α-Glucan (L-FV-II) and β-glucan (L-FV-I) were isolated from fruiting bodies of
Lentinus edodes by extraction with 5% NaOH/0.05% NaBH
4, then precipitation with 1
M acetic acid. The analysis results of Smith degradation, high-performance liquid chromatography (HPLC), infrared spectra (IR),
13C NMR spectra, and optical rotation indicated that L-FV-II is α-(1→3)-
D-glucan with slight (1→6) branch linkages, and L-FV-I is β-(1→3)-
D-glucan containing 10% protein, and with branches. The weight-average molecular weight, M
w, number-average molecular weight, M
n, radii of gyration, <s
2>
1/2, and second virial coefficients, A
2, of L-FV-II in aqueous 0.5
M urea/0.5
M NaOH (obtained from diluting its solution in 1.0
M urea/1.0
M NaOH) and 0.25
M LiCl in dimethylsulfoxide (DMSO/0.25
M LiCl) were measured by light scattering, membrane osmometry, and size exclusion chromatography (SEC). The values of M
w and M
n for L-FV-II in 0.5
M urea/0.5
M NaOH are 24.1×10
4 and 10.9×10
4, respectively, similar to those in DMSO/0.25
M LiCl. It was proved that strong intermolecular hydrogen bonds exist in L-FV-II, resulting in its water-insolubility, but there are not any aggregates or multiple-helix structure for L-FV-II in DMSO/0.25
M LiCl. The chain of α-(1→3)-
D-glucan is more extended in DMSO/0.25
M LiCl than that in the aqueous solution.
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