Susceptibility of complete bacteria and spheroplasts of Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi to rolliniastatin-2.

Rolliniastatin-2 is an acetogenin with elevated cytotoxic activity whose effect on bacteria has not yet been analysed and was isolated by CC from the hexanic extract of Annona diversifolia Saff (Annonaceae) seeds. In this study, we evaluated the susceptibility of Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi as well as spheroplasts of these bacteria to the compound, determining percent inhibition by turbidimetry. The complete bacteria were susceptible to rolliniastatin-2 (28-40% at 2 mg mL(-1)), while spheroplasts showed an increased susceptibility (55-58%, at 1 ng mL(-1)). The most susceptible bacterium was P. aeruginosa, while the spheroplasts of E. coli and S. typhi were most sensitive to the compound's effects.