Structural Modification of the Immunosuppressants FK-506 and Ascomycin Using a Biological Approach

Abstract

Bioconversion was utilized to conduct structural modification of the complex molecules FK-506 and ascomycin. Four interesting microbial reactions, regiospecific O-demethylation, glucosylation, hydroxylation, and phosphorylation, yielding various derivatives of the title compounds, were discovered from screening more than thousand microorganisms including bacteria, actinomycetes, and fungi. The isolated compounds were evaluated for a better understanding of structural and functional features responsible for their biological activity.