Daunorubicin HCl (daunomycin HCl), an anthracycline antibiotic with potent antitumor activity, was first isolated from S. peucetius by scientists from Farmitalia. The mechanism of action of daunomycin is complex and incompletely understood. Daunomycin binds reversibly to double stranded DNA with (G.C) base specificity leading to inhibition of transcription.  Daunomycin activates signalling pathways, including a sphingomyelinase-initiated sphingomyelin-ceramide pathway, mitogen-activated kinase and stress-activated protein/c-Jun N-terminal kinase activation, transcription factors such as nuclear factor kappa B, as well as the Fas/Fas-ligand system.