Vanadium science: chemistry, catalysis, materials, biological and medicinal studies

Vanadium, originally discovered in 1801 by Andrés Manuel del Río in Mexico and rediscovered by Nils Sefström almost 30 years later and named after the Scandinavian goddess of beauty and fertility Vanadis, plays significant roles in biological systems. Moreover, recognition of the remarkable properties of its compounds has led over the decades to extensive research in order to explore the chemistry, biochemistry, medicinal chemistry, toxicology and catalytic properties of vanadium. The basic and applied knowledge consequently developed gathered researchers from all over the world dedicated to vanadium research in a wide range of topics. Starting with the first international meeting in 1997 (Cancun), eleven biannual international symposia centered on vanadium science were held all over the world. Most of these meetings have been summarized in collections of research as listed below.^1–9

The current New Journal of Chemistry themed issue on vanadium emerges from work presented at the 11th International Vanadium Symposium held in Montevideo, Uruguay as well as other contributions from the community. New Journal of Chemistry was chosen because it covers all areas of chemistry and thus can support all the presentations at the International Vanadium Symposium. Coverage of a broad range of contributions in vanadium chemistry is important in order to document the directions of vanadium chemistry and recent progress by the vanadium community in a wide range of topics in the areas of synthesis, coordination chemistry, speciation, theoretical chemistry, catalysis, materials science, biological chemistry, vanadium-based drugs and nanoscience, among other relevant subjects. In the following, we summarize the contributions covered in this themed issue.

Fundamental coordination chemistry was described in a range of different complexes. Lukáš Krivosudský and coworkers reported the coordination chemistry of vanadium(V) complexes of mandelic acid (DOI: 10.1039/C9NJ02275A). Winfried Plass and coworkers investigated the chirality of oxidovanadium(V) centers in complexes with tridentate sugar Schiff-base ligands and characterized the systems using both solid-state and solution state studies (DOI: 10.1039/C9NJ02881A). Syamal Chakrabarti and coworkers synthesized and characterized by crystal structure and DFT calculations oxidoalkoxidovanadium(V) complexes, as well as exploring their biological activities (DOI: 10.1039/C9NJ02471A). Guillermo González and coworkers reported the coordination chemistry in ammonium hexadeca-oxo-heptavanadate microsquares representing a new member of the class of V₇O₁₆ mixed valence nanostructures (DOI: 10.1039/C9NJ02188D). Enrique González-Vergara and coworkers prepared one-dimensional supramolecular chains consisting of [H₂V₁₀O₂₈]⁴⁻ units decorated with 4-dimethylaminopyridinium ions and investigated them theoretically (DOI: 10.1039/C9NJ02097G). Diego Venegas-Yazigi and coworkers characterized experimentally and theoretically the nature of the electronic transitions observed in mixed valence polyoxovanadoborates (DOI: 10.1039/C9NJ02549A).

In the area of catalysis a number of studies were reported. Manas Sutradhar and coworkers investigated the nuclearity of vanadate complexes in the catalytic oxidation of cyclohexane and cyclohexanol (DOI: 10.1039/C9NJ00348G). Mannar Maurya and coworkers prepared new thiosemicarbazone oxidovanadium(IV) and dioxidovanadium(V) complexes and investigated their catalytic potential (DOI: 10.1039/C9NJ01486A). Toshiyuki Moriuchi and coworkers investigated the homocoupling reactions of alcohols using oxovanadium(V) complexes (DOI: 10.1039/C9NJ01905G). Anastasios Keramidas and coworkers prepared polyoxofluorovanadates which exhibited peroxidase like activity using a one pot synthesis (DOI: 10.1039/C9NJ01999E). Pierluca Galloni and coworkers developed a sustainable approach to selectively brominate tetrapyrrolic scaffolds using a vanadium catalyst (DOI: 10.1039/C9NJ02503K).

A number of manuscripts reported research in the area of polyoxometalate chemistry. Yoshihito Hayashi and coworkers synthesized and characterized redox active mixed valence hexamanganese double cubane complexes supported by tetravanadates (DOI: 10.1039/C9NJ02437A). Samar Das and coworkers characterized the fundamental coordination chemistry of a fully reduced {V^IV₁₈O₄₂} host with VO₄³⁻ or Cl⁻ as guest anions (DOI: 10.1039/C9NJ01918A). Annette Rompel and coworkers investigated the interactions of decavanadate with metal ions, generating products that interact more strongly with proteins such as lysozyme, thaumatin, proteinase K and human serum proteins (DOI: 10.1039/C9NJ02495F). Manuel Aureliano showed that polyoxovanadate inhibition of E. coli growth is inversely correlated with Ca²⁺-ATPase activity (DOI: 10.1039/C9NJ01208G).

Applications of vanadium in nanochemistry were reported by several groups. Steve Yu and coworkers reported the selective catalytic oxidation of benzene to phenol by a vanadium oxide nanorod catalyst in CH₃CN using aqueous H₂O₂ and pyrazine-2-carboxylic acid (DOI: 10.1039/C9NJ02514F). The Guerrero-Pérez–Bañares team investigated the potential of nano-sized V-containing mixed oxides to improve the catalytic action of mixed vanadium oxides (DOI: 10.1039/C9NJ01637F). Peter Lay and coworkers reported the high anti-cancer activity of vanadium-doped hydroxyapatite nanoparticles against bone cancer cells (DOI: 10.1039/C9NJ03406D). Ignacio León and coworkers found that lipid nanoparticles were an effective way to deliver Metvan to bone cancer cells (DOI: 10.1039/C9NJ01634A).

Many reports investigated the effects of vanadium compounds in biological systems. Isabel Correia and coworkers reported a biological screening method using naphthoylhydrazone vanadium complexes (DOI: 10.1039/C9NJ01816F). Rupam Dinda and coworkers reported on the synthesis and structure of mixed ligand oxidovanadium(IV) complexes incorporating 2-(arylazo)phenolates and tested their binding to serum albumin and their cytotoxicity (DOI: 10.1039/C9NJ01910C). Evelina Ferrer and coworkers reported a combination of in vitro and infrared spectroscopic analysis of phosphatase inhibition (DOI: 10.1039/C9NJ01638D). Eugenio Garribba and coworkers assessed the effect of secondary interactions, steric hindrance and electric charge on the interactions of V(IV)-oxo compounds with proteins (DOI: 10.1039/C9NJ01956A). Ana Da Costa Ferreira investigated the interactions of an oxindolimine–vanadyl compound with DNA and its cytotoxic effects (DOI: 10.1039/C9NJ02480H). Thanos Salifoglou used V(V)-Schiff base complexes to induce adipogenesis through structure-specific interactions with genetic targets (DOI: 10.1039/C9NJ02520K). Rupam Dinda and coworkers reported studies evaluating the in vitro cytotoxicity and catalytic properties of dioxidovanadium(V) complexes coordinated to azohydrazone ligands (DOI: 10.1039/C9NJ01815H).

The applications of vanadium compounds for therapeutic uses were investigated in vitro and in vivo. Margarida Castro examined the metabolic effects of a coordination complex, VO(dmpp)₂, in an ex vivo¹H-HRMAS NMR study to unveil its pharmacological properties (DOI: 10.1039/C9NJ02491C). The Treviño–González-Vergara team investigated the mechanism by which metformin-decavanadate treatment ameliorates hyperglycemia and the redox balance via Nef-2 in a Type 1 diabetes mellitus model (DOI: 10.1039/C9NJ02460C). Patricia Williams and coworkers reported the improved effects of glycosylated flavonoid vanadium compounds as anticancer agents over other flavonoid vanadium compounds (DOI: 10.1039/C9NJ01039D). Xiaoda Yang and coworkers reported the effects of vanadyl acetylacetonate on Aβ pathogenesis in APP/PS1 transgenic mice (DOI: 10.1039/C9NJ00820A). Dinorah Gambino and coworkers explored homoleptic oxidovanadium(IV) complexes with 8-hydroxyquinoline ligands as prospective antitrypanosomal agents (DOI: 10.1039/C9NJ02589H).

The aims of this issue are to cover recent progress in vanadium science, highlight current and future directions of this area and demonstrate an impressive spread in topic areas. Unfortunately, not all areas that were represented at the International Vanadium Conference are included in this themed issue, although recent publications show that progress has also been made in these areas, and the reader is directed to the work briefly listed below. Presentations at the meeting included the 2018 and 8th Vanadis award winner Armando Pombeiro who presented on the synthesis and catalytic applications of vanadium complexes with N- or O-ligands.¹⁰ Alison Butler described the biochemical and biological impact of vanadium haloperoxidases,¹¹ Debbie C. Crans and coworkers described a new area of immunotherapy, the application of vanadium compounds to enhance anticancer effects,¹² and Tatsuya Ueki presented studies investigating the genetic mechanism of vanadium accumulation and the possible function of vanadium in underwater adhesion in ascidians.¹³ The presentations in these areas combined with the papers presented in this issue document the continued strength of the field and lay a solid background for the International Vanadium Symposium in Cyprus in 2020.

We thank all the contributors, the reviewers and the Royal Society of Chemistry for their valuable support without which this work could not be presented. We believe this special issue will be of interest to a wide range of researchers working on the different topics involving vanadium in 2018.

References

1. V1 was captured in Vanadium Compounds: Chemistry, Biochemistry, and Therapeutic Applications, ed. A. S. Tracey and D. C. Crans, ACS Symposium Series, Oxford University Press, Washington, DC, USA, 1998, vol. 711.
2. V2 was captured in J. Inorg. Biochem., 2000, vol. 80.
3. V3 was captured in a special issue of Coord. Chem. Rev., 2003, vol. 237.
4. V4 was captured in Pure Appl. Chem., 2005, vol. 77.
5. V5 was captured in Vanadium: The Versatile Metal, ed. K. Kustin, J. C. Pessoa and D. C. Crans, ACS Symposium Series, Oxford University Press, Washington, DC, USA, 2007, vol. 974.
6. V6 was captured in J. Inorg. Biochem., 2009, vol. 103 and Pure Appl. Chem., 2009, vol. 81.
7. V7 was captured in Coord. Chem. Rev., 2011, vol. 255.
8. V8 was captured in Dalton Trans., 2013, vol. 42.
9. V9 was captured in J. Inorg. Biochem. 2015, vol. 147 and in Coord. Chem. Rev., 2015, vol. 301–302.
10. I. S. Fomenko, A. L. Gushchin, P. A. Abramov, M. N. Sokolov, L. S. Shul'pina, N. S. Ikonnikov, M. L. Kuznetsov, A. J. L. Pombeiro, Y. N. Kozlov and G. B. Shul'pin, Catalysts, 2019, 9(3), 217.
11. S. D. Springer and A. Butler, Coord. Chem. Rev., 2016, 306, 628–635.
12. M. Selman, C. Rousso, A. Bergeron, H. Hee Son, R. Krishnan, N. A. El-Sayes, O. Varette, A. Chen, F. Tzelepis, J. C. Bell, D. C. Crans and J. S. Diallo, Mol. Ther., 2018, 26(1), 56–69.
13. T. Ueki, K. Koike, I. Fukuba and N. Yamaguchi, Zool. Sci., 2018, 35(6), 535–547.

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