The dependence of the conformation of a (1→3)-β-D-glucan on chain-length in alkaline solution

Induced phase separation in cellulose nanocrystal suspensions containing ionic dye species

“…Congo Red in particular is known to have a very high affinity for cellulose; it has been used in histochemical studies of plant cell walls and as an additive to ''separate'' fibres in the paper industry (Lipic and Bravar 1972). CR is also known to interact with starch and amylose as well as b ) (1 fi 3)-D-glucans as demonstrated by absorption and circular dichroism studies (Carroll and Cheung 1962;Ogawa and Tsurugi 1973;Trisnadi et al 1974;Ogawa and Hatano 1978;Wood, 1980). None of the direct dyes induced phase separation (Table 1), presumably because they bind to the surface of the cellulose nanocrystals and therefore do not compress the electrostatic double layer (they contribute to it and increase the repulsive forces between the cellulose nanocrystals, which will prevent phase separation).…”

Microfibrillar structure of PGG-Glucan in aqueous solution as triple-helix aggregates by small angle x-ray scattering

“…The final concentration of NaOH was 0.43 N, which has been shown to be sufficient to disaggregate ␤-1,3-glucans from the aggregated state (ordered triple-helical structures) to the disaggregated state (single-chain random coil). 16,18,19 Values of specific refractive index increment (dn/dc) of PGG-Glucan were measured by an Optilab DSP (Wyatt Technology Corp.) operating at 633 nm and at 25°C, and are listed as follows: PGG-Glucan in 0.15M NaCl solution, dn/dc ϭ 0.143 mL/g, and PGG-Glucan in 0.4M NaOH/0.15M NaCl solution, dn/dc ϭ 0.145 mL/g. The molecular weight of polymer in the aggregated form (as triple-helical structure) was measured by this system without using a postcolumn delivery system.…”

“…Adding sodium hydroxide, however, yields a single phase solution of PGG-Glucan molecules in a single-chain random-coil conformation. 18,19,23 Figure 6a shows the PGG-Glucan data from Figure 2a together with the background function to be subtracted from the glucan scattering curve. The straight line shown in Figure 6a is a theoretical background.…”

Protection by Aminated Glucan in Experimental Endogenous Peritonitis

“…Japan). This (l-»3)-(J-/7-glucan was par tially hydrolyzed with formic acid as described by Ogawa et al [8], followed by amination as recently described [4], The aminated glucan was tested for the absccncc of endotoxin [2,14],…”