Solubility, photostability and antifungal activity of phenylpropanoids encapsulated in cyclodextrins

• Enhancement of phenylpropanoids solubility and stability by encapsulation in cyclodextrins.
• Preparation of solid complexes loaded with phenylpropanoids.
• Inhibition of growth and spore germination of phytopathogens by phenylpropanoids.
• Antifungal properties maintained in the presence of cyclodextrins.
• Proposition of ecocompatible alternatives to fungicides and preservatives.

Effects of the encapsulation in cyclodextrins (CDs) on the solubility, photostability and antifungal activities of some phenylpropanoids (PPs) were investigated. Solubility experiments were carried out to evaluate the effect of CDs on PPs aqueous solubility. Loading capacities and encapsulation efficiencies of freeze-dried inclusion complexes were determined. Moreover, photostability assays for both inclusion complexes in solution and solid state were performed. Finally, two of the most widespread phytopathogenic fungi, Fusarium oxysporum and Botrytis cinerea, were chosen to examine the antifungal activity of free and encapsulated PPs. Results showed that encapsulation in CDs significantly increased the solubility and photostability of studied PPs (by 2 to 17-fold and 2 to 44-fold, respectively). Free PPs revealed remarkable antifungal properties with isoeugenol showing the lowest half-maximal inhibitory concentration (IC50) values of mycelium growth and spore germination inhibition. Encapsulated PPs, despite their reduced antifungal activity, could be helpful to solve drawbacks such as solubility and stability.