A fluorescent glucose sensor binding covalently to all five hydroxy groups of α-D-glucofuranose. A reinvestigation

摘要: The structures of the complexes between a fluorescent bisboronic acid 7 and glucose have been determined. Shinkai et al.1 previously studied complex they deduced 1,2∶4,6-α-D-glucopyranose bisboronate structure. We shown that this structure is only valid as an initial formed under completely nonaqueous conditions. In presence water pyranose rearranges rapidly into α-D-glucofuranose-1,2∶3,5,6-bisboronate in which all five free hydroxy groups are covalently bound by sensor molecule. A favourable B–N interaction around 1,2-binding site effect o-ammoniomethyl group on pKa value second boronic allow for observed binding at neutral pH. evaluations based 1H 13C NMR data well information obtained from 1JCC coupling constants. fluorescence spectra both were measured discussed. MALDI TOF-MS experiments showed competitive formation 1∶2 (boronic acid∶glucose) conditions physiological levels.