TQF-COSY

For the determination of the sequence and substitution positions of the different monosaccharides of a saponin, a series of proton and carbon 2D-NMR techniques can provide valuable information about the usually crowded regions of the conventional ID spectra. Thus, integrated approaches including ID or 2D H- H homonuclear NMR shift-correlation experiments (DQF- and TQF-COSY, TOCSY or HOHAHA, NOESY, ROESY or CAMELSPIN), and H-detected H-,3C heteronuclear shift correlation (HMQC, HMBC) have proved to be extremely useful. 

The TQF IR COSY enhances the cross peak structure, but again reduces the intensity of diagonal peaks such that even doublet diagonal peaks might decrease to a very low intensity. The TQF is achieved by using an extended phase cycling program as shown in the Check it 5.4.1.4(b). 

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