Experiments to detect long-range heteronuclear shift correlations: LR-J-HSMQC.
The utility of the J-HSMQC experiment to detect long-range CH correlations was investigated. Two new long-range J-compensated pulse sequences, LR-J-HSMQC(80,27) and LR-J-HSMQC(27,80), were developed using the (3beta(x))beta(y) composite 90 degrees pulse sequence. These two experiments were shown to be effective for long-range coupling constants, (n)J(CH), that were greater than 3 Hz. Although the overall sensitivities of the long-range J-HSMQC experiments were slightly lower than that of the conventional decoupled HMBC experiment, their 2D maps showed additional cross peaks that could be useful in structure elucidation. LR-J-HSMQC(27,80) was very efficient in yielding two- and four-bond relay correlations. The utility of the new sequences is demonstrated with strychnine as the sample.
Torres
A M
AM
School of Molecular and Microbial Biosciences, University of Sydney, Sydney, New South Wales 2006, Australia. A.Torres@biochem.usyd.edu.au
Bubb
W A
WA
Kuchel
P W
PW
D019342:Acetic Acid / Q000737:chemistry*; D000179:Acrylates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013331:Strychnine / Q000737:chemistry*
D000179:Acrylates; D013331:Strychnine; C036658:acrylic acid; D019342:Acetic Acid