*2.4. Analysis of Aqueous Extracts by 1H NMR Spectroscopy*

One-dimensional (1D) 1H spectra were obtained using a 600 MHz Avance III NMR spectrometer (Bruker) with a QCI-P cryoprobe with experiments measured at an calibrated temperature of 298K. Temperatures were calibrated using the residual protonated peaks from MeOH in a D4-MeOH sample to avoid radiation damping effects from the high Q value of the QCI-P cryoprobe used [26,27]. For each sample, the spectrometer was locked to D2O and the experiments were measured automatically using ICON NMR and a set of custom macros. Calibrations were carried out for each sample using a short excitation sculpting experiment; these included automated tuning and matching, measurement of the water offset and 90◦ pulse calibration, which was made using the stroboscopic nutation

method of Wu and Otting [28]. The soft pulse power levels were calculated based on attenuated values calculated from the 90◦ pulse. The receiver gain measured for each sample and was limited to a maximum value of 128. A 1D-1H NOESY 100 ms mixing time was run. Data were accumulated over 512 scans with eight dummy scans. A spectral width of 12.02 ppm (7211 Hz) was used, and 32,768 data points were acquired, giving an acquisition time of 2.27 s. Acquisitions were separated by a relaxation delay of 3 s. The relaxation delay was increased, and the acquisition time decreased to provide sufficient water suppression.
