1
|
Matyuska F, Szorcsik A, May NV, Dancs Á, Kováts É, Bényei A, Gajda T. Tailoring the local environment around metal ions: a solution chemical and structural study of some multidentate tripodal ligands. Dalton Trans 2017. [PMID: 28650056 DOI: 10.1039/c7dt00104e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Manganese(ii), copper(ii) and zinc(ii) complexes of four polydentate tripodal ligands (tachpyr (N,N',N''-tris(2-pyridylmethyl)-cis,cis-1,3,5-triaminocyclohexane), trenpyr (tris[2-(2-pyridylmethyl)aminoethyl]amine, tach3pyr (N,N',N''-tris(3-pyridylmethyl)-cis,cis-1,3,5-triaminocyclohexane) and tren3pyr (tris[2-(2-pyridylmethyl)aminoethyl]amine)) were characterized in both solution and solid states. A combined evaluation of potentiometric, UV-VIS, NMR and EPR data allowed the conclusion of both thermodynamic and structural information about the complexes formed in solution. The four tailored polydentate tripodal ligands studied here exhibit a high thermodynamic stability, and a variety of coordination environments/geometries for the studied transition metal ions. Our data indicate that tachpyr is a more efficient zinc(ii) chelator and a similar copper(ii) chelator compared to trenpyr. Considering the higher number of N-donors and conformational flexibility of trenpyr, as well as the energy demanding switch to the triaxial conformation required for metal ion binding of tachpyr, the above observation is surprising and is very likely due to the encapsulating effect of the more rigid tachpyr skeleton. This relative binding preference of tachpyr for zinc(ii) may be related to the observation that zinc(ii) is one of the principal metals targeted by tachpyr in cells. In contrast, trenpyr is a considerably more efficient manganese(ii) chelator, since it acts as a heptadentate ligand in the aqueous Mn(trenpyr) complex. The crystal structures of copper(ii) and zinc(ii) complexes of tachpyr indicated important differences in the ligand conformation, induced by the position of counter ions, as compared to earlier reports. The closely related new ligands, tach3pyr and tren3pyr, have been designed to form oligonuclear complexes. Indeed, we obtained a three dimensional polymer with a copper(ii)/tren3pyr ratio of 11/6. Within this metal-organic framework, three distinctly different copper geometries can be identified: square pyramidal, trigonal bipyramidal and tetrahedral. Two square pyramidal and four trigonal bipyramidal copper centres create a hexanuclear subunit with a large inside cavity. These moieties are linked by tetrahedral copper(ii) centres, constructing the three-dimensional polymer structure. The formation of such polynuclear complexes was not detected in solution. Both tach3pyr and tren3pyr form only mononuclear complexes with square pyramidal and trigonal bipyramidal geometries, respectively.
Collapse
Affiliation(s)
- Ferenc Matyuska
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary.
| | - Attila Szorcsik
- MTA-SZTE Bioinorganic Chemistry Research Group, Dóm tér 7, H-6720 Szeged, Hungary
| | - Nóra V May
- Research Centre for Natural Sciences HAS, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Ágnes Dancs
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary.
| | - Éva Kováts
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics HAS, Konkoly Thege Miklós u. 29-33, H-1121 Budapest, Hungary
| | - Attila Bényei
- Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Tamás Gajda
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary. and MTA-SZTE Bioinorganic Chemistry Research Group, Dóm tér 7, H-6720 Szeged, Hungary
| |
Collapse
|
2
|
Csire G, Demjén J, Timári S, Várnagy K. Electrochemical and SOD activity studies of copper(II) complexes of bis(imidazol-2-yl) derivatives. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.05.053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
3
|
Liu YY, Liu HY, Ma JF, Yang Y, Yang J. Syntheses, structures and photoluminescent properties of Zn(ii) and Cd(ii) coordination polymers with flexible tripodal triazole-containing ligands. CrystEngComm 2013. [DOI: 10.1039/c2ce26958a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
4
|
Sarma R, Kalita D, Baruah JB. Solvent induced reactivity of 3,5-dimethylpyrazole towards zinc (II) carboxylates. Dalton Trans 2009:7428-36. [PMID: 19727464 DOI: 10.1039/b905534g] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of 3,5-dimethylpyrazole with zinc(II)acetate dihydrate and varieties of aromatic carboxylic acids led to formation of mono-nuclear zinc complexes of composition [Zn(HDMP)2(RCO2)2] (R = C6H5, p-CH3-C6H4, p-NO2-C6H4 etc. HDMP = 3,5-dimethylpyrazole) in methanol, whereas the same reactants in dimethylformamide (DMF) gave binuclear 3,5-dimethylpyrazolato bridged zinc carboxylate complexes containing monodentate 3,5-dimethylpyraozole ligands with composition [Zn2(mu-DMP)2(HDMP)2(RCO2)2]. The mononuclear complexes can be converted to the corresponding binuclear complexes by simply dissolving in DMF. The reaction of zinc(II)acetate dihydrate with p-nitrobenzoic acid and 3,5-dimethylpyrazole in different solvents gave solvated mononuclear complexes of the corresponding solvent. All these solvated complexes having the core [Zn(HDMP)2(p-NO2-C6H4CO2)2] contain two structurally independent molecules in the asymmetric unit (Z' = 2).
Collapse
Affiliation(s)
- Rupam Sarma
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781 039, Assam, India
| | | | | |
Collapse
|
5
|
Szilágyi O, Ősz K, Várnagy K, Sanna D, Süli-Vargha H, Sóvágó I, Micera G. Potentiometric and spectroscopic studies on the copper(II) and zinc(II) complexes of bis(imidazol-2-yl) derivatives of tripeptides. Polyhedron 2006. [DOI: 10.1016/j.poly.2006.05.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
6
|
Nomkoko TE, Jackson GE, Nakani BS, Hunter R. Solution chemistry of 1,15-bis(N,N-dimethyl)-5,11-dioxo-8-(N-benzyl)-1,4,8,12,15-pentaazapentadecane with metal ions of biological interest-Insights toward active metal ion containing therapeutics and diagnostic agents. Dalton Trans 2006:4029-38. [PMID: 17028712 DOI: 10.1039/b602977a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The equilibrium constants of Cu(II), Zn(II), Ca(II) and Gd(III) with 1,15-bis(N,N-dimethyl)-5,11-dioxo-8-(N-benzyl)-1,4,8,12,15-pentaazapentadecane (La) have been studied at 25 degrees C and an ionic strength of 0.15 mol dm-3. Copper forms more stable complexes with La than the other metal ions investigated. This is probably due to the ease with which Cu(II) deprotonates the nitrogen donor atoms of the amide groups. UV/Vis spectrophotometric data indicate tetradentate binding of the ligand towards copper in [CuLaH-1] and pentadentate binding in [CuLaH-2]. Octanol-water partition coefficients of Cu(II)-La complexes indicate that although these species are largely hydrophilic, approximately 5.62% of the [CuLaH-1] complex goes into the organic phase. This percentage may promote dermal absorption of copper with a calculated penetration rate of 3.75x10(-4) mm h-1. The [CuLaH-1] species which predominates at pH 7.4 is a poor mimic of native copper-zinc superoxide dismutase. Blood-plasma simulation studies predict that La is unable to increase the low molecular mass copper fraction in vivo. This has been confirmed by biodistribution patterns, which are similar to those of 64CuCl2.
Collapse
Affiliation(s)
- Thembelani E Nomkoko
- Department of Chemistry, University of Transkei, P/Bag X1, Unitra, 5117 Umtata, South Africa
| | | | | | | |
Collapse
|
7
|
Correia I, Dornyei A, Jakusch T, Avecilla F, Kiss T, Costa Pessoa J. Water-Soluble Sal2en- and Reduced Sal2en-Type Ligands: Study of Their CuII and NiII Complexes in the Solid State and in Solution. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600030] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
8
|
|
9
|
|
10
|
Jancsó A, Paksi Z, Jakab N, Gyurcsik B, Rockenbauer A, Gajda T. Solution chemical properties and catecholase-like activity of the copper(ii)–Ac-His-His-Gly-His-OH system, a relevant functional model for copper containing oxidases. Dalton Trans 2005:3187-94. [PMID: 16172644 DOI: 10.1039/b507655b] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The solution chemical properties, superoxide dismutase and catecholase activity of the copper(ii)-Ac-His-His-Gly-His-OH (hhgh) complexes were studied to identify functional and structural models of copper-containing oxidases. The solution speciation was determined in the pH range 3-11 by two independent methods (potentiometry and pH-dependent EPR measurements). The results obtained by the two methods agree very well with each other and show the formation of differently protonated CuH(x)L complexes (where x= 2 ,1, 0, -1, -2, -3) in aqueous solution. The spectroscopic (UV-Vis, CD, EPR) data indicate that the coordination of the imidazole rings is a determinant factor in all these complexes. Amide coordinated complexes are dominant only above pH 8. This offers excellent possibilities for structural/functional modelling of copper(ii) containing metalloenzymes. Indeed, the {3N(im)} coordinated CuL species (pH = 6-7) has efficient superoxide dismutase-like activity. The {3N(im),OH(-)} coordinated CuH(-1)L possesses outstanding activity to catalyze the oxidation of 3,5-di-tert-butylcatechol (H(2)dtbc) by dioxygen in 86 wt% methanol-water, providing the first example that copper(ii)-peptide complexes are able to mimic copper containing oxidases.
Collapse
Affiliation(s)
- A Jancsó
- Department of Chemistry, University of Turku, FIN-20014 Turku, Finland
| | | | | | | | | | | |
Collapse
|
11
|
He H, Linder DP, Rodgers KR, Chakraborty I, Arif AM. A thiazole-containing tripodal ligand: synthesis, characterization, and interactions with metal ions and matrix metalloproteinases. Inorg Chem 2004; 43:2392-401. [PMID: 15046516 DOI: 10.1021/ic034811q] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new tripodal ligand, tris[2-(((2-thiazolyl)methylidene)amino)ethyl]amine (Tatren), has been synthesized and characterized by NMR, IR, and UV-visible absorbance spectroscopy and elemental analysis. Tatren forms stable complexes with transition metal ions (Zn(2+), 1; Mn(2+), 2; Co(2+), 3) and the alkaline earth metal ions (Ca(2+), 4; Mg(2+), 5). Single-crystal X-ray structures of 1, 2, and 5 revealed six-coordinate chelate complexes with formula [M(Tatren)](ClO(4))(2) in which the metal centers are coordinated by three thiazolyl N atoms and three acyclic imine N atoms. Crystals of 1, 2, and 5 are monoclinic, P2(1)/c space group. Crystals of 4 are triclinic, P space group. The Ca(2+) complex is eight-coordinate with all N atoms of Tatren and one water molecule coordinated to the metal ion. Spectrophotometric titrations show that formation constants for the chelates of metal ions are >>1 in methanol. Free Tatren inhibits the catalytic domain of matrix metalloproteinase-13 (MMP-13, collagenase-3) with K(i) = 3.5 +/- 0.6 microM. Molecular mechanics-based docking calculations suggest that one leg of Tatren coordinates to the catalytic Zn(2+) in MMPs-2, -9, and -13 with significant hydrogen bonding to backbone amide groups. High-level DFT calculations suggest that, in the absence of nonbonded interactions between Tatren and the enzyme, the most stable first coordination sphere of the catalytic Zn(2+) is achieved with three imidazolyl groups from His residues and two imine N atoms from one leg of Tatren. While complexes (1-3) do not inhibit MMP-13 to a significant extent, 4 does (K(i) = 30 +/- 10 microM). Hence, this study shows that tripodal chelating ligands of this class and their Ca(2+) complexes have potential as active-site inhibitors for MMPs.
Collapse
Affiliation(s)
- Hongshan He
- Department of Chemistry, North Dakota State University, Fargo, North Dakota 58105-5516, USA
| | | | | | | | | |
Collapse
|