This doctoral thesis is focused on the search for the inhibitors of carbonic anhydrases and thioredoxin reductase. The literature review covers the period from 1922 to 2017. Literature review discloses the information about carbonic anhydrases and thioredoxin reductase, their functions in living organisms and the role in cancer development, as well as the inhibitors of these enzymes. In the result analysis part the synthesis of saccharin derivatives, sulfamoylbenzoic acids and aromatic sulfonamides and their biological evaluation as the inhibitors of carbonic anhydrases is discussed. Part of the thesis is devoted to the synthesis of aziridine derivatives and their evaluation as potential anti-cancer agents. Cytotoxicity and thioredoxin reductase inhibitory activity of aziridines is presented and discussed. The series of 2-alkylsaccharins and 6-sulfamoylsaccharins are synthesized and hydrolized to obtain substituted sulfamoylbenzoic acids. Several series of leakadin derivatives are obtained, intoducing substituents at its ring nitrogen and amido group.