Reagent molecules inside solution domains {R1} and {R2} cannot contact hence react. For this reason solution structure may influence chemical reactivity.

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Changes in the concentration of reagents (0.009–0.2 M) have been shown to dramatically effect the yield and stereoselectivity of glycosylation with a sialic acid based glycosyl donor in a complex nonlinear manner that correlates with changes in the structures of the supramers of the reagents. The yield of disaccharide gradually increases with concentration and levels off at concentrations of glycosyl donor higher than 69 mM. The ratio of anomers is very high at some concentrations (α/β ≈ 20:1), moderate (α/β ≈ 8:1) or very low (α/β ≈ 4:1) at others. The formation of mixed supramers of glycosyl donor and glycosyl acceptor at concentrations exceeding 69 mM was detected by polarimetry and laser light scattering.

O-specific polysaccharide was isolated from Proteus penneri strain 12 (ATCC 33519) lipopolysaccharide (LPS) and studied using NMR spectroscopy, including selective spin-decoupling, one-dimensional NOE, two-dimensional homonuclear correlation spectroscopy, 13C,1H heteronuclear correlation spectroscopy and chemical methods (O-deacetylation, Smith degradation, partial acid hydrolysis followed by borohydride reduction and methylation). The amide of D-galacturonic acid with L-threonine [D-GalA(L-Thr)] was identified as a constituent of the polysaccharide and the following structure of the tetrasaccharide repeating unit was established: [formula: see text] where the degree of O-acetylation at either position varies over 20-40%. Serological study with LPS, its degradation products and related synthetic glycoconjugates (2-acrylamidoethyl glycosides of amides of alpha-D-GalA with L-amino acids copolymerised with acrylamide) showed that D-GalA(L-Thr) plays an important role in manifesting the serological specificity of the P. penneri 12 O-antigen. Serological cross reactions between LPSs of P. penneri 12 and Proteus mirabilis S1959, R14/S1959 (transient-like form), O23 and O28 are discussed.

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Optical rotation of aqueous solutions of D-levoglucosan was studied experimentally in the 0.03-4.0 mol L(-1) concentration range and a nonlinear concentration dependence of specific optical rotation (SR) was revealed. Discontinuities observed in the concentration plot of SR (at 0.1, 0.3, 0.5, 1.0, and 2.0 mol L(-1)) are well correlated with those found by static and dynamic light scattering and identify concentration ranges in which different solution domains (supramers) may exist. The average SR experimental value for a D-levoglucosan aqueous solution ([α]D(28) -58.5±8.7 deg dm(-1) cm(-3) g(-1)) was found to be in good agreement with values obtained by theoretical calculation (TD-DFT/GIAO) of SR for 15 different conformers revealed by conformational sampling at the PCM/B3LYP/6-311++G(2d,2p)//B3LYP/6-31+G(d,p) level, which were shown to be strongly affected by the solvation microenvironment (0, 1, 2, and 3 explicit solvent molecules considered) due to local geometrical changes induced in the solute molecule. This exceptionally high sensitivity of SR makes polarimetry a unique method capable of sensing changes in the structure of supramers detected in this study.

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