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7628674 
Journal Article 
A new glucose-selective fluorescent bisboronic acid. First report of strong alpha-furanose complexation in aqueous solution at physiological pH 
Eggert, H; Frederiksen, J; Morin, C; Norrild, JC; , 
1999 
Yes 
Journal of Organic Chemistry
ISSN: 0022-3263
EISSN: 1520-6904 
AMER CHEMICAL SOC 
WASHINGTON 
3846-3852 
A new bisboronic acid based glucose sensor 7 was synthesized from 9,10-bis(chloromethyl)anthracene and 2,2-dimethyl-1,3-propanediol protected 3-pyridineboronic acid. Due to its ionic structure 7 was found sufficiently water soluble for carbohydrate binding studies at neutral pH by means of NMR spectroscopy, fluorometry, and potentiometry. The pK(a)'s of 7 have been determined to 3.7 and 4.7 by potentiometric titration. From a solution of 7 and glucose (1:1) in water (pH 7.4) we observed the formation of a bisdentate boronic acid complex 7.Glu which has been assigned to a 1,2:3,5 bound alpha-D-glucofuranose complex. The evidence for this furanose structure comprises H-1 and C-13 NMR data with emphasis on the information from (1)J(C-C) coupling constants. Complex 7 Glu shows an increased fluorescence compared to 7. The stability constant for the 1:1 complex (log K = 3.4) was determined from fluorometric titration, potentiometry, and NMR spectroscopy. Boronic acid 7 shows good selectivity for glucose compared to fructose and galactose.