Title : Cocrystal Formation of Natural Flavonoids Synthesis, Physico Chemical Assessment, Antioxidant and Spectroscopic Studies
In recent years, special interest in the prevention and treatment of many civilization diseases is caused by polyphenol compounds that are widespread in the plant world. Dietary flavonoids exert various biological activities like cardioprotective, chemopreventive, and neuroprotective effects which are attributed to their antioxidant, anti-inflammatory, and signaling properties. However, their poor solubility in aqueous solutions and the associated limited bioavailability exclude the development of effective and stable pharmaceutical formulations or dietary supplements. A number of methods are known to improve the pharmacokinetic profile of bioactive compounds, for example, using salts, amorphous dispersions in a polymer matrix, an inorganic matrix as a carrier, nanoparticles, and cocrystals. Especially, crystal engineering and cocrystallization techniques appear as a promising way to modify the bioavailability (e.g., solubility, permeability, and stability) and other physicochemical properties for a wide range of bioactive compounds. Cocrystals are single phase materials composed of two or more different molecular and/or ionic compounds generally in a stoichiometric ratio, bound by noncovalent interactions, predominantly hydrogen bonds, which are neither solvates nor simple salts.
The aim of the presentation is to show the results including the development of the synthesis of new crystalline forms of (-)-epicatechin, (+)-catechin and cardamonin with commonly used coformers which are included in the list of compounds authorized for the safe use as additives to food products, pharmaceutical preparations, and dietary supplements. The chemical characteristics of the obtained cocrystals were confirmed by single crystal X-ray diffraction, FTIR, and Raman techniques. Structural studies were based mainly on the analysis of interactions occurring in the molecular structure, e.g. hydrogen bonds, π···π interactions and supramolecular synthons.