TRIPLE-RESONANCE ISOTOPE-EDITED (TRIED) - A POWERFUL NEW NMR TECHNIQUE FOR STUDYING METABOLISM

A powerful new technique for studying metabolism, Triple-Resonance Iso tope-Edited (TRIED) NMR, is described and demonstrated experimentally. The experiment uses through-bond (scalar) coupling between spins to s elect NMR signals from molecules having H-1-C-13-N-15 labeled triples. Natural-abundance background signal from molecules not containing suc h labeled triples (e.g., signal from H-1-C-12 and H-1-C-13 fragments) is effectively suppressed, with a suppression ratio of approximately 1 0(4):1. This effective filtering of signal from labeled molecules allo ws these species and their metabolites to be detected and characterize d without requiring extensive, time-consuming sample purification. Res ults are presented for C-13,N-15-aminomethylphosphonate (AMPA) in soyb ean and pigweed plant matrices. The potential use of TRIED for studyin g the pharmacokinetics of drugs and extension of the experiment to inc lude the use of magnetic-field gradients for selecting signal from lab eled fragments are also described.