title: Preparation and structural characterisation of O-aminopropyl starch and amylose.
abstract: O-aminopropyl starch was prepared by Michael addition of acrylonitrile and subsequent reduction with freshly prepared cobalt boride and sodium borohydride. In a second approach, the aminopropyl group was introduced via Williamson etherification with N-phthalyl-protected 3-bromo-1-propylamine. The protecting group was removed by borohydride reduction and subsequent hydrolysis in acetic acid. The DS of all samples and the degree of reduction of the cyanoethyl groups were estimated from the 1H NMR spectra. Total monomer composition was determined after methanolysis or hydrolysis and trimethylsilylation by GLC and GCMS. While the regioselectivity in the thermodynamically controlled reaction was O-6 > O-2 > O-3 (50:37:13), the kinetically controlled process showed strongly preferred O-2-etherification (up to 94%) followed by O-6- and O-3-substitution. It could be influenced by choice of solvent (water, Me(2)SO) and base (NaOH, Li-dimsyl).
authors.affiliation: TU Braunschweig, Institut für Lebensmittelchemie, Schleinitzstrasse 20, D-38106 Braunschweig, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Gonera
authors.forename: Vera
authors.initials: V
authors.lastname: Goclik
authors.forename: Marita
authors.initials: M
authors.lastname: Baum
authors.forename: Petra
authors.initials: P
authors.lastname: Mischnick
mesh_terms: D000606:Amino Sugars / Q000138:chemical synthesis*; D000688:Amylose / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D009005:Monosaccharides / Q000032:analysis; D011437:Propylamines / Q000138:chemical synthesis; D013213:Starch / Q000737:chemistry*
chemical_list: D000606:Amino Sugars; D009005:Monosaccharides; D011437:Propylamines; D013213:Starch; D000688:Amylose