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11.
Dr. Johannes Karges Dr. Thirumal Yempala Mickaël Tharaud Prof. Dan Gibson Dr. Gilles Gasser 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7135-7141
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
12.
Tanwar J Datta A Tiwari AK Chaturvedi S Ojha H Allard M Chaudary NK Thirumal M Mishra AK 《Dalton transactions (Cambridge, England : 2003)》2011,40(13):3346-3351
A bis-polyazamacrocycle, 10'-bis(acetamido)ethane-bis[1,4,7-tri(carboxymethane)-1,4,7,10-tetraazacyclododecane] (DO3A-AME-DO3A) was synthesized for application in magnetic resonance imaging. The efficacy of DO3A-AME-DO3A as non ionic magnetic contrast agent was tested by performing relaxometric studies on its gadolinium complex. The longitudinal relaxivity, r(1) and transverse relaxivity, r(2) values were found to be 5.84 mM(-1)s(-1) and 6.82 mM(-1)s(-1), per Gd(III) at pH 7.0, 37 °C. The luminescence properties of europium complex of DO3A-AME-DO3A were investigated in aqueous medium. The lifetime of Eu(2)-DO3A-AME-DO3A in water was found to be 0.786 ms. Emission and luminescence lifetime measurements on the europium complex of DO3A-AME-DO3A gives a hydration number of q = 1.9. The reaction enthalpy and entropy were found to be, ΔH(0) = -(6.2 ± 2) kJ mol(-1), ΔS(0) = - (1.8 ± 0.4) kJ mol(-1)K(-1), and K(Eu)(298) = (1.8 ± 0.1). 相似文献
13.
Halogen-free flame retardant PUF: Effect of melamine compounds on mechanical, thermal and flame retardant properties 总被引:3,自引:0,他引:3
Water blown rigid polyurethane foam (PUF) was prepared with melamine polyphosphate (MPP) and melamine cyanurate (MC) as fire retardant (FR) additives. The effect of these additives on the properties of rigid PUF such as physico-mechanical, morphological, thermo-oxidative stability, flame retardancy and smoke density properties were studied. The mechanical and thermo-oxidative stability of PUF filled with MC was found to be better than those of MPP filled PUF. The insulation property of both MPP and MC filled PUF was improved with respect to the neat PUF. The FR properties of these filled PUF were evaluated by cone calorimeter, limiting oxygen index (LOI), smoke density, rate of burning and char residue estimation. The FR property of MPP filled PUF was better than that of the MC filled PUF. 相似文献
14.
Thirumal Yempala Tomer Babu Subhendu Karmakar Alina Nemirovski Maisaloon Ishan Valentina Gandin Dan Gibson 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18386-18391
Most multi‐action PtIV prodrugs have bioactive ligands containing carboxylates. This is probably due to the ease of carboxylating the OH axial ligands and because following reduction, the active drug is released. A major challenge is to expand the arsenal of bioactive ligands to include those without carboxylates. We describe a general approach for synthesis of PtIV prodrugs that release drugs with OH groups. We linked the OH groups of gemcitabine (Gem), paclitaxel (Tax), and estramustine (EM) to the PtIV derivative of cisplatin by a carbonate bridge. Following reduction, the axial ligands lost CO2, rapidly generating the active drugs. In contrast, succinate‐linked drugs did not readily release the free drugs. The carbonate‐bridged ctc‐[Pt(NH3)2(PhB)(Gem‐Carb)Cl2] was significantly more cytotoxic than the succinate‐bridged ctc‐[Pt(NH3)2(PhB)(Gem‐Suc)Cl2], and more potent and less toxic than gemcitabine, cisplatin, and co‐administration of cisplatin and gemcitabine. 相似文献
15.
Pradeep Kumar Yadalam Thilagar Sivasankari Santhiya Rengaraj Maryam H. Mugri Mohammed Sayed Samar Saeed Khan Mona Awad Kamil Shilpa Bhandi A. Thirumal Raj Shankargouda Patil Artak Heboyan 《Molecules (Basel, Switzerland)》2022,27(9)
Simple SummaryIn spite of substantial investigation, the biological link between periodontitis and rheumatoid arthritis remains unexplained. This study intended to correlate periodontitis and rheumatoid arthritis gene expression patterns to find shared targets for both the disease. We identified the differentially expressed genes (DEGs) in periodontitis and rheumatoid arthritis. The network was built by integrating DEGs and ranking the genes using GeneMANIA. FINDSITEcomb2.0 was used to find a possible inhibitor for the top-ranked gene. Further, the binding effectiveness and protein-ligand complex stability were then determined by molecular docking and molecular dynamics. The network analysis showed IFI44L as a highly ranking gene implicated in most immunological pathways. A virtual screening of 6507 compounds revealed vemurafenib as the best candidate for the IFI44L target. Molecular docking and molecular dynamics modelling revealed the stability of the IFI44L-vemurafenib complex, which suggest IFI44L is potential target and vemurafenib could be the better candidate to treat both diseases.AbstractObjective: Despite extensive research on periodontitis and rheumatoid arthritis, the underlying molecular connectivity between these condition remains largely unknown. This research aimed to integrate periodontitis and rheumatoid arthritis gene expression profiles to identify interconnecting genes and focus to develop a common lead molecule against these inflammatory conditions. Materials and Methods: Differentially expressed genes (DEGs) of periodontitis and rheumatoid arthritis were identified from the datasets retrieved from the Gene Expression Omnibus database. The network was constructed by merging DEGs, and the interconnecting genes were identified and ranked using GeneMANIA. For the selected top ranked gene, the potential inhibitor was searched using FINDSITEcomb2.0. Subsequently, the molecular docking and molecular dynamics were performed to determine the binding efficiency and protein-ligand complex stability, respectively. Results: From the network analysis, IFN-induced protein 44-like (IFI44L) was identified as a top ranked gene involved in most of the immunological pathway. With further virtual screening of 6507 molecules, vemurafenib was identified to be the best fit against the IFI44L target. The binding energy and stability of IFI44L with vemurafenib were investigated using molecular docking and molecular dynamics simulation. Docking results show binding energy of −7.7 Kcal/mol, and the simulation results show stability till 100 ns. Conclusions: The identified IFI44L may represent a common drug target for periodontitis and rheumatoid arthritis. Vemurafenib could be a potent anti-inflammatory drug for both diseases. 相似文献
16.
Zr-modified Auruvillius family of lanthanum bismuth titanate, namely Bi3.25La0.75Ti3?xZrxO12 (BLTZ, x = 0, 0.1, 0.3, 0.5, 0.7 and 1), was prepared by solid-state reaction method. Dielectric properties of the ceramics were studied as a function of temperature. Hysteresis measurements were also performed. Among the composition, Bi3.25La0.75Ti2.9Zr0.1O12 (BLTZ1) showed large remnant polarization compared to the promising ceramic, namely Bi3.25La0.75Ti3O12. The results were corroborated with the pyroelectric, electric polarization and Raman spectroscopic data. 相似文献
17.
We herein report simple and efficient methods for the synthesis of various formyl derivatives of dibenzofuran. The aldehydes reported are prepared in at most three steps and in yields greater than 60% from commercially available dibenzofuran, with one exception where isomers must be separated. The protocols described involve either formylation of previously functionalized dibenzofuran derivatives or the initial introduction of the formyl group and subsequent further functionalization under standard reaction conditions as described. We have also reported an efficient and simple method for the synthesis of key methoxydibenzofurans in high yield (65% overall for two steps). 相似文献
18.
Influence of oxidation state of phosphorus on the thermal and flammability of polyurea and epoxy resin 总被引:1,自引:0,他引:1
The focus of this study is an investigation of the effect of oxidation state of phosphorus in phosphorus-based flame retardants on the thermal and flame retardant properties of polyurea and epoxy resin. Three different oxidation states of phosphorus (phosphite, phosphate and phosphine oxide) additives, with different thermal stabilities at a constant phosphorus content (1.5 wt.%) have been utilized. Thermal and flame retardant properties were studied by TGA and cone calorimetry, respectively. The thermal stability of both polymers decreases upon the incorporation of phosphorus flame retardants irrespective of oxidation state and a greater amount of residue was observed in the case of phosphite. Phosphate was found to be better flame retardant in polyurea, whereas phosphite is suitable for epoxy resin. Phosphite will react with epoxy resin by trans-esterification, which is demonstrated by FTIR and 31P NMR. Further, TG–FTIR and XPS studies also provide information on flame retardancy of both polymers with phosphorus flame retardants. 相似文献
19.
Ashok K. Ganguli Shikha Nangia Meganathan Thirumal Pratibha L. Gai 《Journal of Chemical Sciences》2006,118(1):37-42
Using molten salt route (with NaCl/KCl as the salt) we have been able to synthesize a new form of magnesium tantalate at 850°C.
Powder X-ray diffraction data could be indexed on an orthorhombic unit cell with lattice parameters, ‘a’ = 15.36(1) ?, ‘b’ = 13.38(1) ? and ‘c’ = 12.10(1) ?. High resolution transmission electron microscopy and electron diffraction studies confirm the results obtained
by X-ray studies. Energy dispersive X-ray spectroscopy helps ascertain the composition of MgTa2O6. The title compound shows a dielectric constant of ∼24 with a low dielectric loss of 0.006 at 100 kHz at room temperature.
Dielectric constant is nearly unchanged with rise in temperature while the loss shows a very marginal increase (0.007 at 300°C).
Dedicated to Prof J Gopalakrishnan on his 62nd birthday. 相似文献
20.
M. Thirumal A. K. Ganguli 《Progress in Crystal Growth and Characterization of Materials》2002,44(3):4359-154
There are now many advanced materials, which have been discovered with unique dielectric properties having been designed with an eye to specific applications. One of the areas of current interest to the material scientist and solid state chemist is to find new materials suitable for use as dielectric resonators in microwave applications and to tailor its properties. Among them the ABO3 type perovskite oxides and the AB2O6 (columbite/trirutile) type of oxides where B is either Nb or Ta have been pursued vigorously in the recent past. There is a continuous interest to optimise the dielectric properties by suitable doping at the A-site, B-site and the B′ site of the perovskite related A(B1/3B′2/3O3) structure. In addition there is an increasing demand to discover alternate routes of synthesis, which would afford these oxides at much lower temperatures. We discuss our recent results on some of the above materials. 相似文献