Microbial-catalyzed biotransformations have considerable potential for the generation of an enormous variety of structurally diversified organic compounds, especially natural products with complex structures like triterpenoids, flavonoids, steroids, steroidal saponins, and sesquiterpenoids. They offer efficient and economical ways to produce semisynthetic analogues and novel lead molecules. Microorganisms such as bacteria and fungi could catalyze chemo-, regio-, and stereospecific hydroxylations of diverse substrates that are extremely difficult to produce by chemical routes. During recent years, considerable research has been performed on the microbial transformation of bioactive compounds, in order to obtain biologically active molecules with diverse structural features. In green chemistry, biotransformations are an important chemical methodology toward more sustainable industrial processes.

Six new bicyclic hydroxamic acids were synthesized through an uncommon nitro group rearrangement between β-nitrostyrenes and dimedone. The structures of all the new synthesized compounds were confirmed using a combination of FTIR, ¹H NMR, ¹³C NMR and mass spectral data. Likewise, the cytotoxic activity of the obtained products was evaluated in six different cancer cell lines. Two compounds showed significant potency on two cancer cell lines with IC50 between 9.31±0.1 and 23.38±0.9 μM.