Fructose oligosaccharides containing residues

Robinia pseudacacia resulted in accumulation of free fructose and oligosaccharides containing principally glucose residues. Transfructosidases have also been found in both plant nectar and insect viscera. A trans-glucosidase with specificity different from the other enzymes described occurs in honeydew and manna formed by certain insects. This enzyme is produced by the insects, not the plant, and transfers glucosyl groups to the 3-position of the fructose of sucrose. ... 

Treatment of l-0-(a-D-glucopyranosyl)-D-fructose with hydrogen fluoride in pyridine has afforded a l,T 2,2 dianhydride mixture with the fructose moiety in either the pyranose or furanose fonn. Some novel 1,6-anhydro-lactose derivatives for the synthesis of oligosaccharides containing N-acetyl-lactosamine residues are mentioned in Chapter 4, and a 3,6-anhydroglucofuranose derivative resulting from an unusual molecular rearrangement of a xanthate is described in Chapter 7. 

The mass spectra of n-fructose-containing oligosaccharides as their permethyl derivatives follow, in most respects, the fragmentation patterns of the corresponding trimethylsilyl derivatives (see Section VI,3 p. 91). Permethylated aldobiouronic acids follow fragmentation routes similar to those of permethylated, neutral disaceharides. Thus, the A-series of fragments identifies a glycosyluronic residue (42) (see Scheme 39). 

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