COMPLEX OF GEL-FORMING β-1,3-<scp>d</scp>-GLUCAN WITH CONGORED IN ALKALINE SOLUTION

Ogawa, K.; Tsurugi, Jitsuo; Watanabe, Takehiko

doi:10.1246/cl.1972.689

Cited by 66 publications

(23 citation statements)

References 7 publications

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“…23) Generally, if the wavelength of maximum absorption of the complex with Congo Red shifts to above about 505 nm in 0.1 M sodium hydroxide, it could be considered that the tested polysaccharide contains a triple-helical structure in aqueous solution. 23,31,32) Therefore the maximum absorption of each complex at this alkaline concentration was measured (Table 4). It was clear that the native glucan PSGL-I-1A had a triple-helical conformation, while all other derivatives with carboxymethyl or sulfate group, except P-CM-1, lost the original structure in aqueous solution.…”

Section: Resultsmentioning

confidence: 99%

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Purification, Characterization, and Modification of T Lymphocyte-Stimulating Polysaccharide from Spores of <i>Ganoderma lucidum</i>

et al. 2002

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Ganoderma lucidum, a well-known Chinese medicinal fungus, has been used to promote health and longevity in East Asian countries. Its medical effects on cancer, hypertension, hepatitis, and hypercholesterolemia have been demonstrated by pharmacological studies in the past two decades. [1][2][3][4] This fungus has attracted considerable attention partly because the polysaccharides isolated from the fruit bodies and the mycelium have shown antitumor and hyperglycemic activity. 3,5,6) However, the active components in the spores of G. lucidum have rarely been studied owing to the difficulty in collection and sporoderm-breaking of the spores. Recently, with the successful cultivation of G. lucidum indoors on a large scale and a breakthrough in sporodermbreaking technology, much attention has been paid to chemical components of G. lucidum spores 7,8) and their versatile biological activities.9,10) More recently, we have reported an immunomodulating polysaccharide from the spores of G. lucidum. 11) In the present study, we deal with the purification and characterization of the T lymphocyte-stimulating polysaccharide, based on the activity-guided principle, from the hot-water extract of the sporoderm-broken spores of G. lucidum. A series of sulfated or carboxymethylated derivatives of the polysaccharide were successively prepared and their structures were elucidated by chemical and spectral methods. The solution conformation and T lymphocyte proliferation effect of the polysaccharide and its derivatives are compared and discussed. ExperimentalMaterials Spores of G. lucidum were collected in Shanxi Province, PR China. It was identified by Dr. Xiu-Lan Huang and stored as a voucher specimen (no. 99064) in the Herbarium of Phytochemistry Department of Shanghai Institute of Materia Medica, Shanghai, PR China. Before use, the sporoderm of the spores was ultrasonographically broken and the broken ratio was estimated about 60-80% by electronic microscopy. T-Dextran in a series of different molecular weights was obtained from Pharmacia. Concanavalin (Con A) was from Sigma and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was from Fluka. Medium RPMI-1640 was purchased from Gibco Laboratories. All other reagents were of the highest quality available and were used without further purification.Isolation and Purification of the T Lymphocyte-Stimulating Polysaccharide The sporoderm-broken spores of G. lucidum (1.0 kg), previously defatted with 95% alcohol, were decocted for 6 h with 10 l of water to half the original volume, and the residue was again decocted with 8 l of water. The combined aqueous extract was deproteinated with trichloroacetic acid, and the resulting aqueous fraction was extensively dialyzed against running water for 3 d and then against distilled water for 1 d (molecular weight cutoff 3000-5000 Da). The retentate was concentrated under reduced pressure to a small volume (1.8 l), and 4 volumes of ethanol were added stepwise with stirring at 4°C. Then the mixture was stored overnight at Ϫ10°C. T...

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Section: Resultsmentioning

confidence: 99%

“…Complex Conformation with Congo Red The change in absorption of Congo Red in the presence of the polysaccharide or its derivatives was measured by the procedures of Ogawa et al 23) Each sample solution (2 mg/ml of sodium hydroxide) and 12.2 mM of Congo Red were mixed in equal volumes, and the absorption maximun (l max ) was measured at room temperature.…”

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confidence: 99%

Purification, Characterization, and Modification of T Lymphocyte-Stimulating Polysaccharide from Spores of <i>Ganoderma lucidum</i>

et al. 2002

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“…Ko and Lin (2004) developed a fluorimetric method to determine b-1, 3-glucans with aniline blue as a specific dye which interacts with single helix b-glucans. In the alkaline milieu used, all b-glucans form a single helix (Ogawa, Tsurugi, & Watanabe, 1972). According to Ko and Lin (2004), it is possible to determine the total b-glucan amount directly.…”

Section: Introductionmentioning

confidence: 99%

“…Congo red is used for characterisation of glucan tertiary structures because of its interactions with the triple helix of b-1,3-1,6-glucans (i.e. Ching-Feng, Ming-Ching, & Wei-Hsin, 2007;Ogawa et al, 1972) and because it does not react with other polysaccharides (Sensse & Cramer, 1969). An incorporation of Congo red into the triple helix leads to a bathochromic shift.…”

Section: Introductionmentioning

confidence: 99%

A new colorimetric method to quantify β-1,3-1,6-glucans in comparison with total β-1,3-glucans in edible mushrooms

et al. 2011

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“…One of the frequently employed methods is the so-called congo red analysis, the results of which are correlated with those of other measuring techniques [13][14][15] . These investigations exploit the ability of congo red dye and helical polysaccharides to form a complex with an absorption peak at a wavelength different to that of the free dye 16) . In this complexation six glucose rings bond to each congo red molecule 17) .…”

Section: Congo Red Analysismentioning

confidence: 99%

Influence of the glycosidic linkage on the solution conformation of glucans

Kath

Lange

Kulicke³

1999

Angew. Makromol. Chem.

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In order to gain a better understanding of the influence of β‐glycosidic linkages on the solution conformation of glucans, a comparison was made between the carboxymethyl derivatives of cellulose (CMC, 100% 1,4‐), barley glucan (CMGG, 30 : 70 1,3 : 1,4‐) and curdlan (CMCd, 100% 1,3‐glycosidic), each with an average degree of substitution of DS = 1.0–1.5 and molar masses of 144 000–720 000 g mol–1. For this purpose curdlan and barley glucan were chemically modified, whereas carboxymethylcellulose was available as a commercial sample. Via congo red analysis it was proved for the microbial β‐1,3‐glucans curdlan (unsubstituted) and scleroglucan (one β‐1,6‐linked glucose side group on every third monomer unit) that substituents in glucan derivatives weaken an existing helical structure but that reduction of the molar mass with ultrasound has no influence on the helices. The molecular parameters Mw, Mn, RG, LP and [η] were determined by means of SEC/MALLS measurements and viscometry and the chain mobility was quantified using the 13C NMR relaxation times, T1, of the different polymers. From this it was possible to derive [η]‐Mw relationships. For all samples, the exponent ν of the RG‐MW relationship lay in the range 0.54–0.59, from which it is possible to deduce a coiled solution structure. However, β‐1,3‐glucans occupy 25% less volume than β‐1,4‐glucans and exhibit less chain mobility. Hence β‐1,4‐glucans should be considerably more viscous than β‐1,3‐glucans, as was indeed demonstrated by rheological flow curves of 6% solutions of the carboxymethylglucan derivatives. The zero‐shear viscosity, η0, decreases by 3 decades in the order of CMC > CMGG > CMCd.

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COMPLEX OF GEL-FORMING β-1,3-d-GLUCAN WITH CONGORED IN ALKALINE SOLUTION

Cited by 66 publications

References 7 publications

Purification, Characterization, and Modification of T Lymphocyte-Stimulating Polysaccharide from Spores of <i>Ganoderma lucidum</i>

Purification, Characterization, and Modification of T Lymphocyte-Stimulating Polysaccharide from Spores of <i>Ganoderma lucidum</i>

A new colorimetric method to quantify β-1,3-1,6-glucans in comparison with total β-1,3-glucans in edible mushrooms

Influence of the glycosidic linkage on the solution conformation of glucans

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