Analyses, extensions and comparison of three experimental schemes for measuring ((n)J(CH)+D(CH))-couplings at natural abundance.
Three types of experiments for measuring (n)J(CH) heteronuclear long-range coupling constants are examined and extended with state-of-the-art pulse sequence building-blocks: The use of a HMBC with corresponding reference-HSQC for accurate coupling determination is combined with the constant time technique and the conversion of antiphase magnetization into ZQ/DQ-coherences; CPMG-based LR-CAHSQC and BIRD(r,X)-HSQMBC experiments are examined in detail with respect to their coherence transfer properties; finally, the HSQC-TOCSY-IPAP experiment is introduced, a sequence derived from previously published alpha and beta selective HSQC-TOCSYs using a different spin state selection technique and a recently developed ZQ-suppression method. The experiments are characterized with their advantages and disadvantages and compared using strychnine and menthol as standard molecules.
Kobzar
Kyryl
K
Department Chemie, Organische Chemie II, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany.
Luy
Burkhard
B
D000465:Algorithms; D002244:Carbon / Q000737:chemistry*; D003198:Computer Simulation; D006859:Hydrogen / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D015203:Reproducibility of Results; D012106:Research; D012680:Sensitivity and Specificity
D002244:Carbon; D006859:Hydrogen