Increased yield of biotransformation of exemestane with β-cyclodextrin complexation technique.

In this study, 6-methylenandrosta-4-ene-3,17-dione and Hydroxypropyl-β-cyclodextrin (HP-β-CD) were used to form a complex, which could be then biotransformed by Arthrobacter simplex ATCC6946 to obtain the antitumor drug exemestane. The complex was analyzed by UV, DSC and TG techniques, while the products were analyzed by HPLC, NMR and MS. These results confirmed that the β-cyclodextrin not only improved the water-solubility of 6-methylenandrosta-4-ene-3,17-dione, but also greatly enhanced the biocompatibility during the biotransformation process. This result may be applied to other precursors which have poor aqueous solubility in the biotransformation processes.