1991 Volume 44 Issue 2 Pages 192-199
A series of phenylthiourea and ethylthiourea derivatives of daunorubicin and its congeners was prepared by reaction of the 3'-amino group of the antibiotic with phenylisothiocyanate or ethylisothiocyanate. S-Methylation yielded S-methylisothiouronium salts which when reacted with amines resulted in an intramolecular cyclization with the participation of the neighboring 4'-OH group. The structures and predominant conformations of the thiourea derivatives and daunorubicino(3'-N, 4'-O-d)oxazolines were determined by 1H and 13C NMR. Cytostatic activities of the thiourea and oxazoline derivatives were compared with the cytostatic activities of N-methylurea and N-methyl-N-nitrosourea containing daunorubicin and its congeners. Carminomycin derivatives were endowed with the highest cytostatic activity.