THE CRYSTAL-STRUCTURE OF CYCLOINULOHEXAOSE PRODUCED FROM INULIN BY CYCLOINULO-OLIGOSACCHARIDE FRUCTANOTRANSFERASE

The crystal of cycloinulohexaose trihydrate, C36H60O30.3H2O, is trigonal, space group R3, with unit-cell dimensions a = 24.688 (17), c = 6.477 (3) angstrom for a hexagonal cell, Z = 3. The molecule, which consists of six (2 --> 1)-linked beta-D-fructofuranose residues, has C3 symmetry. The conformations of two D-fructofuranosyl moieties in an asymmetric unit are 4T3 with P = 3481.1-degrees and tau-m = 38.9-degrees for F1, and 4T3 with P = 350.5-degrees and tau-m = 41.2-degrees for F2. The conformations of -O-CH2-C-O-in the 18-crown-6 ring are gauche+ for O-1-C-1-C-2-O-1' (+ 52.3-degrees) and trans for O-1'-C-1'-C-2'-O-1 (+ 163.4-degrees).