Oligosaccharides manninotriose

Synthesis of manninotriose and a higher oligosaccharide,33 by trans-galactosylase action of yeast melibiase on melibiose, has already been noted in a preceding paragraph. 

Fig. 1.—Molecular-rotation relationships of several raffinose-type oligosaccharides. Me, methyl a-D-galactopy ranoside Gl, D-glucose Mb, melibiose Mt, manninotriose Vt, verbascotetraose S, D-glucitol M, melibiitol Ml, manninotriitol Su, sucrose K, raffinose St, stachyose V, verbascose Gb, gentiobiose Ge, gentianose.

It is to be hoped that the application of newer methods of preparation and purification will make manninotriose more accessible to the research worker, so that this structurally well-characterized oligosaccharide can be exploited for use in further physical, chemical, and biochemical investigations. 

Blanchard and Albon observed some oligosaccharide formation when yeast enzyme was cillowed to act on melibiose. Later, a major component was identified as manninotriose by French. Courtois and Petek, studying coffee a-galactosidase, found that D-mannose and sucrose were active as acceptors for a-galactosyl residues, resulting in the formation of epimelibiose [0-a-D-galactopyranosyl-(i - 6)-D-mannose] and raffinose. 

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