A compound comprising three components A, B, and C, which components are covalently bound forming the compound having the structure A-B-C whereincomponent A has a specific binding affinity for antigens,component B is covalently linked to component Acomponent C is a compound having an alkylated purine or pyrimidine moiety such as guanine, cytosine or a Coenzyme A moiety and linked thereto a moiety having a physiological effect with the proviso thatcomponent B has an catalytical or acceptor activity to couple component C with covalently coupled components A-B.
