Synthetic peptide analogs of protein of the lung surface sp-c.

DESCRIBED novel polypeptides of formula (I), wherein A is HO PHE, B is Phe or Trp c is ILE, LEU or being, having activity as pulmonary surfactant, which can be obtained in large quantities with very high purity , AND HAVING A NATURAL EQUALS PULMONARY SURFACTANTS EFFECTIVENESS. They are SUITABLE FOR PRODUCING PHARMACEUTICAL COMPOSITIONS FOR TREATMENT respiratory distress syndrome in premature infants and adults.