SQ 30,957, a new antibiotic produced by Penicillium funiculosum. Taxonomy, fermentation, isolation, structure...

A new antibiotic, SQ 30,957, 4-diazo-3-methoxy-2,5-cyclohexadien-1-one, has been isolated from fermentation broths of Penicillium funiculosum. The structure (1) was deduced from its spectroscopic properties and its degradation reaction. SQ 30,957 has excellent activity against anaerobic bacteria such as Clostridium and Bacteroides and has moderate activity against aerobic bacteria. The compound has an LD50 of less than 17 mg/kg in mice by intraperitoneal administration.