N-Demethylcelesticetin and N-demethyl-7-O-demethylcelesticetin are antibacterial agents produced by Streptomyces caelestis strain 22218a, a mutant of S. caelestis. As in the case of celesticetin, both antibiotics are active mainly against Gram-positive organisms. The present paper describes the production, isolation and properties of two celesticetin-related antibiotics produced by another mutant of S. caelestis designated strain 22218a.