["Chimeric" antibiotics, daunorubicin and its analogs N-acylated with bruneomycin (Streptonigrin)]

Anthracycline antibiotics (daunorubicin, carminomycin and doxorubicin) N-acylated with antibiotic bruneomycin (streptonigrin) have been obtained from the parent compounds upon treatment with N, N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide. These "chimeric" antibiotics are less active both in vitro and in vivo than the parent antibiotics. This demonstrates the stability of the intermolecular amide linkage in these compounds towards chemical and enzymatic hydrolysis as well as their inability to interact with corresponding receptors in contrast to less hindered derivatives of the parent antibiotics.