Measurement of long-range proton-nitrogen coupling constants at natural abundance
The quantitative measurement of long-range proton-nitrogen coupling constants for small and medium-size organic compounds at natural abundance has been limited because of the low-sensitivity of any experiment involving 15N and their small values.
  • Some experiments have been reported to measure 3JN-HA and 3JN-HB in 15N-labeled proteins.
  • Qualitative measurement from ge-2D 1H-15N HMBC spectra
  • Quantitative measurement from ge-2D HSQC-TOCSY ( 99JMR48-137 , 00JMR294-142 99TET2881 ) ge-2D long-range optimized HSQC ( 97TL665 , 99MRC195 ) and ge-2D HMBC ( 96JNP59 , 99MRC195 , 00TET2935 ) experiments.
  • Quantitative measurement from ge-1D HMBC experiment ( 99MRC748 ).
  • Application to conformational analysis of labeled amino acids ( 85MRC474 )