Synthesis Of 3-Amidopybrinc Acid Compunds And A Study Of D-furtos ERcognition

Carbohydrate widely exists in nature, which is treated as one of the three substantial units as protein and nucleic acid. Due to its high affinity for dios, boronic acid group is frequently used for recognizing carbohydrate since the carbohydrate contains polyhydroxy. A fluorescent receptor sensing for saccharide can be constructed while a boronic acid group is linked to a fluorophore.In this paper, nine 3-amidophenylbronic acid compounds were synthesized with a series of different aromatic carboxylic acids and 3-aminobenzeneboronic acid by acyl choride reaction and aminolysis reacation. Five monoboronic acids include: Compound 1 ( [3-(benzoylamino)phenyl] boronic acid ), Compound 2( [3-(nicotinamido)phenyl]boronic acid ), Compound 3( [3-(isonicotinamido)phenyl] boronic acid ), Compound 4 ( [3-[(2,4,6-trifluorobenzoly)amino]phenyl]boronic acid ), Compound 5 ( [3-[(2,3,4,5,6-pentafluorobenzoly) amino] phenyl]bronic acid). Four diboronic acids include: Compound 6 ( [3,3′-[N,N′-(paraphthalmido)] biphenyl]diboronic acid ), Compound 7 ( [3,3′-[N,N′-(isophthalamido)] biphenyl]diboronic acid ), Compound 8 ( [3,3′-[N,N′-(2,6-pyridinedicarboxamido)] biphenyl] diboronic acid ) and Compound 9 ( [3,3′- [N,N′- (2,5- pyridinedicarboxamido)] biphenyl] diboronic acid ). Seven compounds have not been reported in SciFinder except Compound 1 and Compound 2 . All the structures of target products ( Compound 1 ~ 9 ) were characterized by melting point test, IR, 1H NMR. The crystal structures of Compound 3 have determined by X-ray single crystal diffraction analysis.Nine new 3-amidophenylbronic acid compounds as fluorescence receptors for the recognition of D-Fructose were studied. There were non-fluorescent excited from interaction with our products with D-Fructose. So, a general fluorescence assay method called IDA ( indicator displacement assay) could used with Alizarin Red S as the optical reagent to monitor the binding of the unmodified boronic acid compound with the carbohydrate. Due to the difficult problem solved by constructing the three component competitive binding assay, the binding constants could be calculated indirectly and the different interaction mechanisms of monoboronic acids and diboronic acids could be inferred. The experimental results indicated that D-fructose can obviously decrease the fluorescence intensity of Monoboronic acids-ARS System in the buffer of phosphate at pH 7.4 and ethanol based on competitive displacement simply. On the contrary, with the increase of D-fructose, the fluorescence intensity of Diboronic acids-ARS System enhanced first, after that the increasing trend gradually reduced in DMF solvent. Finally it could result in fluorescence quenching effect when the D-fructose concentration reached a certain value. It showed that the different bonding state of two boronic acid groups in diiboronic acids would introduce different fluorescent responses since a large molecular formed through the covalent bonding.