29Si and 13C NMR Spectra of Trimethylsilylated Amino Acids

Article abstract of DOI:10.1002/mrc.1260321005

The 29Si and 13C NMR chemical shifts are reported for trimethylsilyl derivatives of 25 amino acids, the majority of which occur naturally as protein constituents of foodstuffs.The 29Si chemical shifts in trimethylsilyl esters of amino acids roughly correlate linearly with the pK values of the parent amino acid.No such simple correlations were found for the shifts in the fully trimethylsilylated amino acids.The 29Si chemical shifts of various functionalities encountered fall into distinct spectral regions, but the shifts of (CH3)3SiN or (CH3)3SiOOC groups alone are not sufficiently characteristic to identify the acid but their combination is in most cases. - Keywords: 29Si NMR 13C NMR Amino acids Trimethylsilyl derivatives Chemical shifts pK values