Syhthesis of peptides by fragment condensation on a solid support. I. Application in preparation of bradykinin

Two tripeptides and one dipeptide, protected except at the carboxyl ends, have been prepared in solution and used as intermediates in a new synthesis of bradykinin on a solid support. Condensation of the two tripeptides to the resin was effected in satisfactroy yield with dicyclohexylcarbodiimide plus N-hydroxysuccinimide. The partial epimerization that might occur by such an approach was explicitly verified to be without practical importance in this case. The crude product contained only traces of impurities and yielded, after purification, bradykinin of high purity. Both the crude and purified bradykinin exhibited full biological activity.