[Isolation of an antibacterial active tropolone from a Pseudomonas cepacia strain].

In the strain ATCC 17759 of Pseudomonas cepacia a highly antibacterial active substance was found, which could be identified as the tropolone bis-(3-hydroxy-2-oxocyclo-heptatrien-(3,5,7)-yl)-sulfide. This data confirm that tropolones are not only found in plants like western red cedars, but are also occurring as metabolites in bacteria. At least in Pseudomonas cepacia there seems to be an interesting reciprocal correlation between the production of tropolones and of phenacines. The purified tropolone showed a broad antibacterial activity spectrum against gram-positive and gram-negative microorganisms. The MIC-values were situated between 12.5 and greater than 100,0 microgram/ml.