IB-00208, a new cytotoxic polycyclic xanthone produced by a marine-derived Actinomadura. I. Isolation of the strain, taxonomy and biological activites.

A new compound, IB-00208, has been isolated from the fermentation broth of an actinomycete isolated from a marine environment. The strain was identified as Actinomadura sp. by its chemical and phylogenetic characteristics. The compound shows cytotoxic activity on tumor cell lines and bactericidal activity against gram-positive bacteria.