Reaction between carbohydrates and sulfuric acid

Nagasawa, Kinzo; Tohira, Yasuo; Inoue, Yuko; Tanoura, Noriko

doi:10.1016/s0008-6215(00)80261-x

Cited by 76 publications

(12 citation statements)

References 14 publications

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“…Chemical modification of the amino and hydroxyl groups in chitosan with sulfate is of great importance to produce chitosan‐based polyampholytes, which generate water‐soluble chitosan derivatives useful as biomaterials in pharmaceutical applications 3, 17. These processes often require organic solvents, such as tetrahydrofuran or dimethylformamide, to dissolve both the sulfating agents and chitosan and relatively strong sulfating agents, which lead to a nonselective sulfation on the O‐6, O‐3, and N‐2 positions 18–21…”

Section: Introductionmentioning

confidence: 99%

Synthesis and rheological behavior of a novel N‐sulfonate ampholyte chitosan

Yin

et al. 2009

J of Applied Polymer Sci

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Modified chitosan derivatives with different degrees of substitution varying from 0.17 to 0.96 were synthesized by the heterogeneous reaction of chitosan with 3-chloro-2-hydroxy propanesulfate in a neutral aqueous solution. The modified chitosans with a degree of substitution higher than 0.36 were soluble in water, whatsoever the pH. The structures of the polymers were characterized by Fourier transform infrared and 1 H-nuclear magnetic resonance spectroscopies. The potentiometric titration revealed that the modified chitosan had an isoelectric point at around pH ¼ 5.7, and its rheological behaviors in aqueous solution were studied under different conditions. The results showed that the modified chitosan had typical polyampholyte characteristics, which exhibited polyelectrolyte effect at pH ¼ 1.7 or 13 and antipolyelectrolyte effect at pH ¼ 8.

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Section: Introductionmentioning

confidence: 99%

Synthesis and rheological behavior of a novel N‐sulfonate ampholyte chitosan

Yin

et al. 2009

J of Applied Polymer Sci

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“…Chitin and chitosan sulfate esters have been prepared using various sulfation reagents including concentrated sulfuric acid [57], oleum [58], chlorosulfonic acid [59], sulfur trioxide [60], sulfur trioxide complex (e.g. with pyridine [61], trimethylamine [62]).…”

Section: Chitin/chitosanmentioning

confidence: 99%

Design Polysaccharides of Marine Origin: Chemical Modifications to Reach Advanced Versatile Compounds

Chopin¹,

Guillory²,

Weiss³

et al. 2014

COC

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Polysaccharides are among the most abundant macromolecules on Earth. These polymers are easily obtained from various marine resources such as algae, microorganisms and crustacean shells. The structure of these natural carbohydrates is innovative and quite complex. Marine biopolymers represent key scaffolds toward large challenging fields, such as biomedical applications (glycosaminoglycans, regenerative medicine and drug delivery) and tailored biomaterials. Chemical modifications can be applied to modify their final properties in a specific purpose. New functional glycans are achievable and represent a real potential with their intrinsic biocompatibility and biodegradability. Hydroxyl groups are ubiquitous in polysaccharides structure and involved in most of the chemical modifications. The most useful functionalities are ester, ether, amide, amine and alkyl groups. The starting materials could be a natural or depolymerized polymers and the reaction considered with a regioselective point of view. In this review, we will focus on chitin polysaccharide, which is extracted according to industrial processing from exoskeleton of several marine crustaceans. A subsequent deacylation provides chitosan. This marine polysaccharide is very similar to cellulose, a widespread fiber plant organic polymer, except for an amine group on the C2 position instead of a hydroxyl group. Furthermore, seaweeds provide the most abundant sources of polysaccharides: alginates, agar/agarose, carrageenans and fucoidans. In order to improve the original physicochemical and biochemical properties, we will highlight the chemical modifications involving the listed marine polysaccharides of interest. Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site 2

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“…Consequently, it can be assumed that the constitution of the product is heterogeneous. Nagasawa et al [26] prepared sulfated chitin and chitosan by using sulfuric acid, tetrahydrofuran, and phosphorous pentoxide at −20 • C, respectively. The average molecular weight and yield of the both sulfated chitin and chitosan showed the extent of degradation of the polysaccharide structure by concentrated sulfuric acid.…”

Section: Synthesis Of Sulfated Chitin and Chitosanmentioning

confidence: 99%