Exploring the mechanism of flavonoids modification by dimerization strategies and their potential to enhance biological activity.

Flavonoid dimers are being focused due to their particular structure that links two units through CC or C-O-C bonds. This paper provides a comprehensive and systematic overview of the reaction mechanism of flavonoid dimerization and discusses their synthesis process and methods to devise an ideal preparation scheme of flavonoid dimers. Given the polyphenolic hydroxyl groups of dimerized flavonoids as well as their unique bridging molecular structures, we preliminarily explored the link between conformation and function, and discovered their several reinforced bioactivities compared to flavonoid monomers, such as hypolipidemic, antidiabetic, and neuroprotective activities as well as other potential. In contrast to monomer, luteolin dimer demonstrated the remarkably higher activity in inhibiting α-amylase, α-glucosidase and the growth of A. niger (IC50: 0.86 μM), which is even comparable to acarbose and amphotericin B. Therefore, dimerization strategy represents a promising method for structural modification of flavonoid to potential applications in food supplements or pharmaceuticals.