Synthesis of the heptapeptide of the cyclopeptide moiety of polymixin B

Conclusions The synthesis of the heptapeptideN -BOC-N -pelargonyl-L-lysyl-N -Z-L-lysyl-D-phenylalanyl-L-leucyl-N -Z-L-lysyl-N -Z-L-lysyl-L-threonine, a linear analog of the cyclopeptide part of the antibiotic polymixin B, has been effected (yield 63%). The possibility of using this method for the synthesis of peptides on a polymer support without protecting the hydroxyl group of threonine has been shown.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 3, pp. 359–361, 1970