Abstract: | The structure-activity in α-alkylthio-cinnamyl penicillins was studied. These penicillins were prepared by condensing 6-aminopenicillanic acid with α-alkylthio-cinnamic acids. α-Methylthxo-cinnamyl penicillin and its substituted analogues were highly inhibitory to Staphylococcus aureus 209P and some of them were also effective in vitro against benzyl-penicillin-resistant Staphylococcus. trans-α-Methylthio-2-bromo-cinnamyl penicillin, which showed a good in vitro activity, was resistant to penicillinase and was stable in acidic aqueous solution. |