Modeling the structure and infrared spectra of omega-3 fatty acid esters

Wenting Meng, Yaoyukun Jiang, Daniel Rothschild, Mark Lipke, Gene Hall, Lu Wang

Research output: Contribution to journalArticlepeer-review

Abstract

Omega-3 dietary supplements provide a rich source of the active moieties eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which exist in the form of triacylglycerols or ethyl esters. Infrared (IR) spectroscopy provides a rapid and quantitative tool to assess the quality of these products as specific normal modes, in particular the ester carbonyl stretch modes, exhibit characteristic spectral features for the two ester forms of omega-3 fatty acids. To uncover the origin of the observed spectra, in this work, we perform molecular dynamics simulations of EPA and DHA ethyl esters and triacylglycerols to characterize their conformation, packing, and dynamics in the liquid phase and use a mixed quantum/classical approach to calculate their IR absorption spectra in the ester carbonyl stretch region. We show that the ester liquids exhibit slow dynamics in spectral diffusion and translational and rotational motion, consistent with the diffusion ordered NMR spectroscopy measurements. We further demonstrate that the predicted IR spectra are in good agreement with experiments and reveal how a competition between intermolecular and intramolecular interactions gives rise to distinct absorption peaks for the fatty acid esters.

Original languageEnglish (US)
Article number035101
JournalJournal of Chemical Physics
Volume153
Issue number3
DOIs
StatePublished - Jul 21 2020

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Modeling the structure and infrared spectra of omega-3 fatty acid esters'. Together they form a unique fingerprint.

Cite this