Molecular Docking study of the flavonoids quercetin and artemetin front the angiotensin-converting enzyme

Phenolic compounds, such as flavonoids, have aroused great scientific interest due to their diverse pharmacological activities, such as antioxidant, anti-inflammatory, anticancer and antihypertensive, among others. Several studies suggest the mechanisms responsible for the antihypertensive activity of flavonoids, and among them is the inhibitory activity of the angiotensin-converting enzyme (ACE). Thus, the objective of the present study was to perform a molecular docking study of flavonoids quercetin and artemetin against ACE, aiming at a better understanding of the interaction of these flavonoids with the enzyme. The crystallographic structure of the enzymatic target ACE was obtained from the Protein Data Bank database [PDB: 1UZE]. The molecular docking study was performed using Autodock 4.0 software. Gasteiger charge and polar hydrogens needed for the power calculations were added to the enzyme, with the water molecules removed. The grid was positioned in the catalytic region of the enzyme with dimensions on the X-, Y- and Z-axis at 32 Å 30 Å and 38 Å, respectively, spacing 0.375 Å. The Lamarckian Genetic algorithm was chosen to search for the best conformations with 100 runs for each binder. During the search, the enzyme was held rigid and the ligands were kept flexible. Both artemetin and quercetin interacted with the active site of the enzyme attractively. With docking energy at -6.89 kcal/mol, artemetin was more stable in complex with the active site of the enzyme ACE, whereas quercetin presented docking energy at - 6.63 kcal/mol. Both ligands interacted by hydrogen bonds with amino acids GLU 384, TYR 520, HIS 513, HIS 353, GLN 281, LYS 511 and the Zn ion. The study showed that the methodology used in the present study can be well used for the understanding of the interaction of pharmacologically active compounds with target enzymes, saving time and resources.