Complete NMR assignment and conformational analysis of 17-α-ethinylestradiol by using RDCs obtained in grafted graphene oxide

Magn Reson Chem. 2017 Apr;55(4):297-303. doi: 10.1002/mrc.4526. Epub 2016 Oct 11.

Abstract

The 1 H and 13 C NMR spectra of 17-α-ethinylestradiol (EE2), a well-known contraceptive, including diastereotopic methylene groups, were fully assigned with the help of residual dipolar couplings (RDC) measured in the recently developed grafted graphene oxide orienting medium. RDC analysis, which included all 1 DCH couplings and the long-range 2 DCH1 H-C≡13 C coupling, also pointed to the presence of a minor conformation arising from pseudo-rotation of the steroid B ring. Saturation-transfer difference (STD) measurements revealed that the most likely interaction between EE2 and orienting medium occurred on the C and D ring. Copyright © 2016 John Wiley & Sons, Ltd.

Keywords: 13C; 1H; NMR; STD; endocrine disruptors; ethinyl estradiol; grafted graphene oxide; molecular dynamics; prochiral assignment; residual dipolar couplings.

MeSH terms

  • Carbon Isotopes / chemistry
  • Ethinyl Estradiol / chemistry*
  • Graphite / chemistry*
  • Magnetic Resonance Spectroscopy / methods*
  • Models, Molecular
  • Molecular Conformation
  • Molecular Dynamics Simulation
  • Oxides / chemistry*
  • Protons

Substances

  • Carbon Isotopes
  • Oxides
  • Protons
  • Ethinyl Estradiol
  • Graphite