Vanadium biological significance

Much of the recent coordination chemistry of vanadium has been stimulated by interest in the biological significance of the element. Vanadium is important in both reductive and oxidative catalytic transformations " in biological chemistry (see Vanadium in Biology). 

More recent work has involved the preparation and characterization of vanadium(III) complexes with bidentate and multidentate ligands, especially those with nitrogen- and oxygen-donor atoms, because of their biological significance. 

Mukherjee B, Patra B, Mahapatra S, et al. (2004) Vanadium - An element of atypical biological significance. Toxicology Letters 150 135-143. 

A. Biological Significance of Iron, Zinc, Copper, Molybdenum, Cobalt, Chromium, Vanadium, and Nickel... 

Hudson, T. A. F., Vanadium-Toxicology and Biological Significance, Elsevier Publishing Co., New York, 1964. 

Martoja, R., Gouzerh, P., and Monniot, F. (1994) Cytochemical studies of vanadium, tunichromes and related substances in asddians possible biological significance. Oceanog. Mar. Biol. Anna. Rev., 32, 531-556. 

The potentially serious aspects of vanadium pollution, the function of biologically occurring enzyme systems, the role of vanadium on the function of numerous enzymes, and the associated role in the insulin-mimetic vanadium compounds are inextricably linked. The key to our understanding all such functionality relies on understanding the basic chemistry that underlies it. This chemistry is determined to a significant extent by the V(IV) and V(V) oxidation states but clearly is not restricted to these states. Indeed, the redox interplay between the vanadium oxidation states can be a critical aspect of the biological functionality of vanadium, particularly in enzymes such as the vanadium-dependent nitrogenases, where redox reactions are the basis of the enzyme functionality. 

Q. Yan, "Applications of Resonance Raman Spectroscopy to Complexes of Biological and Clinical Significance I. High-Valent Oxo- and Nitridometalloporphyrins II. pu-Oxo Vanadium(III) Dimers III. Antitumor Drug-DNA Intercalators, PhD. Dissertation, University of Houston, 1996. 

Biological, chemical, and physical effects of airborne metals are a direct function of particle size, concentration, and composition. The major parameter governing the significance of natural and anthropogenic emissions of environmentally important metals is particle size. Metals associated with fine particulates are of concern particles larger than about 3-fjim aerodynamic equivalent diameter are minimally respirable, are ineffective in atmospheric interactions, and have a short air residence time. Seventeen environmentally important metals are identified arsenic, beryllium, cadmium, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, antimony, selenium, tin, vanadium, and zinc. This report reviews the major sources of these metals with emphasis on fine particulate emissions. 

Medical Significance. The medical significance of vanadium is unclear because knowledge is incomplete of the conditions necessary to produce vanadium deficiency, dietary components that affect vanadlinn metabolism, and its biological function. 

Absorption of orally administered vanadium compounds has been measured by Cantley and coworkers while investigating the intracellular inhibition of (Na,K)-ATPase activity by sodium vanadate in human erythrocytes [81], They noted that a significant portion of the administered vanadium was in a form not capable of inhibitory activity. EPR spectra of NaVOs-treated erythrocytes showed a characteristic spectrum, indicating that reduction of V(V) to V(IV) had occurred. In one hour, approximately 30% of the added vanadate was reduced, but only vanadium contained within the cells had undergone reduction. Thus, absorption of vanadate, likely fluough a cation transport system, must occur before biological reduction could occur [62]. Further study of this reaction by EPR showed... 

Coordination conqilexes of [V 0] with a variety of ligands constitute the majority of vanadium con oun proposed as IMA s (13,14,18,19). A select few conqilexes have demonstrated significantly increased activity over inorganic vanadium sources (e.g. VOSO4 or [V04] ) through both in vivo (20) and/or in vitro (19,21,22) assays of potential biological effectiveness. 

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