  One of the strategies in combating COVID-19 consists of virtual screening for
possible inhibitors for the attachment of SARS-CoV-2 Spike receptor-binding
domain (RBD) to the human ACE2 receptor. Here, we performed a molecular docking
study to propose potential candidates to prevent the RBD/ACE2 attachment. These
candidates are sixteen different flavonoids present in the peppermint leaf.
Results showed that Luteolin 7-O-neohesperidoside is the peppermint flavonoid
with a higher binding affinity regarding the RBD/ACE2 complex (about -9.18
Kcal/mol). On the other hand, Sakuranetin was the one with the lowest affinity
(about -6.38 Kcal/mol). Binding affinities of the other peppermint flavonoids
ranged from -6.44 Kcal/mol up to -9.05 Kcal/mol. The biding site surface
analysis showed pocket-like regions on the RBD/ACE2 complex that yield several
interactions (mostly hydrogen bonds) between the flavonoid and the amino acid
residues of the proteins. This study can open channels for the understanding of
the roles of flavonoids against COVID-19 infection.
