Variable-temperature ¹H-NMR studies on two C-glycosylflavones

Molecules. 2012 Jul 2;17(7):7914-26. doi: 10.3390/molecules17077914.

Abstract

Two known C-glycosylflavones, swertisin and embinoidin, were isolated from the leaves of Anthurium aripoense, and characterized by room temperature 1D and 2D NMR experiments. At this temperature, the ¹H- and ¹³C-NMR spectra of these C-glycosylflavones revealed doubling of signals, which suggested the presence of two rotamers in solution. Variable-temperature (VT) ¹H-NMR studies supported this hypothesis. The T-ROESY data, in addition to the theoretical (MM2) calculations utilizing the Chem3D Pro software, confirmed the hypothesis that the two rotamers interchange via rotation about the C-glycosidic bond.

MeSH terms

  • Apigenin / chemistry
  • Flavones / chemistry*
  • Isomerism
  • Magnetic Resonance Spectroscopy*
  • Models, Molecular
  • Protons*
  • Temperature*

Substances

  • Flavones
  • Protons
  • swertisin
  • Apigenin