Advertisement

Synthesis, spectroscopic studies of new water-soluble Co(II) and Cu(II) macrocyclic complexes of 4,15-bis(2-hydroxyethyl)-2,4,6,13,15,17-hexaazatricyclodocosane: their interaction studies with calf thymus DNA and guanosine 5′ monophosphate

  • Farukh ArjmandEmail author
  • Mubashira Aziz
  • Mala Chauhan
Original Article

Abstract

New water soluble Co(II) 1, Ni(II) 2 and Cu(II) 3 complexes of 4,15-bis(2-hydroxyethyl)-2,4,6,13,15,17-hexaazatricyclodocosane Co(II) were synthesized and characterized by various techniques, viz. elemental analysis, conductivity measurements, infrared, electronic, ESI-MS, 1H and 13C NMR spectroscopy. Molar conductance measurements in aqueous solution showed that complexes 1, 2 and 3 are ionic in nature. On the basis of spectroscopic data, a square planar geometry was assigned to the complexes involving four N-atoms of the two cyclohexane moieties. Interaction studies of 1 and 3 with CT-DNA were carried using UV/Visible absorption spectroscopy, fluorescence spectrophotometry, cyclic voltammetry and viscosity measurements. Absorption spectral traces reveal 27.7 and 23.3% hyperchromism for complexes 1 and 3, respectively indicative of strong binding to CT-DNA. These results were authenticated by fluorescence quenching experiments and viscosity measurements. The intrinsic binding constants K b of 1 and 3 are 2.94 × 104 and 2.71 × 104 M−1, respectively. Early transition metals show preference for O6 position while later ones copper and cobalt prefer N7 position of DNA base guanine. To validate this hypothesis, interaction studies of copper (II) and cobalt (II) complexes were carried out with 5′GMP, which revealed electrostatic interactions are more favored along with hydrogen bonding than coordinate covalent interaction to N7 position of guanine.

Keywords

Binding studies CT-DNA 5′GMP binding studies NMR and UV/vis Fluorescence Macrocyclic complexes 

Abbreviations

CT-DNA

Calf thymus DNA

CV

Cyclic voltammetry

Cy

Cyclohexane

EthBr

Ethidium bromide

5′GMP

5′Guanosine monophosphate

LF

Ligand field

TCNE

Tetracyanoethylene

Notes

Acknowledgments

The authors are grateful to Council of Scientific and Industrial Research, New Delhi, India for generous financial support (Scheme No. 01 (1982)/05-EMR-II). Thanks to Regional Sophisticated Instrumentation Center, Central Drug Research Institute, Lucknow, India for providing elemental analysis, ESI-MS and NMR, Indian Institute of Technology Bombay, Mumbai, India for EPR measurements and Sophisticated Analytical Instrumentation Facility, Punjab University, Chandigarh, India for running the NMR experiments.

References

  1. 1.
    Wei, W.-H., Fountain, M., Magda, D., Wang, Z., Lecane, P., Mesfin, M., Miles, D., Sessler, J.L.: Gadolinium texaphyrin–methotrexate conjugates. Towards improved cancer chemotherapeutic agents. Org. Biomol. Chem. 3, 3290–3296 (2005)CrossRefGoogle Scholar
  2. 2.
    Mody, T.D., Fu, L., Sessler, J.L.: In: Karlin, K.D. (ed.) Progress in Inorganic Chemistry, vol. 49, p 551. John Wiley & Sons, Ltd, Chichester (2001)Google Scholar
  3. 3.
    Wang, X., Zhang, X., Lin, J., Chen, J., Xu, Q., Guo, Z.: DNA-binding property and antitumor activity of bismuth(III) complex with 1,4,7,10-tetrakis(2-pyridylmethyl)-1,4,7,10-tetraazacyclododecane. Dalton Trans. (12) 2379–2380 (2003)Google Scholar
  4. 4.
    Li, W.P., Meyer, L.A., Anderson, C.J.: Radiopharmaceuticals for positron emission tomography imaging of somatostatin receptor positive tumors. Top. Curr. Chem., 252, 179 Springer Berlin/Heidelberg. (2005); Liu, S.: The role of coordination chemistry in the development of target-specific radiopharmaceuticals. Chem. Soc. Rev. 33, 445–461 (2004); Liu, S., Edwards, D.S.: Fundamentals of receptor-based diagnostic metalloradiopharmaceuticals. Top. Curr. Chem. 222, 259–278 (2002); Liu, S., Edwards, D.S.: Bifunctional chelators for therapeutic lanthanide radiopharmaceuticals. Bioconjug. Chem. 12, 7–34 (2001)Google Scholar
  5. 5.
    Fuzerova, S., Kotek, J., Cisarova, I., Hermann, P., Binnemans, K., Lukes, I.: Cyclam (1,4,8,11-tetraazacyclotetradecane) with one methylphosphonate pendant arm: a new ligand for selective copper(II) binding. Dalton Trans. (17) 2908–2915 (2005)Google Scholar
  6. 6.
    Hegg, E.L., Deal, K.A., Kiessling, L.L., Burstyn, J.N.: Hydrolysis of double-stranded and single-stranded RNA in hairpin structures by the copper(II) macrocycle Cu([9]aneN3)Cl2. Inorg. Chem. 36, 1715–1718 (1997)CrossRefGoogle Scholar
  7. 7.
    Hegg, E.L., Mortimore, S.H., Cheung, C.L., Huyett, J.E., Powell, D.R., Burstyn, J.N.: Structure-reactivity studies in copper(II)-catalyzed phosphodiester hydrolysis. Inorg. Chem. 38, 2961–2968 (1999)CrossRefGoogle Scholar
  8. 8.
    Deal, K.A., Hengge, A.C., Burstyn, J.N.: Characterization of transition states in dichloro(1,4,7-triazacyclononane)copper(II)-catalyzed activated phosphate diester hydrolysis. J. Am. Chem. Soc., 118, 1713–1718 (1996)CrossRefGoogle Scholar
  9. 9.
    Bernhardt, P.V., Kilah, N.L., Meacham, A.P., Meredith, P., Vogel, R.: Immobilisation of electroactive macrocyclic complexes within titania films Dalton Trans. 2508–2575 (2005); Siegfried, L., Kaden, T.A.: Kinetic studies of the on/off reaction of the amino group in the side chain of Cu(II), Ni(II), and Co(II) complexes with 14-membered tetraazamacrocycles. Dalton Trans. (18) 3079–3082 (2005); Choi, K.Y., Lee, H.-H., Park, B.-B., Kim, J.H., Kim, M.W., Ryu, J.W., Suh, M., Suh, I.-H.: Synthesis and properties of nickel(II) and copper(II) complexes of a di-N-acetamide tetraaza macrocycle. Polyhedron. 20, 2003–2009 (2001)Google Scholar
  10. 10.
    Gokel, G.W., Barbour, L.J., Wall, S.L., Meadows, E.S.: Macrocyclic polyethers as probes to assess and understand alkali metal cation–π interactions. Coord. Chem., Rev. 222, 127–154 (2001); Jiang, P., Guo, Z.: Fluorescent detection of zinc in biological systems: recent development on the design of chemosensors and biosensors. Coord. Chem., Rev. 248, 205–229 (2004); Tei, L., Blake, A.J., Bencini, A., Valtancoli, B., Wilson, C., Schroder, M.: Synthesis, solution studies and structural characterisation of complexes of a mixed oxa–aza macrocycle bearing pendant amino arms. J. Chem. Soc., Dalton Trans. (22) 4122–4129 (2000); Mathur, S., Tabassum, S.: Synthesis and characterization of a new macrocyclic copper(II) complex with an N-Glycosidic pendant arm: in vitro cytotoxicity and binding studies with calf-thymus DNA. Chem. Biodiv. 3, 312–325 (2006)Google Scholar
  11. 11.
    Kang, S.G., Kweon, J.K., Jeong, J.H.: Preparation of new tetraaza macrocyclic nickel(II) and copper(II) complexes bearing N-propionic methyl ester groups. Inorg. Chim. Acta. 360, 1875–1882 (2007); Kang, S.G., Kim, M.-S., Choi, J.-S., Whang, D., Kim, K.: Synthesis and characterization of a di-N-hydroxyethylated tetraaza macrocycle and its nickel(II) and copper(II) complexes: crystal structure of the nickel(II) complex. J. Chem. Soc., Dalton Trans. (3) 363–366 (1995)Google Scholar
  12. 12.
    Kikuta, E., Murata, M., Katsube, N., Koike, T., Kimura, E.: Novel Recognition of Thymine base in double stranded DNA by zinc(II)-macrocyclic tetyraamine complexes appended with aromatic groups. J. Am. Chem. Soc. 121, 5426–5436 (1999); Aoki, S., Kimura, E., Highly selective recognition of thymidine mono- and diphosphate nucleotides in aqueous solution by ditopic receptors zinc(II)-Bis(cyclen) complexes(cyclen = 1,4,7,10-Tetraazacyclododecane). J. Am. Chem. Soc. 122, 4542–4548 (2000); Kimura, E., Kitamura, H., Ohtani, K., Loike, T.: Elaboration of selective and efficient recognition of thymine base in dinucleotides (TpT, ApT, CpT, and GpT), single-stranded d(GTGACGCC), and double-stranded d(CGCTAGCG)2 by Zn2+-acridinylcyclen (Acridinylcyclen = (9-Acridinyl)methyl-1,4,7,10-tetraazacyclododecane) J. Am. Chem. Soc. 122, 4668–4677 (2000); Kikuta, E., Matsubara, R., Katsube, N., Koike, T., Kimura, E.: Selective recognition of consecutive G sequence in double-stranded DNA by a Zinc(II)-macrocyclic tetraamine complex appended with an anthraquinone. J. Inorg. Biochem. 82, 239–249 (2000)Google Scholar
  13. 13.
    Wender, P.A., Debrabander, J., Harram, P.G., Jimenez, J.M., Koehler, M.F.T., Lippa, B., Park, C.-M., Siedenbiedel, C., Pettit, G.R.: The design, computer modeling, solution structure, and biological evaluation of synthetic analogs of bryostatin 1. Proc. Natl. Acad. Sci USA, 95, 6624–6629 (1998)CrossRefGoogle Scholar
  14. 14.
    Zhang, C.X., Lippard, S.J.: New metal complexes as potential therapeutics. Curr. Opin. Chem. Biol., 7, 481–489 (2003); Orvig, C., Abrams, M.J., Special issue on medicinal chemistry. Chem. Rev. 99 (9) (1999)Google Scholar
  15. 15.
    Vaidyanathan, V.G., Nair, B.U.: Oxidative cleavage of DNA by tridentate copper (II) complex. J. Inorg. Biochem. 93, 271–276 (2003); Silvestri, A., Barone, G., Ruisi, G., Giudice, M.T., Tumminello, S.: The interaction of native DNA with iron(III)-N,N′-ethylene-bis(salicylideneiminato)-chloride. J. Inorg. Biochem, 98, 589–594 (2004); Ren, R., Yang, P., Zheng, W., Hua, Z.: A simple copper(II)-l-histidine system for efficient hydrolytic cleavage of DNA. Inorg. Chem. 39, 5454–5463 (2000); Yang, P., Wang, H.F., Gao, F., Yang, B.S.: Antitumor activity of the Cu(II)-mitoxantrone complex and its interaction with deoxyribonucleic acid. J. Inorg. Biochem. 62,137–145 (1996)Google Scholar
  16. 16.
    Apelgot, S., Coppey, J., Fromentin, A., Guille, E., Poupon, M.F., Roussel, A.: Altered distribution of copper (64Cu) in tumor-bearing mice and rats. Anticancer Res. 6, 159–164 (1986)Google Scholar
  17. 17.
    Hettich, R., Schneider, H.J.: Cobalt(III) polyamine complexes as catalysts for the hydrolysis of phosphate esters and of DNA. A measurable 10 million-fold rate increase. J. Am. Chem. Soc. 119, 5638–5647 (1997); Delehanty, J.B., Stuart, T.C., Knight, D.A., Goldman, E.-R., Thach, D.C., Bongard, J.E., Chang, E.L.: RNA hydrolysis and inhibition of translation by a Co(III)-cyclen complex. RNA, 11, 831 (2005)Google Scholar
  18. 18.
    Perez, J.M., Kelland, L.R., Montero, E.I., Boxal, F.E., Fuertes, M.A., Alonso, C., Ranninger, C.N.: Antitumor and cellular pharmacological properties of a novel Platinum(IV) complex: trans-[PtCl2(OH)2(Dimethylamine) (Isopropylamine)]. Mol. Pharmacol. 63, 933–944 (2003); Najajreh, Y., Perez, J.M., Ranninger, C. N, Gibson, D.: Novel soluble cationic trans-diaminedichloroplatinum(II) complexes that are active against cisplatin resistant ovarian cancer cell lines. J. Med. Chem. 45, 5189–5195 (2002); Kelland, L.R., Abel, G., Mckeage, M.J., Jones, M., Goddard, P.M., Valenti, M., Murrer, B.A., Harrap, K.R.: Preclinical antitumor evaluation of bis-acetato-ammine-dichloro-cyclohexylamine platinum(IV): an orally active platinum drug. Cancer Res. 53, 2581–2586 (1993)Google Scholar
  19. 19.
    Marmur, J.: Procedure for isolation of deoxyribonucleic acid from microorganism. J. Mol. Biol. 3, 208–214 (1961)CrossRefGoogle Scholar
  20. 20.
    Reicmann, M.E., Rice, S.A., Thomas, C.A., Doty, P.: A further examination of the molecular weight and size of desoxypentose nucleic acid. J. Am. Chem. Soc. 76, 3047–3053 (1954)CrossRefGoogle Scholar
  21. 21.
    Wolfe, A., Shimer, G.H., Meehan, T.: Polycyclic aromatic hydrocarbons physically intercalate into duplex regions of denatured DNA. Biochemistry 26, 6392–6396 (1987)Google Scholar
  22. 22.
    Lakowiez, J.R., Webber, G.: Quenching of fluorescence by oxygen. Probe for structural fluctuations in macromolecules. Biochemistry 12, 4161–4170 (1973)CrossRefGoogle Scholar
  23. 23.
    Cohen, G., Eisenberg, H.: Viscosity and sedimentation study of sonicated DNA–proflavine complexes. Biopolymers 8, 45–55 (1969)CrossRefGoogle Scholar
  24. 24.
    Eriksson, M., Leijon, M., Hiort, C., Norden, B., Graslund, A.: Binding of .DELTA.- and .LAMBDA.-[Ru(phen)3]2+ to [d(CGCGATCGCG)]2 studied by NMR. Biochemistry. 33, 5031–5040 (1994)Google Scholar
  25. 25.
    Nogrady, T.: Medicinal Chemistry, a Biochemical Approach. Oxford University press, New York, Oxford, 1985, p6Google Scholar
  26. 26.
    Comba, P., Luther, S.M., Maas, O., Pritzkow, H., Vielfort, A.: Template synthesis of a tetraazamacrocyclic ligand with two pendant pyridinyl groups: properties of the isomers of the metal-free ligand and of their first-row transition metal compounds. Inorg. Chem. 40, 2335–2345 (2001)CrossRefGoogle Scholar
  27. 27.
    Annigeri, S.M., Sathisha, M.P., Revankar, V.K.: Spectroscopic studies of bridged binuclear complexes of Co(II), Ni(II), Cu(II) and Zn(II). Transit. Met. Chem. 32, 81–87 (2007)CrossRefGoogle Scholar
  28. 28.
    Du, G., Ellern, A., Woo, L.K.: Synthesis and characterization of chiral tetraaza macrocyclic Nickel(II) and Palladium(II) complexes. Inorg. Chem. 42, 873–877 (2003)CrossRefGoogle Scholar
  29. 29.
    Vicente, M., Bastida, R., Lodeiro, C., Macias, A., Parola, A.J., Valencia, L., Spey, S.E.: Metal complexes with a new N4O3 amine pendant-armed macrocyclic ligand: synthesis, characterization, crystal structures, and fluorescence studies. Inorg. Chem. 42, 6768–6779 (2003)CrossRefGoogle Scholar
  30. 30.
    Chen, Y., Liu, Q., Deng, Y., Zhu, H., Chen, C., Fan, H., Liao, D., Gao, E.: Vanadium, molybdenum, and sodium triethanolamine complexes derived from an assembly system containing tetrathiometalate and triethanolamine. Inorg. Chem. 40, 3725–3733 (2001)CrossRefGoogle Scholar
  31. 31.
    Channa, A., Steed, J.W.: Anion and cation binding by a pendant arm cyclam and its macrobicyclic derivatives. Dalton Trans. 2455–2461 (2005)Google Scholar
  32. 32.
    Xie, Y., Bu, W., Chen, A.S.-C., Xu, X., Liu, Q., Zhang, Z.: Synthesis, crystal structure and EPR of a hydrogen bonded two-dimensional network of Cu(II) complex with N-(2-hydroxybenzyl)-2-amino-1-ethanol. Inorg. Chim Acta, 310, 257–260 (2000)CrossRefGoogle Scholar
  33. 33.
    Tabassum, S., Parveen, S., Arjmand, F.: New modulated metallic macrocycles: electrochemistry and their interaction with calf thymus DNA. Acta Biomat. 1, 677–689 (2005)CrossRefGoogle Scholar
  34. 34.
    Gao, J., Reibenspies, J.H., Zingaro, R.A., Woolley, F.R., Martell, A.E., Clearfield, A.: Novel chiral “Calixsalen” macrocycle and chiral robson-type macrocyclic complexes. Inorg. Chem. 44, 232–241 (2005); Gregolinski, J., Lisowski, J., Lis, T.: New 2 + 2, 3 + 3 and 4 + 4 macrocycles derived from 1,2-diaminocyclohexane and 2,6-diformylpyridine. Org. Biomol. Chem. 3, 3161–3166 (2005)Google Scholar
  35. 35.
    Kuhnert, N., Periago, A.L., Rossignolo, G.M.: The synthesis and conformation of oxygenated trianglimine macrocycles. Org. Biomol. Chem., 3, 524–537(2005); Gao, J., Martell, A.E.: Novel chiral N4S2- and N6S3-donor macrocyclic ligands: synthesis, protonation constants, metal-ion binding and asymmetric catalysis in the Henry reaction. Org. Biomol. Chem. 1, 2801–2806 (2003)Google Scholar
  36. 36.
    Li, S.-A., Xia, J., Yang, D.-X., Xu, Y., Li, D.-F., Wu, M.-F., Tang, W.-X.: Carboxyester hydrolysis catalyzed by a novel dicopper(II) complex with an alcohol-pendant macrocycle. Inorg. Chem. 41, 1807–1815 (2002)CrossRefGoogle Scholar
  37. 37.
    Suh, M.P., Kang, S.-G.: Synthesis and properties of nickel(II) and copper(II) complexes of 14-membered hexaaza macrocycles, 1,8-dimethyl- and 1,8-diethyl-1,3,6,8,10,13-hexaazacyclotetradecane. Inorg. Chem. 27, 2544–2546 (1988)CrossRefGoogle Scholar
  38. 38.
    Aneetha, H., Lai, Y.-H., Lin, S.-C., Panneersellvam, K., Lu, T.H., Chang, C.-S.: Copper(II) complexes of tetraaza macrocycles bearing pendant arms: syntheses, structures and properties. J. Chem. Soc., Dalton Trans. 2885–2892 (1999); Prasad, R.N., Agrawal, M., Sharma, S.: Copper(II) complexes of tetraazamacrocycles derived from b-diketones and diaminoalkanes. Indian J. Chem. 43A, 337–340 (2004)Google Scholar
  39. 39.
    Naik, A.D., Annigeri, S.M., Gangadarmath, U.B., Revankar, V.K., Mahale, V.B.: Bimetallic complexes of a potentially pentadentate, acyclic, symmetrical compartmental Schiff base ligand that provides suitable topology for an exogenous bridge. Transit. Met. Chem. 27, 333–336 (2002)CrossRefGoogle Scholar
  40. 40.
    Chauhan, M., Arjmand, F.: Synthesis, characterization and interaction of a new chiral trinuclear complex [bis(aquodiaminotryptophanato) CuII–Sn2IV]chloride with calfthymus DNA. Transit. Met. Chem. 30, 481–487 (2005); Inoue, K.-J., Ohba, M., Okawa, H.: Heterodinuclear MIINiII (M = Co, Ni, Cu, Zn) Complexes of a macrocyclic compartmental ligand. Anomalous EPR of CuIINiII complex by coordination of 1-methylimidazole. Bull. Chem. Soc. Jpn. 75, 99–107 (2002)Google Scholar
  41. 41.
    Srinivasan, S., Athapan, P., Rajagopal, G.: Synthesis, spectral and redox properties of metal complexes of macrocyclic tetraaza chiral Schiff bases. Transit. Met. Chem. 26, 588–593 (2001)CrossRefGoogle Scholar
  42. 42.
    Dong, Y., Lindoy, L.F., Turner, P., Wei, G.: Three-ring, branched cyclam derivatives and their interaction with nickel(II), copper(II), zinc(II) and cadmium(II). Dalton Trans. (8) 1264–1270 (2004)Google Scholar
  43. 43.
    Chandra, S., Sangeetika, Thakur, S.: Electronic, e.p.r., cyclic voltammetric and biological activities of copper(II) complexes with macrocyclic ligands. Transit. Met. Chem. 29, 925–935 (2004)CrossRefGoogle Scholar
  44. 44.
    Escander, G.M., Sala, L.F.: Complexes of Cu(II) with d-aldonic and d-alduronic acids in aqueous solution. Can. J. Chem. 70, 2053–2057 (1992)CrossRefGoogle Scholar
  45. 45.
    Chen, J., Wang, X., Shao, Y., Zhu, J., Li, Y., Xu, Q., Guo, Z.: A trinuclear copper(II) complex of 2,4,6-Tris(di-2-pyridylamine)-1,3,5-triazine shows prominent DNA cleavage activity. Inorg. Chem. 46, 3306–3312 (2007); Chauhan, M., Banerjee, K., Arjmand, F.: DNA binding studies of novel copper (II)containing l-tryptophan as chiral auxillary: in vitro antitumor activity of Cu–Sn2 complex in human neuroblastoma cells. Inorg. Chem. 46, 3072–3082 (2007)Google Scholar
  46. 46.
    Baldini, M., Ferrari, M.-B., Bisceglie, F., Pelosi, G., Pinelli, S., Tarasconi, P.: Cu(II) complexes with heterocyclic substituted thiosemicarbazones: the case of 5-formyluracil. synthesis, characterization, X-ray structures, DNA interaction studies, and biological activity. Inorg. Chem. 42, 2049–2055 (2003); Chauhan, M., Arjmand, F.: Chiral and achiral macrocyclic copper(II) complexes: synthesis, characterization, and comparative binding studies with calf-thymus DNA. Chem. Biodiv. 3, 660–676 (2006)Google Scholar
  47. 47.
    Daniele, P.G., Prenesti, E., Berto, S., Zelano, V., Aruga, R.: Complexes of copper(II) with adenosine or guanosine nucleosides, nucleotides 5′-monophosphate, 2′-deoxynucleosides or 2′-deoxynucleotides 5′-monophosphate in aqueous solution. Ann. Chim., 94, 229–239 (2004); Gao, Y.G., Sriram, M., Wang, A.H.J.: Crystallographic studies of metal ion–DNA interactions: different binding modes of cobalt(II), copper(II) and barium(II) to N7of guanines in Z-DNA and a drug-DNA complex. Nucleic Acids Res. 21, 4093–4101 (1993)Google Scholar
  48. 48.
    Moradell, S., Lorenzo, J., Rovira, A., Robillard, M.S., Aviles, F.X., Moreno, V., de Llorens, R.., Martinez, M.A., Reedijk, J., Llobet, A.: Platinum complexes of diaminocarboxylic acids and their ethyl ester derivatives: the effect of the chelate ring size on antitumor activity and interactions with GMP and DNA. J. Inorg. Biochem. 96, 493–502 (2003)CrossRefGoogle Scholar
  49. 49.
    Robertazzi, A., Platts, J.A.: Binding of transition metal complexes to guanine and guanine–cytosine: hydrogen bonding and covalent effects. J. Biol. Inorg. Chem. 10, 854–866 (2005)CrossRefGoogle Scholar
  50. 50.
    Manning, G.S.: The molecular theory of polyelectrolyte solutions with applications to the electrostatic properties of polynucleotides. Q. Rev. Biophys. 11, 179–246 (1978)CrossRefGoogle Scholar
  51. 51.
    Li, H., Le, X.-Y., Pang, D.W., Deng, H., Xu, Z.H., Lin, Z.-H.: DNA-binding and cleavage studies of novel copper(II) complex with l-phenylalaninate and 1,4,8,9-tetra-aza-triphenylene ligands. J. Inorg. Biochem, 99, 2240–2247 (2005)CrossRefGoogle Scholar
  52. 52.
    Selvakumar, B., Rajendiran, V., Maheswari, P.V., Evans, H.S., Palanaindavar, M.: Structures, spectra, and DNA-binding properties of mixed ligand copper(II) complexes of iminodiacetic acid: the novel role of diimine co-ligands on DNA conformation and hydrolytic and oxidative double strand DNA cleavage. J. Inorg. Biochem. 100, 316–330 (2006)CrossRefGoogle Scholar
  53. 53.
    Selvi, P.T., Evans, H. -S., Palanaindavar, M.: Synthesis, structure and DNA interaction of cobalt(III) bis-complexes of 1,3-bis(2-pyridylimino)isoindoline and 1,4,7-triazacyclononane. J. Inorg. Biochem. 99, 2110–2118 (2005)CrossRefGoogle Scholar
  54. 54.
    Satyanarayana, S., Dabrowiak, J.C., Chaires, J.B.: Tris(phenanthroline)ruthenium(II) enantiomer interactions with DNA: Mode and specificity of binding. Biochemistry. 32, 2573–2584 (1993)Google Scholar
  55. 55.
    Vaidyanathan, V.G., Nair, B.U.: Synthesis, characterization and electrochemical studies of mixed ligand complexes of ruthenium(II) with DNA. Dalton Trans. (17) 2842–2848 (2005)Google Scholar
  56. 56.
    Liu, J., Lu, T.B., Li, H., Zhang, Q., Ji, L.N., Zhang, T.X., Qu, L.H., Zhou, H.: DNA-binding and cleavage studies of a dinuclear copper(II) complex with a 26-membered hexaazamacrocycle. Transit. Met. Chem. 27, 686–690 (2002)CrossRefGoogle Scholar
  57. 57.
    Kang, J., Wu, H., Lu, X., Wang, Y., Zhou, L.: Study on the interaction of new water-soluble porphyrin with DNA. Spectrochim. Acta A, 61, 2041–2047 (2005)CrossRefGoogle Scholar
  58. 58.
    Liu, J., Zhang, T., Lu, T., Qu, L., Zhou, H., Zhang, C., Ji, L.: DNA-binding and cleavage studies of macrocyclic copper(II) complexes. J. Inorg. Biochem. 91, 269–276 (2002)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Department of ChemistryAligarh Muslim UniversityAligarhIndia

Personalised recommendations