Description:
<jats:p>Derivatives of benzylamine and benzamidine were found to be competitive inhibitors of the proteolytic enzymes trypsin, plasmin, and thrombin. The inhibitor activity of these compounds was determined by the inhibition of the hydrolysis of <jats:italic>N</jats:italic>‐α‐benzoyl‐<jats:sc>dl</jats:sc>‐arginine‐4‐nitroanilide, catalyzed by the three enzymes. Inhibitor constants (<jats:italic>K</jats:italic><jats:sub>i</jats:sub>) were ascertained. Relations be‐between the chemical structure and the activity against trypsin, plasmin, and thrombin were deduced by comparing the inhibitor constants. Generally the inhibition of these enzymes by the investigated compounds runs parallel but there exist also some differences especially among the benzylamine derivatives. 4‐Chlorobenzylamine, a strong thrombin inhibitor, is only of low effectiveness against trypsin and plasmin. Derivatives of benzamidine are stronger inhibitors than derivatives of benzylamine. The following compounds proved to be the most potent inhibitors: 4‐amidinophenylpyruvic acid, 4‐aminobenzamidine, and 4‐amidinobenzoic acid benzyl ester. These compounds exhibited also an anticoagulant and antifibrinolytic effect.</jats:p>