EXPLOITING OXIDOREDUCTASES, HYDROLASES AND TRANSAMINASES AS STEREO- AND REGIO-SELECTIVE BIOCATALYSTS IN ORGANIC SYNTHESIS.

The thesis concerns the use of different enzyme classes (namely, oxidoreductases, transferases, and hydrolases) as biocatalysts to achieve the chemo-, regio- and stereo-selective green synthesis of pharmaceutically relevant compounds. The main work has been done with hydroxysteroid dehydrogenases, redox enzymes that naturally work on steroids, which were studied with two main purposes: to shorten the synthesis of valuable bile acids already sold as drugs or with potential biomarker application, and to synthesize active pharmaceutical ingredients of non-steroidal nature. The work has been completed by the study on a peculiar, extremely resistant, redox enzyme, which was isolated from a metagenome in search for novel thermostable hydroxyxsteroid dehydrogenases.