Cyclodextrins as inhibitors of the precipitation of riboflavin-5’-phosphate due to presence of zinc chloride: A NMR investigation

Abstract Several cyclodextrins (CDs) were probed in order to counteract the precipitation of riboflavin-5’-phosphate (or flavin mononucleotide, FMN-P) due to the presence of divalent cations, by exploiting Nuclear Magnetic Resonance (NMR) spectroscopy both for quantitative analyses and stereochemical characterizations. Among CDs, β-cyclodextrin (β-CD) showed the best solubilizing power in virtue of the formation of a 1–2 FMN-P/β-CD complex, the stereochemistry of which was ascertained by ROESY (Rotating-frame Overhauser Enhanced SpectroscopY) measurements.