title: Offset-compensated and zero-quantum suppressed ROESY provides accurate1H-1H distances in small to medium-sized molecules.
abstract: A robust version of the off-resonance ROESY pulse scheme is suggested for the measurement of proton-proton distances or slow chemical exchange in small to medium-sized molecules. The method implements adiabatic ramps to establish a pair of opposite frequency off-resonance spin lock fields - with optionally randomized duration - and adiabatic inversion pulses with simultaneous gradients for efficient zero-quantum suppression. The amended pulse sequence yields pure absorption cross-peaks and works safely for small to medium-sized molecules. The applicability of the method has been demonstrated using small, rigid molecules (strychnine and codeine) and was also applied for a cyclic peptide and a small protein. We found that the pure phase cross-peaks of the new ROESY version are beneficial for distance measurements. The one-dimensional (selective) version of the new method is also powerful for measuring selected pair-wise interactions and distance determination. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Vichem Chemie Research Ltd., Budapest, Hungary.
authors.forename: Sándor
authors.initials: S
authors.lastname: Boros
authors.affiliation: Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
authors.forename: Gyula
authors.initials: G
authors.lastname: Batta
mesh_terms: D003061:Codeine / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010456:Peptides, Cyclic / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D011789:Quantum Theory; D013331:Strychnine / Q000737:chemistry
chemical_list: D010456:Peptides, Cyclic; D011506:Proteins; D006859:Hydrogen; D013331:Strychnine; D003061:Codeine
keywords: NMR; off-resonance ROESY; offset compensation; zero-quantum suppression