Streptopyrrole: An antimicrobial metabolite from Streptomyces armeniacus

A colourless, crystalline metabolite, C14H12ClNO4, named streptopyrrole, has been isolated from submerged fermentation cultures of Streptomyces armeniacus by extraction, followed by chromatographic purification. Its tricyclic molecular framework, seemingly without natural product precedents. as well as its substitution pattern were derived from extensive NMR analysis including H-1-detected INADEQUATE experiments. Streptopyrrole exhibits weak growth inhibitory effect towards a broad range of microorganisms.