Higher Saccharides

2 Higher Saccharides.- Muscaroslde B contains a novel branched-chaln hexasaccharlde which was structurally characterized using FAB m.s. 

The synthesis of the branched-chaln octasaccharide (9), a glycoprotein structural unit, has been achieved. 

Pedersen, and H.Pedersen, Advan. Carbohydr. Chem. Biochon., 1984, 42, 193. 

Schraml, J.Hlrsch, E.Petrakova, E.Krahe, and C.Bllefert, Collect. Czech. 

Dabrowski, P.Hanfland, H.Egge, S.Kuhn, and J.Dabrowski, J. Biol. Chem., 1984, 259, 7648. 

Disaccharides and Higher Saccharides. — Gentiobiose, methyl 3-0-ot-D-gluco-pyranosyl-a-D-glucopyranoside, 6,6 -dibromo-6,6 dideoxy-a,a-trehalose hexa-acetate, 1,2,4,6-tetra-0-acetyl-3-0-(2,3,4,6-tetra-d-acetyl- -D-galactopyranosyl)-a-D-galactopyranose, (Z )-0-/3-D-xylopyranosyHl 6)- 8-D-glucopyranosyloxy- 

Krajewski, Z. Urbaiiczyk-Lipkowska, P. Gluziiiski, J. Bleideljs. and A. Kemme, Acta CrystallogK, Sect B, 1979, 35, 2625. 

Cottier, G. Descotes, R. Faure, H. Loiseleur, and G. Thomas-David, Acta Crystallogr., Sect. B, 1980, 36, 873. 

Neuman, D. Avenel, F. Arene, H. Gillier-Pandraud, J.-R. Pougny, and P. Sinay, Carbo-hydr. Res., 1980, 80, 15. 

The following higher saccharides have been described compound (9), a heptasaccharide hapten (10) and (11),octasaccharlde parts 

Paulsen, Org. Synth. Interdisc. Challenge, Proc. lUPAC Symp., 5th, 1984 (Pub. 1985), 317 (Chem. Abstr., 1986, 104, 110 027). 

Nakayama, G.A.Strobel, and T.Ogawa, Agric. Biol. Chem., 1986, 

Suyama, S.Adachi, T.Toba, T.Sohma, C.-J.Hwang, and T.Itoh, Agric. Biol. 

The heptasaccharlde (12), a glycoprotein component, has been prepared, and the octasaccharide (13) was conformationally characterized. Octasaccharides (9 R = B-D-Gal -(1 )-3-D-G1cNAc ) and (10 R = a-L-Fuc ) have also been synthesized, as 

Yamomoto, T.Nukada, T.Kitajima, and M.Sugimoto, Pure Appl. Chem., 

Morishima, H.Sato, Y.Sato, and S.Zen, Bull. Chem. Soc. Jpn., 

Nimami, K.Yazawa, K.Nakamura, and Z.Tamura, Chem. Pharro  

Compounds 25 and 26 were used as the key reactants in the synthesis of the branched maimononaose 27, the acetal ring system of the former disarming the phenylselenyl group to allow specific reaction of 26 as glycosylating agent. 

Oligomerization of the sulfur-linked cellobiosyl fluoride 28 by use of a cellulase gave a set of products with even numbers of glucose residues of general structure 

lower members of which, up to the decaose, were separated. Higher members of the series were obtained as a mixture. The branched chain decasaccharide 

with and without C-13 labelling in the acetyl group of the sialic acid units. 

In the undecaose set, compounds 31 and 32 have been prepared by chemical 

Krajewski, Z. Urbanczyk-Lipkowsk, P. Gluzinski, J. Bleidelis, and A. Kemme, Acta Crystallogr., 1979, B35, 1248. 

The chemoenzymic synthesis of trimeric SiaLe decasaccharide 49 was achieved by enzymically sialylating and fucosylating the linear hexamer. The analogue 

50 of dimeric SiaLe was made by L-galactosylation with a-l,3-fucosyltrans-ferase.  

The closely related 51 undecasaccharide was made as a prototype of the complex mammalian N-glycans/ as was the dodecamer having an additional P-GlcNAc moiety bonded to 0-4 of the branching P-Man residue.  

A tetramer of a-L-Fuc-(1 2)-6-0-Bn-a-D-Gal-(l- 3)-a-D-GlcNAc-(l- 3)-L-Fuc joined by a-(l- 3) linkages between the fucosyl units gave a linear 24 unit product which was purified by reverse phase chromatography by use of a lipophilic ester derivative.  

This report concentrates almost exclusively on the chemistry of the cydodextrins themselves and disregards the large amount of material that has been reported on the properties of these compounds as binding hosts and the properties of the complexes th form. 

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Oligo- and higher saccharides are produced extensively by acid-and/or enzyme-catalyzed hydrolysis of starch, generally in the form of symps of mixtures (12). These products are classified by thek dextrose equivalency (DE), which is an indication of thek molecular size and is a measure of thek reducing power with the DE value of anhydrous D-glucose defined as 100. 

Effect of Streptomycin on Various Enzymes Responsible for Syntheses and Degradation of Higher Saccharides, S. A. Barker, E. J. Bourne, M. Stacey, and R. B. Ward, Nature, 175 (1955) 203 -204. 

Attack of the OH radical on carbohydrates of low molecular mass gives rise to a variety of products. Indeed, the reaction of radiolytically-generated OH radical with lower hexose sugars produces lower saccharides (for di- and higher saccharide species), uronic and aldonic acids, and 3-, 2- and 1-carbon aldehydic fragments, e.g. 

Wohl4 was the first to refer to the formation of higher saccharides by the action of acids on monosaccharides as reversion. This process, the acid-catalyzed formation of glycosidic bonds between sugar residues, constitutes the most rudimentary form of condensation polymerization. Reversion of oligosaccharides has also been observed. 0 The relationships between the hydrolysis of polysaccharides and the reversion of mono- and oligo-saccha-rides is illustrated for amylose in Fig. 1. 

Oligosaccharides.—Chromatography on paper of di-, tri-, and higher saccharides differs in one important respect from the resolution of monosaccharides. The larger molecules have very low Re values in the solvent... 

DP4+ = Oligosaccharides, maltotetraose and higher saccharides HM = High maltose (IE) = Ion-exchanged... 

Starch is first liquefied and hydrolyzed to specific dextrose equivalents with hydrochloric acid. After evaporation to 60 percent solids, a saccharifying enzyme (fungal a-amylase) is added to continue hydrolysis to the desired level. By choosing two or more types of enzymes (such as a-amylase, -amylase, glu-coamylase, pullulanase) and adjusting the initial acid hydrolysis, syrups with different ratios of dextrose, maltose, and higher saccharides can be obtained.92... 

The structures of the disaccharides and higher saccharides (obtained by partial hydrolysis of polysaccharides) can be examined by periodate or lead tetraacetate oxidation. Ahlborg studied the periodate oxidation of disaccharides and starch dextrins in 0.5 N sulfuric acid. Since the intermediate formate esters were hydrolyzed, these conditions were favorable for overoxidation. The (1 — 4)- and (1 —> 6)-linkages in the starch dextrins were each found to be associated with a characteristic consumption of oxidant. Neumtiller and Vasseur studied periodate oxidation in solutions of various acidities, from strongly acid to neutral, and showed that there were differences between different types of disaccharides. 

A mixture of the hydrolyzate with diatomaceous earth, added as a filter aid, is then filtered on rotary, vacuum, precoated filters. The filtrate is a clear, slightly yellow, sweet-tasting liquor containing about 0.1% of protein and 0.2% of ash. The rest is carbohydrate, made up of 95.0% of D-glucose, 2.0% of maltose, 1.6% of isomaltose, and 1.4% of tri- and higher saccharides. 

High fructose syrups, prepared from starch, are commonly used instead of sugar. They are generally known as high fructose corn syrup (HFCS) containing 30 percent fructose, 35 percent glucose, and 6 percent higher saccharides. They are only 74 percent as sweet as sucrose, therefore more has to be used to achieve the same sweetness. 

It is obvious that the fractions obtained in this manner are non-homogeneous and must contain mixtures of chains of somewhat varying lengths. Fraction PDIX, which was precipitated after concentration of the mother liquor, would be expected to be rather nonhomogeneous. This fraction was examined by means of adsorption analysis by Tiselius and Hahn, and was shown to contain 19% pentasaccharide, 40% hexa-saccharide and 38% of two higher saccharides, presumably hepta- and octasaccharides. The fraction PDXIII was investigated in the same... 

Potato starch (800 g.) in 9 liters of water containing 2 g. of sodium chloride was hydrolyzed at 20° for twenty weeks with 1 g. of pancreatin (Pharm. Svec. Ed. X) (Table XXV). Apart from small amounts of higher saccharides, tetra- and trisaccharides predominate. The total yield of limit dextrins is high, possibly because the pancreatin contains lower amounts of dextrin-splitting enzymes or because its action ceases at a greater distance from the anomalies. 

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