CRYSTAL-STRUCTURE OF AN AMADORI COMPOUND, N-(1-DEOXY-BETA-D-FRUCTOPYRANOS-1-YL)-GLYCINE (D-FRUCTOSE-GLYCINE)

The first crystal structure data on an Amadori compound, N-(1-deoxy-beta-D-fructopyranos-1-yl)glycine, are reported. The space group is P2(1) with Z=2 and cell parameters a=7.246(1), b=10.009(1), c=7.060(1) Angstrom, and beta=101.085(6)degrees. The structure was solved by direct methods and refined to a final R of 2.9% and R(W) of 3.8% for 1385 reflections to give esd's of 0.002 Angstrom in bond lengths and 0.2 degrees in angles. The conformation of the carbohydrate is the normal C-2(5) Pyranose chair. Bond lengths and valence angles compare well with average values from a number of pyranose structures. The molecule of the Amadori compound exists in the zwitterion form and has the C-6-O-6-C-2-C-1-N-C-2'-C-1'-O-1' chain in a zig-zag conformation, that is (together with O-2') substantionally planar. AU hydroxyl, carboxyl, and ring oxygen atoms, and the secondary ammonuim group are involved in hydrogen bonding, which forms a three-dimensional network of two infinite chains that have an ammonium group as a common segment. The shortest intra- and inter-molecular hydrogen bonds involve donors of the pyranosyl moiety and accepters of the amino acid portion, and vice versa.