Chemical Papers

, Volume 72, Issue 4, pp 877–882 | Cite as

Tetracoordinate cobalt(II) complexes with neocuproine: single-molecule magnets with potential biological activity

  • Lukáš Smolko
  • Juraj Černák
  • Juraj Kuchár
  • Danica Sabolová
  • Roman Boča
Original Paper


Interaction of two mononuclear tetracoordinate complexes [Co(dmphen)Br2] and [Co(dmphen)I2] (dmphen = 2,9-dimethyl-1,10-phenanthroline), which have been recently reported to behave as single-molecule magnets (SMMs) in an applied external field, with calf thymus (CT) DNA in solution was studied by spectral methods (UV–Vis, fluorescence, and circular dichroism). Results indicate that both complexes along with their chlorido analogue [Co(dmphen)Cl2] are able to bind with the CT DNA via intercalation, with the values of Stern–Volmer constants obtained from the linear quenching plot in range of 1.86 × 104–2.11 × 104 M−1. Furthermore, Topoisomerase I inhibition studies suggest that all three complexes exhibit inhibition activity at concentrations of 45 μM.


Cobalt(II) complexes UV–Vis spectroscopy DNA binding Topoisomerase I inhibition 



This work was financially supported by Slovak grant agencies (APVV-14-0078 and VEGA 1/0131/16 and 1/0063/17). LS acknowledges support of postdoctoral Grant of P. J. Šafárik University in Košice (I-12-0001-13).


  1. Ahmad M, Afzal M, Tabassum S, Kalińska B, Mrozinski J, Bharadwai PK (2014) Synthesis and structure elucidation of a cobalt(II) complex as topoisomerase I inhibitor in vitro DNA binding, nuclease and RBC hemolysis. Eur J Med Chem 74:683–693. doi: 10.1016/j.ejmech.2013.10.025 CrossRefGoogle Scholar
  2. Almáši M, Vargová Z, Sabolová D, Kudláčová J, Hudecová D, Kuchár J, Očenášová L, Gyȍryová K (2015) Ag(I) and Zn(II) isonicotinate complexes: design, characterization, antimicrobial effect, and CT-DNA binding studies. J Coord Chem 68:4423–4443. doi: 10.1080/00958972.2015.1101074 CrossRefGoogle Scholar
  3. Chang EL, Simmers CH, Knight DA (2010) Cobalt complexes as antiviral and antibacterial agents. Pharmaceuticals 3:1711–1728. doi: 10.3390/ph3061711 CrossRefGoogle Scholar
  4. Craig GA, Murray M (2015) 3d single-ion magnets. Chem Soc Rev 44:2147–3135. doi: 10.1039/C4CS00439F CrossRefGoogle Scholar
  5. Frost JM, Katie LM, Murugesu M (2016) The rise of 3-d single-ion magnets in molecular magnetism: towards materials from molecules? Chem Sci 7:2470–2491. doi: 10.1039/C5SC03224E CrossRefGoogle Scholar
  6. Imrich J, Sabolová D, Vilková M, Kudláčová J (2016) Unexpected regiospecific formation and DNA binding of new 3-(acridin-9-yl)methyl-2-iminothiazolidin-4-ones. J Chem Sci 128:269–277. doi: 10.1007/s12039-015-1023-7 CrossRefGoogle Scholar
  7. Karasawa S, Yoshihara D, Watanabe N, Nakano M, Koga N (2008) Formation of monometallic single-molecule magnets with an Stotal value of 3/2 in diluted frozen solution. Dalton Trans. doi: 10.1039/b800087p Google Scholar
  8. Karasawa S, Nakano K, Tanokashira J, Yamamoto N, Yoshizaki T, Koga N (2012) Magnetic properties of 1:4 complexes of CoCl2 and pyridines carrying carbenes (S0 = 4/2, 6/2, and 8/2) in diluted frozen solution; influence of carbene multiplicity on heterospin single-molecule magnets. Dalton Trans 41:13667–16656. doi: 10.1039/c2dt31288c CrossRefGoogle Scholar
  9. McNaught AD, Wilkinson A (1997) Compendium of chemical terminology (the “Gold Book”), 2nd edn. Blackwell Scientific Publications, Oxford, p 1455Google Scholar
  10. Munteanu CR, Suntharalingam K (2015) Advances in cobalt complexes as anticancer agents. Dalton Trans 44:13796–13808. doi: 10.1039/C5DT02101D CrossRefGoogle Scholar
  11. Pommier Y (2006) Topoisomerase I inhibitors: camptothecins and beyond. Nat Rev Cancer 6:789–802. doi: 10.1038/nrc1977 CrossRefGoogle Scholar
  12. Sabolová D, Kožurková M, Plichta T, Ondrušová Z, Hudecová D, Šimkovič M, Pauliková H, Valent A (2011) Interaction of a copper(II)–Schiff base complexes with calf thymus DNA and their antimicrobial activity. Int J Biol Macromol 48:319–325. doi: 10.1016/j.ijbiomac.2010.12.001 CrossRefGoogle Scholar
  13. Shahabadi N, Mohammadi S (2012) Synthesis characterization and DNA interaction studies of a new Zn(II) complex containing different dinitrogen aromatic ligands. Bioinorg Chem Appl 2012:571913. doi: 10.1155/2012/571913 Google Scholar
  14. Smolko L, Černák J, Dušek M, Miklovič J, Titiš J, Boča R (2015) Three tetracoordinate Co(II) complexes [Co(biq)X2] (X = Cl, Br, I) with easy-plane magnetic anisotropy as field-induced single-molecule magnets. Dalton Trans 44:17565–17571. doi: 10.1039/C5DT02827B CrossRefGoogle Scholar
  15. Smolko L, Černák J, Dušek M, Titiš J, Boča R (2016) Tetracoordinate Co(II) complexes containing bathocuproine and single molecule magnetism. New J Chem 40:6593–6598. doi: 10.1039/C6NJ00372A CrossRefGoogle Scholar
  16. Smolko L, Černák J, Kuchár J, Rajnák C, Titiš J, Boča R (2017) Field-induced slow magnetic relaxation in mononuclear tetracoordinate cobalt(II) complexes containing a neocuproine ligand. Eur J Inorg Chem 2017:3080–3086. doi: 10.1002/ejic.201700293 CrossRefGoogle Scholar
  17. Tsiliou S, Kefala LA, Hatzidimitrou AG, Kessissoglou DP, Perdih F, Papadopoulos AN, Turel I, Psomas G (2016) Cobalt(II) complexes with non-steroidal anti-inflammatory drugs and α-diimines. J Inorg Biochem 160:125–139. doi: 10.1016/j.jinorgbio.2015.12.015 CrossRefGoogle Scholar
  18. Zhao J, Li W, Ma R, Chen S, Ren S, Jiang T (2013) Design, synthesis and DNA interaction study of new potential DNA bis-intercalators based on glucuronic acid. Int J Mol Sci 14:16851–16865. doi: 10.3390/ijms140816851 CrossRefGoogle Scholar

Copyright information

© Institute of Chemistry, Slovak Academy of Sciences 2017

Authors and Affiliations

  1. 1.Department of Medical and Clinical BiochemistryP.J. Šafárik University in KošiceKošiceSlovakia
  2. 2.Department of Inorganic ChemistryP.J. Šafárik University in KošiceKošiceSlovakia
  3. 3.Department of BiochemistryP.J. Šafárik University in KošiceKošiceSlovakia
  4. 4.Department of ChemistryUniversity of SS Cyril and MethodiusTrnavaSlovakia

Personalised recommendations