An analytical ultracentrifugation based study on the conformation of lambda carrageenan in aqueous solution
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Dosyalar
Tarih
2013
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The conformation and heterogeneity of lambda-carrageenan, a sulphonated galactan from red seaweed, solubilised in aqueous solvent with the assistance of microwave irradiation, has been assessed by a combination of analytical ultracentrifugation, size-exclusion chromatography, light scattering and capillary viscometry. Preparations appeared generally unimodal on the basis of sedimentation coefficient distributions from sedimentation velocity although at the highest concentrations a shoulder appears with a sedimentation coefficient approximately 1.1 times greater than that of the main component. Even under conditions commensurate with charge suppression simple linear regression was insufficient to represent non-ideal concentration dependence and the extraction of the Gralen concentration dependence parameter k(s). A more general fitting algorithm was therefore employed. Mark-Houwink-Kuhn-Sakurada analysis of the change in intrinsic viscosity [eta] with molecular weight, together with the Wales-van Holde ratio (combination of k(s), with [eta]) point to an extended flexible conformation for lambda-carrageenan in the (weight average) molecular weight range M-w = 340,000-870,000 g/mol. The origin of the larger sedimentation coefficient component appearing at the higher concentrations is considered. (C) 2013 Elsevier Ltd. All rights reserved.
Açıklama
Anahtar Kelimeler
Lambda-carrageenan, Intrinsic Viscosity, Sedimentation Coefficient, Concentration Dependence, Molar Mass, Extended Flexible Coil
Kaynak
Carbohydrate Polymers
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
97
Sayı
1
