3-Hydroxy-4(1H)-Pyridinone-Containing Linear and Cyclic Hexapeptides and their Iron(III) Comploexese-Synthesis, Property, and the Growth-Promotion Activity

摘要

Linear and cyclic hexapeptides composed of #epsilon#-(3-hydroxy-1,4-dihydro-2-methyl-4-oxo-1-pyridyl)-L-norleucine and glycine or #beta#-alanine residue have been successfully synthesized. These hexapeptides formed 1:1 iron(III) complexes at neutral pH region. Glycine linear (8a)-and #beta#-alaine cyclic hexapeptide (10)-iron(III) complexes predominantly existed in #DELTA#-configuration, while #beta#-alanine linear hexapeptide (8b)-iron(III) complex existed in #LAMBDA#-one. The relative stability constants of 8a, 8b, and 10-iron(III) complexes were estimated to be 31.6, 33.4, and 31.7, respectively. From iron(III) removal from human transferrin, linear hexapeptides (8a,b) were found to efficiently remove iron(III) compared with desferrioxamine B. The growth-promotion activity was also discussed.