Quorum sensing (QS), used by many pathogenic bacteria to express virulence factors, is seen as a new and effective strategy to combat resistant bacteria. In this study, theoretical investigations were made on the structural data of molecules to support the inhibition effects of 2-amino 4-chloro benzoic acid and 4-amino 2-chloro benzoic acid molecules. Theoretical calculations were performed by using the density functional theory with the B3LYP function and aug-cc-pVDZ basis set in the gas phase of the isolated compounds in the ground state. The biological activities of the related compounds were theoretically investigated against Covid-19 protein (PDB ID: 6LU7).