Piericidins C7 and C8, new cytotoxic antibiotics produced by a marine Streptomyces sp.

Piericidins C7 and C8, two new members of the piericidin family, were isolated from a marine actinomycete. The producing organism was identified as Streptomyces sp. based on the cultural, biochemical and chemotaxonomical characteristics as well as the 16S rRNA sequence. Piericidins C7 and C8 showed selective cytotoxicity against rat glia cells transformed with the adenovirus E1A gene (IC50 C7: 1.5 nM, C8: 0.45 nM) and Neuro-2a mouse neuroblastoma cells (IC50 C7: 0.83 nM, C8: 0.21 nM).