The issue of breast cancers, due to their unidentified etiology, has attracted the attention of many doctors and scientists throughout the centuries. Despite extensive research and a variety of therapies, breast cancer still remains one of the main causes of women’s death in highly developed countries. It is worth pointing out the fact that approximately 95% of cancer cases in their initial growth phase show a hormone-dependent nature. For this reason, biologically active hormones (including estrogens and androgens) play a crucial role in the growth and proliferation of tumor cells, and therefore new therapies should focus on the use of pharmaceuticals, which will effectively reduce the delivery of active hormones to cancer cells. One of the main hormone-dependent breast cancer treatment strategies is based on the application of biologically active compounds, which exhibit the ability to inhibit the activity of enzymes responsible for the synthesis of estrogens and androgens. In recent years, intensive research has been conducted to find new and effective STS inhibitors. The aim of this research project is the synthesis of two series of compounds with potential therapeutic applications in the treatment of hormone-dependent cancer. Compounds of SERIES I will exhibit structural similarity to FA through the presents of glutamine acid residue in their structure, which is a very important unit of FA. Moreover, the aforementioned derivatives will have 1,2,3-triazole, coumarin, tyramine, flavone core in their structure, which exhibits geometrical similarity to natural, steroid substrates of STS. Furthermore, this project involves creating a large library of conjugates of folic acid and STS inhibitors (SERIES II). These compounds will be designed based on the results of biological studies for compounds of SERIES I The most promising derivatives will be selected and conjugated to FA molecule. Moreover, all compounds will contain sulfamate pharmacophore in their structure, whose effectiveness has already been proven in the course of our previous studies. In conclusion, STS is a very attractive, new molecular target for the development of hormone-dependent cancer therapy, and therefore the synthesis of novel, effective, and selective STS inhibitors is a crucial challenge for modern medicinal chemistry.