The nature of phosphorylated chrysin-protein interactions involved in noncovalent complex formation by electrospray ionization mass spectroscopy.

In the work described in this paper, chrysin was phosphorylated by a modified Atheron-Todd reaction. The structure of phosphorylated chrysin was determined by elemental analysis, NMR, ESI-MS/MS, and X-ray data. Electrospray ionization results showed that the phosphorylated flavonoids could form noncovalent complexes with many proteins, such as lysozyme, myoglobin, bovine insulin, and cytochrome c, while noncovalent complexes were not detected in the mixed solution of the chrysin and proteins. The research shows that the phosphorylated flavonoids possess relatively stronger affinities and form noncovalent complexes with the proteins more easily than the non-phosphorylated compounds.