Structure Elucidation - Statistical Identification of Correlated Signals
The PLS-DA and the corresponding loading plot allowed the identification of one signal at 3.2 ppm as significantly increased for the samples of group 2 and group 3, but no further significantly changed signals could be identified. A special method called PLS-STOCSY developed by Dieterle et al. was applied, as this method allows identifying signals belonging to the same metabolite even if the signals differ significantly in terms of intensity and even if the signals are overlapped by other signals. PLS-STOCSY assigned the signals at 3.52 ppm and at 4.08 ppm to the same metabolite as the signal at 3.2 ppm.
Result of PLS-STOCSY for the data of the ranking study. Signals at 4.08 ppm and 3.52 ppm were assigned to the same metabolite as the signal at 3.2 ppm.