Binding of Organic Solutes to a Polymer Containing Pendant Sugar Groups

Abstract

Polymers conta;mng sugars as pendant groups are receiving a growing amount of attention because of the possibility for their use in a wide range of applications for which natural polysaccharides are not suitable. Several types of sugar-containing polymers have been developed in order to make use of hydrophilicity/· 2 chirality,3.4 and biological activity 5 · 6 of sugars. From this standpoint, we synthesized an amphiphilic polymer 2, from glucose and chloromethylstyrene as starting materials. 7 The 2 Scheme solution properties of 2 suggested that it behaved as a nonionic polysoap in water, and a spectrophotometric investigation showed that an organic solute such as methyl orange was strongly bound to the hydrophobic regions of 2 in water.The present study was undertaken in order to confirm the solute binding properties of 2 using magnesium 1-anilino-8-naphthalenesulfonate (ANS) as the organic solute. ANS has been used extensively as a hydrophobic probe, that is nonfluorescent in water but becomes highly fluorescent on binding to non-polar regions in proteins, 8 • 9 biomembranes, 10 cyclodextrins, 11 -13 and synthetic polymers. 14 The ANS binding constants of 2 were determined and compared with those of analogs. EXPERIMENTALPolymer 2 used was prepared from its precursor 1 with a number-average degree of polymerization of 420. 7 . ANS, supplied by Nakarai Chemicals, Ltd., was recrystallized twice from hot water. Fluorescence spectra were recorded with a JASCO FP-550 spectrofluorometer at room temperature. The excitation wavelength was 380 nm and both the excitation and emission slits were set at 10 nm. RESULTS AND DISCUSSIONFigure 1 depicts fluorescence emission spectra of ANS in the absence and presence of the polymer 2. Fluorescence of ANS alone was negligible, but 2 induced a striking enhancement of the fluorescence.Simultaneously, the emission maximum A.:;,., also blue-shifted; it decreased abruptly with increasing polymer concentrations and took on a constant value (475 nm) at polymer concentrations higher than 10-3 M. The large blue shift by 50nm on binding to 2 indicates that the bound ANS remained in a hydrophobic microenvironment. It is suggested that the emission maximum of the adsorb-517

Coacervate Thermoresponsive Polysaccharide Nanoparticles as Delivery System for Piroxicam

“…Piroxicam’s affinity to A-HPC was evaluated by determining the binding constant, K a . The Benesi–Hildebrand method allows the investigation of the one-to-one binding process between host and guest molecules using spectrophotometric measurements [ 33 , 34 , 35 ]. K a value was determined in water.…”

Removal of nonionic surfactant by systems based on chloromethylated polystyrene–poly(ethylene glycol)

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Copolymerization Behavior of β-Angelica Lactone and Styrene in the Presence of Organoaluminum Chlorides

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