1H,1H 2D COSY
1H,13C 2D COSY
Analytical Chemistry and Spectroscopy
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
All-trans-(9′Z,11′Z)-(3R,3′S,5′R,6′R)-Pyrrhoxanthin was isolated from a natural bloom of dinoflagellates (mainly Ceratium spp.) and submitted to detailed 1H NMR and 13C NMR analysis, including homonuclear COSY (2D), ROESY (1D and 2D), TOCSY (1D) and 1H-detected one-bond and multiple-bond 1H, 13C COSY. All chemical shifts and coupling constants in the 1H NMR spectrum and all carbons in the 13C NMR spectrum were assigned. The result is consistent with the structure, previously deduced, including relative configuration. A recently proposed variant of the ROESY pulse sequence, called T-ROESY, claimed to suppress undesired TOCSY transfer, provided excellent results free of TOCSY artifacts caused by coherent magnetization transfer via J coupling pathways independent of the choice of the position of the carrier frequency.
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