Analysis of fructofuranose conformations by molecular mechanics

✍ Scribed by Alfred D. French; Vinh Tran

• Publisher: Wiley (John Wiley & Sons)
• Year: 1990
• Tongue: English
• Weight: 819 KB
• Volume: 29
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360291210

✦ Synopsis

Energies for various envelope and twist conformers of a-and p-D-fructofuranose (FF) have been calculated with MMP2 (85). Values of low energy are found near $T conformations, and, secondarily, to ranges near iT shapes. WD-FF has a path through the ' E form for transitions between these forms, as found by other workers for P-D-ribose, while the slightly preferred transition for P-D-FF is through the oE conformer. The majority of conformations of P-D-FF that have been determined by single-crystal diffraction studies are in a fairly deep well, with energy values less than 0.5 kcal/mol above the minimum.

I NTRO D UCTl 0 N

Conformations of molecules based on the ketohexose, fructofuranose (FF) ,' have received less attention than the aldopentoses, ribose and deoxyribose, constituents of the nucleic acid^.^-^ Therefore, less information is available for the construction of molecular models of fructan polymers such as inulin and levan,8 which are based on 0-D-FF, as well as for understanding the small compounds in which residues of these molecules are found. The purposes of this contribution, then, are (1) to provide a perspective on the conformations of FF; and ( 2 ) through the study of both a-and 0-FF, to indicate the conformational effects of subtle changes in the placement of substituents on the furanose ring.