Synthesis and electrochemical study of a new chiral tris-catecholamide analogue of enterobactin

The comparison of siderophore complex redox potentials with those of physiological reductants may aid in the clarification of the mechanism of iron metabolism. In this paper, a new chiral tris-catecholamide compound N,N′,N″-tris-(2,3-dihydroxybenzoyl)-1,1,1-tris-(L-methioninemehyl)-ethane or H6L ( ) has been synthesised in nine steps, and may mimic the release of iron from enterobactin to the agents which are directly involved in cell metabolism. The choice of methionine as a constituent of the siderophore incorporates divalent sulphur which leads to the increase of the reduction potential of the siderophore, and consequently facilitates the iron release [Fe(III)/Fe(II) redox potential E1/2=−0.749 V vs (SCE)].