title: Elimination of Zero-Quantum artifacts and sensitivity enhancement in perfect echo based 2D NOESY.
abstract: Zero-Quantum artifacts seriously degrade the performance of 2D NOESY. Homonuclear J-evolution during t(1) period generates Zero-Quantum and other higher quantum coherences which represent the magnetization loss and the artifacts created. We demonstrate that creation of such artifacts itself can be prevented for shorter t1 period by a perfect echo based decoupling technique during t1 period in a single scan. This is in contrast to existing methods that create unwanted coherence, and subsequently suppress that to produce a clean spectrum with a sensitivity penalty. Although decoupling performance of the present scheme remains robust for echo time 2τ short compared to 1/2J, we show that even a partial decoupling effect for extended t(1) (=2τ) period up to 100 ms along with a Zero-Quantum filter generates NOE spectrum from Cyclosporine A, in which majority of the cross peaks displayed partial sensitivity enhancement with few exceptions. However, in crowded proton spin systems like menthol, the enhancements were not observed and perfect echo NOESY displays similar performance as Zero-Quantum filtered NOESY.
authors: Center of Biomedical Research (Formerly Centre of Biomedical Magnetic Resonance), SGPGIMS Campus, Raebareli Road, Lucknow 226014, India. Electronic address: bikashbaishya@gmail.com.
authors: Bikash
authors: B
authors: Baishya
authors: Center of Biomedical Research (Formerly Centre of Biomedical Magnetic Resonance), SGPGIMS Campus, Raebareli Road, Lucknow 226014, India.
authors: Ajay
authors: A
authors: Verma
mesh_terms: D000465:Algorithms; D016477:Artifacts; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D011789:Quantum Theory; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels
chemical_list: D010455:Peptides; D013113:Spin Labels
keywords: Broadband homonuclear decoupling; J-refocusing; NOESY; Perfect echo (PE); Zero-Quantum