemical properties can be obtained by recrystallization. (b) the 1H-NMR and IR-spectra of solutions of pure sugars show the presence of mixtures (anomeric hemiacetals) and absence of an aldehydic peak is a sufficient indicator that the sugars exist in some other form other than the open-chain form.
    [Show full text]
  • Pentose PO4 Pathway, Fructose, Galactose Metabolism.Pptx
    Pentose PO4 pathway, Fructose, galactose metabolism The Entner Doudoroff pathway begins with hexokinase producing Glucose 6 PO4 , but produce only one ATP. This pathway prevalent in anaerobes such as Pseudomonas, they doe not have a Phosphofructokinase. The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) is a biochemical pathway parallel to glycolysis that generates NADPH and pentoses. While it does involve oxidation of glucose, its primary role is anabolic rather than catabolic. There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol. For each mole of glucose 6 PO4 metabolized to ribulose 5 PO4, 2 moles of NADPH are produced. 6-Phosphogluconate dh is not only an oxidation step but it’s also a decarboxylation reaction. The primary results of the pathway are: The generation of reducing equivalents, in the form of NADPH, used in reductive biosynthesis reactions within cells (e.g. fatty acid synthesis). Production of ribose-5-phosphate (R5P), used in the synthesis of nucleotides and nucleic acids. Production of erythrose-4-phosphate (E4P), used in the synthesis of aromatic amino acids. Transketolase and transaldolase reactions are similar in that they transfer between carbon chains, transketolases 2 carbon units or transaldolases 3 carbon units. Regulation; Glucose-6-phosphate dehydrogenase is the rate- controlling enzyme of this pathway. It is allosterically stimulated by NADP+. The ratio of NADPH:NADP+ is normally about 100:1 in liver cytosol.
    [Show full text]
  • Lecture 7 - the Calvin Cycle and the Pentose Phosphate Pathway
    Lecture 7 - The Calvin Cycle and the Pentose Phosphate Pathway Chem 454: Regulatory Mechanisms in Biochemistry University of Wisconsin-Eau Claire 1 Introduction The Calvin cycle Text The dark reactions of photosynthesis in green plants Reduces carbon from CO2 to hexose (C6H12O6) Requires ATP for free energy and NADPH as a reducing agent. 2 2 Introduction NADH versus Text NADPH 3 3 Introduction The Pentose Phosphate Pathway Used in all organisms Glucose is oxidized and decarboxylated to produce reduced NADPH Used for the synthesis and degradation of pentoses Shares reactions with the Calvin cycle 4 4 1. The Calvin Cycle Source of carbon is CO2 Text Takes place in the stroma of the chloroplasts Comprises three stages Fixation of CO2 by ribulose 1,5-bisphosphate to form two 3-phosphoglycerate molecules Reduction of 3-phosphoglycerate to produce hexose sugars Regeneration of ribulose 1,5-bisphosphate 5 5 1. Calvin Cycle Three stages 6 6 1.1 Stage I: Fixation Incorporation of CO2 into 3-phosphoglycerate 7 7 1.1 Stage I: Fixation Rubisco: Ribulose 1,5- bisphosphate carboxylase/ oxygenase 8 8 1.1 Stage I: Fixation Active site contains a divalent metal ion 9 9 1.2 Rubisco Oxygenase Activity Rubisco also catalyzes a wasteful oxygenase reaction: 10 10 1.3 State II: Formation of Hexoses Reactions similar to those of gluconeogenesis But they take place in the chloroplasts And use NADPH instead of NADH 11 11 1.3 State III: Regeneration of Ribulose 1,5-Bisphosphosphate Involves a sequence of transketolase and aldolase reactions. 12 12 1.3 State III:
    [Show full text]
  • A by Fluorous-Tag Assistance Th
    Angewandte Chemie DOI: 10.1002/ange.200704262 Carbohydrate Microarrays Synthesis and Quantitative Evaluation of Glycero-d-manno-heptose Binding to Concanavalin A by Fluorous-Tag Assistance** Firoz A. Jaipuri, Beatrice Y. M. Collet, and Nicola L. Pohl* Herein we report the first use of a quantitative fluorous approach has proven valuable for the probing of other classes microarray strategy to show that the mannose-binding lectin of small molecules.[2] In the case of histone deacetylase concanavalin A (conA), contrary to prevailing belief, actually inhibitors with dissocation constants of less than 0.1s À1, the can accept modifications of the mannose at the C-6 position in hits found by fluorous microarrays were comparable to those the form of glycero-manno-heptoses found on pathogenic found by techniques such as surface plasmon resonance bacteria (Figure 1). The well-known mannose–conA interac- (SPR) and solution-based biochemical assays.[2a] Ideally, of course, the relative quantification of these binding interac- tions could also be carried out within the same fluorous microarray screening format. ConA is a plant lectin that is widely used like antibodies as research tools and diagnostics to identify the presence of specific sugars, such as mannose, on cells;[3] however, in reality the sugar specificities of lectins have not been tested broadly, especially against less readily available carbohydrates. ConA is the most-studied lectin and is usually considered to bind terminal alpha-linked mannose, glucose, and N-acetylglucos- amine. Earlier inhibition data suggest that modifications at the C-3, C-4, and C-6 positions of the d-mannopyranose deter binding to conA.[4] In particular, the loss of the hydroxy group in the C-6 position as in 6-deoxy-d-mannose and 1,6-anhydro- b-d-manno-pyranose result in complete loss of activity.
    [Show full text]
  • Hexose Oxidase from Chondrus Crispus Expressed in Hansenula Polymorpha
    Chemical and Technical Assessment 63rdJECFA Hexose Oxidase from Chondrus Crispus expressed in Hansenula Polymorpha CHEMICAL AND TECHNICAL ASSESSMENT (CTA) Prepared by Jim Smith and Zofia Olempska-Beer © FAO 2004 1 Summary Hexose oxidase (HOX) is an enzyme that catalyses the oxidation of C6-sugars to their corresponding lactones. A hexose oxidase enzyme produced from a nonpathogenic and nontoxigenic genetically engineered strain of the yeast Hansenula polymorpha has been developed for use in several food applications. It is encoded by the hexose oxidase gene from the red alga Chondrus crispus that is not known to be pathogenic or toxigenic. C. crispus has a long history of use in food in Asia and is a source of carrageenan used in food as a stabilizer. As this alga is not feasible as a production organism for HOX, Danisco has inserted the HOX gene into the yeast Hansenula polymorpha. The information about this enzyme is provided in a dossier submitted to JECFA by Danisco, Inc. (Danisco, 2003). Based on the hexose oxidase cDNA from C. crispus, a synthetic gene was constructed that is more suitable for expression in yeast. The synthetic gene encodes hexose oxidase with the same amino acid sequence as that of the native C. crispus enzyme. The synthetic gene was combined with regulatory sequences, promoter and terminator derived from H. polymorpha, and inserted into the well-known plasmid pBR322. The URA3 gene from Saccharomyces cerevisiae (Baker’s yeast) and the HARS1 sequence from H. polymorpha were also inserted into the plasmid. The URA3 gene serves as a selectable marker to identify cells containing the transformation vector.
    [Show full text]
  • Conversion of D-Ribulose 5-Phosphate to D-Xylulose 5-Phosphate: New Insights from Structural and Biochemical Studies on Human RPE
    The FASEB Journal • Research Communication Conversion of D-ribulose 5-phosphate to D-xylulose 5-phosphate: new insights from structural and biochemical studies on human RPE Wenguang Liang,*,†,1 Songying Ouyang,*,1 Neil Shaw,* Andrzej Joachimiak,‡ Rongguang Zhang,* and Zhi-Jie Liu*,2 *National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; †Graduate University of Chinese Academy of Sciences, Beijing, China; and ‡Structural Biology Center, Argonne National Laboratory, Argonne, Illinois, USA ABSTRACT The pentose phosphate pathway (PPP) such as erythrose 4-phosphate, glyceraldehyde 3-phos- confers protection against oxidative stress by supplying phate, and fructose 6-phosphate that are necessary for NADPH necessary for the regeneration of glutathione, the synthesis of aromatic amino acids and production which detoxifies H2O2 into H2O and O2. RPE functions of energy (Fig. 1) (3, 4). In addition, a majority of the in the PPP, catalyzing the reversible conversion of NADPH used by the human body for biosynthetic D-ribulose 5-phosphate to D-xylulose 5-phosphate and is purposes is supplied by the PPP (5). Interestingly, RPE an important enzyme for cellular response against has been shown to protect cells from oxidative stress via oxidative stress. Here, using structural, biochemical, its participation in PPP for the production of NADPH and functional studies, we show that human D-ribulose (6–8). The protection against reactive oxygen species is ؉ 5-phosphate 3-epimerase (hRPE) uses Fe2 for cataly- exerted by NADPH’s ability to reduce glutathione, sis. Structures of the binary complexes of hRPE with which detoxifies H2O2 into H2O (Fig. 1).
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,713,116 B1 Aldrich Et Al
    USOO6713116B1 (12) United States Patent (10) Patent No.: US 6,713,116 B1 Aldrich et al. (45) Date of Patent: Mar. 30, 2004 (54) SWEET-STABLE ACIDIFIED BEVERAGES 4,957,763 A 9/1990 Saita et al. ................. 426/548 5,169,671. A 12/1992 Harada et al. .............. 426/658 (75) Inventors: Jessica A. Aldrich, Hazlet, NJ (US); 5,380,541 A 1/1995 Beyts et al. ................ 426/548 Lisa Y. Hanger, Basking Ridge, NJ 5.431,929 A 7/1995 Yatka et al. ................... 426/3 5,731,025 A 3/1998 Mitchell ..................... 426/548 (US); Guido Ritter, Laer (DE) 6,322,835 B1 * 11/2001 De Soete et al. ........... 426/453 (73) Assignee: Nutrinova Inc., Somerset, NJ (US) 6,372.277 B1 * 4/2002 Admiraal et al. ........... 426/548 FOREIGN PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 W WO as: : 3.1. - - - - - - - - - - - A23L/1/236 U.S.C. 154(b) by 0 days. WO WO 98/19564 5/1998 ............. A23L/2/60 (21) Appl. No.: 09/675,825 OTHER PUBLICATIONS (22) Filed: Sep. 29, 2000 Widemann et al., “Synergistic Sweeteners”, Food Ingred. and Analysis Int., 19(6):51-52, 55-56 (abstract only), Dec. Related U.S. Application Data 1997.* (63) Continuation-in-part of application No. 09/186,275, filed on sk cited- by examiner Nov. 5, 1998, now abandoned. Primary Examiner Keith Hendricks (60) Pisional application No. 60/079,408, filed on Mar. 26, (74) Attorney, Agent, or Firm-ProPat, L.L.C. (51) Int. Cl.
    [Show full text]
  • Carbohydrate Composition of Endotoxins from R-Type Isogenic Mutants of Shigella Sonnei Studied by Capillary Electrophoresis and GC-MS†
    CROATICA CHEMICA ACTA CCACAA, ISSN 0011-1643, e-ISSN 1334-417X Croat. Chem. Acta 84 (3) (2011) 393–398. CCA-3487 Original Scientific Article Carbohydrate Composition of Endotoxins from R-type Isogenic Mutants of Shigella sonnei Studied by Capillary Electrophoresis and GC-MS† Annamária Bui,a Anikó Kilár,b,c Ágnes Dörnyei,a,c Viktória Poór,a Krisztina Kovács,b Béla Kocsis,b and Ferenc Kilára,c,* aInstitute of Bioanalysis, Faculty of Medicine, University of Pécs, Szigeti út 12., H-7624 Pécs bDepartment of Medical Microbiology and Immunology, Faculty of Medicine, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary cDepartment of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6., H-7624 Pécs, Hungary RECEIVED NOVEMBER 9, 2010; REVISED FEBRUARY 5, 2011; ACCEPTED MAY 13, 2011 Abstract. The carbohydrate composition of the rough-type endotoxins (lipopolysaccharides, LPSs) from Shigella sonnei mutant strains (Shigella sonnei phase II - 4303, 562H, R41 and 4350) was investigated by capillary electrophoresis and GC-MS. The monosaccharides obtained by hydrolysis were determined by capillary electrophoresis combined with laser induced fluorescence detection (CE-LIF) after labeling with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) and by GC-MS as alditol-acetate derivatives. It was ob- tained that the lipopolysaccharides of the isogenic rough mutants are formed in a step-like manner, con- taining no heptose (4350), one D-glycero-D-mannoheptose (562H), or two or three L-glycero-D- mannoheptoses (R41, 4303, respectively) in the deep core region. Besides the heptoses, the longest LPS from the mutant Shigella sonnei 4303 contains hexoses, such as glucoses and galactoses, in a pro- portion of approximately 3:2.
    [Show full text]
  • Analysis of Intact Glycosidic Aroma Precursors in Grapes by High-Performance Liquid Chromatography with a Diode Array Detector
    foods Article Analysis of Intact Glycosidic Aroma Precursors in Grapes by High-Performance Liquid Chromatography with a Diode Array Detector Cristina Cebrián-Tarancón 1 , José Oliva 2, Miguel Ángel Cámara 2, Gonzalo L. Alonso 1 and M. Rosario Salinas 1,* 1 Cátedra de Química Agrícola, E.T.S.I. Agrónomos y Montes, Departamento de Ciencia y Tecnología Agroforestal y Genética, Universidad de Castilla-La Mancha, Avda. de España s/n, 02071 Albacete, Spain; [email protected] (C.C.-T.); [email protected] (G.L.A.) 2 Departamento de Química Agrícola, Geología y Edafología, Facultad de Química, Universidad de Murcia, Campus de Espinardo s/n, 30100 Murcia, Spain; [email protected] (J.O.); [email protected] (M.Á.C.) * Correspondence: [email protected]; Tel.: +34-967-599210; Fax: +34-967-599238 Abstract: Nowadays, the techniques for the analysis of glycosidic precursors in grapes involve changes in the glycoside structure or it is necessary the use of very expensive analytical techniques. In this study, we describe for the first time an approach to analyse intact glycosidic aroma precursors in grapes by high-performance liquid chromatography with a diode array detector (HPLC-DAD), a simple and cheap analytical technique that could be used in wineries. Briefly, the skin of Muscat of Alexandria grapes was extracted using a microwave and purified using solid-phase extraction combining Oasis MCX and LiChrolut EN cartridges. In total, 20 compounds were selected by HPLC-DAD at 195 nm and taking as a reference the spectrum of phenyl β-D-glucopyranoside, whose DAD spectrum showed a first shoulder from 190 to 230 nm and a second around 200–360 nm.
    [Show full text]
  • Carbohydrates: Structure and Function
    CARBOHYDRATES: STRUCTURE AND FUNCTION Color index: . Very important . Extra Information. “ STOP SAYING I WISH, START SAYING I WILL” 435 Biochemistry Team *هذا العمل ﻻ يغني عن المصدر المذاكرة الرئيسي • The structure of carbohydrates of physiological significance. • The main role of carbohydrates in providing and storing of energy. • The structure and function of glycosaminoglycans. OBJECTIVES: 435 Biochemistry Team extra information that might help you 1-synovial fluid: - It is a viscous, non-Newtonian fluid found in the cavities of synovial joints. - the principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement O 2- aldehyde = terminal carbonyl group (RCHO) R H 3- ketone = carbonyl group within (inside) the compound (RCOR’) 435 Biochemistry Team the most abundant organic molecules in nature (CH2O)n Carbohydrates Formula *hydrate of carbon* Function 1-provides important part of energy Diseases caused by disorders of in diet . 2-Acts as the storage form of energy carbohydrate metabolism in the body 3-structural component of cell membrane. 1-Diabetesmellitus. 2-Galactosemia. 3-Glycogen storage disease. 4-Lactoseintolerance. 435 Biochemistry Team Classification of carbohydrates monosaccharides disaccharides oligosaccharides polysaccharides simple sugar Two monosaccharides 3-10 sugar units units more than 10 sugar units Joining of 2 monosaccharides No. of carbon atoms Type of carbonyl by O-glycosidic bond: they contain group they contain - Maltose (α-1, 4)= glucose + glucose -Sucrose (α-1,2)= glucose + fructose - Lactose (β-1,4)= glucose+ galactose Homopolysaccharides Heteropolysaccharides Ketone or aldehyde Homo= same type of sugars Hetero= different types Ketose aldose of sugars branched unBranched -Example: - Contains: - Contains: Examples: aldehyde group glycosaminoglycans ketone group.
    [Show full text]
  • Structural Features
    1 Structural features As defined by the International Union of Pure and Applied Chemistry gly- cans are structures of multiple monosaccharides linked through glycosidic bonds. The terms sugar and saccharide are synonyms, depending on your preference for Arabic (“sukkar”) or Greek (“sakkēaron”). Saccharide is the root for monosaccha- rides (a single carbohydrate unit), oligosaccharides (3 to 20 units) and polysac- charides (large polymers of more than 20 units). Carbohydrates follow the basic formula (CH2O)N>2. Glycolaldehyde (CH2O)2 would be the simplest member of the family if molecules of two C-atoms were not excluded from the biochemical repertoire. Glycolaldehyde has been found in space in cosmic dust surrounding star-forming regions of the Milky Way galaxy. Glycolaldehyde is a precursor of several organic molecules. For example, reaction of glycolaldehyde with propenal, another interstellar molecule, yields ribose, a carbohydrate that is also the backbone of nucleic acids. Figure 1 – The Rho Ophiuchi star-forming region is shown in infrared light as captured by NASA’s Wide-field Infrared Explorer. Glycolaldehyde was identified in the gas surrounding the star-forming region IRAS 16293-2422, which is is the red object in the centre of the marked square. This star-forming region is 26’000 light-years away from Earth. Glycolaldehyde can react with propenal to form ribose. Image source: www.eso.org/public/images/eso1234a/ Beginning the count at three carbon atoms, glyceraldehyde and dihydroxy- acetone share the common chemical formula (CH2O)3 and represent the smallest carbohydrates. As their names imply, glyceraldehyde has an aldehyde group (at C1) and dihydoxyacetone a carbonyl group (at C2).
    [Show full text]