Binding Interaction Between Boronic Acid Derivatives with Monosaccharaides:Effect of Structural Change of Monosaccharaides Upon Binding Using S-V Plots

摘要

Sugar sensing and continuous monitoring of glucose(CGM)play an important and vital role in controlling diabetes.The present enzyme-based sugar sensors have their own drawbacks.Problems associated with them have encouraged alternate approaches to design new sensors.Among many,fluorescent intensity change based sensors are drawing more attention.Fluorescence sensors based on boronic acid derivatives are more popular because of their ability to reversibly bind diol-containing compounds.Here,the binding ability of two boronic acid derivatives,namely 2-methylphenyl boronic acid(B1)and 3-methoxyphenyl boronic acid(B2)with mono saccharides(sugars),is under investigation.The sugar concentration is kept nearly 1000 times more than that of boronic acid.The interactions of B1 and B2 with three saccharides(d-sorbitol,dextrose,and fructose)are studied by absorbance and steady-state fluorescence.Both B1 and B2 fluorescence is quenched by formation of esters with saccharides.The results of absorbance and fluorescence measurements indicate that the studied sugars can be ordered by their affinity to B1 as:d-sorbitol>xylose>dextrose and for B2 as:dextrose>xylose>d-sorbitol.In each case,slope of modified S-V plots is nearly one indicating only a single binding site in boronic acids for sugars.