title: Antibacterial activity of penicillin. I. The nature of the activity of different acyl derivatives of 6-aminopenicillanic acid.
mesh_terms: D004926:Escherichia coli / Q000187:drug effects*; D066298:In Vitro Techniques; D010406:Penicillins / Q000494:pharmacology*; D013210:Staphylococcus / Q000187:drug effects*
chemical_list: D010406:Penicillins