Inhibitors of the cleavage of aclacinomycins

Advances in bioconversion of anthracycline antibiotics

During the last decade new anthracycline-type structures with potential usefulness in cancer treatment have been supplied both by new microbial strains and by bioconversions of precursor molecules employing cells or enzymes. We highlight recent advances in bioconversion of anthracycline structures with the main focus on late transformations such as are carried out by oxidoreductases.

Compartmentation of enzymes interconverting aclacinomycins in Streptomyces species AM 33352

The enzymatic interconversion of the aclacinomycins A (I), Y (II), and B (III) by Streptomyces spec. AM 33352/S 182 producing these aklavinone glycosides was investigated. The enzymes converting I to II and III, as well as vice versa, are located within different compartments separated by the cytoplasmic membrane. Aclacinomycin A (I) is biotransformed to II and III by the cell-free mycelium extract while the entire mycelium carries out the same type of conversion towards the opposite direction. Changes of enzyme activity are correlated to alterations in the ratio of aklavinone glycosides throughout the fermentation. A hypothesis is developed concerning the role of compartmentized oxidoreductase(s) in the passive flux of I from inside the cells to outside.