Search results for "PORP"
showing 10 items of 567 documents
Ethane-Bridged Zinc-Porphyrin Dimers in Langmuir-Shäfer Thin Films: Structural and Spectroscopic Properties
2006
This work reports on the structural and spectroscopic properties of ethane-bridged Zn porphyrin dimers (1) in Langmuir-Scha¨fer (LS) thin films by combining scanning force microscopy (SFM) with film balance, UV-vis absorption, fluorescence, and nanosecond laser flash photolysis measurements. Results show that depending on the surface pressure the Langmuir films of pure 1 can be arranged in two different condensed phases, whereas SFM of the LS films shows characteristic fractal networks constituted by nanoscopic aggregates. The spectral findings agree with a picture in which 1 is apparently present in the anti conformation but aggregated in a sort of H-type structure whose optical features r…
Photocatalytic activity of nano and microcrystalline TiO2 hybrid systems involving phthalocyanine or porphyrin sensitizers
2011
Hybrid photocatalysts based on TiO(2)-anatase matrix, representing the both micro- and nano-structures, impregnated with selected lanthanide diphthalocyanine and metalloporphyrin sensitizers, were compared to evaluate their activity and effectiveness in a water suspension catalytic system designed to degrade 4-nitrophenol (4-NP) in a UV-stimulated reaction. Either type of the anatase catalyst was proved to be effective in mineralizing of 4-NP. However, kinetic studies confirmed that the composite's efficiency basically depends on the nature of the macromolecular sensitizer and to a minor extent on the dimensions (micro/nano) of the TiO(2) particles. The apparent higher activity observed for…
Alkyl and aryl substituted corroles. 3. Reactions of cofacial cobalt biscorroles and porphyrin-corroles with pyridine and carbon monoxide.
2002
The synthesis and characterization of three new cofacial biscorroles and three new linked Co(II) porphyrins and Co(III) corroles with the same face to face orientation are described. The biscorroles are represented as (BCS)Co(2), (BCO)Co(2), (BCX)Co(2) while the porphyrin-corrole dyads are represented as (PCA)Co(2), (PCB)Co(2), (PCO)Co(2) where BC represents the Co(III) cofacial biscorroles and PC represents the porphyrin-corrole complexes which are linked to each other by a dibenzothiophene (S), dibenzofuran (O), or 9,9-dimethylxanthene (X) bridge in the case of the corroles and an anthracene (A), biphenylene (B), or dibenzofuran (O) bridge in the case of the mixed macrocycle derivatives. …
Triplet–Triplet Annihilation Upconversion in a MOF with Acceptor‐Filled Channels
2019
Abstract Photon upconversion has enjoyed increased interest in the last years due to its high potential for solar‐energy harvesting and bioimaging. A challenge for triplet–triplet annihilation upconversion (TTA‐UC) processes is to realize these features in solid materials without undesired phase segregation and detrimental dye aggregation. To achieve this, we combine a palladium porphyrin sensitizer and a 9,10‐diphenylanthracene annihilator within a crystalline mesoporous metal–organic framework using an inverted design. In this modular TTA system, the framework walls constitute the fixed sensitizer, while caprylic acid coats the channels providing a solventlike environment for the mobile a…
Effects of two organotin(IV)(sulfonato phenyl)porphynates on the MAPKs and on the growth of A375 human melanoma cells
2009
Previously we showed apoptotic induction in A375 human melanoma cells using two complexes of the meso-tetra(4-sulfonatophenyl)porphinate (TPPS), (Bu 2 Sn) 2 TPPS and (Bu 3 Sn) 4 TPPS. To understand how these compounds activate apoptosis in melanoma cells we studied MAPKs and the (Bu 2 Sn) 2 TPPS and (Bu 3 Sn) 4 TPPS cellular uptake. Western blotting experiments showed activated protein kinases ERK 1/2, JNK and p38 in 10 μM (Bu 2 Sn) 2 TPPS- and 1 μM (Bu 3 Sn) 4 TPPS-treated melanoma cells, which suggests that the three MAP kinases are involved in the apoptotic death of A375-treated cells. By taking advantage of the porphyrin fluorescence, we found a fast concentration of (Bu 2 Sn) 2 TPPS an…
A Functionalized Noncovalent Macrocyclic Multiporphyrin Assembly from a Dizinc(II) Bis-Porphyrin Receptor and a Free-Base Dipyridylporphyrin
2003
The bis-porphyrin system ZnP 2 , in which two zinc porphyrins are connected by a phenanthroline linker in an oblique fashion, acts as a bifunctional receptor towards the complexation of free-base meso-5,10-bis(4'-pyridyl)-15,20-diphenylporphyrin (4'-cisDPyP). In solution, NMR spectroscopy evidenced quantitative formation of the tris-porphyrin macrocyclic assembly ZnP 2 (4'-cisDPyP), in which the two fragments are held together by two axial 4'-N(pyridyl)-Zn interactions. The remarkable stability of the edifice (an association constant of about 6 x 10 8 M - 1 was determined by UV/Vis absorption and emission titration experiments in toluene) is due to the almost perfect geometrical match betwe…
Triplet-triplet energy transfer controlled by the donor-acceptor distance in rigidly held palladium-containing cofacial bisporphyrins.
2005
Eleven new complexes, including mono-, heterobi-, and homobimetallic cofacial bisporphyrins, (Pd)H 2 DPS, (M)H 2 DPX, (M)H 2 DPB, (PdZn)DPS, (PdZn)DPX, (Pt) 2 DPX, (M) 2 DPB (M=Pd, Pt), and (Pt)P (DPS 4 - = 4,6-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]dibenzothiophene tetraanion, DPX 4 - = 4,5-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]-9,9-dimethylxanthene tetraanion, DPB 4 - =1,8-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]biphenylene tetraanion, P 2 - = 5-phenyl-2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin dianion) have been synthesized and characterized. The photophysical properties of the donor (M)P (M=Pd or Pt, P= porphy…
Haem Biosynthesis and Antioxidant Enzymes in Circulating Cells of Acute Intermittent Porphyria Patients
2016
The aims of the present study were to explore the expression pattern of haem biosynthesis enzymes in circulating cells of patients affected by two types of porphyria (acute intermittent, AIP, and variegate porphyria, VP), together with the antioxidant enzyme pattern in AIP in order to identify a possible situation of oxidative stress. Sixteen and twelve patients affected by AIP and VP, respectively, were analysed with the same numbers of healthy matched controls. Erythrocytes, neutrophils and peripheral blood mononuclear cells (PBMCs) were purified from blood, and RNA and proteins were extracted for quantitative real time PCR (qRT-PCR) and Western-blot analysis, respectively. Porhobilinogen…
Potential Antioxidant Activity of Calcium and Selected Oxidative Stress Markers in Lead- and Cadmium-Exposed Workers
2020
Occupational lead (Pb) and cadmium (Cd) exposure occurs during processing and casting of nonferrous metals such as zinc. In contrast to Pb and Cd, Ca is essential for living organisms due to its important role in a multitude of functions, from cell signaling to bone growth. Pb and Cd exposure affects calcium metabolism in various ways. The aim of this study was to investigate the blood levels of Pb, Cd, and Ca and the levels of selected oxidative stress biomarkers in workers exposed to Pb and Cd. Population groups included 264 male employees in a lead-zinc smelter. The study population was divided into two subgroups based on the median of Ca serum level (2.42 mmol/l): the low-Ca-level group…
Analysis of early biochemical markers and regulation by tin protoporphyrin IX in a model of spontaneous osteoarthritis
2011
Abstract Age-related changes in joint tissues lead to osteoarthritis (OA). Detection of early changes in OA patients may help to initiate treatments before the establishment of irreversible joint destruction. STR/ort mice develop with age a severe degenerative joint disease that resembles human OA thus allowing the investigation of biochemical markers as well as new treatments in an accelerated time frame. We have analyzed the changes in serum levels of different mediators during the early phases of idiopathic OA in STR/ort mice. Serum levels of matrix metalloproteinase-3 (MMP-3) but not those of tumor necrosis factor-α, interleukin(IL)-1β, IL-17 or prostaglandin E 2 correlated with histopa…