This invention relates to the reconstituted surfactant comprising a lipid carrier, natural surfactant protein SP- a particular polypeptide analogue of the C and between 3 and 8, and preferably of a combination of a polypeptide comprising the sequence of a recurring unit consisting of a number of hydrophobic amino acid residues and a basic amino acid residues between 4 and 5.In particular, the present invention relates to reconstituted surfactants comprising the following:a) the lipid vehicleb) in the general formula (I) a polypeptide of at least 20 amino acid residues and not more than 40 amino acid residues having a sequence represented byFeGeIfPfSgSPVHLKRXaBXbGALLpGpLp (I)Here:X is I, L, and an amino acid residue independently selected from the group consisting of nLB is K, is R, H, W, F, Y, and independently an amino acid residue selected from the group consisting of OrnS has 12-22 carbon atoms, preferably an acyl group having 16 carbon atoms It is optionally substituted by, and is connected to the side chain via an ester bond Is, M or a sulfur atom is oxidized M, I, L, and the amino acid residues selected from the group consisting of nLa has a value comprised from 1 to 8 is an integerb is an integer having a value from 1 to 19, comprisinge, f, g, and p is an integer having a value of 0 or 1X a BX b Put the clues and have up to 22 amino acidsc) the general formula (a polypeptide of at least 12 amino acid residues and not more than 60 amino acid residues including a sequence represented by the )B (U a B) x ()hereU is L, I, nL, V, A, M and the group consisting of F isB is K, R, H, and independently an amino acid residue selected from the group consisting of Orn is selected from amino acid residues independentlya is between 3 and 8, preferably an integer having a value from 4 to 5 Andx is between 2 and 6, preferably an integer having a value of 3-4.The present invention is, for example salts of the polypeptides and the pharmaceutically acceptable acetyla
