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Biagiotti G, Salvatore A, Toniolo G, Caselli L, Di Vito M, Cacaci M, Contiero L, Gori T, Maggini M, Sanguinetti M, Berti D, Bugli F, Richichi B, Cicchi S. Metal-Free Antibacterial Additives Based on Graphene Materials and Salicylic Acid: From the Bench to Fabric Applications. ACS APPLIED MATERIALS & INTERFACES 2021; 13:26288-26298. [PMID: 34038082 PMCID: PMC8289172 DOI: 10.1021/acsami.1c02330] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The custom functionalization of a graphene surface allows access to engineered nanomaterials with improved colloidal stability and tailored specific properties, which are available to be employed in a wide range of applications ranging from materials to life science. The high surface area and their intrinsic physical and biological properties make reduced graphene oxide and graphene oxide unique materials for the custom functionalization with bioactive molecules by exploiting different surface chemistries. In this work, preparation (on the gram scale) of reduced graphene oxide and graphene oxide derivatives functionalized with the well-known antibacterial agent salicylic acid is reported. The salicylic acid functionalities offered a stable colloidal dispersion and, in addition, homogeneous absorption on a sample of textile manufacture (i.e., cotton fabrics), as shown by a Raman spectroscopy study, thus providing nanoengineered materials with significant antibacterial activity toward different strains of microorganisms. Surprisingly, graphene surface functionalization also ensured resistance to detergent washing treatments as verified on a model system using the quartz crystal microbalance technique. Therefore, our findings paved the way for the development of antibacterial additives for cotton fabrics in the absence of metal components, thus limiting undesirable side effects.
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Affiliation(s)
- Giacomo Biagiotti
- Department
of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
- INSTM
(Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia
dei Materiali), Via G.
Giusti, 9, 50121 Firenze, Italy
| | - Annalisa Salvatore
- CSGI
(Italian Center for Colloid and Surface Science, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italy
| | - Gianluca Toniolo
- Department
of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
- INSTM
(Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia
dei Materiali), Via G.
Giusti, 9, 50121 Firenze, Italy
| | - Lucrezia Caselli
- Department
of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
- CSGI
(Italian Center for Colloid and Surface Science, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italy
| | - Maura Di Vito
- Dipartimento
di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Dipartimento
di Scienze e Tecnologie Agro-Alimentari, Università di Bologna, Viale G. Fanin 42, 40127 Bologna, Italy
| | - Margherita Cacaci
- Dipartimento
di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Dipartimento
di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Luca Contiero
- Cromology
Italia S.p.A., Via IV Novembre, 4, 55016 Z.I. Porcari, Lucca, Italy
| | - Tommaso Gori
- Beste
S.p.A., Via Primo Levi,
6, 59022 Colle Cantagallo, Prato, Italy
| | - Michele Maggini
- Dipartimento
di Scienze Chimiche, Università degli
Studi di Padova, Via
Marzolo 1, 35131 Padova, Italy
| | - Maurizio Sanguinetti
- Dipartimento
di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Dipartimento
di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Debora Berti
- Department
of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
- CSGI
(Italian Center for Colloid and Surface Science, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italy
| | - Francesca Bugli
- Dipartimento
di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Dipartimento
di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Barbara Richichi
- Department
of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
- INSTM
(Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia
dei Materiali), Via G.
Giusti, 9, 50121 Firenze, Italy
| | - Stefano Cicchi
- Department
of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
- INSTM
(Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia
dei Materiali), Via G.
Giusti, 9, 50121 Firenze, Italy
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Zou Y, Pan R, Liu Y, Liu X, Chen X, Wang J, Wan Z, Guo J, Yang X. Effects of γ-zein peptides on lipid membrane organization: Quartz crystal microbalance with dissipation and Langmuir monolayer studies. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.04.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Battistin F, Siegmund D, Balducci G, Alessio E, Metzler-Nolte N. Ru(ii)-Peptide bioconjugates with the cppH linker (cppH = 2-(2'-pyridyl)pyrimidine-4-carboxylic acid): synthesis, structural characterization, and different stereochemical features between organic and aqueous solvents. Dalton Trans 2019; 48:400-414. [PMID: 30285015 DOI: 10.1039/c8dt03575j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Three new Ru(ii) bioconjugates with the C-terminal hexapeptide sequence of neurotensin, RRPYIL, namely trans,cis-RuCl2(CO)2(cppH-RRPYIL-κNp) (7), [Ru([9]aneS3)(cppH-RRPYIL-κNp)(PTA)](Cl)2 (8), and [Ru([9]aneS3)Cl(cppH-RRPYIL-κNp)]Cl (11), where cppH is the asymmetric linker 2-(2'-pyridyl)pyrimidine-4-carboxylic acid, were prepared in pure form and structurally characterized in solution. The cppH linker is capable of forming stereoisomers (i.e. linkage isomers), depending on whether the nitrogen atom ortho (No) or para (Np) to the carboxylate on C4 in the pyrimidine ring binds the metal ion. Thus, one of the aims of this work was to obtain pairs of stereoisomeric conjugates and investigate their biological (anticancer, antibacterial) activity. A thorough NMR characterization clearly indicated that in all cases exclusively Np conjugates were obtained in pure form. In addition, the NMR studies showed that, whereas in DMSO-d6 each conjugate exists as a single species, in D2O two (7) or even three if not four (8 and 11) very similar stable species form (each one corresponding to an individual compound). Similar results were observed for the cppH-RRPYIL ligand alone. Overall, the NMR findings are consistent with the occurrence of a strong intramolecular stacking interaction between the phenol ring of tyrosine and the pyridyl ring of cppH. Such stacking interactions between aromatic rings are expected to be stronger in water. This interaction leads to two stereoisomeric species in the free cppH-RRPYIL ligand and in the bioconjugate 7, and is somehow modulated by the less symmetrical Ru coordination environments in 8 and 11, affording three to four very similar species.
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Affiliation(s)
- Federica Battistin
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Giorgieri 1, 34127 Trieste, Italy.
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Bratsos I, Alessio E. The Pivotal Role of Ru-dmso Compounds in the Discovery of Well-Behaved Precursors. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800469] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ioannis Bratsos
- Institute of Nanoscience and Nanotechnology (INN); Department of Physical Chemistry; NCSR “DEMOKRITOS”; Aghia Paraskevi Attikis 153 10 Athens Greece
| | - Enzo Alessio
- Department of Chemical and Pharmaceutical Sciences; University of Trieste; Via L. Giorgieri 1 34127 Trieste Italy
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Flamme M, Clarke E, Gasser G, Hollenstein M. Applications of Ruthenium Complexes Covalently Linked to Nucleic Acid Derivatives. Molecules 2018; 23:E1515. [PMID: 29932443 PMCID: PMC6099586 DOI: 10.3390/molecules23071515] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 11/16/2022] Open
Abstract
Oligonucleotides are biopolymers that can be easily modified at various locations. Thereby, the attachment of metal complexes to nucleic acid derivatives has emerged as a common pathway to improve the understanding of biological processes or to steer oligonucleotides towards novel applications such as electron transfer or the construction of nanomaterials. Among the different metal complexes coupled to oligonucleotides, ruthenium complexes, have been extensively studied due to their remarkable properties. The resulting DNA-ruthenium bioconjugates have already demonstrated their potency in numerous applications. Consequently, this review focuses on the recent synthetic methods developed for the preparation of ruthenium complexes covalently linked to oligonucleotides. In addition, the usefulness of such conjugates will be highlighted and their applications from nanotechnologies to therapeutic purposes will be discussed.
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Affiliation(s)
- Marie Flamme
- Laboratory for Inorganic Chemical Biology, Chimie ParisTech, PSL University, F-75005 Paris, France.
- Laboratory for Bioorganic Chemistry of Nucleic Acids, Department of Structural Biology and Chemistry, Institute Pasteur, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France.
| | - Emma Clarke
- Laboratory for Inorganic Chemical Biology, Chimie ParisTech, PSL University, F-75005 Paris, France.
- Laboratory for Bioorganic Chemistry of Nucleic Acids, Department of Structural Biology and Chemistry, Institute Pasteur, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France.
| | - Gilles Gasser
- Laboratory for Inorganic Chemical Biology, Chimie ParisTech, PSL University, F-75005 Paris, France.
| | - Marcel Hollenstein
- Laboratory for Bioorganic Chemistry of Nucleic Acids, Department of Structural Biology and Chemistry, Institute Pasteur, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France.
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John T, Voo ZX, Kubeil C, Abel B, Graham B, Spiccia L, Martin LL. Effects of guanidino modified aminoglycosides on mammalian membranes studied using a quartz crystal microbalance. MEDCHEMCOMM 2017; 8:1112-1120. [PMID: 30108822 PMCID: PMC6072410 DOI: 10.1039/c7md00054e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/24/2017] [Indexed: 01/21/2023]
Abstract
The increase in bacterial and viral resistance to current therapeutics has led to intensive research for new antibacterial and antiviral agents. Among these, aminoglycosides and their guanidino derivatives are potent candidates targeting specific RNA sequences. It is necessary that these substances can pass across mammalian membranes in order to reach their intracellular targets. This study investigated the effects of the aminoglycosides kanamycin A and neomycin B and their guanidino derivatives on mammalian mimetic membranes using a quartz crystal microbalance with dissipation monitoring (QCM-D). Lipid bilayers as membrane models were deposited onto gold coated quartz crystals and aminoglycosides added afterwards. Notably, the guanidino derivatives exhibited an initial stiffening of the membrane layer indicating a quick insertion of the planar guanidino groups into the membrane. The guanidino derivatives also reached their maximum binding to the membrane at lower concentrations than the native compounds. Therefore, these modified aminoglycosides are promising agents for the development of new antimicrobial treatments.
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Affiliation(s)
- Torsten John
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
- Leibniz Institute of Surface Modification, and Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry , Leipzig University , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Zhi Xiang Voo
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
| | - Clemens Kubeil
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
| | - Bernd Abel
- Leibniz Institute of Surface Modification, and Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry , Leipzig University , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Bim Graham
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , 381 Royal Parade , Parkville , VIC 3052 , Australia
| | - Leone Spiccia
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
| | - Lisandra L Martin
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
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Battistin F, Balducci G, Demitri N, Iengo E, Milani B, Alessio E. (15)N NMR spectroscopy unambiguously establishes the coordination mode of the diimine linker 2-(2'-pyridyl)pyrimidine-4-carboxylic acid (cppH) in Ru(ii) complexes. Dalton Trans 2015; 44:15671-82. [PMID: 26251967 DOI: 10.1039/c5dt02361k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated the reactivity of three Ru(ii) precursors -trans,cis,cis-[RuCl2(CO)2(dmso-O)2], cis,fac-[RuCl2(dmso-O)(dmso-S)3], and trans-[RuCl2(dmso-S)4] - towards the diimine linker 2-(2'-pyridyl)pyrimidine-4-carboxylic acid (cppH) or its parent compound 4-methyl-2-(2'-pyridyl)pyrimidine ligand (mpp), in which a methyl group replaces the carboxylic group on the pyrimidine ring. In principle, both cppH and mpp can originate linkage isomers, depending on how the pyrimidine ring binds to ruthenium through the nitrogen atom ortho (N(o)) or para (N(p)) to the group in position 4. The principal aim of this work was to establish a spectroscopic fingerprint for distinguishing the coordination mode of cppH/mpp also in the absence of an X-ray structural characterization. By virtue of the new complexes described here, together with the others previously reported by us, we successfully recorded {(1)H,(15)N}-HMBC NMR spectra at natural abundance of the (15)N isotope on a consistent number of fully characterized Ru(ii)-cppH/mpp compounds, most of them being stereoisomers and/or linkage isomers. Thus, we found that (15)N NMR chemical shifts unambiguously establish the binding mode of cppH and mpp - either through N(o) or N(p)- and can be conveniently applied also in the absence of the X-ray structure. In fact, coordination of cppH to Ru(ii) induces a marked upfield shift for the resonance of the N atoms directly bound to the metal, with coordination induced shifts (CIS) ranging from ca.-45 to -75 ppm, depending on the complex, whereas the unbound N atom resonates at a frequency similar to that of the free ligand. Similar results were found for the complexes of mpp. This work confirmed our previous finding that cppH has no binding preference, whereas mpp binds exclusively through N(p). Interestingly, the two cppH linkage isomers trans,cis-[RuCl2(CO)2(cppH-κN(p))] (5) and trans,cis-[RuCl2(CO)2(cppH-κN(o))] (6) were easily obtained in pure form by exploiting their different solubility properties.
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Affiliation(s)
- Federica Battistin
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy.
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Joshi T, Voo ZX, Graham B, Spiccia L, Martin LL. Real-time examination of aminoglycoside activity towards bacterial mimetic membranes using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D). BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:385-91. [PMID: 25450807 DOI: 10.1016/j.bbamem.2014.10.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 09/03/2014] [Accepted: 10/14/2014] [Indexed: 10/24/2022]
Abstract
The rapid increase in multi-drug resistant bacteria has resulted in previously discontinued treatments being revisited. Aminoglycosides are effective "old" antibacterial agents that fall within this category. Despite extensive usage and understanding of their intracellular targets, there is limited mechanistic knowledge regarding how aminoglycosides penetrate bacterial membranes. Thus, the activity of two well-known aminoglycosides, kanamycin A and neomycin B, towards a bacterial mimetic membrane (DMPC:DMPG (4:1)) was examined using a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D). The macroscopic effect of increasing the aminoglycoside concentration showed that kanamycin A exerts a threshold response, switching from binding to the membrane to disruption of the surface. Neomycin B, however, disrupted the membrane at all concentrations examined. At concentrations above the threshold value observed for kanamycin A, both aminoglycosides revealed similar mechanistic details. That is, they both inserted into the bacterial mimetic lipid bilayer, prior to disruption via loss of materials, presumably aminoglycoside-membrane composites. Depth profile analysis of this membrane interaction was achieved using the overtones of the quartz crystal sensor. The measured data is consistent with a two-stage process in which insertion of the aminoglycoside precedes the 'detergent-like' removal of membranes from the sensor. The results of this study contribute to the insight required for aminoglycosides to be reconsidered as active antimicrobial agents/co-agents by providing details of activity at the bacterial membrane. Kanamycin and neomycin still offer potential as antimicrobial therapeutics for the future and the QCM-D method illustrates great promise for screening new antibacterial or antiviral drug candidates.
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Affiliation(s)
- Tanmaya Joshi
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Zhi Xiang Voo
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Bim Graham
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Leone Spiccia
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
| | - Lisandra L Martin
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
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Sista P, Ghosh K, Martinez JS, Rocha RC. Metallo-Biopolymers: Conjugation Strategies and Applications. POLYM REV 2014. [DOI: 10.1080/15583724.2014.913063] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Gasser G. Preparation of metal-containing peptide nucleic acid bioconjugates on the solid phase. Methods Mol Biol 2014; 1050:55-72. [PMID: 24297350 DOI: 10.1007/978-1-62703-553-8_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptide nucleic acids (PNAs) are a class of artificial DNA/RNA analogues that have unique physicochemical properties, which include a high chemical stability, resistance to nucleases and proteases, and higher mismatch sensitivity than DNA. PNAs were initially anticipated to be useful for application in antisense and antigene therapies; however, their poor cellular uptake has limited their use for such purposes in the "real world." Recently, it has been shown that the addition of metal complexes to these oligonucleotide analogues could open up new avenues for their utilization in various research fields. Such metallo-constructs have shown great promise, for a diverse range of applications, most notably in the biosensing area. In this book chapter, we report on the recent synthetic advances towards the preparation of these "(multi-)metallic PNAs" on the solid phase.
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Affiliation(s)
- Gilles Gasser
- Institute of Inorganic Chemistry, University of Zurich, Zurich, Switzerland
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11
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Iengo E, Demitri N, Balducci G, Alessio E. An irresolute linker: separation, and structural and spectroscopic characterization of the two linkage isomers of a Ru(ii)-(2-(2′-pyridyl)pyrimidine-4-carboxylic acid) complex. Dalton Trans 2014; 43:12160-3. [DOI: 10.1039/c4dt01282h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the first time the two linkage isomers of a Ru(ii) complex with 2-(2′-pyridyl)pyrimidine-4-carboxylic acid (cppH) have been fully characterized individually, both in solution and in the solid state.
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Affiliation(s)
- E. Iengo
- Dipartimento di Scienze Chimiche e Farmaceutiche
- Università di Trieste
- 34127 Trieste, Italy
| | - N. Demitri
- Elettra – Sincrotrone Trieste
- Trieste, Italy
| | - G. Balducci
- Dipartimento di Scienze Chimiche e Farmaceutiche
- Università di Trieste
- 34127 Trieste, Italy
| | - E. Alessio
- Dipartimento di Scienze Chimiche e Farmaceutiche
- Università di Trieste
- 34127 Trieste, Italy
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Joshi T, Patra M, Spiccia L, Gasser G. Di-heterometalation of thiol-functionalized peptide nucleic acids. ARTIFICIAL DNA, PNA & XNA 2013; 4:11-8. [PMID: 23422249 PMCID: PMC3654725 DOI: 10.4161/adna.24019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Revised: 02/14/2013] [Accepted: 02/15/2013] [Indexed: 12/21/2022]
Abstract
As a proof-of-principle, two hetero-bimetallic PNA oligomers containing a ruthenium(II) polypyridyl and a cyclopentadienyl manganese tricarbonyl complex have been prepared by serial combination of solid-phase peptide coupling and in-solution thiol chemistry. Solid-phase N-terminus attachment of Ru(II)-polypyridyl carboxylic acid derivative, C1, onto the thiol-functionalized PNA backbone (H-a-a-g-t-c-t-g-c-linker-cys-NH 2) has been performed by standard peptide coupling method. As two parallel approaches, the strong affinity of thiols for maleimide and haloacetyl group has been exploited for subsequent post-SPPS addition of cymantrene-based organometallic cores, C2 and C3. Michael-like addition and thioether ligation of thiol functionalized PNA1 (H-gly-a-a-g-t-c-t-g-c-linker-cys-NH 2) and PNA2 (C1-a-a-g-t-c-t-g-c-linker-cys-NH 2) to cymantrene maleimide and chloroacetyl derivatives, C2 and C3, respectively, has been performed. The synthesized ruthenium(II)-cymantrenyl PNA oligomers have been characterized by mass spectrometry (ESI-MS) and IR spectroscopy. The distinct Mn-CO vibrational IR stretches, between 1,924-2,074 cm (-1) , have been used as markers to confirm the presence of cymantrenyl units in the PNA sequences and the purity of the HPLC-purified PNA thioethers assessed using LC-MS.
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Affiliation(s)
- Tanmaya Joshi
- Institute of Inorganic Chemistry; University of Zurich; Zurich, Switzerland
| | - Malay Patra
- Institute of Inorganic Chemistry; University of Zurich; Zurich, Switzerland
| | - Leone Spiccia
- ARC Centre of Excellence for Electromaterials Science and School of Chemistry; Monash University; Clayton, VIC Australia
| | - Gilles Gasser
- Institute of Inorganic Chemistry; University of Zurich; Zurich, Switzerland
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Pierroz V, Joshi T, Leonidova A, Mari C, Schur J, Ott I, Spiccia L, Ferrari S, Gasser G. Molecular and cellular characterization of the biological effects of ruthenium(II) complexes incorporating 2-pyridyl-2-pyrimidine-4-carboxylic acid. J Am Chem Soc 2012. [PMID: 23181418 DOI: 10.1021/ja307288s] [Citation(s) in RCA: 255] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A great majority of the Ru complexes currently studied in anticancer research exert their antiproliferative activity, at least partially, through ligand exchange. In recent years, however, coordinatively saturated and substitutionally inert polypyridyl Ru(II) compounds have emerged as potential anticancer drug candidates. In this work, we present the synthesis and detailed characterization of two novel inert Ru(II) complexes, namely, [Ru(bipy)(2)(Cpp-NH-Hex-COOH)](2+) (2) and [Ru(dppz)(2)(CppH)](2+) (3) (bipy = 2,2'-bipyridine; CppH = 2-(2'-pyridyl)pyrimidine-4-carboxylic acid; Cpp-NH-Hex-COOH = 6-(2-(pyridin-2-yl)pyrimidine-4-carboxamido)hexanoic acid; dppz = dipyrido[3,2-a:2',3'-c]phenazine). 3 is of particular interest as it was found to have IC(50) values comparable to cisplatin, a benchmark standard in the field, on three cancer cell lines and a better activity on one cisplatin-resistant cell line than cisplatin itself. The mechanism of action of 3 was then investigated in detail and it could be demonstrated that, although 3 binds to calf-thymus DNA by intercalation, the biological effects that it induces did not involve a nuclear DNA related mode of action. On the contrary, confocal microscopy colocalization studies in HeLa cells showed that 3 specifically targeted mitochondria. This was further correlated by ruthenium quantification using High-resolution atomic absorption spectrometry. Furthermore, as determined by two independent assays, 3 induced apoptosis at a relatively late stage of treatment. The generation of reactive oxygen species could be excluded as the cause of the observed cytotoxicity. It was demonstrated that the mitochondrial membrane potential in HeLa was impaired by 3 as early as 2 h after its introduction and even more with increasing time.
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Affiliation(s)
- Vanessa Pierroz
- Institute of Inorganic Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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