Synthesis and biological investigations of new tuftsin analogs with elongated peptide chain

Abstract
In this paper the synthesis of the following elongated tuftsin analogs: Thr-Lys-Pro-Lys-Thr-Lys-Pro-Lys (I), Thr-Lys-Pro-Lys-Thr-Lys-Pro-Arg (II) and Ala-Lys-Thr-Lys-Pro-Arg-Glu-Gln (III) by the classical method is described. The compound II markedly inhibited the growth of murine sarcoma viruses (MSV).