Description
The conformational preferences and hydrogen-bonding motifs of several potential chemopreventive
hydroxycinnamic derivatives were determined by inelastic neutron scattering spectroscopy. The aim is to
understand their recognized beneficial activity and establish reliable structure–activity relationships for these
types of dietary phytochemicals. A series of phenolic acids with different hydroxyl/methoxyl ring substitution
patterns were studied: trans-cinnamic, p-coumaric, m-coumaric, trans-caffeic and ferulic acids. Their INS
spectra were completely assigned by theoretical calculations performed at the Density Functional Theory
level, for the isolated molecule, dimeric centrosymmetric species and the solid (using plane-wave expansion
approaches). Access to the low energy vibrational region of the spectra enabled the identification of particular
modes associated with intermolecular hydrogen-bonding interactions, which are the determinants of the
main conformational preferences and antioxidant capacity of these systems. The authors are thankful for financial support from the Portuguese
Foundation for Science and Technology – PEst-OE/QUI/UI0070/
2014. The INS work was supported by the European Commission
under the 7th Framework Programme through the Key Action:
Strengthening the European Research Area, Research Infrastructures.
Contract no. CP-CSA_INFRA-2008-1.1.1 Number 226507-
NMI3.
; Batista de Carvalho, Luís A. E. 
