Mono- and Oligo-saccharides

The first two galactocerebrosides were isolated by Thudichum,80 in 1882, from human-brain material, and were designated phrenosin and kerasin.7 The isolation of these compounds is based on solvent extraction and fractional recrystallization,81 although the separation of the pure compounds by these methods is very difficult. Nevertheless, the analytical characterization of phrenosin and kerasin, which was effected by hydrolytic cleavage, was correct. 

Phrenosin gives equimolar amounts of sphingosine, D-galactose, and 2-hydroxytetracosanoic (phrenosinic or cerebronic) acid on acid hydrolysis. Kerasin has similar constituents, but the fatty acid component is tetracosanoic acid. 

During the first three decades of this century, galactocerebrosides were isolated from organs other than the brain and spinal cord of mammals, and from organs of other animals, including birds, fishes, and insects.7 

This group of sugar-lipid conjugates is not limited to organs of animals. For example, similar compounds are found in mushrooms and plant seeds.7 

The linkage between the sphingosine moiety and the D-galactose residue was determined by Carter and Greenwood.83 Catalytic reduc- 

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Treatment of an extracellular polysaccharide of Rhizobium japonicum (an important factor for nitrogen-fixing symbiosis between bacteria and soybeans) with liquid HF (—40°, 30 min) gave mono- and oligo-saccharides involving 0- -D-glucopyranosyl-( 1 - 3)-C>-(4-0-acetyl-a-D-galactopyrano-syluronic acid)-(l— 3)-D-mannose and its 1-fluoride. 

Koizumi, K., Okada, Y., and Fukuda, M., High-performance liquid chromatography of mono- and oligo-saccharides on a graphitized carbon column, Carb. Res., 215, 67, 1991. 

C. J. Hamilton, Enzymes in preparative mono- and oligo-saccharide synthesis, Nat. Prod. Rep., 21 (2004) 365-385. 

C. Fayet and J. Gelas, Reaction of mono- and oligo-saccharides with keto or ethylenic enol ethers as a route to functionalized acetals and monomers for polymerization, Carbohydr. Res. 259 177 (1993). 

However, in the polysaccharides obtained from some mutant strains, there are deviations from this idealized structure.44 Xanthan is relatively resistant to enzymic hydrolysis, but it has been cleaved by an enzyme preparation from a Bacillus sp. at moderate temperatures and in the presence of buffer salts, yielding mono- and oligo-saccharides 45 A partially purified, enzyme preparation46 hydrolyzed deacetylated or depyruvated xanthan, and also xanthan from several wild-type and mutant strains of Xanthomonas. The release of reducing material varied little with xanthan preparations having differences in O-acetyl and pyruvic acetal contents. Under similar conditions of incubation, cellulase acted only on xanthan from mutant strains that had defective side-chain formation. 

In the polysaccharide and the glycoprotein series, permethylated derivatives are almost exclusively used for their solvolytic decomposition and for the analysis of the mono- and oligo-saccharides formed, whereas, in the glycosphingolipid series, the investigation of the permethylated derivatives themselves by physicochemical methods has acquired great importance. They proved to be very convenient both for mass-spectrometric analysis and for n.m.r. spectroscopy (see later). 

L. L. Danilov, S. D. Maltsev, V. N. Shibaev, and N. K. Kochetkov, Synthesis of polyprenyl pyrophosphate sugars from unprotected mono- and oligo-saccharide phosphates, Carbohydr. Res., 88 (1981) 203-211. 

Complex polymers of mono- and oligo-saccharides are ubiquitous components of the bacterial cell wall.1-3 The three major classes are the capsular polysaccharides,... 

Inhibition of Concanavalin A-Dextran 1355-S Precipitation by Mono- and Oligo-saccharides° and Some of Their Derivatives... 

A comparative study of the carbohydrate-binding specificity of four 2-acetamido-2-deoxy-D-galactose-binding lectins (from Dolichos biflorus, Glycine max, Helix pomatia, and Phaseolus lunatus) has been conducted by using a series of model macromolecules for direct precipitation and a variety of mono- and oligo-saccharides as hapten inhibitors.592 The data indicated that the combining site of all four lectins... 

Light, especially ultraviolet irradiation from a low-pressure mercury lamp, activates the browning, with results similar to those obtained by thermal activation.It has also been found that ultraviolet irradiation of starch in aqueous solution oxidizes it to carbon dioxide in 98% yield, but does not produce any mono- and oligo-saccharides. 

Most underivatized mono- and oligo-saccharides are thermally unstable and nonvolatile, and are therefore unsuitable for mass-spectrometric analyses. For m.s., the sugars must be converted into volatile derivatives this is especially important when g.l.c. is used in combination with m.s. Direct derivatization (for example, by acetylation) of a sugar generally generates an anomeric mixture of compounds that should be fractionated before introduction into the mass spectrometer. It is often advantageous... 

Structures of Narbomycin and Related Macrolide Antibiotics and obtained the D.Sc. (habilitation) degree. That same year he moved to the newly formed Institute of Organic Chemistry of the Polish Academy of Sciences (IOC) in Warsaw, first as a Docent (Associate Professor) and from 1973 as a full Professor until the year of his retirement. In 1968, he succeeded Professor Osman Achmatowicz as head of the Department of Synthesis of Natural Products. After reorganization of the Institute and the departure of the alkaloid laboratory to Poznan, he became head of the laboratory responsible for the synthesis of mono- and oligo-saccharides. Between 1979 and 1982 he served as the Research Director of the Institute. After retirement at the age of seventy, he continued his association with the Institute as Professor Emeritus. 

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