Strategy for the vibrational circular dichroism study of a glycosylflavonoid evaluated as its peracetate. The case of bioactive 7-O-β-D-glucopyranosylchrysin

As it is difficult to study polyhydroxylated natural products by vibrational circular dichroism (VCD) due to their very limited solubility in infrared transparent solvents, 7-O-β-D-glucopyranosylchrysin (1), isolated from Mimosa rosei, was acetylated to provide 7-O-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetraacetyl-β-D-glucopyranosyl)-5-acetylchrysin (2). Density functional theory (DFT) VCD spectra of 2 were calculated using the B3LYP, B3PW91, and PBEPBE functionals...