The invention relates to the field of medicine, and more particularly to oncology and immunology. Proposed are novel compounds of general formula (1) or (2), which have an affinity for CD16a. Proposed are novel modified proteins, active toward the CD16a receptor, which are selected from an antibody or an autoantigen and are conjugated by a modified compound selected from a compound of general formula (1) or (2), and which enhance and direct antibody-dependent cell cytotoxicity. The novel modified proteins (conjugates) can be used to destroy a specific target group of cells in an organism, such as cancer cells or autoimmune lymphocytes. Also proposed are methods for producing conjugates, and a pharmaceutical composition and a drug containing modified proteins for the treatment of cancer and autoimmune diseases.
