Analogues of trypsin inhibitor SFTI-1 with disulfide bridge substituted by various length of carbonyl bridges.

Series of eight new monocyclic analogues of trypsin inhibitor SFTI-1 was synthesized by the solid phase method. In these analogues disulfide bridge Cys3 - Cys11 present in native inhibitor was replaced by different-sized carbonyl bridges formed by the amino groups of the side chain of Lys, Orn, Dab or Dap located in positions 3 and/or 11. All analogues appeared to be potent trypsin inhibitors.