Examination of the aspirin acetylation site of human serum albumin by ¹³C NMR spectroscopy

Abstract

Abstract Human serum albumin has been specifically acetylated using aspirin in which the methyl carbon of the acetyl group was enriched to 90% 13 C. A single resonance at 23.13 ppm downfield from tetramethylsilane was observed in 13 C differences spectra obtained at both 25.2 and 45.3 MHz. Chemical shift studies of several model compounds suggest that this is the resonance position to be expected for an acetamide group exposed to solvent. The line width observed for the enriched methyl resonance is consistent with free rotation of the methyl group.