Search results for "PORP"
showing 10 items of 567 documents
Synthesis, structural investigations on organotin(IV) chlorin-e6 complexes, their effect on sea urchin embryonic development and induced apoptosis
2004
Four new organotin(IV) chlorin derivatives, [chlorin=chlorin-e(6)=21H,23H-porphine-2-propanoic acid, 18-carboxy-20-(carboxymethyl)-8-ethenyl-13-ethyl-2,3-di-hydro-3,7,12,17-tetramethyl-(2S-trans)-], with formula (R(2)Sn)(3)(chlorin)(2).2H(2)O (R=Me, n-Bu) and (R(3)Sn)(3)chlorin.2H(2)O (R=Me, Ph) have been synthesized. The solid state and solution phase structures have been investigated by FT-IR, (119)Sn Mössbauer, (1)H and (13)C NMR spectroscopy. In the solid state, (R(2)Sn)(3)(chlorin)(2).2H(2)O complexes contain six coordinated Sn(IV), in a skew trapezoidal environment by forming trans-R(2)SnO(4) polymeric units. As far as (R(3)Sn)(3)chlorin.2H(2)O complexes are concerned, Sn(IV) is five …
Synthesis and Photodynamics of Fluorescent Blue BODIPY-Porphyrin Tweezers Linked by Triazole Rings
2012
Novel zinc porphyrin tweezers in which two zinc porphyrins were connected with π-conjugated boron dipyrromethenes (BDP meso-Por(2) and BDP β-Por(2)) through triazole rings were synthesized to investigate the photoinduced energy transfer and electron transfer. The UV-vis spectrum of BDP β-Por(2) which has less bulky substituents than BDP meso-Por(2) exhibits splitting of the Soret band as a result of the interaction between porphyrins of BDP β-Por(2) in the excited state. Such interaction between porphyrins of both BDP β-Por(2) and BDP meso-Por(2) is dominant at room temperature, while the coordination of the nitrogen atoms of the triazole rings to the zinc ions of the porphyrins occurs at l…
Influence of Age on Cerebral Housekeeping Gene Expression for Normalization of Quantitative Polymerase Chain Reaction after Acute Brain Injury in Mice
2015
To prevent methodological errors of quantitative PCR (qPCR) normalization with reference genes is obligatory. Although known to influence gene expression, impact of age on housekeeping gene expression has not been determined after acute brain lesions such as traumatic brain injury (TBI). Therefore, expression of eight common control genes was investigated at 15 min, 24 h, and 72 h after experimental TBI in 2- and 21-month-old C57Bl6 mice. Expression of β2-microglobulin (B2M), β-actin (ActB), and porphobilinogen deaminase (PBGD) increased after TBI in both ages. β2M demonstrated age-dependent differences and highest inter- and intragroup variations. Expression of cyclophilin A, glyceraldehyd…
XAFS Studies of High-Valent Porphyrinato Manganèse Complexes with Ozone
1997
We produce strong evidence of the interaction of ozone with a series of Manganese (III) porphyrinato complexes to form a well defined reactive intermediate. In the latter species, the Manganese atom which is formally in a tetravalent (IV) state, is (at least) hexacoordinated with the metal unambiguously lying in the basal plane of the four pyrrolic nitrogens of the porphyrin macrocycle. Substitution of Bromine or Chlorine axial ligands by ozonids is most likely to happen. This conclusion is also supported by XANES and EXAFS spectra recorded at the Chlorine K-edge which suggest that ozone may even form with chlorine a complex anion.
Inter- and Intramolecular Anodic Nucleophilic Substitutions of Porphyrins. Reactivity of the resulting products
2020
This manuscript presents the functionalization of porphyrins by anodic nucleophilic substitution (SNAn). After an introduction describing generalities on porphyrin, the 2nd chapter deals with the 2-step synthesis of primary aminoporphyrins. The 1st electrochemical step consists in oxidizing the porphyrin at the 1st oxidation potential in the presence of pyridine. The formed pyridinium-porphyrin is then transformed into an amine by opening the pyridinium fragment by nucleophilic attack of piperidine.The 3rd chapter presents the synthesis and redox reactivity of porphyrins substituted with one (or several) aromatic groups carrying an imine function (thiopyrimidine, quinoline and aminopyridine…
Photoreduction of carbon dioxide to formic acid in aqueous suspension: a comparison between phthalocyanine/TiO2 and porphyrin/TiO2 catalysed processes
2014
Composite materials prepared by loading polycrystalline TiO2 powders with lipophilic highly branched Cu(II)- and metal-free phthalocyanines or porphyrins, which have been used in the past as photocatalysts for photodegradative processes, have been successfully tested for the efficient photoreduction of carbon dioxide in aqueous suspension affording significant amounts of formic acid. The results indicated that the presence of the sensitizers is beneficial for the photoactivity, confirming the important role of Cu(II) co-ordinated in the middle of the macrocycles. A comparison between Cu(II) phthalocyanines and Cu(II) porphyrins indicated that the Cu(II)- phthalocyanine sensitizer was more e…
Pulse EPR methods for studying chemical and biological samples containing transition metals
2006
This review discusses the application of pulse EPR to the characterization of disordered systems, with an emphasis on samples containing transition metals. Electron nuclear double-resonance (ENDOR), electron-spin-echo envelope-modulation (ESEEM), and double electron-electron resonance (DEER) methodologies are outlined. The theory of field modulation is outlined, and its application is illustrated with DEER experiments. The simulation of powder spectra in EPR is discussed, and strategies for optimization are given. The implementation of this armory of techniques is demonstrated on a rich variety of chemical systems: several porphyrin derivatives that are found in proteins and used as model s…
Relation of early Photofrin uptake to photodynamically induced phototoxicity and changes of cell volume in different cell lines.
1994
For efficacy of photodynamic therapy, selective uptake and retention of photoactive substances has been postulated. Therefore, measurements were performed to find out whether the photosensitiser Photofrin® is taken up differently in malignant and non-malignant cells in vitro . In addition, the sensitivity of malignant cells and nonmalignant cells to photodynamic exposure was investigated, by quantifying viability and volume alterations of the cells. Bovine aortic endothelial cells, mouse fibroblasts and amelanotic hamster melanoma cells were suspended in a specially designed incubation chamber under controlled conditions (e.g. pH, p O 2 , p CO 2 and temperature). After establishing constant…
Diorganotin(IV) and triorganotin(IV) complexes of meso-tetra(4-sulfonatophenyl) porphine induce apoptosis in A375 human melanoma cells
2006
The cytotoxic effect of several diorganotin(IV) and triorganotin(IV)-meso-tetra(4-sulfonatophenyl)porphine derivatives was tested and only the (Bu(2)Sn)(2)TPPS and the (Bu(3)Sn)(4)TPPS showed cytotoxicity on A375 human melanoma cells. To examine the pathway of (Bu(2)Sn)(2)TPPS or (Bu(3)Sn)(4)TPPS induced A375 cell death, DNA fragmentation analysis, Annexin V binding and PI uptake as well as caspases activation analysis by Western blot were carried out. A375 cells treated exhibited several typical characteristics of apoptosis. Both the (Bu(2)Sn)(2)TPPS and the (Bu(3)Sn)(4)TPPS compounds activate caspase-8 and caspase-9 leading to caspase-3 activation. Thus, we propose that these two porphiri…
Salivary Microbiota Composition in Patients with Oral Squamous Cell Carcinoma: A Systematic Review.
2022
Background: Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide. Despite recent advances in diagnosis and treatment, in recent years, an increase in the incidence of OSCC has been registered, and the mortality rate is still high. This systematic review aims to identify a potential association between the composition of salivary microbiota and OSCC. Materials and Methods: The protocol for this study was designed following the PRISMA guidelines. Records were identified using different search engines (e.g., Medline/PubMed). Observational studies, in human subjects with histological diagnosis of OSCC, concerning the analysis of salivary microbiota, were selected. …