N-thiolated beta-lactams: a new family of anti-Bacillus agents.

This report describes the evaluation of N-thiolated beta-lactam antibiotics as potential anti-Bacillus agents. N-Thiolated beta-lactams are a new family of antibacterials that previously have been found to selectively inhibit the growth of Staphylococcus bacteria over many other genera of microbes. From the data presented herein, these lactams similarly inhibit a variety of Bacillus species, including Bacillus anthracis. The preliminary structure-activity studies suggest that there is a need to balance the lipophilic character of the C3/C4 groups in order to obtain optimal anti-Bacillus activity. Elongation or extensive branching of the organothio substituent diminishes antibacterial effects, with the sec-butylthio derivative providing the strongest activity.