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51.
Johannes Karges Thirumal Yempala Mickaël Tharaud Dan Gibson Gilles Gasser 《Angewandte Chemie (International ed. in English)》2020,59(18):7069-7075
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. 相似文献
52.
Larica Pathaw Themmila Khamrang Balasubramaniam Selvakumaran Mariappan Murali Pitchan Arul Prakash Mohamed Sultan Mohamed Jaabir Marappan Velusamy 《应用有机金属化学》2021,35(1)
Copper(I) complexes of the types [Cu(N–N)(PPh3)2]NO3 (LC41–LC44) and [Cu(N–N)(PPh3)(NO3)] (LC45) carrying 3‐substituted 1‐pyridine‐2‐ylimidazo[1,5‐a]pyridine (N–N) derivatives and triphenylphosphine (PPh3) ligands have been prepared. The synthesized copper(I)–phosphine complexes were fully characterized by NMR, IR, ESI‐MS and UV–visible spectroscopy as well as by cyclic voltammetry. Selected structures such as LC42, LC43 and LC45 were additionally analysed by single‐crystal X‐ray method, which show that copper(I) centre adopts a highly distorted tetrahedral geometry. The 1H and 13C NMR spectral data of the complexes throw light on the nature of metal–ligand bonding. They display dπ–π* metal‐to‐ligand charge transfer (MLCT) transition and show quasireversible CuI/CuII metal oxidation. Among the copper(I)–phosphine complexes, LC41–LC44 exhibit moderate cytotoxicity (IC50: 24 h, 67–74 μM; 48 h, 58–70 μM) against human lung epithelial adenocarcinoma A549 cells, whereas LC45 displays the best activity (IC50: 24 h, 42 μM; 48 h, 34 μM) for A549 cancer cell line, which is better than that of the commercial antitumor drug cisplatin. All the complexes also displayed excellent selectivity by being relatively inactive against the human lung epithelial L132 normal cell line with selectivity index (SI) values ranging from 3.4 to 7.4. The complexes block cell cycle progression of A549 cells in G0/G1 phase. FACSVerse analyses are suggestive of reactive oxygen species (ROS) generation and apoptotic cell death induced by the LC41, LC43 and LC45. The induction of apoptosis in A549 cells was shown by Annexin V with propidium iodide (PI) and 4′,6‐diamidino‐2‐phenylindole (DAPI) staining methods and established the ability of LC41, LC43 and LC45 to accumulate in the cell nuclei. 相似文献
53.
Rajendiran V Murali M Suresh E Palaniandavar M Periasamy VS Akbarsha MA 《Dalton transactions (Cambridge, England : 2003)》2008,(16):2157-2170
A series of mixed ligand ruthenium(II) complexes [Ru(Hdpa)2(diimine)](ClO4)2, 1-5 where Hdpa is 2,2'-dipyridylamine and diimine is 1,10-phenanthroline (phen) and a modified/extended 1,10-phenanthroline such as, 5,6-dimethyl-1,10-phenanthroline (5,6-dmp), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq), 5-methyldipyrido[3,2-d:2',3'-f]quinoxaline (mdpq) and dipyrido[3,2-a:2',3'-c]phenazine (dppz) have been isolated and characterized by analytical and spectral methods. The complex [Ru(Hdpa)2(phen)](PF6)2 1 has been structurally characterized and the coordination geometry around Ru(II) in it is described as distorted octahedral. 1H NMR spectral data reveal that 1-5 should have a C2 symmetry lying on the diimine plane due to the rapid flapping of the coordinated Hdpa ligands. The interaction of the complexes with calf thymus (CT) DNA has been explored by using absorption and emission spectral and viscometry and electrochemical techniques and the mode of DNA binding of the complexes has been proposed. The DNA binding affinity of the complexes decreases with decrease in number of planar aromatic rings in the co-ligand supporting the intercalation of the diimine co-ligands in between the DNA base pairs. Circular dichroic spectral studies reveal that the complexes 3-5 exhibit induced circular dichroism upon binding to CT DNA. Interestingly, upon interaction with CT DNA all the complexes show an increase in anodic current in the cyclic voltammograms suggesting that they are involved in electrocatalytic guanine oxidation. Interestingly, of all the complexes, only 5 alters the DNA superhelicity upon binding with supercoiled pBR322 DNA, which is consistent with its higher DNA binding affinity. Further, the cytotoxicities of the complexes against human cervical epidermoid carcinoma cell line (ME180) have been examined. Interestingly, 5 exhibits a cytotoxicity against ME180 higher than other complexes with potency approximately 8 times more than cisplatin for 24 h incubation but 4 times lower than cisplatin for 48 h incubation. 相似文献
54.
Dynamic variations in hybridization patterns (rehybridization) were analyzed at B3LYP/6-31G** and MP2/6-31+G* levels. Computations clearly illustrate the generality of rehybridization in a variety of chemical phenomena, which involve structural reorganization in hydrogen-bonded complexes, nonhyperconjugative stereoelectronic effects in saturated heterocycles, Mills-Nixon effect, and contrasting substituent effects in cycloaromatization reactions. 相似文献
55.
Two isomeric dibenzofuran carboxaldehydes, namely 2-methoxydibenzo[b,d]furan-1-carbaldehyde (4) and 2-methoxydibenzo[b,d]furan-3-carbaldehyde (5), were synthesized. Formylation of 2-methoxydibenzo[b,d]furan (3) with α,α-dichloromethyl methyl ether and tin(IV) chloride gave a mixture of aldehydes 4 and 5 in 95 % yield and in a 35:65 ratio. Their 1H and 13C NMR spectral signals were not sufficiently resolved in CDCl3 solution to achieve their complete assignment, but this was possible in DMSO-d 6 with the help of 2D-NMR techniques: NOESY for 1H–1H interactions and HSQC and HMQC experiments for 1H–13C correlations. These aldehydes were used in the synthesis of novel β-phenylethylamines and NBOMe derivatives, which are undergoing biological evaluation. 相似文献
56.
Peshkov VA Pereshivko OP Sharma S Meganathan T Parmar VS Ermolat'ev DS Van der Eycken EV 《The Journal of organic chemistry》2011,76(14):5867-5872
A one-pot protocol based on a Ag(I)-catalyzed cycloisomerization of propargylic ureas, derived from secondary propargylamines and isocyanates, was developed for the generation of the 2-imidazolone core. 相似文献
57.
58.
K. Ramamurthi G. Madhurambal B. Ravindran M. Mariappan S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2011,104(3):943-947
The growth and characterization of a new non-linear organometallic crystal, potassium thiourea thiocyanide (PTT) is reported.
The growth of single crystals was accomplished by the slow evaporation solution growth method. The grown crystals were characterized
by XRD, TG–DTA, UV, and FTIR spectral analyses. PTT has good optical transmission in the entire visible region which is an
essential requirement for a non-linear crystal. TG curve of PTT undergoes complete decomposition between 176 and 1,000 °C
in three steps with corresponding three DTA peaks. The high thermal stability of organometallic crystals are due to strong
bonding existing between the conjugation layers of thiourea molecule and the potassium ions. 相似文献
59.
Nair AS Zhu P Babu VJ Yang S Krishnamoorthy T Murugan R Peng S Ramakrishna S 《Langmuir : the ACS journal of surfaces and colloids》2012,28(15):6202-6206
We report the use of highly porous, dense, and anisotropic TiO(2) derived from electrospun TiO(2)-SiO(2) nanostructures through titanate route in dye-sensitized solar cells. The titanate-derived TiO(2) of high surface areas exhibited superior photovoltaic parameters (efficiency > 7%) in comparison to the respective electrospun TiO(2) nanomaterials and commercially available P-25. 相似文献
60.
The cadmium sulfo selenide CdS1?xSex thin films were chemical bath deposited in aqueous media onto coated glass substrates. As-deposited CdS1?xSex thin films were annealed at 350 °C in air for 30 min. The structural, morphological, compositional and optical properties of deposited CdS1?xSex thin films were studied using X-ray diffractometer (XRD), scanning electron microscopy (SEM), Energy dispersive analysis by X-ray (EDAX), and UV-Vis-NIR spectrophotometer respectively. X-ray diffraction patterns of CdS1?xSex thin films reveal the polycrystalline nature and hexagonal structure. The microstructural parameters such as crystallite size (D), micro strain (?), and dislocation density were calculated and found to depend on compositions. The surface morphology and grain size are found to be influenced with the annealing temperature. The presence of Cd, S and Se of the CdS1?xSex thin films and the composition of CdS1?xSex thin film are estimated by EDAX analysis. The optical transmittance and absorption spectra were recorded in the range 400–2500 nm. The band gap of the CdS1?xSex thin films is found to decrease from 2.5 eV to 1.75 eV. 相似文献