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Title The Carbohydrates [C(H2O)]n Emil Hermann Fischer (1852-1919) F-R Convention The Fischer-Rosanoff Convention CHO CHO CHO H OH H OH C2-OH H OH H OH C3-OH H OH H OH C4-OH H OH H OH C5-OH CH2OH CH2OH C6-CH2OH Fischer Projections Rosanoff Modification D/L Series Fischer-Rosanoff D- and L-Series OH on the right of the highest OH on the left of the highest numbered chiral carbon = D-series. numbered chiral carbon = L-series. D-Aldohexoses The D-Aldohexoses C5 8 right C3 2 right 2 left 2 right 2 left C4 4 right 4 left C2 right left right left right left right left Allose Glucose Gulose Galactose Altrose Mannose Idose Talose All altruists gladly make gum in gallon tanks [L. Fieser] Rxn of Aldoses Reactions of Aldoses CHO =N-NHPh CHO HO OH 3 equiv. PhNHNH2 =N-NHPh 3 equiv. PhNHNH2 OH OH OH OH OH HNO3 OH HNO3 OH OH OH osazone NaBH4 NaBH4 CH2OH CH2OH CH2OH Br2/H2O + PhNH2 + NH3 Br2/H2O CO2H CH2OH CO2H CO2H CH2OH CO2H OH OH OH HO HO HO OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH CH2OH CH2OH CO2H CO2H CH2OH CH2OH aldonic acid alditol aldaric acid aldaric acid alditol aldonic acid achiral achiral Osazones More on Osazones CHO CH2OH CHO O Ca(OH)2 OH Ca(OH)2 HO HO HO HO OH OH OH (Lobry de Bruyn- OH OH Alberda van Eckenstein OH rearrangement, 1895) CH2OH CH2OH CH2OH D-glucose D-fructose D-mannose 1 equiv. 3 equiv. 1 equiv. PhNHNH2 PhNHNH2 PhNHNH2 =N-NHPh =N-NHPh 2 equiv. 2 equiv. =N-NHPh PhNHNH2 HO OH =N-NHPh PhNHNH2 HO HO HO OH OH OH OH OH OH CH2OH CH2OH CH2OH D-glucose phenylhydrazone + PhNH2 + NH3 D-mannose phenylhydrazone F-K and Ruff Chain Lengthening and Shortening of Aldoses CN CHO CN OH HCN OH HCN HO OH OH OH OH Fischer-Kiliani OH Fischer-Kiliani OH OH Synthesis Synthesis OH CH2OH CH2OH CH2OH Fe+++ Pd/BaSO4 H O Pd/BaSO4 pH 4.5, H 2 2 pH 4.5, H 2 Ruff 2 Degradation CHO CO2Ca1/2 CO2Ca1/2 CHO Br2/H2O OH OH HO Br2/H2O HO OH OH OH OH OH OH OH OH OH OH OH OH CH2OH CH2OH CH2OH CH2OH Aldonic acid as Ca salt D-Series Interrelationship Interrelationship of the D-Series of Aldoses via Chain Lengthening and Degradation Which one is Glucose? The Aldohexoses But which one is (+)-glucose? D-series L-series Aldaric Acids/Alditols Rosanoff Formulation of C6 Aldaric Acids and Alditols Terminal groups identical; CO2H or CH2OH Fischer Proof: 1 Fischer’s Proof: Part 1 (+)-Glucose forms an optically active aldaric acid and optically active alditol. •1, 7, 9, 15 eliminated: plane of symmetry, achiral 1 2 3 4 5 6 7 8 X X X X 9 10 11 12 13 14 15 16 Fischer Proof:2 Fischer’s Proof: Part 2 (+)-Glucose and (+)-mannose form the same osazone. If 1, 7, 9, and 15 are not related to (+)-glucose, then they are not related to (+)-mannose nor are 2, 8, 10, and 16 related to (+)-glucose. 1 2 3 4 5 6 7 8 X X X X X X X X 9 10 11 12 13 14 15 16 Fischer Proof:3 Fischer’s Proof: Part 3 (+)-Arabinose affords (-)-glucose and (-)-mannose by Kiliani-Fischer synthesis. (+)-Arabinose must be of the opposite series (D/L)as (+)-glucose and have the same absolute configuration at C3-5 as (-)-glucose and (-)-mannose. What is the structure of arabinose? F P:3, con’t •Arabinose is either or X •Arabinose forms an optically active aldaric acid (arabinaric acid) and optically active alditol X X (arabitol) as its borax complex. •Arabinose is X X and not •(+)-Glucose is one of these structures X Fischer Proof:4 Fischer’s Proof: Part 4 The pentose (+)-xylose affords optically inactive xylaric acid and optically inactive xylitol as its borax complex. • (+)-Xylose can only be one of the following: X X Fischer-Kiliani synthesis of (+)-xylose leads to two new hexoses, (+)-gulose and (+)-idose, both of which form optically active aldaric acids. • These enantiomers cannot be (+)-xylose because their Fischer-Kiliani hexoses (already eliminated) would lead to one optically active and one optically inactive aldaric acid. • (+)-Xylose must be one of the remaining two structures. Fischer Proof:5 Fischer’s Proof: Part 5 •(+)-Arabinose •(+)-Glucose/(+)-Mannose •(+)-Xylose •(+)-Gulose/(+)-Idose Fischer Proof:5, con’t Fischer’s Proof: Part 5 (+)-Glucose and (-)-gulose form the same optically active aldaric acid, glucaric acid. identical or identical • (+)-Glucose must be either Fischer Proof:5, con’t-2 Fischer’s Proof: Part 5 • (+)-Mannose must be one of these hexoses, the C2 epimer of (+)-glucose. identical rotate 180o mannaric acid rotate 180o identical • Mannaric acid is formed from a single hexose. Fischer Proof:6 Fischer’s Proof: Part 6 But which enantiomer of glucose is (+)-glucose? Just Guess! D-glucose L-glucose • Fischer arbitrarily assigned the D-series to the dextrorotatory enantiomer. • Sixty years later (1951), he was proved correct when Bijvoet related (+)-glucose to (+)-tartaric acid. • Fischer: All sugars related to D-(+)-glucose by chemical correlation belong to the D-series. Fischer’s Flaw A Flaw in the Fischer Scheme (+)-Glucose (-)-Glucose Identical Achiral Mucic Acid (An Aldaric Acid) (+)-Galactose (-)-Galactose "Two aldoses can produce the same dibasic acid only if they belong to the same stereochemical family. That this, however, is erroneous as a general proposition, may be readily seen from the fact that the two enantiomorphous galactoses - plainly belong to the opposite families - yield the same mucic acid.” A. M. Rosanoff-1906 Rosanoff’s Wheel Rosanoff’s Reorganization of the Carbohydrates •Arranged by successive Kiliani syntheses • The D- and L- assignments were Fischer’s based on chemical correlation with D-(+)-glucose, an unreliable scheme. 2 4 8 16 λ-series δ-series mirror plane Evolution of Signage Evolution of Signage Optical Activity Configuration Fischer-1891 +/- d,l Rosanoff-1906 +/- δ,λ Today +/- = d,l D,L D-Aldohexoses The D-Series of Aldoses aldotriose (+)-glyceraldehyde aldotetrose (-)-erythrose (+)-threose aldo pentose (-)-ribose (-)-arabinose (+)-xylose (-)-lyxose aldo hexose (+)allose (+)-altrose (+)-glucose (+)-mannose (-)-gulose (-)-idose (+)-galactose (+)-talose All altruists gladly make gum in gallon tanks [L. Fieser] Fischer Projections Fischer Projections of Glucose CHO CHO 2 OH OH HO 3 HO = 4 OH OH form hemiacetals between 5 OH HOH2C C5-OH and C1 CH2OH OH o D-(+)-Glucose rotate C5 about C4 by 120 Anomers Fischer Projections of Glucopyranose Anomers right left HO C C OH beta alpha OH OH HO HO OH OH O O CH2OH CH2OH β-D-(+)-Glucopyranose α-D-(+)-Glucopyranose Haworth Haworth Projections of Glucopyranose Anomers up (top) beta CH OH down (bottom) CH2OH 2 OH alpha O O OH OH OH OH OH OH OH β-D-(+)-Glucopyranose α-D-(+)-Glucopyranose Conformational Glucopyranose Chair Conformations of Glucopyranose Anomers up (top) down (bottom) beta alpha OH OH O O HO H O OH HO HO OH OH OH β-D-(+)-Glucopyranose α-D-(+)-Glucopyranose Old Salt How an Old Salt Remembers port starboard left right red light green light fewer letters more letters beta alpha up down top bottom Mutarotation Mutarotation of Anomers OH OH O O HO H O OH HO HO OH OH OH β-D-(+)-Glucopyranose α-D-(+)-Glucopyranose Crystallizes above 98oC Crystallizes below 98oC equilibrium pure β-anomer mixture pure α-anomer H2O H2O mp 150oC [α] = +52.6o mp 146oC o o [α]D = +18.7 [α]D = +112.2 β/α =64/36 Ring Sizes of Hexoses Ring Sizes of Hexoses Hexose Pyranose Form (%α/%β) Furanose Form allose 92 8 altrose 70 30 glucose ~100(36.5/63.5) <1 mannose ~100(67/33) <1 gulose 97 3 idose 75 25 galactose 93(27.5/72.5) 7 talose 69 31 fructose 67 33 Periodic acid Periodic Acid Cleavage of Carbohydrates as a Diagnostic Tool OH HIO4 2 CH2=O OH OH HIO4 HIO4 CHO OH CH2=O + CH2=O + HCO2H OH OH H O HO 2 OH HIO4 OH Formaldehyde (CH2O) arises from a primary alcohols Formic acid (HCO2H) arises from a secondary alcohols Periodic Acid Diagnostic Periodic Acid Cleavage of Carbohydrates as a Diagnostic Tool OH HIO4 OH 2 CH2=O + HCO2H OH • RCH2OH CH2=O • R2CHOH HCO2H CHO • RCH=O HCO2H HIO4 OH CH2=O + 2 HCO2H • R2C=O CO2 OH OH HIO CO2H HIO 4 4 CH =O + CO O CH2=O + 2 2 OH OH Periodic on Carbohydrates Periodic Acid Cleavage of Carbohydrates CHO HCO2H OH HCO2H HO HCO2H OH HCO2H OH HCO2H CH2OH H2CO OH H2CO CO D-glucose O 2 HO HCO2H OH HCO2H OH HCO2H CH2OH H2CO CH2OH H2CO HO HCO H 2 D-fructose HO HCO2H OH HCO2H OH HCO2H CH2OH H2CO D-mannitol Methylation Methylation of Pyranoses: Pyranosides OH OH O + O CH3OH, H HO HO HO HO HO HO OH OCH3 CH3I Ag2O (CH3)2SO4 NaOH OCH3 OCH3 + O H3O O CH3O CH3O CH3O CH3O CH3O CH3O OH OCH3 Ring Size Ring Size of Pyranosides CO2H OCH3 O OCH HNO3 3 CH3O CH3O CH3O CO2H CH3O CO2H HNO3 HNO3 CO2H OCH OCH3 3 O CH3O CH3O OCH CH3O 3 CH3O OH CO2H via oxidation of the enol of the ketone Periodic on Glycosides Periodic Acid Cleavage of Methyl α-Glucopyranoside OH OH HIO O 4 OHC O HO HCO H OHC HO 2 HO OCH3 OCH3 + H3O CHO OH + OHCCHO + CH3OH OH glyoxal D-glyceraldehyde Enzymes Enzymatic Cleavage of Glucosides HO HO O O HO HO OCH HO HO 3 HO HO + OCH3 H3O Methyl α-D-glucoside Methyl β-D-glucoside maltase emulsin HO HO O O HO OH HO HO HO HO HO OH α-D-glucose β-D-glucose Tollens The Silver Mirror Test HO O Tollens reagent HO no reaction HO + - Ag(NH3)2 OH HO OCH3 Methyl -D-glucoside non-reducing sugar (a glycoside) CO2H HO OH O Tollens reagent HO HO OH o HO + - + Ag Ag(NH3)2 OH HO OH OH silver mirror CH2OH D-glucose reducing sugar (an aldose) www.chem-pics.co.uk/download.htm Tollens 2 The Silver Mirror Test HO OH CH2OH OH enediol O O + - Ag(NH3)2 OH OH HO HO OH HO OH OH OH OH OH CH2OH β-D-fructofuranose CH2OH D-fructose + - Ag(NH3)2 OH CO2H CHO OH + - OH o Ag(NH3)2 OH Ag + HO HO OH OH silver mirror OH OH CH2OH CH2OH Aldoses and ketoses are reducing sugars Intro: Di- and Polysaccharides Disaccharides and Polysaccharides Sucrose/Olestra α-D-Glucopyranosyl- β -D-fructofuranoside or β-D-Fructofuranosyl-α-D-glucopyranoside OH OOCR O O HO RCOO HO acetal RCOO HO RCOO O HO O RCOO O O ketal HO RCOO OH OOCR HO RCOO Sucrose Olestra (non-reducing sugar) (R=n-CnH2n+1; n=6-8) Woodward Sucrose is Formed from Glucose and Fructose This discussion brings to mind a wonderful story told to me by Professor Harry Wasserman (Yale), who during the late 1940's was a graduate student of Professor R.
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    4202-B: Nucleic acids and Carbohydrates L-4 Deoxy sugars In these sugars one of the OH groups is replaced by a hydrogen. 2-Deoxyribose (oxygen missing at C-2 position) is an important example of a deoxy sugar. It is important component of DNA, and lack of C-2 hydroxyl provide additional stability to it as compared to RNA as no intramolecular nuclephilic attack on phosphate chain can occur. Amino sugars In amino sugars one of the OH groups is replaced by an amino group. These molecules allow proteins and sugars to combine and produce structures of remarkable variety and beauty. The most common amino sugars are N-acetyl glucosamine and N-acetyl galactosamine, which differ only in stereochemistry. The hard outer skeletons of insects and crustaceans contain chitin, a polymer very like cellulose but made of N-acetyl glucosamine instead of glucose itself. It coils up in a similar way and provides the toughness of crab shells and beetle cases. Some important antibiotics contain amino sugars. For example, the three subunits of the antibiotic gentamicin are deoxyamino sugars (the middle subunit is missing the ring oxygen). N-Acetyl glucosamine N-Acetyl galactosamine Gentamicin, an antibiotic Cell membranes must not be so impermeable as they need to allow the passage of water and complex molecules. These membranes contain glycoproteins—proteins with amino sugar residues attached to asparagine, serine, or threonine in the protein. The attachment is at the anomeric position so that these compounds are O- or N-glycosides of the amino sugars. The structure below shows N-acetyl galactosamine attached to an asparagine residue as an N-glycoside.
  • Food Carbohydrates: Monosaccharides and Oligosaccharides

    Food Carbohydrates: Monosaccharides and Oligosaccharides

    Paper No. 01 Paper Title: Food Chemistry Module-04: Food carbohydrates: Monosaccharides and Oligosaccharides Monosaccharides The simplest form of carbohydrates is the monosaccharide. Monosaccharides are either aldoses or ketoses. Aldoses such as glucose consists of a carbon backbone and a carbonyl group (C=O) located at the end of the chain. Ketoses such as fructose consists of a carbon backbone with a carbonyl group located at any other carbon in the chain. The remaining carbon atoms are bound to hydroxyl groups (-OH). Monosaccharide classifications based on the number of carbons Number Category of Examples Name Carbons 4 Tetrose Erythrose, Threose 5 Pentose Arabinose, Ribose, Ribulose, Xylose, Xylulose, Lyxose Allose, Altrose, Fructose, Galactose, Glucose, Gulose, Idose, 6 Hexose Mannose, Sorbose, Talose, Tagatose 7 Heptose Sedoheptulose, Mannoheptulose Monosaccharides Three common sugars glucose, galactose and fructose share the same molecular formula: C6H12O6. Because of their six carbon atoms, each is a hexose. Although all three share the same molecular formula, the arrangement of atoms differs in each case. Substances such as these three, which have identical molecular formulas but different structural formulas, are known as structural isomers. Glucose "Blood sugar" is the immediate source of energy for cellular respiration. Glucose, which is also referred to as dextrose, is a moderately sweet sugar found in vegetables and fruit. When glucose is fermented by the enzyme zymase, in yeast, it results in the formation of carbon dioxide and ethyl alcohol. It is the basic structure to which all carbohydrates are reduced to in the end, for transport via the bloodstream and use by the cells of the body.
  • Mannaric Acid and Mannaric Acid Polyamides: Synthesis and Characterization

    Mannaric Acid and Mannaric Acid Polyamides: Synthesis and Characterization

    University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 2008 Mannaric Acid and Mannaric Acid Polyamides: Synthesis and Characterization Chrissie Ann Carpenter The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation Carpenter, Chrissie Ann, "Mannaric Acid and Mannaric Acid Polyamides: Synthesis and Characterization" (2008). Graduate Student Theses, Dissertations, & Professional Papers. 642. https://scholarworks.umt.edu/etd/642 This Dissertation is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. MANNARIC ACID AND MANNARIC ACID POLYAMIDES: SYNTHESIS AND CHARACTERIZATION By CHRISSIE ANN CARPENTER B.A. Chemistry, Carroll College, Helena, Montana, USA, 2002 Dissertation Presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemistry The University of Montana Missoula, MT 29 September 2008 Approved by: Dr. David A. Strobel, Dean Graduate School Dr. Donald E. Kiely, Chairperson Chemistry Dr. Merilyn Manley-Harris Chemistry Dr. Christopher P. Palmer Chemistry Dr. Holly Thompson Chemistry Dr. Andrew Ware Physics Carpenter, Chrissie A., Ph.D., Fall 2008 Chemistry Mannaric Acid and Mannaric Acid Polyamides: Synthesis and Characterization Chairperson: Donald E. Kiely D-Mannose, an aldohexose and a C-2 epimer of the common monosaccharide D- glucose, occurs in a pyranose ring form as a component of a variety of plant polysaccharides and is the third most abundant naturally occurring aldohexose after D- glucose and D-galactose, respectively.