EPIDERSTATIN, A NEW INHIBITOR OF THE MITOGENIC ACTIVITY INDUCED BY EPIDERMAL GROWTH FACTOR

I. TAXONOMY, FERMENTATION, ISOLATION AND CHARACTERIZATION

Abstract

Inhibitors of mitogenic activity induced by epidermal growth factor (EGF) were screened from culture broths of soil microorganisms. A strain of actinomycetes has been found to produce a new glutarimide antibiotic named epiderstatin which inhibits the incorporation of [³H]thymidine into quiescent animal cells stimulated by EGF. Taxonomic studies have revealed that the producing strain belongs to a subspecies of Streptomyces pulveraceus, thus the name, Streptomyces pulveraceus subsp. epiderstagenes was given to this strain. The molecular formula (C₁₅H₂₀N₂O₄) and UV profile (λ_max 295 nm) of the antibiotic are distinct from other known antibiotics. It inhibited the incorporation of [³H]thymidine into quiescent cells stronger than into growing cells.