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Dissimilar effect of organometallic ruthenium complexes on the viability of MDR and non-MDR experimental models. J Inorg Biochem 2024; 257:112614. [PMID: 38781850 DOI: 10.1016/j.jinorgbio.2024.112614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 05/15/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
Ruthenium complexes containing triphenylphosphine diamide ligands were prepared, characterized, and tested for their biological activity against various cancer cell lines and the malaria parasite, Plasmodium falciparum. The effect of M (mono-substituted) and B (bis-substituted) complexes on the human cervical carcinoma (HeLa) cell line was investigated using the MTT assay. Five (B2, B3, B5, B6, and B13) of the 24 synthesized ruthenium complexes showed significant effects with IC50 values ranging between 0.3 and 2.3 μM. Evaluation of the potential biomolecular targets of B2 and B13 by fluorescence spectroscopy revealed relevant interactions with BSA and only a weak affinity for ctDNA. Complexes M2, B2, M13 and B13 were selected for further biological characterization. Their effect on the viability of two ovarian cancer cell lines was compared to normal cell lines, denoting their selectivity. Upon treatment of four different drug-resistant gynaecological cancer cell lines, differing in their multidrug-resistant phenotypes, the efficacy of the bis-substituted complexes was shown to be greater than their mono-substituted counterparts. The non-MDR cells are sensitive to all the tested complexes, compared to MDR cells which are less sensitive. Upon investigation of complexes M2, M13, B2, and B13 against sensitive and multidrug-resistant parasite strains of P. falciparum, the bis-substituted complexes were again shown to be the most potent, with submicromolar activity against both strains. Furthermore, the resistance indexes for the complexes were approximately equal to 1, which is at least 5-fold lower than chloroquine diphosphate, suggesting the ability of these complexes to retain their activity in resistant forms of the parasite.
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2
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Turn-on fluorescence of ruthenium pyrene complexes in response to bovine serum albumin. Dalton Trans 2023; 52:11698-11704. [PMID: 37555301 DOI: 10.1039/d3dt02289g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Two novel pyrene triphenylphosphine ruthenium conjugates act as fluorescent turn-on beacons for serum albumin, being non-fluorescent in aqueous media but exhibiting strong emission upon binding to BSA. The selective cytotoxicity of the compounds against tumour cells is enhanced upon irradiation by UV-light, paving the way for application in photodynamic therapy under two-photon excitation.
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3
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Synthesis, characterisation and biological evaluation of monometallic Re(I) and heterobimetallic Re(I)/Fe(II) complexes with a 1,2,3-triazolyl pyridine chelating moiety. Dalton Trans 2023. [PMID: 37366535 DOI: 10.1039/d3dt01070h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Bioorganometallic complexes have attracted considerable interest and have shown promise for potential application in the treatment and diagnosis of cancer, as well as bioimaging agents, some acting as theranostic agents. The series of novel ferrocene, benzimidazo[1,2-a]quinoline and fluorescein derivatives with bidentate pyridyl-1,2,3-triazole and 2,2'-dipyridylamine and their tricarbonylrhenium(I) complexes was prepared and fully characterised by NMR, single-crystal X-ray diffraction, UV-Vis and fluorescence spectroscopy in biorelevant conditions. The fluorescein and benzimidazo[1,2-a]quinoline ligands and their complexes with Re(I) showed interactions with ds-DNA/RNA and HSA, characterised by thermal denaturation measurements, fluorimetric and circular dichroism titrations. The binding constants revealed that addition of Re(I) increases the affinity of fluorescein but decreases the affinity of benzimidazo[1,2-a]quinoline. The complexation of Re(I) had the opposite effect on fluorescein and benzimidazo[1,2-a]quinoline ligands' fluorimetric sensitivity upon biomacromolecule binding, Re(I) fluorescein complex emission being strongly quenched by DNA/RNA or HSA, while emission of Re(I) benzimidazo[1,2-a]quinolone complex was enhanced, particularly for HSA, making it a promising fluorescent probe. Some mono- and heterobimetallic complexes showed considerable antiproliferative activity on colon cancer cells (CT26 and HT29), with ferrocene dipyridylamine complexes exhibiting the best inhibitory activity, comparable to cisplatin. The correlation of the cytotoxicity data with the linker type between the ferrocene and the 1,2,3-triazole ring suggests that direct binding of the metallocene to the 1,2,3-triazole is favourable for antitumor activity. The Re(I) benzimidazo[1,2-a]quinolone complex showed moderate antiproliferative activity, in contrast to the Re(I) fluorescein complex, which exhibited weak activity on CT26 cells and no activity on HT29 cells. The accumulation of the Re(I) benzimidazo[1,2-a]quinolone complex in the lysosomes of CT26 cells indicates the site of its bioactivity, thus making this complex a potential theranostic agent.
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4
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Ferrocene conjugates linked by 1,2,3‐triazole and their Zn(II) and Cu(II) complexes: Synthesis, characterization and biological activity. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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5
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Tandem amide coupling and hydroamination: unexpected benzotriazole oxide addition to the propiolic acid triple bond. NEW J CHEM 2022. [DOI: 10.1039/d2nj02587f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An unexpected tandem reaction consisting of amide coupling and hydroamination occurring with common triazole coupling reagents.
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6
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Tuning the coordination properties of chiral pseudopeptide bis(2-picolyl)amine and iminodiacetamide ligands in Zn( ii) and Cu( ii) complexes. Dalton Trans 2022; 51:17008-17021. [DOI: 10.1039/d2dt02895f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Modifications of the chiral side chains of bpa and imda ligands lead to different metal ion coordination and hydrogen bonding ability.
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8
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Induction of Λ-helicity in a zinc complex with an alanine-appended aminopyridine ligand. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2021; 77:449-457. [PMID: 34350842 DOI: 10.1107/s2053229621006471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/21/2021] [Indexed: 11/10/2022]
Abstract
The crystal structure of tris[dimethyl 5-({1-[(pyridin-2-yl-κN)carbamoyl-κO]ethyl}carbamoyl)benzene-1,3-dicarboxylate]zinc(II) dinitrate acetonitrile trisolvate, [Zn(C19H19N3O6)3](NO3)2·3CH3CN or [Zn(L)3](NO3)2·3CH3CN, (1), has been determined by single-crystal X-ray diffraction. The neutral ligand L coordinates to the Zn2+ cation in a bidentate fashion via the pyridine N atom and an amide O atom, forming a six-membered chelate ring. The Λ-helical chirality of the Zn2+ coordination sphere is induced by pendant L-alanine residues through stacking interactions between the arene groups of two coordinated ligands, assisted by a hydrogen bond between amide groups bonded to the stacked arene rings. The third ligand is coordinated to the Zn2+ cation by the same six-membered chelate ring, but in the opposite direction with respect to the analogous chelate rings of the first two coordinated ligands. Besides ionic interactions between [ZnL3]2+ complexes and NO3- anions, several types of hydrogen bonds and intermolecular stacking interactions contribute to the stability of the solid-state phase.
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9
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Abstract
A ferrocene pseudopeptide chiroptical switch sensitive to solvent exchange and acid addition with a response in the visible region of CD spectra.
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10
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Symmetry breaking in the solid state of 9,10-anthracene amino acid conjugates as seen by X-ray diffraction and NMR spectroscopy. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Copper(ii) and zinc(ii) complexes of mono- and bis-1,2,3-triazole-substituted heterocyclic ligands. Dalton Trans 2020; 49:9002-9015. [PMID: 32558875 DOI: 10.1039/d0dt01244k] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chelating 1,4-disubstituted mono- (8a-8d) and bis-1,2,3-triazole-based (9a-11a) ligands were prepared by regioselective copper(i)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of l-phenylalanine methyl ester to 11a. Cu(ii) and Zn(ii) complexes were prepared and single crystal structures were determined for complexes 8aCu, 8dCu, 9cCu and 10cCu, as well as the free ligands 10a and 10c. The in situ prepared Zn(ii) complexes were studied by NMR spectroscopy, while the stoichiometry of the Cu(ii) complexes in solution was determined by UV-Vis titrations and confirmed by the electronic structure DFT calculations at the (SMD)/M05-2X/6-31+G(d)/LanL2DZ+ECP level of theory.
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12
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Stereochemistry of Hexacoordinated Zn(II), Cu(II), Ni(II), and Co(II) Complexes with Iminodiacetamide Ligands. Inorg Chem 2019; 58:16445-16457. [PMID: 31774277 DOI: 10.1021/acs.inorgchem.9b02200] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Metal complexes of iminodiacetamide (imda) ligands and metal ions Zn(II), Cu(II), Ni(II), and Co(II) were prepared using eight imda ligands (L1-L8) substituted with groups of different steric and electronic properties on the central amine N atom (H atom, methyl, isopropyl, and benzyl) and the para position of the phenyl rings (nitro and dimethylamino). The effect of these substituents on the stoichiometry (ML and ML2), geometry, and stereochemistry (mer, trans-fac, cis-fac) of the complexes was studied in the solid state, in solution, and by density functional theory calculations. Single-crystal and powder X-ray diffraction, thermogravimetry, and IR spectroscopy showed that in the solid state imda ligands preferentially form trans-fac ML2 complexes, with the exception of the cis-fac complex 7Zn. NMR spectroscopy of diamagnetic Zn(II) and paramagnetic Co(II) complexes revealed the formation of both ML and ML2 complexes in solution, which was also confirmed by UV-vis titrations. Variable-temperature NMR was used to study the effect of the substituent on the central amine N atom on the Zn-N bond strength and nitrogen inversion. The relative stabilities of the isomers were rationalized by computations and the optimized structures used for geometry analysis.
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13
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Organometallic ruthenium(II)-arene complexes with triphenylphosphine amino acid bioconjugates: Synthesis, characterization and biological properties. Bioorg Chem 2019; 87:432-446. [DOI: 10.1016/j.bioorg.2019.03.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 03/05/2019] [Accepted: 03/15/2019] [Indexed: 12/25/2022]
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14
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Cover Feature: “Backdoor Induction” of Chirality: Trans-1,2-cyclohexanediamine as Key Building Block for Asymmetric Hydrogenation Catalysts (Eur. J. Org. Chem. 11/2019). European J Org Chem 2019. [DOI: 10.1002/ejoc.201900306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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15
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“Backdoor Induction” of Chirality: Trans-1,2-cyclohexanediamine as Key Building Block for Asymmetric Hydrogenation Catalysts. European J Org Chem 2018. [DOI: 10.1002/ejoc.201801647] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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16
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Controlling orthogonal self-assembly through cis–trans isomerization of a non-covalent palladium complex dimer. Chem Commun (Camb) 2018; 54:2094-2097. [DOI: 10.1039/c7cc09537f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Self-assembly of a chiral complex dimer held by 16 hydrogen bonds was controlled through configurational isomerization of the metal center.
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17
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cis
- versus trans
-Square-Planar Palladium(II) and Platinum(II) Complexes with Triphenylphosphine Amino Acid Bioconjugates. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700679] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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18
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A Case Study of Supramolecular Organization: One Ferrocene Substituted Iminodiacetamide and its Chloroform Solvate. CROAT CHEM ACTA 2017. [DOI: 10.5562/cca3270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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19
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Metal-induced supramolecular chirality inversion of small self-assembled molecules in solution. Chem Commun (Camb) 2017; 53:1945-1948. [DOI: 10.1039/c6cc09203a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first example of supramolecular chirality inversion of small self-assembled ligands in solution by complexation to metal ions is presented.
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20
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Hydrophobic–hydrophilic post-cross-linked polystyrene/poly (methyl acryloyl diethylenetriamine) interpenetrating polymer networks and its adsorption properties. J Colloid Interface Sci 2016; 463:61-8. [DOI: 10.1016/j.jcis.2015.10.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/08/2015] [Accepted: 10/17/2015] [Indexed: 10/22/2022]
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21
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Synthesis and characterization of ML and ML2 metal complexes with amino acid substituted bis(2-picolyl)amine ligands. Dalton Trans 2015; 45:2845-58. [PMID: 26616422 DOI: 10.1039/c5dt03387j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Metal complexes with ML or ML2 stoichiometry have been isolated in the reaction of Zn(NO3)2, ZnBr2 or M(NO3)2/NaBF4, M = Zn(ii), Co(ii) or Ni(ii), with either amino acid or amine substituted tridentate nitrogen ligands based on bis(2-picolyl)amine (bpa) or bis(2-quinaldyl)amine (bqa). The stoichiometry (M : L = 1 : 1 or 1 : 2) and stereochemistry (mer, trans-fac or cis-fac) of the products have been studied by NMR and IR spectroscopy, X-ray single crystal analysis and quantum-chemical calculations with an implicit SMD solvation model.
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22
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Crystal structure and gelation properties of naphthalene bioconjugates. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315093389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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23
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When protein-based biomineralization meets hydrothermal synthesis: the nanostructures of the as-prepared materials are independent of the protein types. Chem Commun (Camb) 2015; 51:17076-9. [DOI: 10.1039/c5cc06846k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proteins were proved to be type-independent templates for the biomineralization of iron ions into hematite mesocrystals with tunable structures and morphologies under hydrothermal conditions.
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24
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“Backdoor Induction” of Chirality: Asymmetric Hydrogenation with Rhodium(I) Complexes of Triphenylphosphane-Substituted β-Turn Mimetics. Organometallics 2014. [DOI: 10.1021/om5005385] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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25
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“Backdoor Induction” of Chirality in Asymmetric Hydrogenation with Rhodium(I) Complexes of Amino Acid Substituted Triphenylphosphane Ligands. European J Org Chem 2013. [DOI: 10.1002/ejoc.201301011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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27
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28
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A systematic evaluation of different hydrogen bonding patterns in unsymmetrical 1,n′-disubstituted ferrocenoyl peptides. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.01.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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29
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The X-ray Single Crystal Structures of an Acid-functionalized Bis(2-picolyl)amine (bpa) Ligand with Palladium(II) and Zinc(II) Display Different Intermoleclar Interactions around the Common (H2O)2(anion)2 Motif. Z Anorg Allg Chem 2007. [DOI: 10.1002/zaac.200700294] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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Synthesis and Characterization of CuII Complexes with Amino Acid Substituted Di(2-pyridyl)amine Ligands. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700273] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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32
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Reversible site-specific tagging of enzymatically synthesized RNAs using aldehyde-hydrazine chemistry and protease-cleavable linkers. Nucleic Acids Res 2007; 35:e25. [PMID: 17259220 PMCID: PMC1851632 DOI: 10.1093/nar/gkl1110] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The investigation of RNA structure, dynamics and biological function often requires the site-specific incorporation of non-natural moieties. Here we describe the functionalization of RNA transcripts by aldehyde–hydrazine chemistry using a simple initiator nucleotide that carries an acetal-protected aldehyde function. This initiator nucleotide was efficiently incorporated into RNA, and the modified RNAs were quantitatively coupled to a peptide derivative displaying a hydrazine moiety at one end, a biotin tag at the other, and a trypsin-cleavable sequence in between. RNA conjugates could be easily isolated by affinity chromatography on streptavidin agarose and quantitatively cleaved off the support by trypsin treatment without detectable RNA degradation. The strategy described here may allow the incorporation of various new features into enzymatically synthesized RNA under mild conditions.
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33
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1,n′-Disubstituted ferrocenoyl amino acids and dipeptides: Conformational analysis by CD spectroscopy, X-ray crystallography, and DFT calculations. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2006.04.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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34
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Helically Chiral Ferrocene Peptides Containing 1′-Aminoferrocene-1-Carboxylic Acid Subunits as Turn Inducers. Chemistry 2006; 12:4965-80. [PMID: 16721886 DOI: 10.1002/chem.200600156] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We present a detailed structural study of peptide derivatives of 1'-aminoferrocene-1-carboxylic acid (ferrocene amino acid, Fca), one of the simplest organometallic amino acids. Fca was incorporated into di- to pentapeptides with D- and L-alanine residues attached to either the carboxy or amino group, or to both. Crystallographic and spectroscopic studies (circular dicroism (CD), IR, and NMR) of about two dozen compounds were used to gain a detailed insight into their structures in the solid state as well as in solution. Four derivatives were characterized by single-crystal X-ray analysis, namely Boc-Fca-Ala-OMe (16), Boc-Fca-D-Ala-OMe (17), Boc-Fca-beta-Ala-OMe (18), and Boc-Ala-Fca-Ala-Ala-OMe (21) (Boc=tert-butyloxycarbamyl). CD spectroscopy is an extremely useful tool to elucidate the helical chirality of the metallocene core. Unlike in all other known ferrocene peptides, the helical chirality of the ferrocene is governed solely by the chirality of the amino acid attached to the N terminus of Fca. Depending on the degree of substitution of both cyclopentadiene (Cp) rings, different hydrogen-bonding patterns are realized. (1)H NMR and IR spectroscopy, together with the results from X-ray crystallography, give detailed information regarding not only the hydrogen-bonding patterns of the compounds, but also the equilibria between different conformers in solution. Differences in chemical shifts of NH protons in dimethyl sulfoxide ([D(6)]DMSO) and CDCl(3), that is, the variation ratio (vr), is used for the first time as a measure of the hydrogen-bonding strength of individual COHN bonds in ferrocenoyl peptides. In dipeptides with one intramolecular hydrogen bond between the pendant chains, for example, in dipeptide 16, an equilibrium between hydrogen-bonded and open forms is observed, as testified by a vr value of around 0.5. Higher peptides, such as tetrapeptide 21, are able to form two intramolecular hydrogen bonds stabilizing one single conformation in CDCl(3) solution (vr approximately 0). Due to the low barrier of Cp-ring rotation, new and unnatural hydrogen-bonding patterns are emerging. The systematic work described herein lays a solid foundation for the rational design of metallocene peptides with unusual structures and properties.
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Abstract
Ferrocene peptide conjugates display an array of structural features including helical ferrocene based chirality and a number of different intramolecular hydrogen bonding patterns. In this tutorial review we present a rigorous nomenclature for these systems, followed by a section that summarises and categorises the structures known to date. The issues discussed herein are of general relevance for all metallocene-based chiral transition metal catalysts and peptide turn mimetics.
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36
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Amino acid and peptide bioconjugates of copper(II) and zinc(II) complexes with a modified N,N-bis(2-picolyl)amine ligand. Inorg Chem 2005; 44:5405-15. [PMID: 16022539 DOI: 10.1021/ic048343b] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Four chelating nitrogen ligands 2-5 derived from N,N-bis(2-picolyl)amine (bpa, 1) were synthesized, namely, (PyCH(2))(2)N-CH(2)-p-C(6)H(4)-CO(2)R (R = Me, 2, and R = H, 3) and (PyCH(2))(2)N-(CH(2))(n)-CO(2)H (n = 2, 4, and n = 5, 5). Amino acid conjugates 6 and 7 were formed by condensation of 3 with H-Phe-OMe and H-betaAla-OMe, respectively. Cu(II) and Zn(II) complexes of 1-7 were prepared and fully characterized. The X-ray structures of 1(Zn), 2(Zn), 4(Cu), and 7(Cu) were determined. The Zn complexes 1(Zn) and 2(Zn) as well as 7(Cu) show a distorted trigonal bipyramidal coordination environment in the solid state. An octahedral complex is observed for 4(Cu) which forms chains along the crystallographic b axis by intermolecular coordination of the carboxylic acid to the metal ion of a neighboring complex. Ligand 3 was used to prepare the peptide bioconjugate 8 (3-Ahx-Pro-Lys-Lys-Lys-Arg-Lys-Phe-NH(2)) with a nuclear localization signal (nls) heptapeptide by solid phase synthesis. Cu(II) and Zn(II) complexes of 8 were synthesized in situ and studied by FAB-MS, ESI-MS, UV/vis, and EPR (for 8(Cu)), and FAB-MS, ESI-MS, and NMR (for 8(Zn)). All spectroscopic results clearly support metal coordination to the bpa ligand in the bioconjugates 8(M), even in the presence of other potential ligands from amino acid side chains of the peptide. We suggest metal-peptide conjugates like 8(M) as artificial metallochaperones because they have the potential to deliver metal ions to specific compartments in the cell as determined by the peptide moieties.
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37
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Unsymmetrical 1,n′-disubstituted ferrocenoyl peptides: convenient one pot synthesis and solution structures by CD and NMR spectroscopy. NEW J CHEM 2005. [DOI: 10.1039/b504187b] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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The first oligopeptide derivative of 1′-aminoferrocene-1-carboxylic acid shows helical chirality with antiparallel strands. Chem Commun (Camb) 2004:2004-5. [PMID: 15340643 DOI: 10.1039/b407771g] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The unnatural organometallic amino acid 1'-aminoferrocene-1-carboxylic acid (Fca) induces a turn structure in a tetrapeptide with anti-parallel strands which is stabilized by two intra-molecular hydrogen bonds in the solid state and in solution.
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39
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Electron ionisation induced fragmentation of fused norbornene analogues containing SiMe2 or GeMe2 and oxygen bridges. Migration of SiMe2 and GeMe2 groups. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2001; 15:462-465. [PMID: 11268129 DOI: 10.1002/rcm.256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The main electron ionisation induced fragmentation processes of fused norbornene analogues containing SiMe2 or GeMe2 and oxygen bridges, as well as their dependence on substitution, were investigated using mass (MS) and tandem mass (MS/MS) spectrometric analysis. Formation of the rearrangement ions of m/z 176 in the mass spectra of fused norbornene analogues containing SiMe2 and m/z 222 in the mass spectrum of norbornene analogues containing GeMe2 provides firm evidence for the migration of a SiMe2 and GeMe2 bridge, respectively.
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Enantioselectivity in cyclopropanation catalyzed by Cu(I) complexes increased by π stacking of two monodentate oxazoline ligands. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1381-1169(96)00113-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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