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Porphyrin

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https://www.readbyqxmd.com/read/27911452/rationally-encapsulated-gold-nanorods-improving-both-linear-and-nonlinear-photoacoustic-imaging-contrast-in-vivo
#1
Fei Gao, Linyi Bai, Siyu Liu, Ruochong Zhang, Jingtao Zhang, Xiaohua Feng, Yuanjin Zheng, Yanli Zhao
Photoacoustic tomography has emerged as a promising non-invasive imaging technique that integrates the merits of high optical contrast with high ultrasound resolution in deep scattering medium. Unfortunately, the blood background in vivo seriously impedes the quality of imaging due to its comparable optical absorption with contrast agents, especially in conventional linear photoacoustic imaging modality. In this study, we demonstrated that two hybrids consisting of gold nanorods (Au NRs) and zinc tetra(4-pyridyl)porphyrin (ZnTPP) exhibited a synergetic effect in improving optical absorption, conversion efficiency from light to heat, and thermoelastic expansion, leading to a notable enhancement in both linear (four times greater) and nonlinear (more than six times) photoacoustic signals as compared with conventional Au NRs...
December 2, 2016: Nanoscale
https://www.readbyqxmd.com/read/27904897/molecular-engineering-for-efficient-and-selective-iron-porphyrin-catalysts-for-electrochemical-reduction-of-co2-to-co
#2
Ram B Ambre, Quentin Daniel, Ting Fan, Hong Chen, Biaobiao Zhang, Lei Wang, Mårten S G Ahlquist, Lele Duan, Licheng Sun
Iron porphyrins Fe-pE, Fe-mE, and Fe-oE were synthesized and their electrochemical behavior for CO2 reduction to CO has been investigated. The controlled potential electrolysis of Fe-mE gave exclusive 65% Faradaic efficiency (FE) whereas Fe-oE achieved quasi-quantitative 98% FE (2% H2) for CO production.
December 1, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27901135/construction-of-cyclic-arrays-of-zn-porphyrin-units-and-their-guest-binding-at-the-solid-liquid-interface
#3
Kohei Iritani, Kazukuni Tahara, Keiji Hirose, Steven De Feyter, Yoshito Tobe
Cyclic arrays consisting of six zinc-porphyrin units are constructed by the supramolecular self-assembly of a dehydrobenzo[12]-annulene derivative having three zinc porphyrin units at the liquid/graphite interface. Binding with C60 furnishes cyclic hexameric arrays of the complexes on the surface.
November 30, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27901014/stacked-antiaromatic-porphyrins
#4
Ryo Nozawa, Hiroko Tanaka, Won-Young Cha, Yongseok Hong, Ichiro Hisaki, Soji Shimizu, Ji-Young Shin, Tim Kowalczyk, Stephan Irle, Dongho Kim, Hiroshi Shinokubo
Aromaticity is a key concept in organic chemistry. Even though this concept has already been theoretically extrapolated to three dimensions, it usually still remains restricted to planar molecules in organic chemistry textbooks. Stacking of antiaromatic π-systems has been proposed to induce three-dimensional aromaticity as a result of strong frontier orbital interactions. However, experimental evidence to support this prediction still remains elusive so far. Here we report that close stacking of antiaromatic porphyrins diminishes their inherent antiaromaticity in the solid state as well as in solution...
November 30, 2016: Nature Communications
https://www.readbyqxmd.com/read/27897999/charge-transfer-enhancement-in-the-d-%C3%AF-a-type-porphyrin-dyes-a-density-functional-theory-dft-and-time-dependent-density-functional-theory-td-dft-study
#5
Guo-Jun Kang, Chao Song, Xue-Feng Ren
The electronic geometries and optical properties of two D-π-A type zinc porphyrin dyes (NCH₃-YD2 and TPhe-YD) were systematically investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) to reveal the origin of significantly altered charge transfer enhancement by changing the electron donor of the famous porphyrin-based sensitizer YD2-o-C8. The molecular geometries and photophysical properties of dyes before and after binding to the TiO₂ cluster were fully investigated...
November 25, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27893187/-to-twist-or-not-to-twist-figure-of-eight-and-planar-structures-of-octaphyrins
#6
REVIEW
Neelam Shivran, Santosh C Gadekar, Venkataramanarao G Anand
Amongst the various porphyrinoids, octaphyrin has attracted significant attention owing to its diverse syntheses, conformations, and metal-ligation properties. Octaphyrin is a higher homologue of porphyrin and is formed by linking together heterocycles such as pyrrole, furan, thiophene, and selenophene through α-α or α-meso carbon bonds. The planar conformation is mainly achieved through inversion of the heterocyclic units from the center of macrocycle; avoiding meso-bridges; introducing a para-quinodimethane bridge; employing a neo-confusion approach; protonation; and by generating dianionic species...
November 28, 2016: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/27889618/cell-death-mechanistic-study-of-photodynamic-therapy-against-breast-cancer-cells-utilizing-liposomal-delivery-of-5-10-15-20-tetrakis-benzo-b-thiophene-porphyrin
#7
Geewoo Nam, Sabarinathan Rangasamy, Hee Ju, Annie Agnes Suganya Samson, Joon Myong Song
5,10,15,20-Tetrakis(benzo[b]thiophene) porphyrin (BTP) is a newly synthesized hydrophobic photosensitizer with fluorescence quantum yield in toluene: ΦF=0.062. Previously, its limitations in solubility had hindered scientific experimentation regarding its photodynamic effects on cancer cells. By utilizing various compositions of liposomes in order to alter the solubility of BTP, the photocytotoxicity, reactive oxygen species generation, and subcellular localization of the liposomal BTP were identified in this work...
November 12, 2016: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/27888164/optimizing-zn-porphyrin-based-photosensitizers-for-efficient-antibacterial-photodynamic-therapy
#8
Khazna Alenezi, Artak Tovmasyan, Ines Batinic-Haberle, Ludmil T Benov
INTRODUCTION: Efficient photodynamic inactivation of microbes requires highly efficient photosensitizers which kill microbial cells, but spare host tissues. One way to achieve such selectivity is to use photosensitizers that are rapidly taken up by microbes and, when applied at low concentrations, efficiently kill them after a short illumination. Design of such photosensitizers requires insight into molecular properties which are critical for antimicrobial photo-efficiency. This study explores the contribution of molecular shape and exposure of charges, to the antimicrobial activity of tetra-cationic Zn porphyrin-based photosensitizers...
November 22, 2016: Photodiagnosis and Photodynamic Therapy
https://www.readbyqxmd.com/read/27886311/flexible-synthesis-of-cationic-peptide-porphyrin-derivatives-for-light-triggered-drug-delivery-and-photodynamic-therapy
#9
R Dondi, E Yaghini, K M Tewari, L Wang, F Giuntini, M Loizidou, A J MacRobert, I M Eggleston
Efficient syntheses of cell-penetrating peptide-porphyrin conjugates are described using a variety of bioconjugation chemistries. This provides a flexible means to convert essentially hydrophobic tetrapyrolle photosensitisers into amphiphilic derivatives which are well-suited for use in light-triggered drug delivery by photochemical internalisation (PCI) and targeted photodynamic therapy (PDT).
November 25, 2016: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/27882008/increase-in-activity-of-na-k-atpase-by-porphyrin-compounds-as-treatment-for-dysnatremias-caused-by-diabetes-mellitus
#10
Abdul Hai, Nadeem Kizilbash
OBJECTIVE: The aim of this study was to test the action of Porphyrin compounds, Tetraphenylporphine sulfonate (TPPS), 5,10,15,20-Tetrakis (4-sulfonatophenyl) porphyrinato Iron(III) Chloride (FeTPPS) and 5,10,15,20-Tetrakis (4-sulfonatophenyl) porphyrinato Iron(III) nitrosyl Chloride (FeNOTPPS), on Na+, K+ -ATPase of cell membrane of erythrocytes. METHODS: Enzymatic assays, measuring the amount of inorganic phosphate produced, were used to estimate the activity of Na(+), K(+)-ATPase...
September 2016: Pakistan Journal of Medical Sciences Quarterly
https://www.readbyqxmd.com/read/27877238/sphingomyelin-liposomes-containing-porphyrin-phospholipid-for-irinotecan-chemophototherapy
#11
Kevin A Carter, Dandan Luo, Aida Razi, Jumin Geng, Shuai Shao, Joaquin Ortega, Jonathan F Lovell
Porphyrin-phospholipid (PoP) liposomes can entrap anti-cancer agents and release them in response to near infrared (NIR) light. Doxorubicin, when remotely loaded via an ammonium sulfate gradient at a high drug-to-lipid ratio, formed elongated crystals that altered liposome morphology and could not be loaded into liposomes with higher PoP content. On the other hand, irinotecan could also be remotely loaded but did not form large crystals and did not induce liposome elongation. The loading, stability, and NIR light-triggered release of irinotecan in PoP liposomes was altered by the types of lipids used and the presence of PEGylation...
2016: Theranostics
https://www.readbyqxmd.com/read/27874144/a-novel-photosensitizer-an-l-glutamide-lipid-conjugate-with-improved-properties-for-photodynamic-therapy
#12
Erica Nathan, K Vijayashree, A Harikrishna, Makoto Takafuji, Hirokuni Jintoku, Hirotaka Ihara, N M Rao
Photosensitizers (PS) are used in photodynamic therapy to treat several cancers. The efficacy of photodynamic therapy (PDT) could be further improved by overcoming aggregation-dependent quenching of PS and by improving the biodistribution of the PS. In this work we attempted to overcome these issues by conjugating a PS with a lipid molecule and tested the liposomes prepared with this PS conjugated lipid for PDT. A novel lipid-porphyrin conjugate (1 : 1) was synthesized by attaching a PS, 5-(4-methoxycarbonylphenyl)-10,15,20-triphenyl-(21)H,(23)H-porphine, to the head group of a glutamide lipid...
November 30, 2016: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/27871506/elective-cholecystectomy-performed-on-patient-with-variegate-porphyria-propofol-based-total-intravenous-anesthesia-with-target-controlled-infusion
#13
Adam Kuźmiński, Michał Aporowicz, Monika Brol, Anna Żołnowska, Maciej Masternak
Porphyria is caused by disorders of enzymes that synthetize porphyrins. Both elective and emergency surgical procedures on patient suffering from porphyria may provoke acute symptoms. These patients require special anesthetic management since some of commonly used anesthetic agents may also induce acute manifestation of porphyria. We present the case of 53-year-old woman previously diagnosed with porphyria who underwent elective laparoscopic cholecystectomy. Propofol-based total intravenous anesthesia with target-controlled infusion was used...
December 2016: Journal of Clinical Anesthesia
https://www.readbyqxmd.com/read/27870953/comparative-no2-sensing-in-cobalt-and-metal-free-porphyrin-nanotubes
#14
Yucheng Wang, Pan Ma, Feifei Song, Shuncheng Yao, Changlong Chen, Peihua Zhu
In the present study, the nanotubes of 5-(4-hydroxyphenyl)-10, 15, 20-tri(4-chlorophenyl) porphyrin (p-HTClPP) (1) and 5-(4-hydroxyphenyl)-10, 15, 20-tri(4-chlorophenyl) porphyrin cobalt (p-HTClPPCo) (2) were successfully prepared by using anodize alumina oxide (AAO) template method. The p-HTClPP and p-HTClPPCo nanotubes have been confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), electronic absorption spectra, fluorescence spectroscopy, fourier transform infrared spectroscopy (FT-IR), low-angle X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) techniques...
November 9, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27869128/tuning-the-electrical-conductance-of-metalloporphyrin-supramolecular-wires
#15
Mohammed Noori, Albert C Aragonès, Giuseppe Di Palma, Nadim Darwish, Steven W D Bailey, Qusiy Al-Galiby, Iain Grace, David B Amabilino, Arántzazu González-Campo, Ismael Díez-Pérez, Colin J Lambert
In contrast with conventional single-molecule junctions, in which the current flows parallel to the long axis or plane of a molecule, we investigate the transport properties of M(II)-5,15-diphenylporphyrin (M-DPP) single-molecule junctions (M=Co, Ni, Cu, or Zn divalent metal ions), in which the current flows perpendicular to the plane of the porphyrin. Novel STM-based conductance measurements combined with quantum transport calculations demonstrate that current-perpendicular-to-the-plane (CPP) junctions have three-orders-of-magnitude higher electrical conductances than their current-in-plane (CIP) counterparts, ranging from 2...
November 21, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27868323/light-induced-porphyrin-based-spectroscopic-ruler-for-nanometer-distance-measurements
#16
Marilena Di Valentin, Marco Albertini, Maria Giulia Dal Farra, Enrico Zurlo, Laura Orian, Antonino Polimeno, Marina Gobbo, Donatella Carbonera
We present a novel pulsed electron paramagnetic resonance (EPR) spectroscopic ruler to test the performance of a recently developed spin-labeling method based on the photoexcited triplet state (S=1). Four-pulse electron double resonance (PELDOR) experiments are carried out on a series of helical peptides, labeled at the N-terminal end with the porphyrin moiety, which can be excited to the triplet state, and with the nitroxide at various sequence positions, spanning distances in the range 1.8-8 nm. The PELDOR traces provide accurate distance measurements for all the ruler series, showing deep envelope modulations at frequencies varying in a progressive way according to the increasing distance between the spin labels...
November 21, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27862435/inverse-kinetic-and-equilibrium-isotopic-effect-on-self-assembly-and-supramolecular-chirality-of-porphyrin-j-aggregates
#17
Roberto Zagami, Andrea Romeo, Maria A Castriciano, Luigi Monsù Scolaro
When mixtures of D2O/DCl are used to foster the self-assembly formation of TPPS4 porphyrin J-aggregates in aqueous solutions, an inverse kinetic isotopic effect of 0.4 and an inverse equilibrium isotopic effect of 0.6 are clearly detected. Most importantly, the addition of at least 10% D2O causes an inversion in the handedness of the final chiral J-aggregates, thus evidencing an important role of deuterium in driving the enantiomeric excess in the scalemic mixture of such supramolecular assemblies.
November 10, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27860468/porphyrin-based-carbon-dots-for-photodynamic-therapy-of-hepatoma
#18
Yang Li, Xiaohua Zheng, Xiaoyu Zhang, Shi Liu, Qing Pei, Min Zheng, Zhigang Xie
Porphyrin-containing carbon dots (CDs) possess ultrasmall size, excellent water solubility, and photostability. These CDs can effectively generate cytotoxic singlet oxygen upon irradiation, and induce the cell apoptosis. Photodynamic ability of CDs inhibits the growth of hepatoma. This work not only sheds light on developing functional carbon dots, but also highlights the importance of special-structure precursor molecules in synthesizing functional CDs.
November 18, 2016: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/27859870/covalent-functionalization-of-nanosheets-of-mos%C3%A2-and-mose%C3%A2-by-substituted-benzenes-and-other-organic-molecules
#19
Pratap Vishnoi, Archana Sampath, Umesh V Waghmare, C N R Rao
Covalent functionalization has been effectively employed to attach benzene functionalities to MoS₂ and MoSe₂ nanosheets by the reaction with para-substituted iodobenzenes bearing OCH₃, H and NO₂ as the substituents, where the electron-donating and electron-withdrawing power of the para-substituent varies significantly. The functionalization is based on the formation of a C-S or C-Se linkage at the expense of the C-I bond on reaction of the iodobenzene with electron-rich 1T-MoS₂ or MoSe₂. The degree of functionalization is in the 4%-24% range, the value increasing with the electron-withdrawing power of the para-substituent...
November 17, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27859737/meso-meso-linked-diarylamine-fused-porphyrin-dimers
#20
Norihito Fukui, Hideki Yorimitsu, Atsuhiro Osuka
A meso-meso-linked diphenylamine-fused porphyrin dimer and its methoxy-substituted analogue were synthesized from a meso-meso-linked porphyrin dimer by a reaction sequence involving Ir-catalyzed β-selective borylation, iodination, meso-chlorination, and SN Ar reactions with diarylamines followed by electron-transfer-mediated intramolecular double C-H/C-I coupling. While these dimers commonly display characteristic split Soret bands and small oxidation potentials, they produced different products upon oxidation with tris(4-bromophenyl)aminium hexachloroantimonate...
November 15, 2016: Chemistry: a European Journal
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