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Regioselective synthesis of sulfated guar gum: comparative studies of structure and antioxidant activities.
- Source :
-
International journal of biological macromolecules [Int J Biol Macromol] 2013 Nov; Vol. 62, pp. 734-40. Date of Electronic Publication: 2013 Oct 10. - Publication Year :
- 2013
-
Abstract
- We reported here a new synthesis of C-2 and C-3 sulfated guar gum (SRSGG) with low degree of substitution (DSS) of 0.58, employing triphenylchloromethane (TrCl) as a protected precursor. The yield and DSTr (calculated from the weight of triphenylmethanol) of triphenylmethylated GG (GGTr) was 165.6% and 0.71, respectively. In addition, low ratio (1:4) of chlorosulfuric acid to pyridine (1:4) was chosen in sulfation reaction since the protecting group was slightly sensitive to acid. Results of FT-IR and (13)C NMR spectroscopy indicated that C-2 and C-3 substitution was predominant but not fully sulfated in SRSGG. Size-exclusion chromatograph combined with multi-angle laser photometer (SEC-LLS) showed a decrease in molecular weight in the reaction. This might be due to the degradation in sulfation and deprotection process. Finally, we investigated the effect of structure features on the antioxidant activities in vitro. Vitro antioxidant experiments revealed that the regioselective sulfation at C-2 and C-3 and low molecular weight afforded strong antioxidant activities showing a much higher scavenging abilities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical than that by the known C-6-sulfated derivative. The antioxidant activities of sulfated polysaccharides were not a function of a single factor but a combination of molecular weight, DSS and substitution positions.<br /> (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)
- Subjects :
- Antioxidants chemical synthesis
Galactans chemical synthesis
Hydroxyl Radical antagonists & inhibitors
Mannans chemical synthesis
Nuclear Magnetic Resonance, Biomolecular
Oxidation-Reduction drug effects
Plant Gums chemical synthesis
Spectroscopy, Fourier Transform Infrared
Superoxides antagonists & inhibitors
Antioxidants chemistry
Antioxidants pharmacology
Galactans chemistry
Galactans pharmacology
Mannans chemistry
Mannans pharmacology
Plant Gums chemistry
Plant Gums pharmacology
Sulfuric Acid Esters chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1879-0003
- Volume :
- 62
- Database :
- MEDLINE
- Journal :
- International journal of biological macromolecules
- Publication Type :
- Academic Journal
- Accession number :
- 24120962
- Full Text :
- https://doi.org/10.1016/j.ijbiomac.2013.10.005