Tetrahydrocurcumin encapsulation in cyclodextrins for water solubility improvement: Synthesis, characterization and antifungal activity as a new biofungicide

The solubility of the scarcely water-soluble molecule tetrahydrocurcumin (THC), a promising curcumin derivative to be used as biopesticide, was enhanced through formation inclusion complexes with different cyclodextrins (CDs). Randomly methylated β-cyclodextrin (MeβCD) gave best results among CDs whose size, substituent or structure changing. Differential scanning calorimetry well 1H- and 2D-Nuclear Magnetic Resonance (NMR) proved THC in MeβCD. Rotating-frame Overhauser effect spectroscopy NMR especially illustrated specific interactions aromatic protons located inside CD cavity. complex between MeβCD studied using Higuchi Connor method, giving an association constant 591 M−1. THC-loaded did not show any growth inhibition target fungus Fusarium graminearum. However, polymers exhibited 25% fungal growth, thus making them material for solvent-free, aqueous bio-based fungicide formulations.