## 3 Results and Discussion
### Docking Analysis  
#### 3.2.1 Molecular Interactions between CYP 3A4 (1 TQN PDB ID) and AFB1, B2, G1, and G2  
Table 2 summarizes the outcome of the dockings between the aflat B1, B2, G1, and G2 with the protein CYP3A4. The docking results between 1 TQN and the AF were used to analyze the main differences in the active site, as different methodologies were used in the initial geometry optimization of the aflat (see Scheme 1). The computations showed no significant differences when using the functional M06-2X or B3 LYP in the determination of the AF molecular geometries. However, the results of the binding energy indicated that this energy was more stable when the M06-2X functional was used.  
In agreement with the calculations, the structural difference between aflat B and G could be responsible for the hydrogen bond formation--that is, for the hydrogen bond with the oxygen atom belonging to the second lactone ring of the G group (See Figure 2) and those with the residues of the active site. This significant behavior was not observed in the B group.  
Figure 3 shows the interaction types obtained with the docking calculations. It is important to note that the B group stability is determined only by \(\pi\)-\(\pi\) interactions, which are indicated by yellow tubes. Furthermore, the G group presented hydrogen bonds and fewer \(\pi\)-\(\pi\) interactions. The hydrogen bonds are indicated with green dotted lines in Figure 3.  
A cation-\(\pi\) interaction between Arg 105 and the C17 atom of aflat B1 and B2 was found. This interaction was observed with both functionals, M06-2X and B3 LYP. The orientation of the best conformation also differs between groups (see Figure 3). In aflat B1 and B2, the HEM group of CYP3A4 attracts the oxygen atom of the lactone and pentone rings, making a planar conformation  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Ligand**} & **DFT** & **Binding** & & & \\  & **Functional/** & **Energy** & **Active Site** & **Bonds** & **Interactions** \\ \hline \multirow{4}{*}{AFB1} & \multirow{2}{*}{B3 LYP} & \multirow{2}{*}{\(-8.53\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Thr309, Ala370, Arg372, Leu373, & 0 & 5 \\  & & & Glu374, HEM508 & & & \\ \cline{2-6}  & \multirow{2}{*}{M06-2X} & \multirow{2}{*}{\(-8.78\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Thr309, Ala370, Arg372, Leu373, & 0 & 5 \\  & & & Glu374, HEM508 & & & \\ \hline \multirow{4}{*}{AFG1} & \multirow{2}{*}{B3 LYP} & \multirow{2}{*}{\(-8.44\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Ala370, Arg372, Leu373, Glu374, & & 22 \(-\) O5 & \\  & & & & HEM 508 & Ser119 – O7 & \\ \cline{2-6}  & \multirow{2}{*}{M06-2X} & \multirow{2}{*}{\(-8.70\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Ala370, Arg372, Leu373, Glu374, & & 21 \(-\) O5 & \\  & & & HEM 508 & Ser119 – O7 & 2 \\ \hline \multirow{4}{*}{AFB2} & \multirow{2}{*}{B3 LYP} & \multirow{2}{*}{\(-8.77\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Thr309, Ala370, Arg372, Leu373, & 0 & 5 \\  & & & Glu374, HEM508 & & \\ \cline{2-6}  & \multirow{2}{*}{M06-2X} & \multirow{2}{*}{\(-8.86\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Th309, Ala370, Arg372, Leu373, & 0 & 5 \\  & & & Glu374, HEM508. & & \\ \hline \multirow{4}{*}{AFG2} & \multirow{2}{*}{B3 LYP} & \multirow{2}{*}{\(-8.40\)} & Arg105, Ser119, Arg212, Ala305, & & \\  & & & Ala370, Arg372, Leu373, Glu374, & & 22 \(-\) O5 & \\ \cline{1-1} \cline{2-6}  & \multirow{2}{*}{M06-2X} & \multirow{2}{*}{\(-8.39\)} & Arg105, Ser119, Arg212, Ala305, & & Ser119 – O7 & \\ \cline{1-1}  & & & Ala370, Arg372, Glu374, HEM508 & & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Analysis of the molecular interactions between CYP3A4 (1 TQN PDB ID) and aflat provided by molecular docking simulations.  
promoting \(\pi\)-\(\pi\) interactions, while in the G group the same oxygen atom interacts with the residues of the active site.