4-Hydroxy-2-cyclopentenone: an anti-Pseudomonas and cytotoxic component from Passiflora tetrandra.

4-Hydroxy-2-cyclopentenone is responsible for the anti-bacterial activity of an extract of leaves from Passiflora tetrandra with minimum inhibitory doses (MID) of ca. 10 micrograms/disk against Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa. 4-Hydroxy-2-cyclopentenone is also cytotoxic to P388 murine leukemia cells (IC50 of less than 1 microgram/ml).