Insulinderivater, deres anvendelse og farmaceutisk præparat indeholdende mindst ét sådant insulinderivat

Insulin derivatives of the formula II with an isoelectric point between 5 and 8.5, with improved stability in weakly acid aqueous medium and with specific action profile and the physiologically tolerated salts of these insulin derivatives for the treatment of diabetes mellitus; formula II is: in which R is H or H-Phe, R is a genetically encodable L-amino acid which contains no amide group, R is the residue of a neutral, genetically encodable L-amino acid, R is a physiological acceptable organic group which is basic in nature and has up to 50 C atoms, in whose structure 0 to 3 alpha -amino acids are involved and whose terminal carboxyl group which is present where appropriate can be free, in the form of an ester, in the form of an amide, in the form of a lactone or reduced to CH2OH, and X is a genetically encodable L-amino acid.