103946-54-9Relevant articles and documents
DNA interaction and photonicking properties of DNA-targeted acridine (2,2′-bipyridine)platinum(II) complexes
Gude, Lourdes,Fernandez, Maria-Jose,Grant, Kathryn B,Lorente, Antonio
, p. 3135 - 3139 (2002)
Synthesis of two (2,2′-bipyridine)platinum(II) complexes tethered to one or two acridine chromophores is reported. These acridine complexes efficiently unwind and photocleave supercoiled plasmid DNA under physiological conditions of temperature and pH.
Synthesis and Biological Evaluation of Ru(II) and Pt(II) Complexes Bearing Carboxyl Groups as Potential Anticancer Targeted Drugs
Martínez, Mángeles,Carranza, M. Pilar,Massaguer, Anna,Santos, Lucia,Organero, Juan A.,Aliende, Cristina,De Llorens, Rafael,Ng-Choi, Iteng,Feliu, Lidia,Planas, Marta,Rodríguez, Ana M.,Manzano, Blanca R.,Espino, Gustavo,Jalón, Félix A.
, p. 13679 - 13696 (2017)
The synthesis and characterization of Pt(II) (1 and 2) and Ru(II) arene (3 and 4) or polypyridine (5 and 6) complexes is described. With the aim of having a functional group to form bioconjugates, one uncoordinated carboxyl group has been introduced in all complexes. Some of the complexes were selected for their potential in photodynamic therapy (PDT). The molecular structures of complexes 2 and 5, as well as that of the sodium salt of the 4′-(4-carboxyphenyl)-2,2′:6′,2″-terpyridine ligand (cptpy), were determined by X-ray diffraction. Different techniques were used to evaluate the binding capacity to model DNA molecules, and MTT cytotoxicity assays were performed against four cell lines. Compounds 3, 4, and 5 showed little tendency to bind to DNA and exhibited poor biological activity. Compound 2 behaves as bonded to DNA probably through a covalent interaction, although its cytotoxicity was very low. Compound 1 and possibly 6, both of which contain a cptpy ligand, were able to intercalate with DNA, but toxicity was not observed for 6. However, compound 1 was active in all cell lines tested. Clonogenic assays and apoptosis induction studies were also performed on the PC-3 line for 1. The photodynamic behavior for complexes 1, 5, and 6 indicated that their nuclease activity was enhanced after irradiation at = 447 nm. The cell viability was significantly reduced only in the case of 5. The different behavior in the absence or presence of light makes complex 5 a potential prodrug of interest in PDT. Molecular docking studies followed by molecular dynamics simulations for 1 and the counterpart without the carboxyl group confirmed the experimental data that pointed to an intercalation mechanism. The cytotoxicity of 1 and the potential of 5 in PDT make them good candidates for subsequent conjugation, through the carboxyl group, to "selected peptides" which could facilitate the selective vectorization of the complex toward receptors that are overexpressed in neoplastic cell lines.
A Multi-action and Multi-target RuII–PtIV Conjugate Combining Cancer-Activated Chemotherapy and Photodynamic Therapy to Overcome Drug Resistant Cancers
Gasser, Gilles,Gibson, Dan,Karges, Johannes,Tharaud, Micka?l,Yempala, Thirumal
, p. 7069 - 7075 (2020)
PtII complexes are commonly used to treat cancer. To reduce their side effects and improve their pharmacological properties, PtIV complexes are being developed as prodrug candidates that are activated by reduction in cancer cells. Concomitantly, RuII polypyridine complexes have gained much attention as photosensitizers for use in photodynamic therapy due to their attractive characteristics. In this article, a novel PtIV–RuII conjugate, which combines cancer activated chemotherapy with PDT, is presented. Upon entering the cancer cell, the PtIV centre is reduced to PtII and the axial ligands including the RuII complex and phenylbutyrate are released. As each component has its individual targets, the conjugate exerts a multi-target and multi-action effect with (photo-)cytotoxicity values upon irradiation up to 595 nm in the low nanomolar range in various (drug resistant) 2D monolayer cancer cells and 3D multicellular tumour spheroids.
Detection of NaCN in aqueous media using a calixarene-based fluoroionophore containing ruthenium(ii)-bipyridine as the fluorogenic unit
Maity, Debdeep,Vyas, Gaurav,Bhatt, Madhuri,Paul, Parimal
, p. 6151 - 6159 (2015)
A new molecular sensor containing calixarene and ruthenium(ii)-bipyridine as the fluorophore bridged by an amide moiety has been synthesised and characterized, and its anion binding properties have been investigated. It selectively detected cyanide in 95:5 water:acetonitrile when sodium salts of various anions such as F-, Cl-, Br-, I-, PO42-, IO4-, BO3-, CH3COO-, CN- and SO42- were investigated. The recognition event was monitored by fluorescence spectroscopy and the lower detection limit found was 70 ppb. However, when tetrabutylammonium salts of the same anions were used then, in addition to CN-, CH3COO- was also detected under similar experimental conditions. Interestingly, CN- exhibited substantial quenching, whereas CH3COO- showed an enhancement in emission intensity. The interaction of anions with the fluoroionophore was also monitored by electrochemical technique and the result obtained is consistent to that found by fluorogenic method. Binding constants were determined from emission titration, composition of the anion-complexes formed were determined from mass and emission titration data, mechanistic aspects of the interaction have been discussed with the aid of NMR data and the role of cations in the contrast fluorescent off and on behaviour has also been discussed. This sensor has also been used to estimate cyanide in real samples and the result obtained is satisfactory. This journal is
Shallow Distance Dependence for Proton-Coupled Tyrosine Oxidation in Oligoproline Peptides
Koronkiewicz, Brian,Swierk, John,Regan, Kevin,Mayer, James M.
, p. 12106 - 12118 (2020)
We have explored the kinetic effect of increasing electron transfer (ET) distance in a biomimetic, proton-coupled electron-transfer (PCET) system. Biological ET often occurs simultaneously with proton transfer (PT) in order to avoid the high-energy, charged intermediates resulting from the stepwise transfer of protons and electrons. These concerted proton-electron-transfer (CPET) reactions are implicated in numerous biological ET pathways. In many cases, PT is coupled to long-range ET. While many studies have shown that the rate of ET is sensitive to the distance between the electron donor and acceptor, extensions to biological CPET reactions are sparse. The possibility of a unique ET distance dependence for CPET reactions deserves further exploration, as this could have implications for how we understand biological ET. We therefore explored the ET distance dependence for the CPET oxidation of tyrosine in a model system. We prepared a series of metallopeptides with a tyrosine separated from a Ru(bpy)32+ complex by an oligoproline bridge of increasing length. Rate constants for intramolecular tyrosine oxidation were measured using the flash-quench transient absorption technique in aqueous solutions. The rate constants for tyrosine oxidation decreased by 125-fold with three added proline residues between tyrosine and the oxidant. By comparison, related intramolecular ET rate constants in very similar constructs were reported to decrease by 4-5 orders of magnitude over the same number of prolines. The observed shallow distance dependence for tyrosine oxidation is proposed to originate in part from the requirement for stronger oxidants, leading to a smaller hole-transfer effective tunneling barrier height. The shallow distance dependence observed here and extensions to distance-dependent CPET reactions have potential implications for long-range charge transfers.
Photosensitization of novel ruthenium-functionalized photoconductive polymers: Effect of ruthenium complex as photosensitizer
Moon, Jong-Sik,Kim, Chuntae,Kim, Won-Geun,Kim, Inhong,Kyhm, Kwangseuk,Oh, Jin-Woo,Kim, Nakjoong
, p. 141 - 147 (2015)
Owing to their efficient photo-charge generation, ruthenium derivatives are emerging as an important class of photosensitizers. Despite their promising characteristics, several deficiencies, such as the relatively low quantum yield and short lifetime of t
Synthesis and characterization of oligoproline-based molecular assemblies for light harvesting
Aldridge III, W. Steven,Hornstein, Brooks J.,Serron, Scafford,Dattelbaum, Dana M.,Schoonover, Jon R.,Meyer, Thomas J.
, p. 5186 - 5190 (2006)
Helical oligoproline arrays provide a structurally well-defined environment for building photochemical energy conversion assemblies. The use of solid-phase peptide synthesis (SPPS) to prepare four such arrays, consisting of 16, 17, 18, and 19 amino acid residues, is described here. Each array contains the chromophore [Rub′2m](PF6)2 (b′ = 4,4′-diethylamidocarbonyl-2,2′-bipyridine; m = 4-methyl-2,2′- dipyridine-4′-carboxylic acid) and the electron transfer donor PTZ (phenothiazine). The arrays differ systematically in the distance between the redox-active metal complex and PTZ sites. They have been used in photophysical studies to provide insight into the distance dependence of electron transfer. (J. Am. Chem. Soc. 2004, 126, 14506-14514). This work describes the synthesis, purification, and characterization of the oligoproline arrays, including a general procedure for the synthesis of related arrays.
Persistent photoconductivity in chemically modified single-wall carbon nanotubes
Khairoutdinov, Rafail F.,Doubova, Larissa V.,Haddon, Robert C.,Saraf, Laxmikant
, p. 19976 - 19981 (2004)
Control of the conductivity of single wall carbon nanotubes (SWNTs) is crucial for the use of carbon nanotubes in molecular electronics. We report a new fundamental characteristic of semiconducting SWNTs: the persistent photoconductivity of chemically modified carbon nanotube films. Illumination of carboxylated semiconducting SWNTs with ultraviolet or visible light causes a persistent decrease in the conductivity of semiconducting films. The photoinduced conductivity persists in the dark with a characteristic half-life of 35 s to 1.2 ?? 103 s at room temperature and an activation energy of 0.35 eV. Infrared illumination restores the conductivity of SWNT films. Ultraviolet and visible light illumination partially refills empty valence band states of chemically modified SWNTs by electron injection from the dopant sites. Photoinduced injection of electrons is accompanied by a decrease of the conductivity of the p-doped SWNT film, because of neutralization of holes by injected electrons. Covalent attachment of ruthenium(II)-tris(2,2a?2- bipyridine) (Ru(bpy)32+) to SWNTs makes carbon nanotubes sensitive to light that has been absorbed by the ruthenium complex and makes the carbon nanotubes persistently photoconductive. The photoconductivity of Ru(bpy)32+-SWNT films is presumably due to the injection of holes from *Ru(bpy)32+ to SWNT with a quantum yield of 0.55. Persistently photoconductive SWNTs have potential uses as nanosized optical switches, photodetectors, electrooptical information storage devices, and chemical sensors.
Metal-triggered radial self-assembly of collagen peptide fibers
Przybyla, David E.,Chmielewski, Jean
, p. 12610 - 12611 (2008)
A metal-triggered self-assembling collagen peptide was designed and synthesized to generate fibers through a radial growth mechanism. The assembly of the fibers was made possible through the placement of a bipyridine ligands within the center of the triple helix and was triggered by the addition of Fe(II). Copyright
Covalent hybrids based on Re(i) tricarbonyl complexes and polypyridine-functionalized polyoxometalate: Synthesis, characterization and electronic properties
Auvray, Thomas,Santoni, Marie-Pierre,Hasenknopf, Bernold,Hanan, Garry S.
, p. 10029 - 10036 (2017)
A series of [Re(CO)3Br(N^N)] (N^N = substituted 2,2′-bipyridine ligand) complexes based on polypyridine-functionalized Dawson polyoxometalate (1-3) has been synthesized. The new hybrids (4-6) were characterized by various analytical techniques, including absorption, vibrational and luminescence spectroscopies as well as electrochemistry. Both units, the polyoxometalate and the transition metal complex, retain their intrinsic properties. Their combination in the newly prepared hybrids results in improved photosensitization in the high-energy visible region. However, a complete quenching of the emission for the [Re(CO)3Br(N^N)] complexes is observed due to formation of a charge separated state, Re(ii)-POM-, as shown by quenching experiments as well as theoretical modelling via DFT.
Double-phosphorescence emission probe and preparation method thereof
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Paragraph 0036; 0040; 0044; 0045, (2020/06/16)
The invention discloses a double-phosphorescence emission probe and a preparation method thereof; the double-phosphorescence emission probe capable of detecting oxygen and metal ions is constructed byutilizing the response of a bis(2-pyridylmethyl)amine structure to metal ions and the response of a double-phosphorescence emission iridium complex to oxygen. Compared with a single-phosphorescence emission iridium complex probe disclosed in the prior art, the double-phosphorescence emission probe provides a new idea for simultaneous detection of multiple detection targets by a single probe; thepreparation process of the double-phosphorescence emission iridium complex is simple, reaction conditions are mild, and operability is high.
