The synthesis and characterization of cadmium and mercury complexes of selenocyanate of the type [(L)M(SeCN)2] are described, where L is L-Histidine (His) or L-Glycine (Gly) and M is Cd2+ or Hg2+. These complexes are obtained by the reaction of 1 equivalent of respective amino acids with metal diselenocyanate precursor in a mixture of solvents (methanol？:？water = 1？:？1). These synthesized compounds are characterized by analytical and various spectroscopic techniques such as elemental analysis (EA), IR, and NMR in solution and in the solid state for and . The in vitro antibacterial activities of these complexes have been investigated with standard type cultures of Escherichia coli (MTCC 443), Klebsiella pneumoniae (MTCC 109), Pseudomonas aeruginosa (MTCC 1688), Salmonella typhi (MTCC 733), and Staphylococcus aureus (MTCC 737). 1. Introduction Since the metal ions play vital roles in a number of biological processes such as biomolecules stabilizations, enzyme regulations, transportation of fluids through transmembrane channels, and so forth [1–3], numerous metal ions amino acids complexes also act as potent antifungal, antibacterial, and anticancer drugs [4–6]. Therefore, the extensive studies of these metallic species have been dedicated to understand the impact on living systems. It is well known that metal-binding proteins cover a large fraction of the total protein, and they are actively participating in several essential life processes [2, 3]. Therefore, understanding of the physicochemical and biochemical properties of metals with amino acids becomes indispensible and a broad area of research for several years [7–11]. Among all amino acids found in nature, Histidine is often found as a ligand in various types of metalloenzymes because it is the key amino acids residue in many enzymatic reactions [12]. This is may be due to its stereochemical location of the coordinating atom in Histidine. The Histidine skeleton contains the imidazole side group having two nitrogen atoms capable of participating in metal-ligand coordination sphere thereby it can take on various metal-bound forms in proteins. Thus, it is important to know the coordination modes of the Histidine (His) and Glycine (Gly) ligands to understand the reaction mechanism of metalloenzymes [13]. The coordination modes of various metal ions with amino acids have been the topic of discussion for a long period of time, and the ideas to get the binding modes are not easy to predict for amino acids with large side chain such as Histidine [16], because of different types of donor atoms present in
References
[1]
F. R. Keene, J. A. Smith, and J. G. Collins, “Metal complexes as structure-selective binding agents for nucleic acids,” Coordination Chemistry Reviews, vol. 253, no. 15-16, pp. 2021–2035, 2009.
[2]
J. A. Drewry and P. T. Gunning, “Recent advances in biosensory and medicinal therapeutic applications of zinc(II) and copper(II) coordination complexes,” Coordination Chemistry Reviews, vol. 255, no. 3-4, pp. 459–472, 2011.
[3]
T. Marino, N. Russo, and M. Toscano, “Potential energy surfaces for the gas-phase interaction between α-alanine and alkali metal ions (Li+, Na+, K+). A density functional study,” Inorganic Chemistry, vol. 40, no. 25, pp. 6439–6443, 2001.
[4]
C. Orvig and M. J. Abrams, “Medicinal inorganic chemistry: introduction,” Chemical Reviews, vol. 99, no. 9, pp. 2201–2204, 1999.
[5]
Z. Guo and P. J. Sadler, “Medicinal inorganic chemistry,” Advances in Inorganic Chemistry, vol. 49, pp. 183–306, 1999.
[6]
P. C. Bruijnincx and P. J. Sadler, “New trends for metal complexes with anticancer activity,” Current Opinion in Chemical Biology, vol. 12, no. 2, pp. 197–206, 2008.
[7]
M. Peschke, A. T. Blades, and P. Kebarle, “Metalloion-ligand binding energies and biological function of metalloenzymes such as carbonic anhydrase. A study based on ab initio calculations and experimental ion-ligand equilibria in the gas phase,” Journal of the American Chemical Society, vol. 122, no. 7, pp. 1492–1505, 2000.
[8]
T. Marino, N. Russo, and M. Toscano, “Gas-phase metal ion (Li+, Na+, Cu+) affinities of glycine and alanine,” Journal of Inorganic Biochemistry, vol. 79, no. 1–4, pp. 179–185, 2000.
[9]
T. Marino, M. Toscano, N. Russo, and A. Grannd, “Structural and electronic characterization of the complexes obtained by the interaction between bare and hydrated first-row transition-metal ions (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+) and glycine,” The Journal of Physical Chemistry B, vol. 110, no. 48, pp. 24666–24673, 2006.
[10]
H. Ai, Y. Bu, and K. Han, “Glycine-Zn+/Zn2+ and their hydrates: on the number of water molecules necessary to stabilize the switterionic glycine-Zn+/Zn2+ over the nonzwitterionic ones,” Journal of Chemical Physics, vol. 118, no. 24, p. 10973, 2003.
[11]
H. Pesonen, A. Sillanpa？, R. Aksela, and K. Laasonen, “Density functional complexation study of metal ions with poly(carboxylic acid) ligands—part 1: poly(acrylic acid) and poly(α-hydroxy acrylic acid),” Polymer, vol. 46, no. 26, pp. 12641–12652, 2005.
[12]
K. Hasegawa, T. Ono, and T. Noguchi, “Ab initio density functional theory calculations and vibrational analysis of zinc-bound 4-methylimidazole as a model of a histidine ligand in metalloenzymes,” Journal of Physical Chemistry A, vol. 106, no. 14, pp. 3377–3390, 2002.
[13]
J. A. Leary, Z. Zhou, S. A. Ogden, and T. D. Williams, “Investigations of gas-phase lithium-peptide adducts: tandem. mass spectrometry and semiempirical studies,” Journal of the American Society for Mass Spectrometry, vol. 1, no. 6, pp. 473–480, 1990.
[14]
S. L. Li, J. Y. Wu, Y. P. Tian et al., “Design, crystal growth, characterization, and second-order nonlinear optical properties of two new three-dimensional coordination polymers containing selenocyanate ligands,” European Journal of Inorganic Chemistry, no. 14, pp. 2900–2907, 2006.
[15]
M. Nasiruzzaman Shaikh, B. A. Al-Maythalony, M. I. M. Wazeer, and A. A. Isab, “Complexations of 2-thiouracil and 2,4-dithiouracil with Cd(SeCN)2 and Hg(SeCN)2: NMR and anti-bacterial activity studies,” Spectroscopy, vol. 25, no. 3-4, pp. 187–195, 2011.
[16]
P. Barraud, M. Schubert, and F. H. T. Allain, “A strong chemical shift signature provides the coordination mode of histidines in zinc-binding proteins,” Journal of Biomolecular NMR, vol. 53, no. 2, pp. 93–101, 2012.
[17]
M. I. M. Wazeer, A. A. Isab, and M. Fettouhi, “New cadmium chloride complexes with imidazolidine-2-thione and its derivatives: X-ray structures, solid state and solution NMR and antimicrobial activity studies,” Polyhedron, vol. 26, no. 8, pp. 1725–1730, 2007.
[18]
J. Boeckmann, T. Reinert, and C. N？ther, “Investigations on the thermal reactivity of and selenocyanato coordination compounds,” Zeitschrift für Anorganische und Allgemeine Chemie, vol. 637, no. 7-8, pp. 940–946, 2011.
[19]
S. N. Shukla, P. Gaur, S. Mathews, S. Khan, and A. Srivastava, “Synthesis, characterization, catalytic and biological activity of some bimetallic selenocyanate Lewis acid derivatives of N , - bis (2-chlorobenzylidene)ethylenediamine,” Journal of Coordination Chemistry, vol. 61, no. 24, pp. 3913–3921, 2008.
[20]
S. Sain, T. K. Maji, G. Mostafa, T. H. Lu, M. Y. Chiang, and N. R. Chaudhuri, “Self assembly towards the construction of molecular ladder and rectangular grid of cadmium(II)-selenocyanate,” Polyhedron, vol. 21, no. 22, pp. 2293–2299, 2002.
[21]
T. K. Maji, S. Sain, G. Mostafa, D. Das, T. H. Lu, and N. R. Chaudhuri, “Synthesis and crystal structure of selenocyanato bridged two dimensional supramolecular coordination compounds of cadmium(II),” Journal of the Chemical Society, Dalton Transactions, no. 21, pp. 3149–3153, 2001.
[22]
A. A. Isab and M. I. M. Wazeer, “Complexation of Zn(II), Cd(II) and Hg(II) with thiourea and selenourea: a , , , and solution and solid-state NMR study,” Journal of Coordination Chemistry, vol. 58, no. 6, pp. 529–537, 2005.
[23]
S. Hayashi and K. Hayamizu, “Chemical shift standards in high-resolution solid-state NMR (2) nuclei,” Bulletin of the Chemical Society of Japan, vol. 64, no. 2, pp. 688–690, 1991.
[24]
W. Kemp, NMR in Chemistry, Macmillan Education Ltd., London, UK, 1986.
[25]
K. Eichele and R. E. Wasylischen, W: Simulation Package, Version 1. 4. 4, Dalhousie University, Halifax, Canada; University of Tubingen, Tübingen, Germany, 2001.
[26]
M. J. Colaneri and J. Peisach, “A single crystal EPR and ESEEM analysis of Cu(II)-doped bis(L-histidinato)cadmium dihydrate,” Journal of the American Chemical Society, vol. 117, no. 23, pp. 6308–6315, 1995.
[27]
N. U. Zhanpeisov, M. Matsuoka, H. Yamashita, and M. Anpo, “Cluster quantum chemical ab initio study on the interaction of NO molecules with highly dispersed titanium oxides incorporated into silicalite and zeolites,” Journal of Physical Chemistry B, vol. 102, no. 35, pp. 6915–6920, 1998.
[28]
A. Nicklass, M. Dolg, H. Stoll, and H. Preuss, “Ab initio energy-adjusted pseudopotentials for the noble gases Ne through Xe: calculation of atomic dipole and quadrupole polarizabilities,” The Journal of Chemical Physics, vol. 102, no. 22, pp. 8942–8952, 1995.
[29]
M. Frisch, G. Trucks, H. Schlegel et al., Gaussian 09, Rev. A. 1, Gaussian Inc., Wallingford, Conn, USA, 2009.
[30]
V. Navarro, M. L. Villarreal, G. Rojas, and X. Lozoya, “Antimicrobial evaluation of some plants used in Mexican traditional medicine for the treatment of infectious diseases,” Journal of Ethnopharmacology, vol. 53, no. 3, pp. 143–147, 1996.
[31]
P. Brooks and N. Davidson, “Mercury (II) complexes of imidazole and histidine,” Journal of the American Chemical Society, vol. 82, no. 9, pp. 2118–2123, 1960.
[32]
A. Renuka, K. Shakuntala, and P. C. Srinivasan, Indian Journal of Chemistry, vol. 37A, p. 5, 1998.
