N-(9-Fluorenylmethyloxycarbonyl)-N-[4-(t-butyloxycarbonylamino)butyl]-glycine

Kommentar: Alkylating the Nitrogen of an amide bond results in peptoid structures, which leads to conformational restrains, like N-methylation and allows backbone derivatisation. Altering cytotoxicity, bacterial cell selectivity and receptor pharmacology through formation of peptoid derivatives have been published for Cilengitide, Piscidin 1, and MC3, MC4 and MC5 receptor agonist. This building block enables design of macrocycles through intermolecular crosslinking or backbone stabilization through intermolecular ring-closure. References: The Backbone N (4-Azidobutyl) Linker for the Preparation of Peptide Chimera; Ana I. Fernández-Llamazares, Jesús García, Jaume Adan, David Meunier, Francesc Mitjans, Jan Spengler, and Fernando Albericio; Org. Lett. 2013; 15(17): 4572-4575. DOI: 10.1021/ol402150m. Twice tied tight: Enforcing conformational order in bicyclic peptoid oligomers; Sidonie B. L. Vollrath, Stefan Bräse and Kent Kirshenbaum; Chem. Sci. 2012; 3: 2726-2731. DOI: 10.1039/c2sc20473h. Peptoid-Peptide Hybrids as Potent Novel Melanocortin Receptor Ligands; John A. W. Kruijtzer, Wouter A. J. Nijenhuis, Nienke Wanders, Willem Hendrik Gispen, Rob M. J. Liskamp, and Roger A. H. Adan; J. Med. Chem. 2005; 48: 4224-4230. DOI: 10.1021/jm0490033. Structural flexibility and the positive charges are the key factors in bacterial cell selectivity and membrane penetration of peptoid-substituted analog of Piscidin; Jin-Kyoung Kim, Sung-Ah Lee, Soyoung Shin, Jee-Young Lee, Ki-Woong Jeong, Yong Hai Nan, Yong Sun Park, Song Yub Shin, Yangmee Kim; Biochimica et Biophysica Acta 2010; 1798: 1913-1925. DOI: 10.1016/j.bbamem.2010.06.026.