title: Hadamard Homonuclear Broadband Decoupled TOCSY NMR: Improved Efficacy in Detecting Long-range Chemical Shift Correlations.
abstract: The importance of Hadamard encoding pulses in one-dimensional pure shift yielded by the chirp excitation version of selective total correlation spectroscopy (1D PSYCHE-TOCSY) experiments is discussed for chemical-shift analysis of complex natural products at ultrahigh resolution. Herein, we adapted HnHadamard matrices to 1D PSYCHE-TOCSY and observed an overall circa square root of n-fold enhancement in the signal-to-noise (S/N) ratio when compared to conventional 1D PSYCHE-TOCSY recorded by refocusing only one spin at a time. This enhancement in S/N facilitates the observation of very weak long-range chemical-shift correlations from Hadamard-encoded PSYCHE-TOCSY (HE-PSYCHE-TOCSY). The proposed method will have a significant impact on structure determination of complex isolated/ synthetic natural products.
authors.affiliation: UM-DAE-Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Santa Cruz, Mumbai, 400 098, India.
authors.forename: Veera Mohana Rao
authors.initials: VM
authors.lastname: Kakita
authors.affiliation: UM-DAE-Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Santa Cruz, Mumbai, 400 098, India.|Department of Chemical Sciences, Tata Institute of Fundamental Research (TIFR), 1-Homi Bhabha Road, Colaba, Mumbai, 400 005, India.
authors.forename: Ramakrishna V
authors.initials: RV
authors.lastname: Hosur
mesh_terms: D001688:Biological Products / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D059629:Signal-To-Noise Ratio
chemical_list: D001688:Biological Products
keywords: chemical shift; homodecoupling; natural products; nuclear magnetic resonance; total correlation spectroscopy