Nucleoside 2',3'-Cyclic Monophosphates in Aphanizomenon flos-aquae Detected through Nuclear Magnetic Resonance and Mass Spectrometry.

Aphanizomenon flos-aquae (AFA) cyanobacteria from Klamath Lake (Oregon) are considered a "superfood" due to their broad nutritional profile that has proved to have health-enhancing properties. The AFA metabolome is quite complex. Here, we present a study that, combining multinuclear 1H, 31P, and 13C Nuclear Magnetic Resonance (NMR) spectroscopy and high-resolution mass spectrometry, led to the detection of uncommon phosphorylated metabolites in AFA. We focused our attention on 31P NMR signals at 20 ppm, a chemical shift that usually points to the presence of phosphonates. The molecules contributing to 20 ppm 31P NMR signals revealed, instead, to be nucleoside 2',3'-cyclic monophosphates. These metabolites were fully characterized by multinuclear 1H, 31P, and 13C NMR spectroscopy and high-resolution mass spectrometry.