Leptomycin

Leptomycin B is a secondary metabolite produced by Streptomyces spp.

Leptomycin B (LMB) was originally discovered as a potent anti-fungal antibiotic. Leptomycin B was found to cause cell elongation of the fission yeast Schizosaccharomyces pombe. Since then this elongation effect has been used for the bioassay of leptomycin. However, recent data shows that Leptomycin causes G1 cell cycle arrest in mammalian cells and is a potent anti-tumor agent against murine experimental tumors in combination therapy.