| A novel carbohydrate receptor based on the structure of the antibiotic polymxin B was synthesized. The receptor was a cyclic heptapeptide, which was bridged using 2, 2'-bi pyridine-5,5'-dicarboxylic acid. The association constants of the receptor and a variety of sugars were determined using UV/Vis and fluorescence spectroscopy and observed log K a values are in the range from 3 .8 to 4.1 for the pentoses, logKa 3.3 to 3.8 for the hexoxes and 0 to 2.9 logKa values from 0-2.9 for disaccharides and logKa of 2.6 to 3.11 for the charged sugars.; We demonstrated that polymixin based receptors are capable of binding various monosaccharide substrates in aqueous media, displaying structure selectivity with respect to monosaccharide ring size. |
