Laser light-scattering studies of pachyman

Ding, Qiong; Jiang, Suhong; Zhang, Lina; Wu, Chi

doi:10.1016/s0008-6215(98)00105-0

Cited by 30 publications

(17 citation statements)

References 25 publications

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“…1). The general trend of higher values decreasing from more than 2 to ∼1, indicative of more extended conformations for the lower molar mass molecules, is not surprising in general and more specifically for charged polysaccharides, [41] such as alginate. Similar to other polysaccharides, alginates show high chain stiffness due to the rigidity of the six-membered sugar ring.…”

Section: Determination Of the Alginate Size Distributions In The Absementioning

confidence: 90%

Asymmetrical Flow Field Flow Fractionation - Multidetection System as a Tool for Studying Metal - Alginate Interactions

Alasonati

Stolpe²,

Benincasa³

et al. 2006

Environ. Chem.

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Abstract. The present study explores the potential use of asymmetrical flow field flow fractionation (aFlFFF) with a multidetection system for the study of metal-alginate interactions. aFlFFF, coupled on-line to a differential refractive index and seven angle laser light scattering detectors was used to provide information on the alginate size distributions. In parallel, the metal distributions of metal-alginate complexes were probed by aFlFFF-high resolution inductively coupled plasma-mass spectrometry. Average values and continuous distributions of molar masses, radiuses of gyration and hydrodynamic radiuses, which are critical for understanding the role of alginates as carriers of metal pollutants, were evaluated in presence of Pb or Cd and compared with those in metal-free solutions of alginate. The values of number average and weight average molar mass, weight average radius of gyration and shape factor for alginate were 150 and 188 kg mol −1 , 53 nm and 1.7, respectively. Alginate molar mass and radius of gyration distributions were slightly shifted to higher values by the addition of micromolar concentrations of Pb or Cd. The alginate size distribution in the presence of Cd was similar to the alginate-alone control, whereas in the presence of Pb the size distribution was broader with a shift of the maximum toward higher molar masses.

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Section: Determination Of the Alginate Size Distributions In The Absementioning

confidence: 90%

Asymmetrical Flow Field Flow Fractionation - Multidetection System as a Tool for Studying Metal - Alginate Interactions

Alasonati

Stolpe²,

Benincasa³

et al. 2006

Environ. Chem.

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“…3 Although a monosaccharide unit is common to many polysaccharides, its linkage mode varies and characteristic functions properties will appear accordingly. It is worth noting that polysaccharides in aqueous solution exhibit different chain conformation such as single helix, 4 triple helix, 5 random coil, 6 and aggregate, 7 even if their backbone all are β-(1 → 3)-D-glucan. However, conformation and its transition from an ordered state to a disordered for β-(1 → 3)-D-glucan in solution have not been fully investigated.…”

mentioning

confidence: 99%

Transition from Triple Helix to Coil of Lentinan in Solution Measured by SEC, Viscometry, and 13C NMR

Zhang

Zhou

et al. 2002

Polym J

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ABSTRACT:Lentinan, β-(1 → 3)-D-glucan with (1 → 6) branching, was isolated from Lentinus edodes. Weightaverage molecular weight M w , radius of gyration < s 2 > 1/2 z and intrinsic viscosity [η] of Lentinan in 0.2 M NaCl aqueous solution, dimethylsulfoxide (DMSO) and water/DMSO mixtures were measured by light scattering (LS), size exclusion chromatography (SEC) combined with LS, and viscometry. The results indicated that the glucan exists mainly as triple-helical chains in 0.2 M NaCl aqueous solution and water/DMSO mixtures with over 20 wt% water content, and as single-flexible chain in DMSO. The data from SEC-LS, viscosity and 13 C NMR measurements proved strongly that the helix-coil conformation transition occurred in a narrow range from 80 to 85 wt% DMSO aqueous solution, accompanying with obvious changes of M w , < s Chihara et al. have reported that the β-(1 → 3)-Dglucan, Lentinan, obtained from Lentinus edodes has a strong antitumour activity against sarcoma 180 implanted subcutaneous in mice. 1 Thereby, the importance of the polysaccharides has provided a major impetus for increasing attention. Particularly mushroom polysaccharides have been used as functional food, and are developed in the field of new drugs. 2 The structural analysis may offer the most fundamental knowledge to understand the functions of polysaccharide, but the diversity and irregularity of polysaccharide chain make the structural analysis a formidable task. 3 Although a monosaccharide unit is common to many polysaccharides, its linkage mode varies and characteristic functions properties will appear accordingly. It is worth noting that polysaccharides in aqueous solution exhibit different chain conformation such as single helix, 4 triple helix, 5 random coil, 6 and aggregate, 7 even if their backbone all are β-(1 → 3)-D-glucan. However, conformation and its transition from an ordered state to a disordered for β-(1 → 3)-D-glucan in solution have not been fully investigated.Helix conformations of β-(1 → 3)-D-glucan with two (1 → 6)-glucosyl side groups for every five residues isolated from Lentinus edodes have been reported, based on analysis from the results of X-Ray diffraction 8 and 13 C NMR. 9-12 However, it has long been suspected to be a triple helix of the β-D-glucan in aqueous solution without strong evidence. In our recent work, 13 experimental results from light scattering have indicated that the predominant species of the β-D-glucan in 0.5 M NaCl aqueous solution exist as triple-helical chains with high rigidity, and in dimethylsulfoxide (DMSO) as single-flexible chains. The single or multiple helices of biopolymers in aqueous solution aggregate easily to form gel. The gelation and the helical state may be induced by lowering the temperature, by changing the solvent, or by adding salt. 14 The gel-forming ability of polysaccharide is of considerable importance in view of their biological functions. 15 Moreover, helixcoil transitions are important in biology, as they appear in proteins and DNA. 16 In this work, the conformation ...

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“…Therefore, G(⌫) can be transformed into G(D) by using ⌫/q 2 ϭ D, which is shown in the insert of Figure 1, indicating that the pachyman in DMSO has a unimodel translational diffusion coefficient distribution rather than bimodel distribution caused by STRUCTURE OF PACHYMAN AGGREGATES aggregation. 22 Further, the average hydrodynamic radius ͗R h ͘ is related to ͗D͘ through the Stokes-Einstein equation: ͗R h ͘ ϭ K B T/ (6͗D͘). Both the static and dynamic LLS results of the three samples are summarized in Table I.…”

Section: Resultsmentioning

confidence: 99%

“…21 Previously, we have investigated the polysaccharide PC3, a linear ␤-(1 3 3)-D-glucan from the sclerotium of Poria cocos, and found the aggregation phenomenon in aqueous solution using dynamic laser light scattering, analytical size-exclusion chromatography (SEC), viscometry, and membrane osmometry under different conditions. [22][23][24] These results proved that the polysaccharide formed aggregates in aqueous solution or in dimethyl sulfoxide (DMSO) with LiCl absorbed moisture, and the aggregates can be broken by DMSO without water, cadoxen, or at 80°C. The purpose of this article is to study in detail the kinetics and geometry of polysaccharide aggregates by static and dynamic LLS to elucidate the feature of aggregates using different models.…”

Section: Introductionmentioning

confidence: 82%

Formation and structure of pachyman aggregates in dimethyl sulfoxide containing water

Ding

Zhang

1999

J. Polym. Sci. B Polym. Phys.

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Laser light-scattering studies of pachyman

Cited by 30 publications

References 25 publications

Asymmetrical Flow Field Flow Fractionation - Multidetection System as a Tool for Studying Metal - Alginate Interactions

Asymmetrical Flow Field Flow Fractionation - Multidetection System as a Tool for Studying Metal - Alginate Interactions

Transition from Triple Helix to Coil of Lentinan in Solution Measured by SEC, Viscometry, and 13C NMR

Formation and structure of pachyman aggregates in dimethyl sulfoxide containing water

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