Novel microbial metabolites of the phoslactomycins family induce production of colony-stimulating factors by bone marrow stromal cells. I. Taxonomy, fermentation and biological properties.

Three metabolites were isolated from the culture broth of an actinomycete strain identified as Streptomyces platensis SANK 60191, that induce the production of colony-stimulating factors (CSFs) by stromal cell line KM-102 at ED50 concentrations from 40 to 200 ng/ml. The compounds induced quantities of granulocyte CSF (G-CSF) and granulocyte-macrophage CSF (GM-CSF) comparable to those induced by interleukin-1, a strong CSF inducer. These metabolites were called leustroducsins (A, B and C) and were later found to be structurally related to phoslactomycins. This is the first report of CSF inducing activity by members of the phoslactomycin class.