Coordination chemistry of vitamin B6 and derivatives: A structural overview

The coordination behaviour of ligands containing the vitamin B-6 vitamers [pyridoxal (PL), pyridoxine (PN), pyridoxamine (PM) and their 5'-phosphates] is reviewed in the light of the structural information derived from X-ray studies. The review includes the complexes of the simple vitamers themselves or simple derivatives thereof; those of the Schiff bases resulting from their condensation with each other or with amino acids or other amino derivatives; and the metal compounds formed by hydrazones that contain the PL moiety. Taken together, these ligands exhibit a wide variety of coordination possibilities, the vitamer moiety usually playing a significant role. The biological relevance and therapeutic potential of some of these compounds are also reviewed. (c) 2012 Elsevier B.V. All rights reserved.