The work continues the study on the peculiarities of the interaction of 1,3,7-trimethylxanthine (caffeine) compounds with polyoxometalates of molybdenum and tungsten with the artificial radical of 1,3,5- triphenylverdazyl (TFV). Using the example of a model reaction with the TFV radical, these compounds showed a special antiradical action. Based on the research results, it was found that the nature of the destruction of the radical when interacting with (HСaf)3[PМ12O40]∙6H2O (where М = Мо, W) differs from most known systems, which are characterized by a mechanism of disproportionation. The data obtained confirmed the previously made assumption about the chemical nature of these interactions. To establish the stoichiometry of the reaction between TFV and (HСaf)3[PW12O40], electrochemical studies were conducted which showed that the activity of the radical is restored after exceeding the concentration ratio of 12 : 1, respectively. The synergism of the components of the compound (HСaf)3[PW12O40] is shown: when TFV interacts with H3[PW12O40], the maximum cathode current characteristic of TFV occurs at a concentration ratio of 4 : 1, respectively, while caffeine has no antiradical effect at all. Previously obtained data from X-ray diffraction analysis of compounds (HСaf)3[PMo12O40]∙6H2O, (HСaf)3[PW12O40]∙6H2O prove that the orientation of protonated caffeine relative to polyoxamethalate-anion is possible due to hydrogen bonds =O…H–N=. This process can result in the delocalization of the charge over the entire O-enriched surface, by all twelve groups [О–Ме–О]-, which are part of the POM, making the latter active centers capable of interacting with TFV.
Therefore, the data presented correlate with the previously obtained results of spectrophotometric analysis and X-ray diffraction data and confirm the previously made conclusions.
Dianat S., Bordbar A. K., Tangestaninejad S., Yadollahi B., Amiri R., Zarkesh-Esfahani S. H., et al. In vitro antitumor activity of free and nano-encapsulated Na5[PMo10V2O40]•nH2O and its binding properties with ctDNA by using combined spectroscopic methods. J InorgBiochem. 2015. 152: 74–81.
Mizuno N., Yamaguchi K., Kamata K. Epoxidation of olefins with hydrogen peroxide catalyzed by polyoxometalates. CoordinChem Rev. 2005. 249 (17–18): 1944–1956.
Hill C. L. Progress and challenges in polyoxometalate-based catalysis and catalytic materials chemistry. J MolCatal a-Chem. 2007. 262 (1–2): 2–6.
Du D. Y., Qin J. S., Li S. L., Lan Y. Q., Wang X. L., Su Z. M. 3d-4f Heterometallic Complexes for the Construction of POM-based Inorganic-Organic Hybrid Compounds: from Nanoclusters to One-Dimensional Ladder-Like Chains. Aust J Chem. 2010. 63 (9): 1389–1395.
Muller A., Peters F., Pope M. T., Gatteschi D. Polyoxometalates: Very large clusters –Nanoscale magnets. Chem Rev. 1998. 98 (1): 239–271.
Kortz U., Muller A., van Slageren J., Schnack J., Dalal N. S., Dressel M. Polyoxometalates: Fascinating structures, unique magnetic properties. CoordinChem Rev. 2009. 253 (19–20): 2315–2327.
Izarova M. P, Kortz U. Edelmetalle in Polyoxometallaten. AngewandteChemie-International Edition. 2012. 124 (38): 9630–9649.
Dolbecq A., Dumas E., Mayer C. R., Mialane P. Hybrid Organic-Inorganic Polyoxometalate Compounds: From Structural Diversity to Applications. Chem Rev. 2010. 110 (10): 6009–6048.
Yamase T., Fujita H., Fukushima K. Medical chemistry of polyoxometalates. Part 1. Potent antitumor activity of polyoxomolybdates on animal transplantable tumors and human cancer xenograft. InorgChimActa. 1988. 151 (1):15–8.
Dianat S., Bordbar A. K., Tangestaninejad S., Yadollahi B., Zarkesh-Esfahani S. H., Habibi P. ctDNA binding affinity and in vitro antitumor activity of three Keggin type polyoxotungestates. J PhotochPhotobio B. 2013. 124: 27–33.
Wang X. H., Liu J. F., Li J. X., Yang Y., Liu J. T., Bin L., et al. Synthesis and antitumor activity of cyclopentadienyltitanium substituted polyoxotungstate [CoW11O39(CpTi)]7- (CP = η5)-C5H5). J InorgBiochem. 2003. 94 (3): 279–284.
Liu J. T., Lu Y. F., Fan S. D. Synthesis, Spectroscopic Characterization and Antitumoral Activities of Cyclopentadienylvanadium Derivatives of Polyoxotungstates. SpectroscSpect Anal. 2012. 32 (9): 2512–2604.
Lee C. H., Cheng S. H., Huang I. P., Souris J. S., Yang C. S., Mou C. Y., et al. Intracellular pH-Responsive Mesoporous Silica Nanoparticles for the Controlled Release of Anticancer Chemotherapeutics. AngewChemInt Edit. 2010. 49 (44): 8214.
Panteleieva O. S., Shtemenko A. V., Domasevitch K. V. Face-to-face stacking of caffeinium and [PMVI12O40]3− ions: A synthon for crystal engineering with purine. Inorganic Chemistry Communications. 2018. 94: 119–122.
Panteleieva O. S., Plyasovska K. A., Shtemenko A. V. Interaction of complex compounds of 1,3,7-trimethylxanthine with anions of polyoxometalates of molybdenum and tungsten with atifical radical. Journal of Chemistry and Technologies. 2019. 27 (2): 141–148. [in Ukrainian].
Tretiak, S. Yu. Vzaymodeistvyebyiadernykhklasterovrenyia(III), soderzhashchykhsviazmetall – metallpovyshennoikratnosty so svobodnыmyradykalamy (Unpublished doctoral dissertation). Ukrainian State University of Chemical Technology, Dnipropetrovsk, Ukraine. 2009 [in Russian].
Dehtiarev L. S., Maletyn Yu. A., Stetsenko A. A. O dysproportsyonyrovanyyverdazylnыkhradykalov v prysutstvyyyonovtsynka y kadmyiaZhurn. Obshcheikhymyy. 1981.51 (10): 2387–2388. [in Russian].
Panteleieva, O. S., Shtemenko, O. V. Syntez, budova ta antyradykalnadiiakompleksnykhspoluk 1,3,7 – trymetylksantyniiu z anionamy polioksometalativmolibdenu ta volframu. Zbirnyknaukovykh prats. XVII Naukovakonf. «Lvivskikhimichnichytannia - 2019» .2019. 11. [in Ukrainian].