Benzanthrins A and B, a new class of quinone antibiotics. I. Discovery, fermentation and antibacterial activity.

Nocardia lurida has been shown to produce two novel quinone antibiotics, benzanthrins A and B. The antibiotics were discovered in concentrated butanol extracts of fermentation broths and were separated by TLC and HPLC. Benzanthrins A and B were produced in a fermentation medium consisting of glucose, yeast, selected peptones and CaCO3. The antibiotics were present primarily at 66 hours in shake flask fermentations and from 66 to 162 hours in 14-liter fermentors. Benzanthrins A and B inhibited a number of Gram-positive pathogenic bacteria but were inactive against Gram-negative bacteria.