title: Accurate measurement of long-range heteronuclear coupling constants from undistorted multiplets of an enhanced CPMG-HSQMBC experiment.
abstract: Here, we present a modified CPMG-HSQMBC experiment which is capable to reduce the detrimental phase twists in the "long-range" connectivity multiplets caused by proton-proton couplings. We demonstrate that concerted CPMG pulse trains applied on both nuclei in the starting CPMG-INEPT transfer step can considerably be improved by composite pi pulses that compensate for pulse imperfections and off-resonance effects. Experimental optimization of the interpulse delay within the CPMG cycle was found to be crucial in order to achieve the best possible "decoupling" of homonuclear coupling modulation.
authors.affiliation: Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4010 Debrecen, Hungary. kover@tigris.unideb.hu
authors.forename: Katalin E
authors.initials: KE
authors.lastname: Kövér
authors.forename: Gyula
authors.initials: G
authors.lastname: Batta
authors.forename: Krisztina
authors.initials: K
authors.lastname: Fehér
mesh_terms: D006020:Glycopeptides / Q000737:chemistry*; D015394:Molecular Structure; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*
chemical_list: D006020:Glycopeptides; D009587:Nitrogen Isotopes; C053759:eremomycin