Milk oligosaccharides

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 ... 

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. 

Chaturvedi, P., Warren, C. D., Altaye, M., Morrow, A. L., Ruiz-Palacios, G. M., Pickering, L. K., and Newburg, D. S. (2001). Fucosylated human milk oligosaccharides vary between individuals and over the course of lactation. Glycobiology 11,365-372. 

Coppa, G. V., Zampini, L., Galeazzi, T., Facinelli, B., Ferrante, L., Capretti, R., and Orazio, G. (2006). Human milk oligosaccharides inhibit the adhesion to Caco-2 cells of diarrheal pathogens Escherichia coli, Vibrio cholerae, and Salmonella fyris. Pediatr. Res. 59, 377-382. 

Martin-Sosa, S., Martin, M.-J., and Hueso, P. (2002). The sialylated fraction of milk oligosaccharides is partially responsible for binding to enterotoxigenic and uropathogenic Escherichia coli human strains. /. Nutr. 132,3067-3072. 

Pfenninger, A. Karas, M. Finke, B. Stahl, B. Stractural Analysis of Un-derivatized Neutral Human Milk Oligosaccharides in the Negative Ion Mode by Nano-ESl MS (Part 1 Methodology). J. Am. Soc. Mass Spectrom. 2002, 13, 1331-1340. 

Engfer, M. B., Stahl, B., Finke, B., Sawatzki, G., and Daniel, H. (2000). Human milk oligosaccharides are resistant to enzymatic hydrolysis in the upper gastrointestinal tract. Am. ]. Clin. Nutr. 71,1589-1596. 

Newburg, D. S. (2000). Are all human milks created equal Variation in human milk oligosaccharides. /. Pediatr. Gastroenterol. Nutr. 30,131-133. 

In other reports, the lipase-catalyzed acylation of benzylidene derivatives of sugars, useful intermediates in the synthesis of oligosaccharides, has been described [42]. For example, the esterification of 4,6-O-benzylidene-a-D-glucopy-ranoside (13) with vinyl acetate by action of Pseudomonas cepacia lipase gave quantitatively the 2-O-acetate 13a. [42b] As a third case, it deserves to be mentioned the extensive work of Russo and coworkers for the chemo-enzymatic synthesis of milk oligosaccharides [43]. 

In normal urine, only faint bands are usually seen below the raffinose standard. In neonates, many violet bands are encountered below the raffinose standard (most likely milk oligosaccharides), in which case repeated testing is recommended at the age of 6 months to 1 year. 

Bahr, U., and Karas, M. (1999). Differentiation of isobaric peptides and human milk oligosaccharides by exact mass measurements using electrospray ionization orthogonal time-of-flight analysis. Rapid Commun. Mass Spectrom. 13 1052-1058. 

A. Pfenninger, M. Karas, B. Finke, and B. Stahl, Structural analysis of underivatized neutral human milk oligosaccharides in the negative ion mode by nano-electrospray MSn (Part 2 Application to isomeric mixtures), J. Am. Soc. Mass Spectrom., 13 (2002) 1341-1348. 

Two pentasaccharides occur in the mixture of milk oligosaccharides. Lacto-iV-fucopentaose I readily gives an alkali-stable disaccharide, 2-0-(a-L-fucosyl)-D-galactose on alkaline degradation knowledge of the structure of this disaccharide, together with data from methylation studies, leads to the assignment of the structure of an a-L-fucosyl-(lacto-iV-tetraose) for the pentasaccharide.273... 

In addition to H(O) substances, Matsumoto and Osawa198 reported hemagglutination inhibition by B and A substances and neuraminidase-digested, porcine submaxillary-mucin. Although Lea substance did not inhibit, a closely related milk oligosaccharide, lacto-N-fucopentaose II, did exhibit activity in this assay. On screening 22 invertebrate extracts, Baldo and coworkers found eel-serum-reactive material in 15 species.881... 

The use of primary fragment ions is not enough to allow for extensive structural characterization. Careful examination, however, of the secondary fragmentation pathways provides a more precise means to identify some, but not all, of the structural characteristics for the substance under study. Aspinall (82MI7) reviewed a useful example in which the permethylated alditols from the milk oligosaccharides lacto-N-tetraose [Gai- (1 3)-Glc- l 3)-Gal-... 

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