Synthesis and Structural Identification of Taxifolin Sulfate Conjugates

Taxifolin is a naturally occurring flavonoid widely found in plants and foods. It possesses various biological activities and exhibits low toxicity, making it a promising candidate for the prevention and treatment of various diseases. Moreover, taxifolin metabolites particularly sulfate conjugates are gaining attention as biologically significant compounds. Although taxifolin metabolites can be comprehensively detected, their chemical structures remain unclear. Therefore, in this study, simple synthesis methods are established for these compounds further advance the research on taxifolin sulfate conjugates. Four taxifolin sulfate conjugates were synthesized using taxifolin as the starting material. Taxifolin 3- O -sulfate and 7- O -sulfate were obtained via a stepwise synthesis employing protective groups, and 3′- O -sulfate and 4′- O -sulfate were directly synthesized from taxifolin and isolated using high-performance liquid chromatography. The chemical structures of the sulfate conjugates were subsequently elucidated using NMR and mass spectroscopy.