Interactions of chlorogenic acid and isochlorogenic acid A with model lipid bilayer membranes: Insights from molecular dynamics simulations

Because of the negative side-effects of synthetic preservatives, the naturally-occurring polyphenols aroused intense interest of researchers. It has been suggested that chlorogenic acid (CA) and isochlorogenic acid A (iso-CAA) were good candidates to replace the synthetic preservatives. Moreover, the bactericidal activity of iso-CAA was stronger than CA, and the anti-bacterial activities of iso-CAA and CA were highly membrane-dependent. However, the mechanisms were still unclear. Therefore, in the present study, we investigated the mechanisms of the interactions between the two polyphenols and lipid bilayers through molecular dynamics simulations. The results revealed that iso-CAA could be inserted much deeper into POPG lipid bilayer than CA. We also found that hydrophobic interactions and hydrogen bonds both contributed to the insertion of iso-CAA into the POPG lipid bilayer, and the quinic acid moiety was the key structure in iso-CAA to form hydrogen bonds with POPG lipid bilayer. We believed that these findings would provide more useful information to explain the stronger bactericidal activity of iso-CAA than CA at the atomic level. [Display omitted] •Mechanisms of the interaction of iso-CAA and CA with the bilayers were studied by MD.•iso-CAA could be inserted much deeper into POPG lipid bilayer than CA.•Hydrophobic interactions and h-bonds contributed to the insertion of iso-CAA into POPG bilayer.•Quinic acid moiety was the key structure to form h-bonds with POPG bilayer.