The current study aims to elucidate the possible reasons for the significantly different pharmacological behavior of platinum(IV) complexes with cisplatin-, carboplatin- or nedaplatin-like cores and how this difference can be related to their main physicochemical properties. Chlorido-containing complexes are reduced fast (within hours) by ascorbate and are able to unwind plasmid DNA in the presence of ascorbate, while their tri- and tetracarboxylato analogs are generally inert under the same conditions. Comparison of the lipophilicity, cellular accumulation and cytotoxicity of the investigated platinum compounds revealed the necessity to define new structure-property/activity relationships (SPRs and SARs). The higher activity and improved accumulation of platinum(IV) complexes bearing Cl(-) in equatorial position cannot only be attributed to passive diffusion facilitated by their lipophilicity. Therefore, further platinum accumulation experiments under conditions where active/facilitated transport mechanisms are suppressed were performed. Under hypothermic conditions (4°C), accumulation of dichloridoplatinum(IV) complexes is reduced down to 10% of the amount determined at 37°C. These findings suggest the involvement of active and/or facilitated transport in cellular uptake of platinum(IV) complexes with a cisplatin-like core. Studies with ATP depletion mediated by oligomycin and low glucose partially confirmed these observations, but their feasibility was severely limited in the adherent cell culture setting.
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http://dx.doi.org/10.1016/j.jinorgbio.2016.03.005 | DOI Listing |
ACS Cent Sci
December 2024
Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Over 90% of cancer patients succumb to metastasis, yet conventional frontline therapy struggles to halt the progression of metastatic tumors. Targeted radionuclide therapy, which delivers radiation precisely to tumor sites, shows promise for treating metastasis. The rational design of a prodrug activation platform using radionuclides would be an ideal approach to synergize chemotherapy with targeted radionuclide therapy, yet it has not been established.
View Article and Find Full Text PDFInorg Chem
December 2024
Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain.
Dicationic, -symmetrical, tris-chelate Pt(IV) complexes of general formula [Pt(trz)(N∧N)](OTf), bearing two cyclometalated 4-butyl-3-methyl-1-phenyl-1-1,2,3-triazol-5-ylidene (trz) ligands and one aromatic diimine [N∧N = 2,2'-bipyridine (bpy, ), 4,4'-di--butyl-2,2'-bipyridine (dbbpy, ), 4,4'-dimethoxi-2,2'-bipyridine (dMeO-bpy, ), 1,10-phenanthroline (phen, ), 4,7-diphenyl-1,10-phenanthroline (bphen, ), dipyrido[3,2-:2',3'-]phenazine (dppz, ), or 2,3-diphenylpyrazino[2,3-][1,10]phenanthroline (dpprzphen, )] are obtained through chloride abstraction from [PtCl(trz)] () using AgOTf in the presence of the corresponding diimine. Complexes show long-lived phosphorescence from LC excited states involving the diimine ligand, with quantum yields that reach 0.18 in solution and 0.
View Article and Find Full Text PDFSmall
December 2024
Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, 741246, India.
Transition metal complex-loaded nanosystems (TMCNs) represent a cutting-edge platform for stimuli (light, ultrasound)-responsive cancer therapies. These nanosystems, incorporating metals such as manganese(II), zinc(II), ruthenium(II), rhenium(I), iridium(III), and platinum(IV), significantly enhance the efficacy of light-activated therapies, including photodynamic therapy (PDT) and photothermal therapy (PTT), as well as ultrasound-activated treatments like sonodynamic therapy (SDT). TMCNs based on ruthenium(II), rhenium(I), and iridium(III) improve PDT, while manganese(II) and iridium(III) demonstrate exceptional sonosensitizing properties.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, Brandon University, 270 18th Street, Brandon, Manitoba R7A 6A9, Canada.
Aerobic oxidation of a dimethylplatinum(II) complex featuring 1,1-di(2-pyridyl)ethanol as a supporting ligand leads to the formation of two unexpected Pt complexes (in ∼1:1 ratio), neither of which results from direct oxidation typical for Pt centers supported by popular κ-(,) ligands. While one product features an isomerized Pt center stabilized by the κ-(,,) ligand coordination mode, surprisingly, the other product results from intramolecular activation of the ligand methyl fragment. Mechanistic studies, reactivity of model complexes, and DFT calculations reveal that the critical proton-responsive nature of the ligand allows formation of intermediates that result in a concerted metalation deprotonation (CMD)-like C-H activation at Pt.
View Article and Find Full Text PDFCurr Res Pharmacol Drug Discov
October 2024
School of Arts and Sciences, Department of Natural Sciences, Lebanese American University, Byblos, Mount Lebanon, Lebanon.
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