title: Evaluation of C-(beta-D-galactosyl) and C-(2-deoxy-D-lyxo-hex-1-enopyranosyl) (D-galactal type) derivatives as inhibitors of beta-D-galactosidase from Escherichia coli.
abstract: C-(2-Deoxy-D-lyxo-hex-1-enopyranosyl)formamide was prepared from acetylated C-(beta-D-galactopyranosyl)formamide by a radical-mediated bromination-zinc/N-methylimidazole-induced reductive elimination-Zemplén deacetylation reaction sequence. The preparation of acetylated 5-(2-deoxy-D-lyxo-hex-1-enopyranosyl)tetrazole was improved. Methyl C-(2-deoxy-D-lyxo-hex-1-enopyranosyl)formimidate was transformed by benzylamine into N-benzyl-C-(2-deoxy-D-lyxo-hex-1-enopyranosyl)formamidine and, after hydrolysis to methyl C-(2-deoxy-D-lyxo-hex-1-enopyranosyl)formate, into N-benzyl-C-(2-deoxy-D-lyxo-hex-1-enopyranosyl)formamide. A series of C-(beta-D-galactopyranosyl) and C-(2-deoxy-D-lyxo-hex-1-enopyranosyl) derivatives was comparatively investigated for E. coli beta-D-galactosidase inhibitory activity. N-Benzyl-C-(2-deoxy-D-lyxo-hex-1-enopyranosyl)formamidine was the best inhibitor and had K(i) = 6 microM (on the basis of its free base concentration, K(i) = 8.3 nM was obtained). Basicity and hydrophobicity of the aglycon proved to be more important factors for the inhibition than the conformation of the sugar ring.
authors.affiliation: Department of Biochemistry, Lajos Kossuth University, Debrecen, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Kiss
authors.forename: L
authors.initials: L
authors.lastname: Somsák
mesh_terms: D002236:Carbohydrate Conformation; D004791:Enzyme Inhibitors / Q000138:chemical synthesis*; D004926:Escherichia coli / Q000201:enzymology*; D005559:Formamides / Q000138:chemical synthesis / Q000494:pharmacology; D005690:Galactose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D005697:Galactosides / Q000138:chemical synthesis* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D001616:beta-Galactosidase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D005559:Formamides; D005697:Galactosides; C002038:galactal; D001616:beta-Galactosidase; D005690:Galactose