Anti-aging derivatives of cycloastragenol produced by biotransformation

Abstract

In this study, the microbial transformation of cycloastragenol (CA) by the fungi <i>Mucor subtilissimus</i> AS 3.2456 and <i>Aspergillus oryzae</i> AS 3.407 yielded 19 metabolites. Their structures were established based on extensive NMR and HR-MS data analyses, and six of them are new compounds. The two fungal strains exhibited distinct biocatalytic features. <i>M. subtilissimus</i> could catalyse hydroxylation and carbonylation reactions meanwhile the fragile 9,19-cyclopropane ring remained intact. <i>A. oryzae</i> preferred to catalyse hydroxylation, acetylation and ring expansion reactions. These highly specific reactions are difficult to achieve by chemical synthesis, particularly under mild conditions. Furthermore, we found that most of the metabolites could significantly extend the lifespan of <i>Caenorhabditis elegans</i> at 50 µM. These biotransformed derivatives of CA could be potential anti-aging agents.