Figure 4. NMR spectra of polar fractions.
1H-NMR spectra of the polar fractions: diagnostic signals of the nucleosides adenosine and guanosine are contained in the sonicated fractions, while uridine can only be detected in the fraction that was ground and sonicated with probe head. It shall be noted that, even at 500 MHz, a minimum of 128 scans had to be accumulated in order to achieve sufficient signal/noise for identification of the highly coupled signals of the extract components and for reliable qNMR quantification.