Influence of the peptide chain length of new elongated tuftsin analogs on phagocytosis process

In this paper the synthesis of the following elongated tuftsin analogs: Arg-Thr-Lys-Pro-Arg (1), Pro-Arg-Thr-Lys-Pro-Arg(II), Lys-Pro-Arg-Thr-Lys-Pro-Arg(III) and Thr-Lys-Pro-Arg-Thr-Lys-Pro-Arg(IV) by classical and solid-phase methods are described. The obtained peptides were tested for their biological activity: restoration of the phagocytosis of defected granulocytes from blood of children with acute lymphoblastic leukemia (ALL).