ELSA-PSYCHE:\nAn Improved Method for Protecting Pure\nShift Spectra from Artifacts

Numerous <sup>1</sup>H–<sup>1</sup>H <i>J</i> couplings\ncontribute to complex multiplets in <sup>1</sup>H nuclear magnetic\nresonance spectroscopy, leading to an ambiguous spectral assignment,\nparticularly for strongly coupled protons. Although the PSYCHE approach\nhas proven to be effective in simplifying complex spectra by collapsing <i>J</i> couplings, the PSYCHE pure shift spectrum of strongly\ncoupled protons always suffers from sideband artifacts and baseline\noscillations, which impede spectral identification. Herein, we introduce\na novel universal technique designed to separate artifacts from the\ndesired absorption-mode pure shift signals. This new study will significantly\nbenefit the development of molecular structure elucidations and composition\nanalysis in the fields of chemistry, biochemistry, and metabonomics.