Structural Evaluation and Toxicological Study of a Bitter Masking Bioactive Flavanone, ‘Eriodictyol’

A computational structural analysis of a bitter masking flavonoid, eriodictyol, has been performed under DFT/B3LYP level of theory and 6-31 + G (d, p) as basis set. The molecule has a band gap of 4.38 eV and has absorption characteristics in the UV-B region so that it can be used as a UV-B filter. A detailed NMR (13C NMR and 1H NMR) analysis and that of spin-spin coupling constant (J) values are reported. The EFG tensor values of all the nuclei in the molecule are evaluated. The lowest energy conformer obtained from the Potential Energy Scanning has been employed for spectral analysis including IR, Raman, UV-Visible, and NMR. The computed 13C NMR and 1H NMR spectra efficiently explain the structure of eriodictyol. The J values of CH coupling are found to be the highest and that of OH coupling is found to be negative. The EFG values increase with the electronegativity of the attached atom/group. Since most of the studies are reported on the derivatives of eriodictyol, a detailed structural analysis of the parent molecule is particularly important. As eriodictyol is bioactive, knowledge about its structure will be useful in explaining the mechanisms of bioactivity it has shown and also the EFG studies are highly relevant in the study of complex formation of eriodictyol with transition metals. The toxicological analysis shows that eriodictyol is nontoxic, nonmutagenic, nontumorigenic, and nonirritant. The positive drug score indicates that eriodictyol can be used as a potential drug. The NMR spectroscopic analysis can be extended in future to study the interactions of eriodictyol-protein complexes.