1
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Hakkennes MLA, Meijer MS, Menzel JP, Goetz AC, Van Duijn R, Siegler MA, Buda F, Bonnet S. Ligand Rigidity Steers the Selectivity and Efficiency of the Photosubstitution Reaction of Strained Ruthenium Polypyridyl Complexes. J Am Chem Soc 2023. [PMID: 37294954 DOI: 10.1021/jacs.3c03543] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
While photosubstitution reactions in metal complexes are usually thought of as dissociative processes poorly dependent on the environment, they are, in fact, very sensitive to solvent effects. Therefore, it is crucial to explicitly consider solvent molecules in theoretical models of these reactions. Here, we experimentally and computationally investigated the selectivity of the photosubstitution of diimine chelates in a series of sterically strained ruthenium(II) polypyridyl complexes in water and acetonitrile. The complexes differ essentially by the rigidity of the chelates, which strongly influenced the observed selectivity of the photosubstitution. As the ratio between the different photoproducts was also influenced by the solvent, we developed a full density functional theory modeling of the reaction mechanism that included explicit solvent molecules. Three reaction pathways leading to photodissociation were identified on the triplet hypersurface, each characterized by either one or two energy barriers. Photodissociation in water was promoted by a proton transfer in the triplet state, which was facilitated by the dissociated pyridine ring acting as a pendent base. We show that the temperature variation of the photosubstitution quantum yield is an excellent tool to compare theory with experiments. An unusual phenomenon was observed for one of the compounds in acetonitrile, for which an increase in temperature led to a surprising decrease in the photosubstitution reaction rate. We interpret this experimental observation based on complete mapping of the triplet hypersurface of this complex, revealing thermal deactivation to the singlet ground state through intersystem crossing.
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Affiliation(s)
- Matthijs L A Hakkennes
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Michael S Meijer
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Jan Paul Menzel
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Anne-Charlotte Goetz
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Roy Van Duijn
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Maxime A Siegler
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
| | - Francesco Buda
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
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2
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Synthesis and photobiological evaluation of Ru(II) complexes with expanded chelate polypyridyl ligands. J Inorg Biochem 2023; 238:112031. [PMID: 36327501 DOI: 10.1016/j.jinorgbio.2022.112031] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
Abstract
Photoreactive Ru(II) complexes capable of ejecting ligands have been used extensively for photocaging applications and for the creation of "photocisplatin" reagents. The incorporation of distortion into the structure of the coordination complex lowers the energy of dissociative excited states, increasing the yield of the photosubstitution reaction. While steric clash between ligands induced by adding substituents at the coordinating face of the ligand has been extensively utilized, a lesser known, more subtle approach is to distort the coordination sphere by altering the chelate ring size. Here a systematic study was performed to alter metal-ligand bond lengths, angles, and to cause intraligand distortion by introducing a "linker" atom or group between two pyridine rings. The synthesis, photochemistry, and photobiology of five Ru(II) complexes containing CH2, NH, O, and S-linked dipyridine ligands was investigated. All systems where stable in the dark, and three of the five were photochemically active in buffer. While a clear periodic trend was not observed, this study lays the foundation for the creation of photoactive systems utilizing an alternative type of distortion to facilitate photosubstitution reactions.
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3
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Eastham K, Scattergood PA, Chu D, Boota RZ, Soupart A, Alary F, Dixon IM, Rice CR, Hardman SJO, Elliott PIP. Not All 3MC States Are the Same: The Role of 3MC cis States in the Photochemical N ∧N Ligand Release from [Ru(bpy) 2(N ∧N)] 2+ Complexes. Inorg Chem 2022; 61:19907-19924. [PMID: 36450138 DOI: 10.1021/acs.inorgchem.2c03146] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Ruthenium(II) complexes feature prominently in the development of agents for photoactivated chemotherapy; however, the excited-state mechanisms by which photochemical ligand release operates remain unclear. We report here a systematic experimental and computational study of a series of complexes [Ru(bpy)2(N∧N)]2+ (bpy = 2,2'-bipyridyl; N∧N = bpy (1), 6-methyl-2,2'-bipyridyl (2), 6,6'-dimethyl-2,2'-bipyridyl (3), 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (4), 1-benzyl-4-(6-methylpyrid-2-yl)-1,2,3-triazole (5), 1,1'-dibenzyl-4,4'-bi-1,2,3-triazolyl (6)), in which we probe the contribution to the promotion of photochemical N∧N ligand release of the introduction of sterically encumbering methyl substituents and the electronic effect of replacement of pyridine by 1,2,3-triazole donors in the N∧N ligand. Complexes 2 to 6 all release the ligand N∧N on irradiation in acetonitrile solution to yield cis-[Ru(bpy)2(NCMe)2]2+, with resultant photorelease quantum yields that at first seem counter-intuitive and span a broad range. The data show that incorporation of a single sterically encumbering methyl substituent on the N∧N ligand (2 and 5) leads to a significantly enhanced rate of triplet metal-to-ligand charge-transfer (3MLCT) state deactivation but with little promotion of photoreactivity, whereas replacement of pyridine by triazole donors (4 and 6) leads to a similar rate of 3MLCT deactivation but with much greater photochemical reactivity. The data reported here, discussed in conjunction with previously reported data on related complexes, suggest that monomethylation in 2 and 5 sterically inhibits the formation of a 3MCcis state but promotes the population of 3MCtrans states which rapidly deactivate 3MLCT states and are prone to mediating ground-state recovery. On the other hand, increased photochemical reactivity in 4 and 6 seems to stem from the accessibility of 3MCcis states. The data provide important insights into the excited-state mechanism of photochemical ligand release by Ru(II) tris-bidentate complexes.
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Affiliation(s)
- Katie Eastham
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Paul A Scattergood
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Danny Chu
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Rayhaan Z Boota
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Adrien Soupart
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - Fabienne Alary
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - Isabelle M Dixon
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - Craig R Rice
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Paul I P Elliott
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
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4
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McCullough AB, Chen J, Valentine NP, Franklin TM, Cantrell AP, Darnell VM, Qureshi Q, Hanson K, Shell SM, Ashford DL. Balancing the interplay between ligand ejection and therapeutic window light absorption in ruthenium polypyridyl complexes. Dalton Trans 2022; 51:10186-10197. [PMID: 35735218 DOI: 10.1039/d2dt01237e] [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
Ruthenium polypyridyl complexes have gained significant interest as photochemotherapies (PCTs) where their excited-state properties play a critical role in the photo-cytotoxicity mechanism and efficacy. Herein we report a systematic electrochemical, spectrochemical, and photophysical analysis of a series of ruthenium(II) polypyridyl complexes of the type [Ru(bpy)2(N-N)]2+ (where bpy = 2,2'-bipyridine; N-N is a bidentate polypyridyl ligand) designed to mimic PCTs. In this series, the N-N ligand was modified through increased conjugation and/or incorporation of electronegative heteroatoms to shift the metal-to-ligand charge-transfer (MLCT) absorptions near the therapeutic window for PCTs (600-1100 nm) while incorporating steric bulk to trigger photoinduced ligand dissociation. The lowest energy MLCT absorptions were red-shifted from λmax = 454 nm to 564 nm, with emission energies decreasing from λmax = 620 nm to 850 nm. Photoinduced ligand ejection and temperature-dependent emission studies revealed an important interplay between red-shifting MLCT absorptions and accessing the dissociative 3dd* states, with energy barriers between the 3MLCT* and 3dd* states ranging from 850 cm-1 to 2580 cm-1 for the complexes measured. This work demonstrates the importance of understanding both the MLCT manifold and 3dd* state energy levels in the future design of ligands and complexes for PCT.
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Affiliation(s)
- Annie B McCullough
- Department of Natural Sciences, Tusculum University, Greeneville, Tennessee, 37745, USA.
| | - Jiaqi Chen
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Nathaniel P Valentine
- Department of Natural Sciences, Tusculum University, Greeneville, Tennessee, 37745, USA.
| | - Toney M Franklin
- Department of Natural Sciences, Tusculum University, Greeneville, Tennessee, 37745, USA.
| | - Andrew P Cantrell
- Department of Natural Sciences, Tusculum University, Greeneville, Tennessee, 37745, USA.
| | - Vayda M Darnell
- Department of Natural Sciences, Tusculum University, Greeneville, Tennessee, 37745, USA.
| | - Qasim Qureshi
- Department of Natural Sciences, University of Virginia's College at Wise, Wise, Virginia, 24293, USA
| | - Kenneth Hanson
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Steven M Shell
- Department of Natural Sciences, University of Virginia's College at Wise, Wise, Virginia, 24293, USA
| | - Dennis L Ashford
- Department of Natural Sciences, Tusculum University, Greeneville, Tennessee, 37745, USA.
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5
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Papish ET, Oladipupo OE. Factors that influence singlet oxygen formation vs. ligand substitution for light-activated ruthenium anticancer compounds. Curr Opin Chem Biol 2022; 68:102143. [PMID: 35483128 DOI: 10.1016/j.cbpa.2022.102143] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 11/03/2022]
Abstract
This review focuses on light-activated ruthenium anticancer compounds and the factors that influence which pathway is favored. Photodynamic therapy (PDT) is favored by π expansion and the presence of low-lying triplet excited states (e.g. 3MLCT, 3IL). Photoactivated chemotherapy (PACT) refers to light-driven ligand dissociation to give a toxic metal complex or a toxic ligand upon photo substitution. This process is driven by steric bulk near the metal center and weak metal-ligand bonds to create a low-energy 3MC state with antibonding character. With protic dihydroxybipyridine ligands, ligand charge can play a key role in these processes, with a more electron-rich deprotonated ligand favoring PDT and an electron-poor protonated ligand favoring PACT in several cases.
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Affiliation(s)
- Elizabeth T Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.
| | - Olaitan E Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
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6
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Lima M, Marchi RC, Cardoso C, Cook N, Pazin W, Kock F, Venancio T, Martí A, Carlos RM. Bidentate Coordination of 2Apy in cis‐[Ru(phen)2(2Apy)]2+ Aiming at Photobiological Studies. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202101015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Marcia Lima
- IFPI: Instituto Federal de Educacao Ciencia e Tecnologia do Piaui Chemistry BRAZIL
| | | | - Carolina Cardoso
- Instituto Federal de Educacao Ciencia e Tecnologia de Sao Paulo chemistry BRAZIL
| | | | | | - Flavio Kock
- UFSCar: Universidade Federal de Sao Carlos Chemistry BRAZIL
| | - Tiago Venancio
- UFSCar: Universidade Federal de Sao Carlos Chemistry BRAZIL
| | | | - Rose Maria Carlos
- Universidade Federal de Sao Carlos Química Rod Washington Luis Km 235 13565-905 São Carlos-SP BRAZIL
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7
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Oladipupo O, Brown SR, Lamb RW, Gray JL, Cameron CG, DeRegnaucourt AR, Ward NA, Hall JF, Xu Y, Petersen CM, Qu F, Shrestha AB, Thompson MK, Bonizzoni M, Webster CE, McFarland SA, Kim Y, Papish ET. Light-responsive and Protic Ruthenium Compounds Bearing Bathophenanthroline and Dihydroxybipyridine Ligands Achieve Nanomolar Toxicity towards Breast Cancer Cells. Photochem Photobiol 2022; 98:102-116. [PMID: 34411308 PMCID: PMC8810589 DOI: 10.1111/php.13508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 08/16/2021] [Indexed: 01/03/2023]
Abstract
We report new ruthenium complexes bearing the lipophilic bathophenanthroline (BPhen) ligand and dihydroxybipyridine (dhbp) ligands which differ in the placement of the OH groups ([(BPhen)2 Ru(n,n'-dhbp)]Cl2 with n = 6 and 4 in 1A and 2A , respectively). Full characterization data are reported for 1A and 2A and single crystal X-ray diffraction for 1A . Both 1A and 2A are diprotic acids. We have studied 1A , 1B , 2A , and 2B (B = deprotonated forms) by UV-vis spectroscopy and 1 photodissociates, but 2 is light stable. Luminescence studies reveal that the basic forms have lower energy 3 MLCT states relative to the acidic forms. Complexes 1A and 2A produce singlet oxygen with quantum yields of 0.05 and 0.68, respectively, in acetonitrile. Complexes 1 and 2 are both photocytotoxic toward breast cancer cells, with complex 2 showing EC50 light values as low as 0.50 μM with PI values as high as >200 vs. MCF7. Computational studies were used to predict the energies of the 3 MLCT and 3 MC states. An inaccessible 3 MC state for 2B suggests a rationale for why photodissociation does not occur with the 4,4'-dhbp ligand. Low dark toxicity combined with an accessible 3 MLCT state for 1 O2 generation explains the excellent photocytotoxicity of 2.
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Affiliation(s)
- Olaitan Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Spenser R. Brown
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Robert W. Lamb
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Jessica L. Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, TX 76019, USA
| | - Alexa R. DeRegnaucourt
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Nicholas A. Ward
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - James Fletcher Hall
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Yifei Xu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Courtney M. Petersen
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Ambar B. Shrestha
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Matthew K. Thompson
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Marco Bonizzoni
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, TX 76019, USA
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Elizabeth T. Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
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8
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Cole HD, Roque JA, Shi G, Lifshits LM, Ramasamy E, Barrett PC, Hodges RO, Cameron CG, McFarland SA. Anticancer Agent with Inexplicable Potency in Extreme Hypoxia: Characterizing a Light-Triggered Ruthenium Ubertoxin. J Am Chem Soc 2021; 144:9543-9547. [PMID: 34882381 DOI: 10.1021/jacs.1c09010] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tumor hypoxia renders treatments ineffective that are directly (e.g., radiotherapy and photodynamic therapy) or indirectly (e.g., chemotherapy) dependent on tumor oxygenation. This study introduces a ruthenium compound as a light-responsive anticancer agent that is water-soluble, has minimal dark cytotoxicity, is active at concentrations as low as 170 pM in ∼18.5% O2 normoxia and near 10 nM in 1% O2 hypoxia, and exhibits phototherapeutic indices as large as >500,000 in normoxia and >5,800 in 1% O2 hypoxia using broadband visible and monochromatic blue light treatments. These are the largest values reported to date for any compound class. We highlight the response in four different cell lines to improve rigor and reproducibility in the identification of promising clinical candidates.
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Affiliation(s)
- Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - John A Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States.,Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Liubov M Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Elamparuthi Ramasamy
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Rachel O Hodges
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
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9
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Chen Y, Bai L, Zhang P, Zhao H, Zhou Q. The Development of Ru(II)-Based Photoactivated Chemotherapy Agents. Molecules 2021; 26:5679. [PMID: 34577150 PMCID: PMC8465985 DOI: 10.3390/molecules26185679] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 01/10/2023] Open
Abstract
Photoactivated chemotherapy (PACT) is a novel cancer treatment method that has drawn increasing attention due to its high selectivity and low side effects by spatio-temporal control of irradiation. Compared with photodynamic therapy (PDT), oxygen-independent PACT is more suitable for treating hypoxic tumors. By finely tuning ligand structures and coordination configurations, many Ru(II) complexes can undergo photoinduced ligand dissociation, and the resulting Ru(II) aqua species and/or free ligands may have anticancer activity, showing their potential as PACT agents. In this mini-review, we summarized the progress in Ru(II)-based PACT agents, as well as challenges that researchers in this field still face.
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Affiliation(s)
- Yongjie Chen
- Research Center for Pharmacodynamic Evaluation Engineering Technology of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; (L.B.); (P.Z.); (H.Z.)
| | - Lijuan Bai
- Research Center for Pharmacodynamic Evaluation Engineering Technology of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; (L.B.); (P.Z.); (H.Z.)
| | - Pu Zhang
- Research Center for Pharmacodynamic Evaluation Engineering Technology of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; (L.B.); (P.Z.); (H.Z.)
| | - Hua Zhao
- Research Center for Pharmacodynamic Evaluation Engineering Technology of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; (L.B.); (P.Z.); (H.Z.)
| | - Qianxiong Zhou
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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10
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Dixon IM, Bonnet S, Alary F, Cuny J. Photoinduced Ligand Exchange Dynamics of a Polypyridyl Ruthenium Complex in Aqueous Solution. J Phys Chem Lett 2021; 12:7278-7284. [PMID: 34323082 DOI: 10.1021/acs.jpclett.1c01424] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The understanding of photoinduced ligand exchange mechanisms in polypyridyl ruthenium(II) complexes operating in aqueous solution is of crucial importance to rationalize their photoreactivity. Herein, we demonstrate that a synergetic use of ab initio molecular dynamics simulations and static calculations, both conducted at the DFT level, can provide a full understanding of photosubstitution mechanisms of a monodentate ligand by a solvent water molecule in archetypal ruthenium complexes in explicit water. The simulations show that the photoinduced loss of a monodentate ligand generates an unreactive 16-electron species in a hitherto undescribed pentacoordinated triplet excited state that converts, via an easily accessible crossing point, to a reactive 16-electron singlet ground state, which combines with a solvent water molecule to yield the experimentally observed aqua complex in less than 10 ps. This work paves the way for the rational design of novel photoactive metal complexes relevant for biological applications.
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Affiliation(s)
- Isabelle M Dixon
- Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier, Laboratoire de Chimie et Physique Quantiques, 31062 Toulouse Cedex 9, France
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
| | - Fabienne Alary
- Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier, Laboratoire de Chimie et Physique Quantiques, 31062 Toulouse Cedex 9, France
| | - Jérôme Cuny
- Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier, Laboratoire de Chimie et Physique Quantiques, 31062 Toulouse Cedex 9, France
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11
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Hachey AC, Havrylyuk D, Glazer EC. Biological activities of polypyridyl-type ligands: implications for bioinorganic chemistry and light-activated metal complexes. Curr Opin Chem Biol 2021; 61:191-202. [PMID: 33799087 DOI: 10.1016/j.cbpa.2021.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/24/2021] [Accepted: 01/31/2021] [Indexed: 12/16/2022]
Abstract
Polypyridyl coordinating ligands are common in metal complexes used in medicinal inorganic chemistry. These ligands possess intrinsic cytotoxicity, but detailed data on this phenomenon are sparse, and cytotoxicity values vary widely and are often irreproducible. To provide new insights into the biological effects of bipyridyl-type ligands and structurally related metal-binding systems, reports of free ligand cytotoxicity were reviewed. The cytotoxicity of 25 derivatives of 2,2'-bipyridine and 1,10-phenanthroline demonstrates that there is no correlation between IC50 values and ligand properties such as pKa, log D, polarizability volume, and electron density, as indicated by NMR shifts. As a result of these observations, as well as the various reported mechanisms of action of polypyridyl ligands, we offer the hypothesis that biological effects are governed by the availability of and affinity for specific metal ions within the experimental model.
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Affiliation(s)
- Austin C Hachey
- Department of Chemistry, The University of Kentucky, 505 Rose St, Lexington, KY 40506, USA
| | - Dmytro Havrylyuk
- Department of Chemistry, The University of Kentucky, 505 Rose St, Lexington, KY 40506, USA
| | - Edith C Glazer
- Department of Chemistry, The University of Kentucky, 505 Rose St, Lexington, KY 40506, USA.
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12
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Smithen DA, Monro S, Pinto M, Roque J, Diaz-Rodriguez RM, Yin H, Cameron CG, Thompson A, McFarland SA. Bis[pyrrolyl Ru(ii)] triads: a new class of photosensitizers for metal-organic photodynamic therapy. Chem Sci 2020; 11:12047-12069. [PMID: 33738086 PMCID: PMC7953431 DOI: 10.1039/d0sc04500d] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022] Open
Abstract
A new family of ten dinuclear Ru(ii) complexes based on the bis[pyrrolyl Ru(ii)] triad scaffold, where two Ru(bpy)2 centers are separated by a variety of organic linkers, was prepared to evaluate the influence of the organic chromophore on the spectroscopic and in vitro photodynamic therapy (PDT) properties of the compounds. The bis[pyrrolyl Ru(ii)] triads absorbed strongly throughout the visible region, with several members having molar extinction coefficients (ε) ≥ 104 at 600-620 nm and longer. Phosphorescence quantum yields (Φ p) were generally less than 0.1% and in some cases undetectable. The singlet oxygen quantum yields (Φ Δ) ranged from 5% to 77% and generally correlated with their photocytotoxicities toward human leukemia (HL-60) cells regardless of the wavelength of light used. Dark cytotoxicities varied ten-fold, with EC50 values in the range of 10-100 μM and phototherapeutic indices (PIs) as large as 5400 and 260 with broadband visible (28 J cm-2, 7.8 mW cm-2) and 625 nm red (100 J cm-2, 42 mW cm-2) light, respectively. The bis[pyrrolyl Ru(ii)] triad with a pyrenyl linker (5h) was especially potent, with an EC50 value of 1 nM and PI > 27 000 with visible light and subnanomolar activity with 625 nm light (100 J cm-2, 28 mW cm-2). The lead compound 5h was also tested in a tumor spheroid assay using the HL60 cell line and exhibited greater photocytotoxicity in this more resistant model (EC50 = 60 nM and PI > 1200 with 625 nm light) despite a lower dark cytotoxicity. The in vitro PDT effects of 5h extended to bacteria, where submicromolar EC50 values and PIs >300 against S. mutans and S. aureus were obtained with visible light. This activity was attenuated with 625 nm red light, but PIs were still near 50. The ligand-localized 3ππ* state contributed by the pyrenyl linker of 5h likely plays a key role in its phototoxic effects toward cancer cells and bacteria.
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Affiliation(s)
- Deborah A Smithen
- Department of Chemistry , Dalhousie University , P. O. Box 15000 , Halifax , NS B3H 4R2 , Canada .
| | - Susan Monro
- Department of Chemistry , Acadia University , Wolfville , NS B4P 2R6 , Canada
| | - Mitch Pinto
- Department of Chemistry , Acadia University , Wolfville , NS B4P 2R6 , Canada
| | - John Roque
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , PO Box 26170 , Greensboro , NC 27402-6170 , USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , 700 Planetarium Pl , Arlington , TX 76019-0065 , USA .
| | - Roberto M Diaz-Rodriguez
- Department of Chemistry , Dalhousie University , P. O. Box 15000 , Halifax , NS B3H 4R2 , Canada .
| | - Huimin Yin
- Department of Chemistry , Acadia University , Wolfville , NS B4P 2R6 , Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , 700 Planetarium Pl , Arlington , TX 76019-0065 , USA .
| | - Alison Thompson
- Department of Chemistry , Dalhousie University , P. O. Box 15000 , Halifax , NS B3H 4R2 , Canada .
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , 700 Planetarium Pl , Arlington , TX 76019-0065 , USA .
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13
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Roque JA, Barrett PC, Cole HD, Lifshits LM, Bradner E, Shi G, von Dohlen D, Kim S, Russo N, Deep G, Cameron CG, Alberto ME, McFarland SA. Os(II) Oligothienyl Complexes as a Hypoxia-Active Photosensitizer Class for Photodynamic Therapy. Inorg Chem 2020; 59:16341-16360. [PMID: 33126792 PMCID: PMC7669743 DOI: 10.1021/acs.inorgchem.0c02137] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hypoxia presents a challenge to anticancer therapy, reducing the efficacy of many available treatments. Photodynamic therapy is particularly susceptible to hypoxia, given that its mechanism relies on oxygen. Herein, we introduce two new osmium-based polypyridyl photosensitizers that are active in hypoxia. The lead compounds emerged from a systematic study of two Os(II) polypyridyl families derived from 2,2'-bipyridine (bpy) or 4,4'-dimethyl-2,2'-bipyridine (dmb) as coligands combined with imidazo[4,5-f][1,10]phenanthroline ligands tethered to n = 0-4 thiophenes (IP-nT). The compounds were characterized and investigated for their spectroscopic and (photo)biological activities. The two hypoxia-active Os(II) photosensitizers had n = 4 thiophenes, with the bpy analogue 1-4T being the most potent. In normoxia, 1-4T had low nanomolar activity (half-maximal effective concentration (EC50) = 1-13 nM) with phototherapeutic indices (PI) ranging from 5500 to 55 000 with red and visible light, respectively. A sub-micromolar potency was maintained even in hypoxia (1% O2), with light EC50 and PI values of 732-812 nM and 68-76, respectively -currently among the largest PIs for hypoxic photoactivity. This high degree of activity coincided with a low-energy, long-lived (0.98-3.6 μs) mixed-character intraligand charge-transfer (3ILCT)/ligand-to-ligand charge-transfer (3LLCT) state only accessible in quaterthiophene complexes 1-4T and 2-4T. The coligand identity strongly influenced the photophysical and photobiological results in this study, whereby the bpy coligand led to longer lifetimes (3.6 μs) and more potent photo-cytotoxicity relative to those of dmb. The unactivated compounds were relatively nontoxic both in vitro and in vivo. The maximum tolerated dose for 1-4T and 2-4T in mice was greater than or equal to 200 mg kg-1, an excellent starting point for future in vivo validation.
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Affiliation(s)
- John A. Roque
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Patrick C. Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Liubov M. Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Evan Bradner
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
| | - Ge Shi
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia B3H 1×5, Canada
| | - David von Dohlen
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
| | - Susy Kim
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, 27157 USA
| | - Nino Russo
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende, 87036 Italy
| | - Gagan Deep
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, 27157 USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Marta E. Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende, 87036 Italy
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
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14
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Roque JA, Barrett PC, Cole HD, Lifshits LM, Shi G, Monro S, von Dohlen D, Kim S, Russo N, Deep G, Cameron CG, Alberto ME, McFarland SA. Breaking the barrier: an osmium photosensitizer with unprecedented hypoxic phototoxicity for real world photodynamic therapy. Chem Sci 2020; 11:9784-9806. [PMID: 33738085 PMCID: PMC7953430 DOI: 10.1039/d0sc03008b] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/03/2020] [Indexed: 12/15/2022] Open
Abstract
Hypoxia presents a two-fold challenge in the treatment of cancer, as low oxygen conditions induce biological changes that make malignant tissues simultaneously more aggressive and less susceptible to standard chemotherapy. This paper reports the first metal-based photosensitizer that approaches the ideal properties for a phototherapy agent. The Os(phen)2-based scaffold was combined with a series of IP-nT ligands, where phen = 1,10-phenanthroline and IP-nT = imidazo[4,5-f][1,10]phenanthroline tethered to n = 0-4 thiophene rings. Os-4T (n = 4) emerged as the most promising complex in the series, with picomolar activity and a phototherapeutic index (PI) exceeding 106 in normoxia. The photosensitizer exhibited an unprecedented PI > 90 (EC50 = 0.651 μM) in hypoxia (1% O2) with visible and green light, and a PI > 70 with red light. Os-4T was also active with 733 nm near-infrared light (EC50 = 0.803 μM, PI = 77) under normoxia. Both computation and spectroscopic studies confirmed a switch in the nature of the lowest-lying triplet excited state from triplet metal-to-ligand charge transfer (3MLCT) to intraligand charge transfer (3ILCT) at n = 3, with a lower energy and longer lifetime for n = 4. All compounds in the series were relatively nontoxic in the dark but became increasingly phototoxic with additional thiophenes. These normoxic and hypoxic activities are the largest reported to date, demonstrating the utility of osmium for phototherapy applications. Moreover, Os-4T had a maximum tolerated dose (MTD) in mice that was >200 mg kg-1, which positions this photosensitizer as an excellent candidate for in vivo applications.
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Affiliation(s)
- John A Roque
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
| | - Houston D Cole
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Liubov M Lifshits
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Ge Shi
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia , B4P 2R6 Canada
| | - Susan Monro
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia , B4P 2R6 Canada
| | - David von Dohlen
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
| | - Susy Kim
- Department of Cancer Biology , Wake Forest School of Medicine , Winston Salem , NC , 27157, USA
| | - Nino Russo
- Dipartimento di Chimica e Tecnologie Chimiche , Università della Calabria , Arcavacata di Rende , 87036 Italy .
| | - Gagan Deep
- Department of Cancer Biology , Wake Forest School of Medicine , Winston Salem , NC , 27157, USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Marta E Alberto
- Dipartimento di Chimica e Tecnologie Chimiche , Università della Calabria , Arcavacata di Rende , 87036 Italy .
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia , B4P 2R6 Canada
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15
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Soupart A, Alary F, Heully JL, Elliott PIP, Dixon IM. Theoretical Study of the Full Photosolvolysis Mechanism of [Ru(bpy)3]2+: Providing a General Mechanistic Roadmap for the Photochemistry of [Ru(N^N)3]2+-Type Complexes toward Both Cis and Trans Photoproducts. Inorg Chem 2020; 59:14679-14695. [DOI: 10.1021/acs.inorgchem.0c01843] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Adrien Soupart
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
| | - Fabienne Alary
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
| | - Jean-Louis Heully
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
| | - Paul I. P. Elliott
- Department of Chemistry and Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Isabelle M. Dixon
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
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16
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Havrylyuk D, Heidary DK, Sun Y, Parkin S, Glazer EC. Photochemical and Photobiological Properties of Pyridyl-pyrazol(in)e-Based Ruthenium(II) Complexes with Sub-micromolar Cytotoxicity for Phototherapy. ACS OMEGA 2020; 5:18894-18906. [PMID: 32775891 PMCID: PMC7408248 DOI: 10.1021/acsomega.0c02079] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/10/2020] [Indexed: 05/09/2023]
Abstract
The discovery of new light-triggered prodrugs based on ruthenium (II) complexes is a promising approach for photoactivated chemotherapy (PACT). The light-mediated activation of "strained" Ru(II) polypyridyl complexes resulted in ligand release and produced a ligand-deficient metal center capable of forming covalent adducts with biomolecules such as DNA. Based on the strategy of exploiting structural distortion to activate photochemistry, biologically active small molecules were coordinated to a Ru(II) scaffold to create light-triggered dual-action agents. Thirteen new Ru(II) complexes with pyridyl-pyrazol(in)e ligands were synthesized, and their photochemical reactivity and anticancer properties were investigated. Isomeric bidentate ligands were investigated, where "regular" ligands (where the coordinated nitrogens in the heterocycles are linked by C-C atoms) were compared to "inverse" isomers (where the coordinated nitrogens in the heterocycles are linked by C-N atoms). Coordination of the regular 3-(pyrid-2-yl)-pyrazol(in)es to a Ru(II) bis-dimethylphenanthroline scaffold yielded photoresponsive compounds with promising photochemical and biological properties, in contrast to the inverse 1-(pyrid-2-yl)-pyrazolines. The introduction of a phenyl ring to the 1N-pyrazoline cycle increased the distortion in complexes and improved ligand release upon light irradiation (470 nm) up to 5-fold in aqueous media. Compounds 1-8, containing pyridyl-pyrazol(in)e ligands, were at least 20-80-fold more potent than the parent pyridyl-pyrazol(in)es, and exhibited biological activity in the dark, with half-maximal inhibitory concentration (IC50) values ranging from 0.2 to 7.6 μM in the HL60 cell line, with complete growth inhibition upon light irradiation. The diversification of coligands and introduction of a carboxylic acid into the Ru(II) complex resulted in compounds 9-12, with up to 146-fold improved phototoxicity indices compared with complexes 1-8.
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17
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Soupart A, Alary F, Heully JL, Elliott PI, Dixon IM. Recent progress in ligand photorelease reaction mechanisms: Theoretical insights focusing on Ru(II) 3MC states. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213184] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Roque J, Havrylyuk D, Barrett PC, Sainuddin T, McCain J, Colón K, Sparks WT, Bradner E, Monro S, Heidary D, Cameron CG, Glazer EC, McFarland SA. Strained, Photoejecting Ru(II) Complexes that are Cytotoxic Under Hypoxic Conditions. Photochem Photobiol 2019; 96:327-339. [PMID: 31691282 DOI: 10.1111/php.13174] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/14/2019] [Indexed: 01/01/2023]
Abstract
A series of strained Ru(II) complexes were studied for potential anticancer activity in hypoxic tissues. The complexes were constructed with methylated ligands that were photolabile and an imidizo[4,5-f][1,10]phenanthroline ligand that contained an appended aromatic group to potentially allow for contributions of ligand-centered excited states. A systematic variation of the size and energy of the aromatic group was performed using systems containing 1-4 fused rings, and the photochemical and photobiological behaviors of all complexes were assessed. The structure and nature of the aromatic group had a subtle impact on photochemistry, altering environmental sensitivity, and had a significant impact on cellular cytotoxicity and photobiology. Up to 5-fold differences in cytotoxicity were observed in the absence of light activation; this rose to 50-fold differences upon exposure to 453 nm light. Most significantly, one complex retained activity under conditions with 1% O2 , which is used to induce hypoxic changes. This system exhibited a photocytotoxicity index (PI) of 15, which is in marked contrast to most other Ru(II) complexes, including those designed for O2 -independent mechanisms of action.
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Affiliation(s)
- John Roque
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | | | - Patrick C Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Tariq Sainuddin
- Department of Chemistry, Acadia University, Wolfville, Canada
| | - Julia McCain
- Department of Chemistry, Acadia University, Wolfville, Canada
| | - Katsuya Colón
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - William T Sparks
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Evan Bradner
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Susan Monro
- Department of Chemistry, Acadia University, Wolfville, Canada
| | - David Heidary
- Department of Chemistry, University of Kentucky, Lexington, KY
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Edith C Glazer
- Department of Chemistry, University of Kentucky, Lexington, KY
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC.,Department of Chemistry, Acadia University, Wolfville, Canada
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19
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Kuncewicz J, Dąbrowski JM, Kyzioł A, Brindell M, Łabuz P, Mazuryk O, Macyk W, Stochel G. Perspectives of molecular and nanostructured systems with d- and f-block metals in photogeneration of reactive oxygen species for medical strategies. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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20
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Turlington MD, Troian-Gautier L, Sampaio RN, Beauvilliers EE, Meyer GJ. Ligand Control of Supramolecular Chloride Photorelease. Inorg Chem 2018; 57:5624-5631. [DOI: 10.1021/acs.inorgchem.8b00559] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Michael D. Turlington
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Ludovic Troian-Gautier
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Renato N. Sampaio
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Evan E. Beauvilliers
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Gerald J. Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
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21
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22
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Sohrabi M, Amirnasr M, Meghdadi S, Lutz M, Bikhof Torbati M, Farrokhpour H. A highly selective fluorescence turn-on chemosensor for Zn2+, and its application in live cell imaging, and as a colorimetric sensor for Co2+: experimental and TD-DFT calculations. NEW J CHEM 2018. [DOI: 10.1039/c8nj01580e] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A highly sensitive quinoline based “dual” chemosensor used for fluorometric detection of Zn2+, live-cell imaging, and colorimetric detection of Co2+.
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Affiliation(s)
- Marzieh Sohrabi
- Department of Chemistry
- Isfahan University of Technology
- Isfahan 8415683111
- Iran
| | - Mehdi Amirnasr
- Department of Chemistry
- Isfahan University of Technology
- Isfahan 8415683111
- Iran
| | - Soraia Meghdadi
- Department of Chemistry
- Isfahan University of Technology
- Isfahan 8415683111
- Iran
| | - Martin Lutz
- Crystal and Structural Chemistry
- Bijvoet Center for Biomolecular Research
- Faculty of Science
- Utrecht University
- 3584 CH Utrecht
| | - Maryam Bikhof Torbati
- Department of Biology
- College of Science
- Yadegar-e-Imam Khomeini (RAH) Shahr-e-Rey Branch
- Islamic Azad University
- Tehran
| | - Hossein Farrokhpour
- Department of Chemistry
- Isfahan University of Technology
- Isfahan 8415683111
- Iran
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23
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Laramée-Milette B, Nastasi F, Puntoriero F, Campagna S, Hanan GS. Photo-Induced Assembly of a Luminescent Tetraruthenium Square. Chemistry 2017; 23:16497-16504. [PMID: 28922481 DOI: 10.1002/chem.201702714] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Indexed: 01/05/2023]
Abstract
Self-assembly is a powerful synthetic tool that has led to the development of one-, two- and three-dimensional architectures. From MOFs to molecular flasks, self-assembled materials have proven to be of great interest to the scientific community. Here we describe a strategy for the construction and de-construction of a supramolecular structure through unprecedented photo-induced assembly and dis-assembly. The combination of two approaches, a [n×1]-directional bonding strategy and a ligand photo-dissociation strategy, allows the photo-induced assembly of a polypyridyl RuII precursor into a discrete molecular square. Diffusion-ordered NMR spectroscopy confirmed the synthesis of a higher volume species, while the identity of the species was established by high-resolution mass spectrometry and single-crystal X-ray diffraction studies. The self-assembled square is not obtained by classical thermal techniques in similar conditions, but is obtained only by light-irradiation. The tetraruthenium square has an excited-state lifetime (135 ns), 40 times that of its mononuclear precursor and its luminescence quantum yield (1.0 %) is three orders of magnitude higher. These remarkable luminescence properties are closely related to the relatively rigid square structure of the tetraruthenium assembly, as suggested by slow radiationless decay and transient absorption spectroscopy. The results described herein are a rare example of photo-induced assembly and dis-assembly processes, and can open the way to a new avenue in supramolecular chemistry, leading to the preparation of structurally organized supermolecules by photochemical techniques.
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Affiliation(s)
- Baptiste Laramée-Milette
- Département de Chimie, Université de Montréal, 5155 Ch. de la Rampe, Pavillon J.-A. Bombardier, Montréal, QC, H3T 2B1, Canada
| | - Francesco Nastasi
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, and, Centro di ricerca interuniversitario per la conversione chimica dell'energia solare (SOLAR-CHEM), 98166, Messina, Italy
| | - Fausto Puntoriero
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, and, Centro di ricerca interuniversitario per la conversione chimica dell'energia solare (SOLAR-CHEM), 98166, Messina, Italy
| | - Sebastiano Campagna
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, and, Centro di ricerca interuniversitario per la conversione chimica dell'energia solare (SOLAR-CHEM), 98166, Messina, Italy
| | - Garry S Hanan
- Département de Chimie, Université de Montréal, 5155 Ch. de la Rampe, Pavillon J.-A. Bombardier, Montréal, QC, H3T 2B1, Canada
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24
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Griffith C, Dayoub AS, Jaranatne T, Alatrash N, Mohamedi A, Abayan K, Breitbach ZS, Armstrong DW, MacDonnell FM. Cellular and cell-free studies of catalytic DNA cleavage by ruthenium polypyridyl complexes containing redox-active intercalating ligands. Chem Sci 2017; 8:3726-3740. [PMID: 28553531 PMCID: PMC5428021 DOI: 10.1039/c6sc04094b] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/08/2017] [Indexed: 01/21/2023] Open
Abstract
The ruthenium(ii) polypyridyl complexes (RPCs), [(phen)2Ru(tatpp)]2+ (32+ ) and [(phen)2Ru(tatpp)Ru(phen)2]4+ (44+ ) are shown to cleave DNA in cell-free studies in the presence of a mild reducing agent, i.e. glutathione (GSH), in a manner that is enhanced upon lowering the [O2]. Reactive oxygen species (ROS) are involved in the cleavage process as hydroxy radical scavengers attenuate the cleavage activity. Cleavage experiments in the presence of superoxide dismutase (SOD) and catalase reveal a central role for H2O2 as the immediate precursor for hydroxy radicals. A mechanism is proposed which explains the inverse [O2] dependence and ROS data and involves redox cycling between three DNA-bound redox isomers of 32+ or 44+ . Cultured non-small cell lung cancer cells (H358) are sensitive to 32+ and 44+ with IC50 values of 13 and 15 μM, respectively, and xenograft H358 tumors in nude mice show substantial (∼80%) regression relative to untreated tumors when the mice are treated with enantiopure versions of 32+ and 44+ (Yadav et al. Mol Cancer Res, 2013, 12, 643). Fluorescence microscopy of H358 cells treated with 15 μM 44+ reveals enhanced intracellular ROS production in as little as 2 h post treatment. Detection of phosphorylated ATM via immunofluorescence within 2 h of treatment with 44+ reveals initiation of the DNA damage repair machinery due to the ROS insult and DNA double strand breaks (DSBs) in the nuclei of H358 cells and is confirmed using the γH2AX assay. The cell data for 32+ is less clear but DNA damage occurs. Notably, cells treated with [Ru(diphenylphen)3]2+ (IC50 1.7 μM) show no extra ROS production and no DNA damage by either the pATM or γH2AX even after 22 h. The enhanced DNA cleavage under low [O2] (4 μM) seen in cell-free cleavage assays of 32+ and 44+ is only partially reflected in the cytotoxicity of 32+ and 44+ in H358, HCC2998, HOP-62 and Hs766t under hypoxia (1.1% O2) relative to normoxia (18% O2). Cells treated with RPC 32+ show up to a two-fold enhancement in the IC50 under hypoxia whereas cells treated with RPC 44+ gave the same IC50 whether under hypoxia or normoxia.
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Affiliation(s)
- Cynthia Griffith
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Adam S Dayoub
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Thamara Jaranatne
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Nagham Alatrash
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Ali Mohamedi
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Kenneth Abayan
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Zachary S Breitbach
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Daniel W Armstrong
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Frederick M MacDonnell
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
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25
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Cuello-Garibo JA, Pérez-Gallent E, van der Boon L, Siegler MA, Bonnet S. Influence of the Steric Bulk and Solvent on the Photoreactivity of Ruthenium Polypyridyl Complexes Coordinated to l-Proline. Inorg Chem 2017; 56:4818-4828. [PMID: 28406644 PMCID: PMC5415878 DOI: 10.1021/acs.inorgchem.6b02794] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
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Ruthenium polypyridyl complexes are
good candidates for photoactivated chemotherapy (PACT) provided that
they are stable in the dark but efficiently photosubstitute one of
their ligands. Here the use of the natural amino acid l-proline
as a protecting ligand for ruthenium-based PACT compounds is investigated
in the series of complexes Λ-[Ru(bpy)2(l-prol)]PF6 ([1a]PF6; bpy = 2,2′-bipyridine
and l-prol = l-proline), Λ-[Ru(bpy)(dmbpy)(l-prol)]PF6 ([2a]PF6 and
[2b]PF6; dmbpy = 6,6′-dimethyl-2,2′-bipyridine),
and Λ-[Ru(dmbpy)2(l-prol)]PF6 ([3a]PF6). The synthesis of the tris-heteroleptic
complex bearing the dissymmetric proline ligand yielded only two of
the four possible regioisomers, called [2a]PF6 and [2b]PF6. Both isomers were isolated
and characterized by a combination of spectroscopy and density functional
theory calculations. The photoreactivity of all four complexes [1a]PF6, [2a]PF6, [2b]PF6, and [3a]PF6 was
studied in water (H2O) and acetonitrile (MeCN) using UV–vis
spectroscopy, circular dichroism spectroscopy, mass spectrometry,
and 1H NMR spectroscopy. In H2O, upon visible-light
irradiation in the presence of oxygen, no photosubstitution took place,
but the amine of complex [1a]PF6 was photooxidized
to an imine. Contrary to expectations, enhancing the steric strain
by the addition of two ([2b]PF6) or four ([3a]PF6) methyl substituents did not lead, in phosphate-buffered
saline (PBS), to ligand photosubstitution. However, it prevented photoxidation,
probably as a consequence of the electron-donating effect of the methyl
substituents. In addition, whereas [2b]PF6 was photostable in PBS, [2a]PF6 quantitatively
isomerized to [2b]PF6 upon light irradiation.
In pure MeCN, [2a]PF6 and [3a]PF6 showed non-selective photosubstitution of both the l-proline and dmbpy ligands, whereas the non-strained complex
[1a]PF6 was photostable. Finally, in H2O–MeCN mixtures, [3a]PF6 showed
selective photosubstitution of l-proline, thus demonstrating
the active role played by the solvent on the photoreactivity of this
series of complexes. The role of the solvent polarity and coordination
properties on the photochemical properties of polypyridyl complexes
is discussed. Three ruthenium polypyridyl l-proline complexes with increasing strain (R, R′ = H
or Me) were synthesized and their photoreactivities studied in phosphate-buffered
saline, pure acetonitrile (MeCN), and water−MeCN mixtures.
Depending on the number of methyl groups, on the presence of air,
and on the nature of the solvent, either photoisomerization, photooxidation
of l-proline, selective photosubstitution, or nonselective
photosubstitution was observed.
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Affiliation(s)
- Jordi-Amat Cuello-Garibo
- Leiden Institute of Chemistry, Universiteit Leiden , Einsteinweg 55 2333 CC, Leiden, The Netherlands
| | - Elena Pérez-Gallent
- Leiden Institute of Chemistry, Universiteit Leiden , Einsteinweg 55 2333 CC, Leiden, The Netherlands
| | - Lennard van der Boon
- Leiden Institute of Chemistry, Universiteit Leiden , Einsteinweg 55 2333 CC, Leiden, The Netherlands
| | - Maxime A Siegler
- Small Molecule X-ray Crystallography Facility, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Universiteit Leiden , Einsteinweg 55 2333 CC, Leiden, The Netherlands
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26
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Braumüller M, Staniszewska M, Guthmuller J, Rau S. CLICK 'n' Sleep: Light-Switch Behavior of Triazole-Containing Tris(bipyridyl)ruthenium Complexes. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600964] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Markus Braumüller
- Anorganische Chemie I; Universität Ulm; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Magdalena Staniszewska
- Faculty of Applied Physics and Mathematics; Gdańsk University of Technology; Narutowicza 11/12 80-233 Gdańsk Poland
| | - Julien Guthmuller
- Faculty of Applied Physics and Mathematics; Gdańsk University of Technology; Narutowicza 11/12 80-233 Gdańsk Poland
| | - Sven Rau
- Anorganische Chemie I; Universität Ulm; Albert-Einstein-Allee 11 89081 Ulm Germany
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27
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Ultrafast in cellulo photoinduced dynamics processes of the paradigm molecular light switch [Ru(bpy)2dppz](2.). Sci Rep 2016; 6:33547. [PMID: 27644587 PMCID: PMC5028833 DOI: 10.1038/srep33547] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/30/2016] [Indexed: 01/22/2023] Open
Abstract
An in cellulo study of the ultrafast excited state processes in the paradigm molecular light switch [Ru(bpy)2dppz]2+ by localized pump-probe spectroscopy is reported for the first time. The localization of [Ru(bpy)2dppz]2+ in HepG2 cells is verified by emission microscopy and the characteristic photoinduced picosecond dynamics of the molecular light switch is observed in cellulo. The observation of the typical phosphorescence stemming from a 3MLCT state suggests that the [Ru(bpy)2dppz]2+ complex intercalates with the DNA in the nucleus. The results presented for this benchmark coordination compound reveal the necessity to study the photoinduced processes in coordination compounds for intracellular use, e.g. as sensors or as photodrugs, in the actual biological target environment in order to derive a detailed molecular mechanistic understanding of the excited-state properties of the systems in the actual biological target environment.
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28
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Wachter E, Moyá D, Parkin S, Glazer EC. Ruthenium Complex "Light Switches" that are Selective for Different G-Quadruplex Structures. Chemistry 2016; 22:550-9. [PMID: 26560887 PMCID: PMC4703525 DOI: 10.1002/chem.201503203] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Indexed: 01/03/2023]
Abstract
Recognition and regulation of G-quadruplex nucleic acid structures is an important goal for the development of chemical tools and medicinal agents. The addition of a bromo-substituent to the dipyridylphenazine (dppz) ligands in the photophysical "light switch", [Ru(bpy)2 dppz](2+) , and the photochemical "light switch", [Ru(bpy)2 dmdppz](2+) , creates compounds with increased selectivity for an intermolecular parallel G-quadruplex and the mixed-hybrid G-quadruplex, respectively. When [Ru(bpy)2 dppz-Br](2+) and [Ru(bpy)2 dmdppz-Br](2+) are incubated with the G-quadruplexes, they have a stabilizing effect on the DNA structures. Activation of [Ru(bpy)2 dmdppz-Br](2+) with light results in covalent adduct formation with the DNA. These complexes demonstrate that subtle chemical modifications of Ru(II) complexes can alter G-quadruplex selectivity, and could be useful for the rational design of in vivo G-quadruplex probes.
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Affiliation(s)
- Erin Wachter
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, KY 40506 (USA)
| | - Diego Moyá
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, KY 40506 (USA)
| | - Sean Parkin
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, KY 40506 (USA)
| | - Edith C Glazer
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, KY 40506 (USA).
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