Condensation Reaction between Angiotensin II and Dicarboxylic Acid in Water at High Temperature without Any Catalytic Agent Additive

The condensation reaction of angiotensin II and tartaric acid in water at 100-140 degrees C proceeded without any added catalytic agent. One of the products, N-CO-tartarylangiotensin II, was confirmed by LC-MS, positive-ion MALDI-MS, and the fluorescamine method as a condensation product. The initial concentration of the substrates, temperatures, and initial pH affected the yield of the product. The higher concentrations and temperatures increased the concentration of the condensation product. The optimal pH for the condensation reaction was 3.0. The other C4 saturated dicarboxylic acids, malic and succinic acids, were also condensed by angiotensin II.