Linear oligosaccharides

Xylans as true homopolymers occur in seaweeds of the Palmariales and Nemaliales, however, their backbone consists of Xylp residues linked by -(1 3) (Type X3, Fig. la) or mixed -(1 3, 1 -> 4)-glycosidic linkages (Type Xmy Fig. lb). They are assumed mainly to have a structural function in the cell-wall architecture, but a reserve function cannot be ruled out [4]. From the microfibrils of green algae (Siphonales) such as Caulerpa and Bryop-sis sp., X3 was isolated and the structure confirmed by methylation analysis, C-NMR spectroscopy [7], as well as by mass spectrometry of enzymically released linear oligosaccharides up to a degree of polymerization (DP) of... 

T—temporary anomeric substituent Scheme 1.8 Linear oligosaccharide synthesis. 

Phenomenological chiral discrimination of various permethylated linear oligosaccharides toward organic amines has been examined by using the FAB-MS-EL guest method." " " As shown in Table 15, permethylated fructo-oligosaccharides, especially the permethylated 1 -fructonystose (MeFruNys in Scheme 8), display a remarkable chiral discrimination ability." If compared to linear... 

Table 16 Rate constants k X 10 cm molecule s and selectivities kr>lki) of selected amino acids with CD and linear oligosaccharides. All hosts are permethylated...

In our search for more versatile approaches toward linear oligosaccharides we developed a new solid-phase method combining the use of an orthogonal25,26 protected universal building block with powerful perbenzylated acceptors bound on the resin. After initial attachment of the first building... 

None of the enzymes discussed so far can hydrolyze the a-1,6 bonds present in starch. These branch points are cleaved hydrolytically by the debranching enzyme (EC 3.2.1.41), which releases linear oligosaccharides for further metabolism by amylases or phosphorylase. 

Schonberger, B.P. Jansen, A.C.A. Janssen, L.H.M. The acid hydrolysis of cyclodextrins and linear oligosaccharides a comparative study. Proceedings of 4th International Symposium on Cyclodextrins. Huber, O., Szejtli, J., Eds. Kluwer Academic Publishers Dordrecht, The Netherlands, 1988 61-63. 

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