Streptoxamine, an unprecedented benzoisoindole-deferoxamine hybrid from the locust-derived Streptomyces sp. HKHCa2.

An unusual benzoisoindole-deferoxamine hybrid, streptoxamine (1), has been isolated from the ethyl acetate crude extract of the fermentation broth of a locust-associated actinomycete, Streptomyces sp. HKHCa2, which was isolated from an insect, Oxya chinensis. The structure of this secondary metabolite was elucidated on the basis of its one-dimension, two-dimension NMR, and mass spectroscopic data. This natural product features a hybrid pattern of a benzoisoindole with an “iron carrier” deferoxamine B through C-N linkage. Compound 1 showed weak antibacterial activity against the gram-positive bacteria, Staphylococcus aureus and Mycobacterium smegmatis.