26 arbohydrates SURSE
26.3 IRALITY F MNSAARIDES 2 (R)-glyceraldehyde 25 [α] D = + 13.5 o 2 Fischer projection carbonyl group at top carbonyl near top 2 2 2 2 Fischer projection D-galactose 2 2 Fischer projection D-fructose
26.3 IRALITY F MNSAARIDES Aldoses mirror plane 2 2 ( 2 ) n ( 2 ) n 2 a D aldose 2 an L aldose 2 2 2 2 2 D-glyceraldehyde D-ribose D-glucose D-fructose
26.3 IRALITY F MNSAARIDES Aldoses Figure 26.1 Structures of D-Aldoses Aldotriose 2 D-glyceraldehyde Aldotetroses 2 D-erythrose 2 D-threose Aldopentoses 2 2 2 2 D-ribose D-arabinose D-xylose D-lyxose Aldohexoses 2 2 2 2 2 2 2 2 D-allose D-altrose D-glucose D-mannose D-gulose D-idose D-galactose D-talose
26.3 IRALITY F MNSAARIDES Aldoses Figure 26.2 Enantiomeric Relationship of D- and L-Monosaccharides The D- and L-monosaccharides have reversed, mirror image configurations at every chiral center. mirror D-gluco configuration L-gluco configuration 2 2 D-glucose D-glucose Determines D configuration Determines L configuration
26.3 IRALITY F MNSAARIDES Ketoses Figure 26.3 Structures of D-2-Ketoses Ketotriose 2 2 dihydroxyacetone Ketotetrose 2 2 D-erythulose 2 2 Ketopentoses 2 D-xylulose 2 D-ribulose Ketohexoses 2 2 2 2 2 2 2 2 D-tagatose D-sorbose D-psicose D-fructose
26.3 IRALITY F MNSAARIDES Less ommon Monosaccharides 2 2 (a 3-ketopentose) 2 2-deoxy-D-ribose N 2 N 3 2 D-2-glucosamine 2 N-acetyl-D-2-glucosamine 2 2 D-apiose
26.4 ISMERIZATINS F MNSAARIDES Epimers 1 1 1 2 2 3 3-2 epimers 2 3 4 4 4-4 epimers 5 5 5 2 2 6 6 6 2 D-galactose D-glucose D-mannose R R R epimer 1 enediol epimer 2 (E and Z)
26.4 ISMERIZATINS F MNSAARIDES Epimers Figure 26.4 Isomerization of Aldoses via an Enediol Intermediate not chiral 2 2 2 D-glucose enediol D-mannose
26.4 ISMERIZATINS F MNSAARIDES Interconversion of Aldoses and Ketoses R (an aldolse) R (an enediol) 2 R (a ketose) 2 glucose-6-phosphate isomerase 2 P 3 2-2 P 3 2- D-glucose-6-phosphate D-fructose-6-phosphate
26.5 YLI MNSAARIDES: EMIAETALS AND EMIKETALS 5-hydroxypentanal furan pyran K = 20 or + D-glucose α-d-glucopyranose β-d-glucopyranose
26.5 YLI MNSAARIDES: EMIAETALS AND EMIKETALS -5 hydroxyl group rotation around -3-4 σ bond -5 hydroxyl group bond formation gives hemiacetal -1 group -1 D-glucose α-d-glucopyranose -1 axial β-d-glucopyranose -1 equatorial
26.5 YLI MNSAARIDES: EMIAETALS AND EMIKETALS 2 2 2 2 + 2 2 D-fructose α-d-fructofuranose β-d-fructofuranose
26.5 YLI MNSAARIDES: EMIAETALS AND EMIKETALS Table 26.1 omposition of Monosaccharides at Equilibrium in Solution (in percent) Monosaccharide Pyranose Furanose D-glucose 36 64 α β α β D-mannose 67 32 0.8 0.2 D-galactose 31 69 D-allose 18 70 5 7 D-altrose 27 40 20 13 D-idose 38 38 10 14 D-talose 40 29 20 11 D-arabinose 63 34 2 1 D-ribose 20 56 6 18 D-xylose 27 63 D-fructose 2 66 7 25
26.5 YLI MNSAARIDES: EMIAETALS AND EMIKETALS aworth Projection Formulas Figure 26.5 aworth Projections of a Pyranose and a Furanose 2 The -6 2 group is "up" in a aworth projection of a D-pyranose or D-furanose. 2 2 The α-hydroxy group at -1 is "down" in a aworth projection of an α-d-pyranose or furanose. It is "up" in the β anomer. aworth projection of β-d-glucopyranose aworth projection of α-d-fructofuranose
26.5 YLI MNSAARIDES: EMIAETALS AND EMIKETALS Mutarotation α-d-glucopyranose β-d-glucopyranose D-glucose crystalize from methanol crystalize from acetic acid α-d-glucopyranose mp 146 o [α] D = + 112.2 o β-d-glucopyranose mp 150 o [α] D = + 18.7 o
26.6 REDUTIN AND XIDATIN F MNSAARIDES Reduction of Monosaccharides NaB 4 α-d-glucopyranose D-glucose D-glucitol 2 reduced 2 D-glucitol (D-sorbitol) (an alditol)
26.6 REDUTIN AND XIDATIN F MNSAARIDES xidation of Monosaccharides α-d-glucopyranose [] D-glucose D-gluconic acid 2 oxidized 2 D-gluconic acid (an aldonic acid)
26.6 REDUTIN AND XIDATIN F MNSAARIDES xidation of Monosaccharides α-d-glucopyranose 1 o alcohol [] D-glucose D-glucaric acid 2 oxidized 2 D-glucaric acid (an aldaric acid) oxidized
26.6 REDUTIN AND XIDATIN F MNSAARIDES xidation of Monosaccharides α-d-glucopyranose 1 o alcohol NADP + -dependent dehydrogenase 2 D-glucuronic acid
26.7 GLYSIDES R R' + R' + R R' R' + (a hemiacetal) (an acetal) R R' + R' + R R' R' + (a hemiketal) (a ketal) β-glycosidic bond 3 aglycone methyl β-d-glucopyranoside
26.7 GLYSIDES resonance-stabilized oxocarbocation intermediate β-d-glucose + -
26.7 GLYSIDES Figure 26.7 Formation of α and β Glysosides 3 - + 3 3 - + 3 3 methyl β-d-glycopyranoside 3 methyl α-d-glycopyranoside
26.8 DISAARIDES Maltose α-(1,4') glycosidic bond 4--(α-D-glucopyranosyl)-β-D-glucopyranose (maltose) β-anomer of glucose, the agylcone.
26.8 DISAARIDES Maltose Figure 26.8 Molecular Model of Maltose. The monosaccharide unit on the left is the hemiacetal of the α-d-glucopyranosyl unit. It is linked by an α-(1,4 ) glycosidic bond to β-d-glucopyranose, the aglycone. The oxygen atom of the glycosidic bond is approximately in the center of the structure, between the two rings. It is projected down, axial, and therefore α. It is linked to -4 of the aglycone, and so the link is axial-equatorial. α-axial oxygen of (1,4 )-gycosidic bond β-equatorial hydroxyl group α-d-glucopyranosyl unit 4--(α-D-glucopyranosyl)-β-D-glucopyranose (maltose) β-d-glucopyranose unit, the aglycone
26.8 DISAARIDES ellobiose β-d-glucopyranosyl unit β-(1,4') glycosidic bond 4--(β-D-glucopyranosyl)-β-D-glucopyranose (cellobiose) β-anomer of glucose, the agylcone.
26.8 DISAARIDES ellobiose Figure 26.9 Molecular Model of ellobiose The monosaccharide unit on the left is the β-d-glucopyranosyl portion of cellobiose. It is linked by a β-(1,4 ) glycosidic bond to β-d-glucopyranose, the aglycone. The oxygen atom of the glycosidic bond is approximately in the center of the structure, between the two rings. It is projected up, equatorial, and therefore it is β. It is linked to -4 of the aglycone, and so the link is equatorial-equatorial. β-glycosidic bond β-d-glucopyranosyl unit 1 4 β-equatorial hydroxyl group β-d-glucopyranose unit, the aglycone 4--(β-D-glucopyranosyl)-β-D-glucopyranose (cellobiose)
26.8 DISAARIDES Lactose β-d-glucopyranosyl unit β-(1,4') glycosidic bond 4--(β-D-glucopyranosyl)-β-D-glucopyranose (cellobiose) β-anomer of glucose, the agylcone.
26.8 DISAARIDES Lactose -4 epimer of glucose β-d-galactopyranosyl unit β-(1,4') glycosidic bond 4--(β-D-galactopyranosyl)-β-D-glucopyranose (lactose) β-anomer of glucose, the agylcone.
26.8 DISAARIDES Lactose Figure 26.10 Molecular Model of Lactose The monosaccharide unit on the left is the β-d-galactopyranosyl portion of cellobiose. It is linked by a β-(1,4 ) glycosidic bond to β-d-glucopyranose, the aglycone. Galactose is the -4 epimer of glucose. Thus, the hydroxyl group at -4, which is equatorial in glucose, is axial in galactose. β-glycosidic bond β-d-galactopyranosyl unit 1 4 β-equatorial hydroxyl group -4 epimer of glucose, axial hydroxyl group 4--(β-D-galactopyranosyl)-β-D-glucopyranose (lactose) β-d-glucopyranose unit, the aglycone
26.8 DISAARIDES Sucrose 2 α-anomer of glucose β-anomer of fructose (1,2')-glycosidic bond 2 α-d-glucopyranosyl-β-d-fructofuranoside (sucrose)
26.8 DISAARIDES Sucrose Figure 26.11 Molecular Model of Sucrose The monosaccharide unit on the left is the α-d-galactopyranosyl portion of sucrose. It is linked by a (1,2 ) glycosidic bond to β-d-fructofuranose. Thus, the anomeric carbons of the monomers are linked by a glycosidic bond. Sucrose is an acetal. Therefore, it is a nonreducing sugar. α-d-glucopyranosyl unit α 1 β 2 β-d-fructofuranose unit α-d-glucopyranosyl-β-d-fructofuranoside (sucrose)
26.9 PLYSAARIDES β-(1,4')-glycosidic bonds cellulose Figure 26.12 Structures of Polysaccharides α-(1,4')-glycosidic bonds amylose α-(1,6')-glycosidic bonds at branch points α-(1,4')-glycosidic bonds amylopectin (or glycogen)
26.9 PLYSAARIDES Figure 26.13 Three α-d-glucopyranosyl Groups in Amylose When we say that a polymer is linear we mean that the polymer contains no branches. Amylose coils into a helix. 4 α-(1,4 )-glycosidic bonds 1 α 4 4 α 1 1 α-d-glucopyranosyl groups Trisaccharide segment of amylose
26.10 EMIAL DETERMINATIN F MNSAARIDE STRUTURES Periodate xidation I 4 aldehyde or ketone + aldehyde or ketone vicinal diol in monosaccharide R R I 4 + an aldehyde formaldehyde vicinal diol at 1 o alcohol
26.10 EMIAL DETERMINATIN F MNSAARIDE STRUTURES Periodate xidation I 4 formic acid + 2 + (an aldehyde) R R (an aldose) 2 R + 2 2 R I 4 + 2 R formaldehyde (a ketose) (a carboxylic acid) I 4 + R R
26.10 EMIAL DETERMINATIN F MNSAARIDE STRUTURES xidation and ptical Activity 2 N 3 plane of symmetry 2 D-galactose 2 optically inactive aldaric acid
26.10 EMIAL DETERMINATIN F MNSAARIDE STRUTURES Formation of sazones NN 6 5 N 2 N 6 5 NN 6 5 ( 2 ) n 2 (an aldose) ( 2 ) n 2 (an osazone) 2 NN 6 5 N 2 N 6 5 NN 6 5 ( 2 ) n 2 (a ketose) ( 2 ) n 2 (an osazone)
26.10 EMIAL DETERMINATIN F MNSAARIDE STRUTURES hain Extension of Aldoses + 2 D-ribose 2 2 D-allose D-altrose oxidation oxidation 2 2 2 D-aldaric acid (optically inactive) 2 (+)-D-altraric acid
26.10 EMIAL DETERMINATIN F MNSAARIDE STRUTURES hain Shortening of Aldoses N N N 2 Ac 2 Ac Ac R (one diastereomer) R (an oxime) R N Ac Ac 3 N 3 + 3 + N R R R
26.11 DETERMINATIN F RING SIZE 2 3 3 methyl α-d-ribofuranoside methyl α-d-ribopyranoside 2 3 I 4-2 3 methyl α-d-ribofuranoside dialdehyde product 3 I 4-3 + 2 methyl α-d-ribopyranoside dialdehyde product
26.11 DETERMINATIN F RING SIZE β-d-glucopyranose ( 3 ) 2 S 4 3 3 3 3 methyl 2,3,4,6-tetra--methyl-β-Dglucopyranoside 3 3 + 3 3 3 3 2,3,4,6-tetra--methyl-β-D-glucopyranose
26.11 DETERMINATIN F RING SIZE 3 2 3 3 3 oxidation 3 3 2 3 2,3,4,6-tetra--methyl-D-glucose 2 dicarboxylic acid product
26.12 EMIAL DETERMINATIN F DISAARIDE STRUTURE 2 2 ( 3 ) 2 S 4 3 3 3 2 3 3 3 2 3 3 lactose octamethyllactose 3 2 3 3 3 2 3 2 3 3 3 3 2 3 3 3 + 3 3 + 3 3 octamethyllactose 2,3,4,6-tetra--methyl-D-galactose 2,3,6-tri--methyl-D-glucose
26.13 UMAN BLD GRUP ANTIGENS N 3 N 3 3 N-acetylgalactosamine (GalNAc) N-acetylglucosamine (GlcNAc) 6-deoxy-a-L-galactose (a-l-fucose)
26.13 UMAN BLD GRUP ANTIGENS Type A N β-galnac Gal 3 N 2 β-glcnac protein 3 3 α-l-fucose Type B Gal Gal 3 N 2 β-glcnac protein 3 α-l-fucose Type 3 galactose N 2 β-glcnac protein 3 α-l-fucose
26.13 UMAN BLD GRUP ANTIGENS β-d-galactopyranosyl β-(1,4 )-glycosidic bond 6 2 α-(1,2 )-glycosidic bond 2 α 1 1 β 4 6 1 α-l-fucopyranosyl β-glcnac group 6 Type Blood Group Antigen