The development of sparsomycin as an anti-tumour drug

The synthesis of sparsomycin and eight lipophilic analogues is discussed. Sparsomycin, a bacterial metabolite, is a potent inhibitor of protein biosynthesis; in addition it has anti-tumour properties. Structure-activity relationship studies indicate that the anti-tumour activity is a direct consequence of the inhibition of protein synthesis. Two of the analogues show a higher anti-tumour activity in vitro as well as in vivo, and are less toxic to mice than sparsomycin. Finally, some properties of sparsomycin are discussed: the drug potentiates the cytotoxicity of cisplatin and is selectively active on tumour cells without affecting human bone-marrow.