Oligosaccharides neutral

The first paper on the bioactive polysaccharides from Glycyrrhiza uralensis roots was published in 1996 by Kiyohara et al. [57]. They isolated a pectic type polymer with anti-complementary and mitogenic activity that was an acidic pectin, possibly containing rhamnogalacturonan type I as part of the total structure. Degradation of the uronic acid part of the molecule decreased both types of bio activities. The neutral oligosaccharide chains were shown to retain some of the activities of the native polymer, but it was suggested that they should be attached to the acidic core to retain maximum activity. 

In a study completed during the early development of f.a.b.-m.s., both f.d. and f.a.b. were used to characterize 101 fractions containing neutral oligosaccharides isolated from human milk. Samples were examined as their peracetylated alditols. In subsequent work, the structures of two minor acidic oligosaccharides from human milk were investigated. The per-methylated derivatives were analyzed by f.a.b.-m.s., and their compositions and sequences were defined by the f.a.b. data. Methylation analysis and partial formolysis were the other principal methods used. 

Figure 7. Complement activating potency of the ramified region and its neutral oligosaccharides from the pectins of Angelica acutiloba...

Pectic polysaccharide from roots of Glycyrrhiza uralensis Possible contribution of neutral oligosaccharide in the galacturonase resistant region to anti-complementary and mitogenic activities... 

ANTI-COMPLEMENTARY AND MITOGENIC ACTIVITIES OF NEUTRAL OLIGOSACCHARIDE CHAINS DERIVED FROM PG-lc... 

Figure 4 Effect of neutral oligosaccharide-alditol fractions derived from PG-lc by lithium degradation on mitogenic activity of PG-lc...

Plant material fractionation. The detailed steps of isolation and separation of oligosaccharide fractions were described earlier [10]. Pectin was separated by boiling the cell walls in 0.5 M ammonium-oxalate buffer, pH 5.2 at 100 C for Ih. The dialyzed solution of pectin was hydrolyzed with 0.15M HCl for 3h at 100 C. Neutralized and desalted hydrolysate was loaded to the column (lx90cm) filled with biogel TSK HW-40 (Toyo Soda, Japan) equilibrated and eluted with 50mM sodium acetate (pH 5.2) at a rate of 0.3ml/min. In all fractions (1ml) the sugars were determined by o-toluidine method (Resnikov et al., 1982) and fraction IP was collected as shown on Figure 1. 

Alkaline conditions are used so frequently in carbohydrate separations on CarboPac columns that it should be pointed out that acidic conditions are suitable for separation of acidic sugars. Figure 24 shows the separation of sialic acid containing oligosaccharides.256 Alkaline conditions were used for neutral milk oligosaccharides and mucin oligosaccharide alditols were characterized similarly.257 The carbohydrates released from yeast mannopro-tein with N-acetyl-P-D-glucosaminidase were also fractionated on CarboPac ... 

Blanken, W. M., Bergh, M. L. E., Koppen, P. L., and van den Eijnden, D.H., High-pressure liquid chromatography of neutral oligosaccharides effects of structural parameters, Anal. Biochem., 145, 322, 1985. 

Reddy, G. P. and Bush, C. A., High-performance anion exchange chromatography of neutral milk oligosaccharides and oligosaccharide alditols derived from mucin glycoprotein, Anal. Biochem., 198, 278, 1991. 

Thurl, S., Offermanns, J., Muller-Werner, B., and Sawatzki, G., Determination of neutral oligosaccharide fractions from human milk by gel permeation chromatography, /. Chromatogr., 568, 291, 1991. 

J. G. Joyce, I. J. Krauss, H. C. Song, D. W. Opalka, K. M. Grimm, D. D. Nahas, M. T. Esser, R. Hrin, M. Feng, V. Y. Dudkin, M. Chastain, J. W. Shiver, et al., An oligosaccharide-based HIV-1 2G12 mimotope vaccine induces carbohydrate-specific antibodies that fail to neutralize HIV-1 virions, Proc. Natl. Acad. Sci. USA, 105 (2008) 15684-15689. 

The partially methylated monosaccharides obtained on depolymerization of the permethylated sample are preferably analyzed as acetates by g.l.c.-m.s., as shown by Bjomdal and coworkers.41,42 The neutral sugars and the amino sugars obtained in acetolysis-acid hydrolysis are reduced, and acetylated for the analysis, and the amino-hexitol and the neuraminic acid residues are acetylated after methanolysis. Identification with the aid of g.l.c.-m.s. has been described for all of the common components of protein- and lipid-linked glycans and oligosaccharides from animal cells, namely, the neutral sugars,41-43 hexitols,44 hexosamines,29,43,45,46 aminohexitols,31,32 and neuraminic acids.33,34,47... 

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