Quantum Chemistry Research About The Interaction Of Ceramide With F~- And Na~+ Separately

Objective:As ceramide occupies an important place in the skin cutin layer and cell membrane,so add the typical monovalent irons F- and Na+ into the ceramide dimers to simulate ion-molecular interaction between amide molecule(N-(hydroxymethyl)-acetamide, named as “ha”) dimers with F- and Na+, and inspect the cooperativity effect of F-, Na+ and ceramide dimers, respectively. Then discuss the effect of cooperativity effect on ion-drugs transdermal absorption and other relevant physiological processes.Methods:The ceramide(N-(hydroxymethyl)-acetamide, named as “ha”)selected as model molecule, F- and Na+ were added into the ceramide dimers to form trimer compound,respectively. Quantization method is used to determine the structure parameters of complex,energy and thermodynamics parameters, etc. First, using Gaussian View softwaret to make the model structure of the ceramide, and transform the structure in; Secondly, under the level of HF/6-311G** to primary optimize, then to get the optimal structure under the B3LYP/6-311++G** level to senior optimize for single and compounds again; Finally, at the level of B3LYP/6-311++G** and MP2/6-311++G**, compute the structure parameters and thermodynamic parameters of complex, and analyzed the AIM, the interaction energy,surface electrostatic potential analysis and thermodynamics analysis, etc. The cooperativity effects between the O/N–H???F- anionic hydrogen-bonding and O/N–H???O hydrogenbonding interactions and electrostatic potentials in the1:2(F-:N-(Hydroxymethyl)acetamide(signed as “ha”)) ternary systems are investigated,and the cooperativity effects between the O/N–H???O hydrogen-bonding and Na+???O cation-molecule interactions in the “Na+???ha???ha” systems were investigated, respectively.Results:The study showed that there is positive cooperativity effect between O/N-H???F- and O/N-H???O interaction, and the negative cooperativity effect exists in only O/N-H???F-hydrogen bond or form N-???H-F hydrogen bond of "FH???ha???ha" complex. AIM analysis and electron density can verify the existence of the negative cooperativity effect. In“Na+???ha???ha” system, the O/N-H???O and Na+???O interactions are reduced, lead to the negative cooperativity effect, especially the compounds only exist Na+???O interaction.Transfer electron density and favorable enthalpy change contribution can prove the existence of the negative cooperativity effect. These results suggest that the ternary complex is more easily formed by the pathway in which Na+ binds to “ha???ha” than that formed by the pathway in which another ceramide add to “Na+???ha” binary system.Conclusions:The artical reveals the nature of cooperativity effect between ion-molecular interactions and hydrogen bonding interaction of F-, Na+ interact with ceramide-binary system, respectively. To clarify F-, Na+and other ions-drugs on the processes of percutaneous penetration, getting into cell membrane to play efficacy and other relevant physiological processes provides the theoretical foundation.