Synthesis of Cyanoethyl Inulin, Aminopropyl Inulin and Carboxyethyl Inulin

Abstract

Inulin was cyanoethylated by reaction with acrylonitrile in the presence of aqueous sodium hydroxide. Products with a degree of substution (ds) from 0.2 to 1.6 were prepared. The materials were analyzed using NMR spectroscopy and GPC analysis. The nitrile groups of cyanoethyl inulin were converted into amino groups by reduction with sodium borohydride in the presence of a transition metal chloride (CoCl2.6H2O). Furthermore, the nitrile groups were hydrolyzed towards carboxylates using hydrogen peroxide in alkaline medium. The polycarboxylate obtained by this means was shown to possess good calcium carbonate crystallization inhibition properties.

Inulin as a Carrier for Contrast Agents in Magnetic Resonance Imaging

“…[16] O-(Aminopropyl)inulin (API) was selected as a starting material as it is easily accessible through the cyanoethylation of inulin. [17] Reduction of the nitrile groups was accomplished with Li metal in liquid ammonia/methanol at low temperature to yield the amino-substituted inulin API. [18] Studies have indicated that the cyanoethyl groups in cyanoethyl inulin (CEI) are distributed uniformly along the inulin chain and that within each fructose unit, the 4-position is the most reactive toward cyanoethylation.…”

“…[15] The coordination cage is completed by one bound water molecule. [15] For the API-DO3ASQ conjugates, the formation of Gd III complexes was achieved by using an NMR titration procedure in which complete complexation is detected by monitoring the 17 O NMR signal of the solvent water. [3] In a typical experiment, a solution of the ligand in D 2 O is placed in a 10 mm NMR tube and titrated with solid portions of GdCl 3´6 H 2 O at 75 8C while maintaining neutral pH.…”

“…The amount of API-DO3ASQ required for back titration of the excess Gd III may then be determined by evaluation of the chemical shift data (see Figure 1 for plot). From the titration data, and from the known degrees of substitution in the ligand conjugates, we were able to determine the average relative composition of Gd III chelate/inulin chain as 17 Variable-temperature 17 relaxation-time measurements at several temperatures (5, 15, 25, 37, and 45 8C), at magnetic-field strengths varying between 2.5 Â 10 À4 and 1.2 T (NMRD), and by variable-temperature 17 O NMR shift and relaxation measurements in order to assess the relaxation processes in this system. For comparison, NMRD measurements on the nonconjugated [Gd(API-DO3ASQ)] complex were included in this study.…”

“…Nuclear magnetic resonance dispersion (NMRD) investigations and variable-temperature 17 O NMR measurements of the complexes formed with Gd III were conducted in order to assess their relaxation-enhancing abilities and to gain insight into the parameters which govern these relaxation processes.…”

Synthesis and reduction of 2-nitroalkyl polysaccharide ethers

“…In the literature, various claims are made and attempts described to synthesize polysaccharides with primary or secondary amino functionalities (Cimecioglu, Ball, Kaoplan & Huang, 1994;Daly & Munir, 1984;Hebeish, Waly, Higazy & Abdel-Mahdy, 1994;Kerr & Neukom, 1952;Verraest, Silva, Peters & van Bekkum, 1996;Verraest, Zitha-Bovens & van Bekkum, 1998;Wolfrom, Taha & Horton, 1963). However, none of the routes to these are suitable for large scale synthesis.…”