[Convalent binding of various tetra- and tricyclic heterocycles with isothiocyanate structure to human serum albumin and bovine gamma globulin. Part 24: Immunosuppressive agent - antigen conjugates (author's transl)].

In view of their potential activity as antigen-specific immunosuppressive agents, the authors produced conjugates by treating the tri- and tetracyclic compounds 1-8 (with isothiocyanate structure) with human serum albumin (HSA) and bovine gamma globulin (BGG). In certain cases the conjugates of BGG were obtained only under conditions leading to protein degeneration. The corresponding products were devoid of antigen-specific immunosuppressive activity and must be considered to be merely repository forms of the respective low-molecular compounds. In contrast, the conjugates of HSA could be obtained under conditions under which no protein denaturation was detectable. These conjugates may be used for the planned investigation. After reaction of the isothiocyanates with the proteins, time dependent changes were observed in the ultraviolet spectra of some conjugates, the possible causes of which are discussed.