## 3 Results and Discussion
### Interaction Mechanism between Peptides and Esters  
In order to gain a deeper understanding of how peptide-esters and peptide-alcohol complexes interact in simulated solutions, it is imperative to investigate the interaction between peptides and esters or alcohols by determining the equilibrium constant and thermodynamic parameters [51]. As illustrated in Table 2, the binding abilities of different peptides with ethyl acetate and ethyl lactate vary. The binding ability between the peptide and ethyl acetate was as follows: PA > PV > GSH > DF > PL > GL. Similarly, the binding ability between the peptide and ethyl lactate was as follows: GSH > PA > GL > PL > PV > DF. This indicates that the peptide PA exhibited the strongest binding affinity for ethyl acetate, whereas the peptide GL exhibited the weakest binding affinity for ethyl acetate. The peptide GSH exhibited the strongest binding affinity for ethyl lactate, and the peptide DF exhibited the weakest binding affinity for ethyl lactate. Meanwhile, the equilibrium constants of the same peptide for various esters were compared. For instance, the equilibrium constants for peptide PA, ethyl acetate, and ethyl lactate were 82.0, 73 mol/L, and 621.37 mol/L, respectively. This suggests that the effect of the same peptide on various ester compounds varied depending on the mechanism of action. By determining the enthalpy and entropy changes of peptides at various temperatures, we were able to gain a better understanding of the specific sorts of contact forces involved. [PERSON] [26] evaluated the thermodynamic characteristics of the interaction between peptides and volatile compounds in order to ascertain their mechanism of interaction. The interactions between PA, PV, and PL with ethyl acetate and ethyl lactate can be ascribed to van der Waals forces or hydrogen bonds. In the same way, the connections between GL and DF with ethyl acetate are influenced by hydrophobic contacts, but the connections between GL and DF with ethyl lactate are influenced by van der Waals forces or hydrogen bonding. Furthermore, the interactions involving GSH with ethyl acetate and ethyl lactate are likewise characterized by hydrophobicity. The interactions between small-molecule compounds and peptides mostly include weak intermolecular forces, such as hydrogen \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **PA** & **PV** & **GL** & **DF** & **PL** & **GSH** \\ \hline K\({}_{1}\) (mol/L) & 820.73 & 783.37 & 136.03 & 230.44 & 180.71 & 250.38 \\ K\({}_{2}\) (mol/L) & 621.37 & 237.25 & 303.89 & 178.39 & 284.24 & 1087.33 \\ \(\Delta\)G\({}_{1}\)\({}^{0}\) (KJ/mol) & \(-\)16.62 & \(-\)16.51 & \(-\)12.17 & \(-\)13.48 & \(-\)12.87 & \(-\)13.68 \\ \(\Delta\)G\({}_{2}\)\({}^{0}\) (KJ/mol) & \(-\)15.93 & \(-\)13.54 & \(-\)14.15 & \(-\)12.84 & \(-\)13.99 & \(-\)17.32 \\ \(\Delta\)H\({}_{1}\)\({}^{0}\) (KJ/mol) & \(-\)35.52 & \(-\)24.02 & 5.36 & 5.85 & \(-\)25.22 & 19.8 \\ \(\Delta\)H\({}_{2}\)\({}^{0}\) (KJ/mol) & \(-\)26.67 & \(-\)48.75 & \(-\)24.84 & \(-\)26.01 & \(-\)32.03 & 6.35 \\ \(\Delta\)S\({}_{1}\)\({}^{0}\) (J/mol) & \(-\)63.42 & \(-\)7.51 & 58.8 & 64.86 & \(-\)41.44 & 112.3 \\ \(\Delta\)S\({}_{2}\)\({}^{0}\) (J/mol) & \(-\)36.04 & \(-\)35.21 & \(-\)35.87 & \(-\)44.16 & \(-\)60.04 & 79.42 \\ \hline \hline \end{tabular} Where K\({}_{1}\), \(\Delta\)G\({}_{1}\)\({}^{0}\), AH\({}_{1}\)\({}^{0}\), AS\({}_{1}\)\({}^{0}\) represents the thermodynamic parameters of peptide and ethyl acetate, K\({}_{2}\), \(\Delta\)G\({}_{2}\)\({}^{0}\), AS\({}_{2}\)\({}^{0}\) represents the thermodynamic parameters of peptide and ethyl lactate.  
\end{table} 
Table 2: Thermodynamic parameters of the interaction between peptides and esters. bonding, Van der Waals forces, electrostatic forces, and hydrophobic forces [51; 52]. This is similar to the result of [PERSON] [32], who demonstrated that a cyclic peptide largely interacts with 4-ethylguaiacol via hydrogen bonding. Specifically, the C=O group can attach to OH-, and the amino acid residues in the peptide may create hydrogen bonds with the hydroxyl group.