Synthesis and Siderophore Activity of Albomycin-like Peptides Derived from N5-Acetyl-N5-hydroxy-L-ornithine

Article abstract of DOI:10.1021/jm00107a013

N⁵-Acetyl-N⁵-hydroxy-L-ornithine (1), the key constituent of several microbial siderophores, has been synthesized in 23percent yield overall from N-Cbz-L-glutamic acid 1-tert-butyl ester (6) derived from L-glutamic acid.Reduction of 6 to 7 and treatment with N-(trichloroethoxy)carbonyl>-O-benzylhydroxylamine (8), and diethyl azodicarboxylate and triphenylphosphine followed by deprotection produced the protected N⁵-acetyl-N⁵-hydroxy-L-ornithine derivatives 11 and 12 in large quantities (10-20 g).Following α-amino and α-carboxyl deprotections of 11 and 12, EEDQ <2-ethoxy-N-(ethoxycarbonyl)-1,2-dihydroquinoline> mediated peptide coupling and final deprotection provided amino acid 1 and six albomycin-like peptides (20, 23, 25, 28, 35, and 36).The growth-promoting ability of each was evaluated with the siderophore biosynthesis mutant Shigella flexneri SA240 (SA 100 iucD:Tn5).These results indicate that substantial modification of the framework of peptide-based siderophores can be tolerated by microbial iron-transport systems.