Application of tetrabutylammonium salt of N-(9-fluorenylmethoxycarbonyl)cysteic acid for solid phase peptide synthesis: Preparation of endothelin antagonistic cyclic pentapeptides

Abstract

Abstract According to the Fmoc strategy, highly potent endothelin antagonistic cyclic pentapeptides possessing cysteic acid residue(s) were prepared in solid phase peptide synthesis. Use of a tetrabutylammonium salt overcame low solubility of N-(9-fluorenylmethoxycarbonyl)cysteic acid in a conventional solvent such as DMF.