Antibacterial activity of N-phenylmaleimides, N-phenylsuccinimides and related compounds. Structure-activity relationships.

The antibacterial activity of several phyllanthimide analogs were investigated by the Minimum Inhibitory Concentration Method (MIC) against E. coli and S. aureus. It was found that maleimides were approximately 30 times more active than succinimides indicating that the cyclic imido double bond is an important factor related to the activity. Electron-donor and electron-withdrawing substituents in the aromatic ring of N-phenylmaleimides decrease the activity of these compounds indicating the possibility of steric effects. The distance between the aromatic and the imido rings when separated by methylene groups does not affect the antibacterial activity.