Biosynthetic anthracyclines

This review summarizes the structure, the occurrence and the available data concerning the bioactivity of biosynthetic anthracyclines. The anthracyclines represent an important family of natural products produced by microorganisms of Streptomyces and related genera and include clinically useful agents for the medical treatment of human cancer. Chemically, the anthracyclines are glycosides characterized by a quinone tetracyclic aglycone and one or more deoxysugar units, mostly belonging to the L-hexopyranoside series, comprising generally an aminosugar. The different compounds belonging to this family are structurally related as they share a common biosynthetic pathway. Although some statements concerning structure activity relationships and molecular requirements for activity can be made, published data are not adequate for the comparative evaluation of potential antitumor efficacy of biosynthetic anthracyclines. This family of natural products is therefore still open for pharmacological investigation.