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The structural features of the water-soluble p-carboxybenzyl 4-O-methylglucuronoxylan derivative (CBGX), prepared by reaction of xylan with p-carboxybenzyl bromide in aqueous alkali, were characterised by various one-dimensional (1D)- and 2D-NMR techniques applied to the intact derivative as well as to both the oligosaccharide (XO) and resistant (XR) fractions obtained by digestion of CBGX with endo-β- d -xylanase. The real substitution of the xylan backbone with carboxybenzyl (CB) groups was unambiguously determined by the HMBC-NMR technique. The CB groups were located predominantly at the O-2 position of the xylosyl residues. The degrees of substitution of CBGX with 4-O-methylglucuronic acid units (DSU) and CB groups (DSCB) were 0.10 and 0.11, respectively. Thus, every fifth xylose unit of the main chain, on an average, bears either an acidic side chain or a CB substituent. The different proportions of both the substituents in XO and XR fractions suggested the distribution along the xylan backbone to be blockwise rather than uniform. The physicochemical properties of CBGX were characterised by means of viscometry, sedimentation velocity and HPGPC giving a relatively low intrinsic viscosity (53 ml g−1) and similar values of the mean molecular mass (Mw) 27,000 g mol−1 and (Mapp) 34,000 g mol−1, respectively. CBGX exhibited remarkable emulsifying and protein foam-stabilising activities.

Flow birefringence of dextran solutions in dimethylsulphoxide was studied and the intrinsic optical anisotropy (α 1 -α 2 ) of its chains was determined to be +12.5×10 −25 cm 3 . The dependence of birefringence in dextran films of different thickness on the angle of incidence of polarized light was then studied and the surface birefringence of the film was determined. The dependence of surface birefringence on film thickness has made it possible to determine the effective thickness of the anisotropic near-surface layer, while the comparison of the surface birefringence with the value of (α 1 -α 2 ) enabled the estimation of the orientation of the molecular fragments with respect to the film surface.

The hydrodynamic properties of poly(propylene imine) dendrimers, modified with outer-surface β-thiolactosyl residues (“lactodendrimers”) of generation number 1–5, have been investigated by velocity sedimentation, translational diffusion, and viscosity measurements in 0.165% NaCl aqueous solution. It has been demonstrated that apparent molecular weights (from the Svedberg equation) MsD of synthetic lactodendrimers, determined by sedimentation and diffusion experiments, are consistent with complete functionalization of initial poly(propylene imine) dendrimers with sugar residues. The values of MsD range from 1900 to 45000 Da for generation numbers 1–5. Corresponding hydrodynamic (“equivalent Stokes”) radii range from ∼10 to ∼37 A. Scaling relations of the conformation-dependent sedimentation coefficient, translational diffusion coefficient and intrinsic viscosity with molecular weight have been considered in detail and are all indicative of a spherical molecule with an inhomogeneous distribution of density (Mark–Houwink–Kuhn–Sakurada a, b and e, coefficients of ∼0.24, ∼0.69 and ∼0.31, respectively).

The Benoit model for β1-4 glucans is considered taking into account intrachain hydrogen bonds. This model is basis for calculation of equilibrium rigidity of chains with completely free rotation. Analysis of the experimental value of equilibrium rigidity is carried out and the fraction of hinge C(1)OC(4) bonds about which rotation is free is evaluated.