In this work, we showed that comparison between experimental and theoretical H-1 NMR chemical shift patterns, calculated using Density Functional Theory (DFT), can be used for the prediction of molecular structure of flavonoids in solution, what is experimentally accessible for gas phase (electron diffraction methods) and solid samples (X-ray diffraction). The best match between B3LYP/6-31G(d,p)-PCM H-1 NMR calculations for B ring rotated structures and experimental spectra can provide information on the conformation adopted by polyphenols in solution (usually DMSO-d(6), acetone-d(6) as solvents), which may differ from solid state and gas phase observed structures, and also DFT optimized geometry in the vacuum. (C) 2017 Elsevier B.V. All rights reserved.