Cyrmenins, New β-Methoxyacrylate Inhibitors of the Electron Transport Production, Isolation, Physico-chemical and Biological Properties

Abstract

New antibiotic compounds, named cyrmenins, were isolated from the culture broth of strains of the myxobacteria Cystobacter armeniaca and Archangium gephyra. The compounds belong to the group of β-methoxyacrylate (MOA) inhibitors and are the first naturally occuring nitrogen-linked MOAs. The cyrmenins show nearly the same antifungal activity as strobilurin A, but are less toxic in a growth inhibition assay with L929 mouse cells. Cyrmenins inhibit NADH oxidation by submitochondrial particles from beef heart. Investigations by difference spectroscopy showed that cyrmenin B₁ blocks the electron transport within the cytochrome bc₁-segment (complex III) of the respiratory chain.