Advancements in Penicillin Resistance: The Discovery and Characteristics of Quinacillin

Researchers have synthesized a modified penicillin compound to combat staphylococcal infections resistant to traditional penicillin. This compound, (carboxymethyl)phenylbenzylpenicillin, has shown effectiveness against different levels of penicillin resistance in Staphylococcus aureus, with the minimum inhibitory concentration varying accordingly.

In addition to this, various semisynthetic penicillins were evaluated for their inhibitory concentrations against the same bacteria. A range of side chain acids were tested, with each showing different levels of effectiveness.

The synthesis of a specific derivative, 3-carboxy-2-quinoxalinecarbonylpenicillin (quinacillin), was detailed. It was prepared through a chemical reaction and resulted in a salt that was characterized by its melting point and optical rotation.

Further, the aqueous solution of this salt was treated to yield the final product, which was characterized by its appearance, melting point, and water content. The anhydrous form of the compound was also described, noting its hygroscopic nature and stability.

Testing the bacteriostatic activity of the compound in various agar media showed a range of minimum inhibitory concentrations against several bacterial species, indicating its potential effectiveness.

Lastly, the compound's activity was compared to benzylpenicillin against clinical strains of S. aureus, demonstrating its superior performance at inhibiting bacterial growth. The minimum inhibitory concentrations of some of its derivatives were also provided.