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Rapid acquisition of 1 H– 13 C and 1 H– 15 N heteronuclear chemical shift correlation data at the submilligram level using SMIDG (submicro inverse‐detection gradient) NMR probe technology
Author(s) -
Martin Gary E.,
Hadden Chad E.,
Tackie Albert N.,
Sharaf Maged M. H.,
Schiff Paul L.
Publication year - 1999
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/(sici)1097-458x(199908)37:8<529::aid-mrc486>3.0.co;2-5
Subject(s) - heteronuclear molecule , chemistry , chemical shift , carbon 13 nmr , inverse , analytical chemistry (journal) , heteronuclear single quantum coherence spectroscopy , correlation , homonuclear molecule , two dimensional nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , nuclear magnetic resonance spectroscopy , molecule , chromatography , stereochemistry , physics , organic chemistry , mathematics , geometry
The application of submicro inverse‐detection gradient (SMIDG) NMR probe technology at 600 MHz is demonstrated for the rapid acquisition of both 1 H– 13 C and 1 H– 15 N heteronuclear chemical shift correlation data. Using a 750 µg ( ca 1.5 µmol, MW 505) sample of the complex spirononacyclic alkaloid cryptospirolepine, the acquisition of 1 H– 13 C direct correlation GHSQC data is possible as rapidly as 34 s. Fully resolved GHSQC data are accessible in < 5 min. The acquisition of well digitized 1 H– 13 C long‐range heteronuclear shift correlation data (GHMBC) in 16 min is demonstrated. The acquisition of 1 H– 15 N direct heteronuclear shift correlation data at natural abundance with ca 15 : 1 signal‐to‐noise ratio is possible in < 50 min despite the inherently much lower sensitivity of 15 N relative to 13 C as a structural probe. Finally, long‐range correlations to three of the four nitrogens in the alkaloid are identified in a 1 H– 15 N long‐range (GHMBC) spectrum acquired overnight. The ability to characterize rapidly the chemical structures of submilligram sample quantities using rigorous heteronuclear shift correlation methods realistically offers the possibility of employing heteronuclear correlation techniques for the first time in the characterization of compounds with limited solution stability at the submilligram level. Copyright © 1999 John Wiley & Sons, Ltd.