REACTION OF REDUCING SUGARS WITH SULFATHIAZOLE AND IMPORTANCE OF THIS REACTION TO SULFONAMIDE RESIDUE ANALYSIS USING CHROMATOGRAPHIC, COLORIMETRIC, MICROBIOLOGICAL, OR ELISA METHODS

Studies with sulfathiazole (ST) as a representative sulfonamide demonstrated that the N4aromatic amino group of sulfonamides can react with reducing sugars to form a variety of different sugarbound compounds. ST was not destroyed in this reaction, and free ST could be produced from some of these sugar-bound compounds by aqueous dilution and, especially, by acidification. Different effects of these sugar-bound ST compounds, especially the N4-linked ST Amadori compound, were noted on various methods of sulfonamide residue analysis. The sugar-bound ST compounds exhibited chromatographic behavior different from that of free ST, did not visualize with a common TLC Bratton-Marshall spray specific for sulfonamides, did not inhibit the growth of Escherichia coli and Staphylococcus aureus strains susceptible to free ST, but did inhibit binding of antisera in an indirect competitive enzyme-linked immunosorbent assay (ELISA) as much as 33 times greater, on a molar basis, than free ST. © 1990, American Chemical Society. All rights reserved.