Immunsuppressiva-Antigen-Konjugate. VIII. Darstellung von 6-Mercaptopurin-Protein-Konjugaten nach dem Azid-Verfahren

Immunosuppressant-Antigen Conjugates. VIII. Preparation of 6-Thiopurine-Protein Conjugates by the Azide Method 6-Carboxymethyl-thiopurine was coupled with human serum albumin (HSA) and bovine serum globuline in the presence of a water soluble carbodiimide. Under these conditions, reaction of HSA with the carbodiimide led to electrophoretically detectable changes. Therefore, further conjugates were prepared by the azide method. The used azides, N-(6-benzylthiopurin- and 6-methylthiopurin-9-yl)-acetyl azide, were obtained from the hydrazides. The prepared conjugates contained upto 4.2% thiopurine, determined by spectrophotometry. It was not possible to obtain an azide from purinyl-(6)-thioacethydrazide.