scholarly journals Indium as a central metal enhances the photosensitizing efficacy of benzoporphyrin derivatives

2011 ◽  
Vol 15 (11n12) ◽  
pp. 1310-1316 ◽  
Author(s):  
Courtney Saenz ◽  
Manivannan Ethirajan ◽  
Gary Iacobucci ◽  
Ankit Pandey ◽  
Joseph R. Missert ◽  
...  
Keyword(s):  
Intracellular Localization ◽  
Dimethyl Ester ◽  
Calf Serum ◽  
Central Metal ◽  
Hypsochromic Shift ◽  
Bovine Calf Serum ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Long Wavelength Absorption Band

Compared to benzoporphyrin derivative-dimethyl ester (BPD-DME) and its 8-(1′-hexyloxy)ethyl analog the corresponding In(III) complexes showed enhanced in vitro photosensitizing efficacy in Colon26 tumor cells, which could be due to their higher singlet oxygen producing ability. In both organic (methanol) and aqueous Bovine Calf Serum (17% BCS) solutions the metalated analogs were significantly more stable than the parent photosensitizers. Presence of Indium as a central metal gave 13–25 nm hypsochromic shift to the long wavelength absorption band with reduced absorption and fluorescence intensity. The insertion of metal did not produce any difference in intracellular localization of the photosensitizers and were mainly localized in mitochondria.

scholarly journals Электронное строение и спектрально-флуоресцентные свойства лазерных красителей тиопирило-4-трикарбоцианинов

2021 ◽  
Vol 129 (7) ◽  
pp. 862
Author(s):  
А.А. Ищенко ◽  
И.В. Курдюкова ◽  
М.В. Богданович ◽  
С.Л. Бондарев ◽  
А.А. Романенко ◽  
...  
Keyword(s):  
Radiative Transition ◽  
Polymethine Chain ◽  
Long Wavelength ◽  
Vibronic Interactions ◽  
Wide Range ◽  
Wavelength Absorption ◽  
Fluorescent State ◽  
Long Wavelength Absorption Band ◽  
Angle Of Rotation ◽  
Ab Initio Dft

It was found that the long-wavelength absorption band of the laser dye IR 1061 and its analogue with an unsubstituted polymethine chain is strongly broadened and decreases in intensity in polar solvents, while the fluorescence band remains narrow and practically does not change in a wide range of solvent polarities. Based on the quantum-chemical calculations of these dyes by the ab initio DFT/B3LYP/6-31G (d,p) and TDDFT methods, taking into account the polarity of the medium by the PCM method, it is shown that the reason for this difference is the weakening of solvation in the fluorescent state as compared to the ground state due to the greater equalization of the charge in the first than in the latter. An increase in the alternation of bond orders in the polymethine chain in the fluorescent state was found, which causes an increase of vibronic interactions in the radiative transition as compared to the absorptive one. Spectral effects caused by a change in the angle of rotation of phenyl groups in the thiopyrylium cycle upon excitation have been analyzed.

In vitro friction and lubrication of large bearing hip prostheses

2009 ◽  
Vol 224 (7) ◽  
pp. 853-864 ◽  
Author(s):  
S Flanagan ◽  
E Jones ◽  
C Birkinshaw
Keyword(s):  
Large Diameter ◽  
Calf Serum ◽  
Mixed Lubrication ◽  
Joint Stability ◽  
Bovine Calf Serum ◽  
Reinforced Polymer ◽  
Metal On Metal ◽  
Different Diameters ◽  
Friction And Lubrication

New material combinations and designs of artificial hip implants are being introduced in an effort to improve proprioception and functional longevity. Larger joints in particular are being developed to improve joint stability, and it is thought that these larger implants will be more satisfactory for younger and more physically active patients. The study detailed here used a hip friction simulator to assess the friction and lubrication properties of large-diameter hip bearings of metal-on-metal and ceramic-on-reinforced-polymer couplings. Joints of different diameters were evaluated to determine what effect, if any, bearing diameter had on lubrication. In addition, the effects of lubricant type are considered, using carboxymethyl cellulose and bovine calf serum, and the physiological lubricant is shown to be considerably more effective at reducing friction. The frictional studies showed that the metal-on-metal joints worked under a mixed lubrication regime, producing similar friction factor values to each other. The addition of bovine calf serum (BCS) reduced the friction. The ceramic-on-reinforced-polymer samples were shown to operate with high friction factors and mixed lubrication. When tested with BCS, the larger-diameter bearings showed a decrease in friction compared with the smaller-size bearings, and the addition of BCS resulted in an increase in friction, unlike the metal-on-metal system. The study demonstrated that the component's diameter had little or no influence on the lubrication and friction of the large bearing combinations tested.

Erstmaliger Nachweis von π–π Dimerenbildung bei stabilen 1,4-Dialkylchinoxalinium-Radikalkationen. Struktur, Spektroskopie und Magnetismus / First Evidence for π-π-Dimerization of the Stable 1,4-Dialkylquinoxalinium Radical Cations. Structure, Spectroscopy and Magnetism

1993 ◽  
Vol 48 (9) ◽  
pp. 1181-1186 ◽  
Author(s):  
H.-D. Hausen ◽  
Wolfgang Kaim ◽  
Andreas Schulz ◽  
Michael Moscherosch ◽  
Jeanne Jordanov
Keyword(s):  
Solid State ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Cation Radical ◽  
Radical Cations ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Molecular Structure Analysis ◽  
Long Wavelength Absorption Band ◽  
Quinoxaline Ring

Crystal and molecular structure analysis of 1,4-diethylquinoxalinium iodide shows a virtually planar quinoxaline ring with 11 conjugated π-electrons. In contrast to the triiodide of the 1,4,6,7-tetramethyl derivative or to the tetraphenylborate salt of 1,4-diethylquinoxalinium cation radical the iodide exhibits π-π-dimerized radical cations in the solid state with synplanar ethyl groups and a rather small intermolecular distance of about 315 pm between the π-planes of the primarily interacting 1,4-diazine rings. Solid state magnetic measurements between 2 and 300 K show considerably diminished magnetic moments due to partial spin-pairing, and UV/VIS spectroscopic measurements in acetonitrile reflect the π—π-interaction in solution through the appearance of a long-wavelength absorption band.

Elaboration of an unexplored substitution site in synthetic bacteriochlorins

2015 ◽  
Vol 19 (07) ◽  
pp. 887-902 ◽  
Author(s):  
Nuonuo Zhang ◽  
Kanumuri Ramesh Reddy ◽  
Jianbing Jiang ◽  
Masahiko Taniguchi ◽  
Roger D. Sommer ◽  
...  
Keyword(s):  
Bathochromic Shift ◽  
Fluorescence Emission ◽  
Bacterial Photosynthesis ◽  
Alkoxy Group ◽  
The Self ◽  
X Ray ◽  
Long Wavelength ◽  
Substitution Site ◽  
Wavelength Absorption ◽  
Long Wavelength Absorption Band

The ability to introduce substituents at designated sites about the perimeter of synthetic bacteriochlorins – analogs of bacteriochlorophylls of bacterial photosynthesis – remains a subject of ongoing study. Here, the self-condensation of a dihydrodipyrrin-dioxolane affords a 5-[2-(trimethylsiloxy)ethoxy]bacteriochlorin. Like a 5-methoxybacteriochlorin, the latter undergoes regioselective bromination at the 15-position, directed by the distal 5-alkoxy group. On the other hand, attempted bromination of a bacteriochlorin bearing a 5-(2-hydroxyethoxy) group resulted in intramolecular ether formation with the adjacent β-pyrroline position to give an annulated dioxepine ring (confirmed by single-crystal X-ray structural analysis). The hydroxyethoxy group at the 5-position can be derivatized by acylation. In addition, the installation of auxochromes (methoxycarbonyl, phenylethynyl) at the β-pyrrole rings causes a substantial bathochromic shift of the long-wavelength absorption band (812 nm) and companion fluorescence emission band (821 nm). Taken together, the modification of the 5-substituent complements existing methods for installing a single substituent on the bacteriochlorin macrocycle.

Synthesis and spectroscopic properties of benzo- and naphthofuryl-3-hydroxychromones

2001 ◽  
Vol 79 (4) ◽  
pp. 358-363 ◽  
Author(s):  
Andrey S Klymchenko ◽  
Turan Ozturk ◽  
Vasyl G Pivovarenko ◽  
Alexander P Demchenko
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Spectroscopic Properties ◽  
Molecular Probe ◽  
Absorption Bands ◽  
Methyl Group ◽  
Long Wavelength ◽  
Excited State Proton Transfer ◽  
Wavelength Absorption ◽  
Long Wavelength Absorption Band

With the focus of designing new fluorescent probes, four new 3-hydroxy-chromone derivatives bearing benzofuran and naphthofuran groups were synthesized. They show bathochromic absorption shifts relative to 3-hydroxyflavone with the ability of retention to display the excited-state proton transfer. Disruption of the planarity by the methyl group in the furan ring leads to a decrease of both the extinction coefficient and the contribution of long wavelength absorption band, while molecules without a methyl group showed two distinct absorption bands. Shifts to longer wavelengths are also observed in fluorescent spectra, and the absence of the methyl group results in a dramatic increase of fluorescence quantum yield and lifetime. Of the extended 3-hydroxychromone derivatives, 3-hydroxy-2-naphtho[2,1-b]furan-2-yl-chromone has shown comparable, and in some cases better, absorption and fluorescence properties than the 3-hydroxychromones synthesized so far, which make it a highly promising candidate as molecular probe for analytical chemistry, biophysics, and cellular biology.Key words: benzo- and naphthofuryl-3-hydroxyflavone, synthesis, electronic spectra, fluorescence, excited state proton transfer.

scholarly journals The fluorescence analysis of laser photolysis of phenols in water

2002 ◽  
Vol 4 (2) ◽  
pp. 79-83 ◽  
Author(s):  
O. Tchaikovskaya ◽  
I. Sokolova ◽  
O. Bazyl ◽  
V. Swetlichnyi ◽  
T. Kopylova ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Laser Light ◽  
Fluorescence Analysis ◽  
Dynamic Changes ◽  
Long Wavelength ◽  
Chlorine Substitution ◽  
Wavelength Absorption ◽  
Chemical Techniques ◽  
Long Wavelength Absorption Band ◽  
Photolysis Of Phenol

Photolysis of phenol andp-chlorophenol exposed to KrCl- and Nd-YAG laser light is studied by electron spectroscopy and fluorescence and quantum chemical techniques. The decrease of the quantum yield of phenol fluorescence with increase in the excitation energy is not related to dynamic changes in the intramolecular photophysical processes; rather this is a result of increased photoreaction efficiency. Chlorine substitution for para-state of phenol is shown to strengthen the OH-bond in excitation into the long wavelength absorption band.

scholarly journals Whole Ovine Ovaries as a Model for Human: Perfusion with CryoprotectantsIn VivoandIn Vitro

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Vladimir Isachenko ◽  
Gohar Rahimi ◽  
Maria Dattena ◽  
Peter Mallmann ◽  
Saltanat Baikoshkarova ◽  
...  
Keyword(s):  
High Temperature ◽  
Calf Serum ◽  
Surgical Removal ◽  
Vascular Pedicle ◽  
Perfusion Medium ◽  
Bovine Calf Serum ◽  
Freezing Medium ◽  
Human Ovaries

These experiments were performed to test the perfusion of ovine as a model for human ovaries by cryoprotectantsin vivoat high temperature when the permeability of capillaries is high and when blood is insensibly replaced by the solution of cryoprotectants. By our hypothetical supposition, ovaries could be saturated by cryoprotectants before their surgical removal. The objective was to examine the effectiveness of perfusion of ovine ovaries with vascular pediclein vivoandin vitro.Arteria ovaricawas cannuled and ovaries were perfused by Leibovitz L-15 medium + 100 IU/mL heparin + 5% bovine calf serum + 6% dimethyl sulfoxide + 6% ethylene glycol + 0.15 M sucrose + Indian inkin vivoandin vitro. In the first and second cycle of experiments, ovaries (n=13andn=23) were perfusedin vivoandin vitro, respectively, during 60 min with the rate of perfusion 50 mL/h (0.8 mL/min). It was established within vivoperfusion that only about 10% of ovarian tissues were perfused due to an appearance of multiple anastomoses when the perfusion medium goes fromarteria ovaricatoarteria uterinawithout inflow into the ovaries. It was concluded thatin vitroperfusion of ovine intact ovaries with vascular pedicle by freezing medium is more effective than this manipulation performedin vivo.

Surface photochemistry: use of spiropyrans as indicators of surface polarity

1984 ◽  
Vol 62 (5) ◽  
pp. 1001-1002 ◽  
Author(s):  
Paul De Mayo ◽  
Ali Safarzadeh-Amiri ◽  
S. King Wong
Keyword(s):  
Absorption Band ◽  
Silica Gel ◽  
Solvent Polarity ◽  
Surface Polarity ◽  
Long Wavelength ◽  
Wavelength Absorption Band ◽  
Wavelength Absorption ◽  
Long Wavelength Absorption Band

The position of the long wavelength absorption band in the spectrum of a spiropyran is sensitive to solvent polarity. This property has been used to determine the polarity of the silica gel surface.

Synthesis of perylene-porphyrin dyads for light-harvesting studies

2002 ◽  
Vol 06 (10) ◽  
pp. 626-642 ◽  
Author(s):  
Robert S. Loewe ◽  
Kin-ya Tomizaki ◽  
Fabien Chevalier ◽  
Jonathan S. Lindsey
Keyword(s):  
Ground State ◽  
Light Harvesting ◽  
Molecular Architecture ◽  
Efficient Energy Transfer ◽  
Aryl Group ◽  
Long Wavelength ◽  
Efficient Energy ◽  
Wavelength Absorption ◽  
Meso Position ◽  
Long Wavelength Absorption Band

The spectral coverage of porphyrin-based light-harvesting arrays can be enhanced through the use of suitable accessory pigments. Perylene-monoimide dyes can serve as valuable accessory pigments with porphyrins. To investigate the choice of perylene-monoimide and the effects of molecular architecture on light-harvesting efficacy, five perylene-porphyrin dyads were prepared. Each dyad employs a diphenylethyne linker that bridges the perylene N-imide site and the porphyrin meso-position. Three dyads incorporate a mono-phenoxy perylene at the o-, m-, or p-position of the meso-aryl group on the porphyrin. The two remaining dyads incorporate a perylene-monoimide (bearing zero or three phenoxy substituents) at the p-position of the meso-aryl group on the porphyrin. The introduction of phenoxy groups on the perylenes increases the solubility, a key requirement for use in light-harvesting arrays. The long-wavelength absorption band of the perylene shifts from 506 nm to 532 or 533 nm upon substitution with one or three phenoxy groups, respectively. The synthesis of the dyads entails Pd -mediated coupling of a bromo-perylene and an ethynyl porphyrin, or the mixed-aldehyde condensation with a perylene-aldehyde, mesitaldehyde, and pyrrole. Five perylene-monoimide dyes bearing an ethyne or bromo substituent at the p-position of the N-aryl unit were developed for this modular chemistry. Each perylene-porphyrin dyad exhibits efficient energy transfer from the excited perylene to the ground-state porphyrin.

scholarly journals Studies on photodynamic mechanism of a novel chlorine derivative (TDPC) and its antitumor effect for photodynamic therapy in vitro and in vivo

2015 ◽  
Vol 08 (01) ◽  
pp. 1540001 ◽  
Author(s):  
Ying Ye ◽  
Lai-Xing Wang ◽  
Dan-Ping Zhang ◽  
Yi-Jia Yan ◽  
Zhi-Long Chen
Keyword(s):  
Photodynamic Therapy ◽  
Drug Candidate ◽  
Rt Pcr ◽  
Oxygen Generation ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Chlorine Derivative ◽  
Necrosis Factor

Photodynamic therapy (PDT) represents a promising method for treatment of cancerous tumors. The chemical and physical properties of used photosensitizer (PS) play key roles in the treatment efficacy. In this study, a novel PS, 5,10,15,20-tetrakis((5-dipropylamino)pentyl)-chlorin (TDPC) which displayed a characteristic long wavelength absorption peak at 650 nm were synthesized. It also shows a singlet oxygen generation rate of 4.257 min-1. Generally, TDPC is localized in mitochondria and nucleus of cell. After light irradiation with 650 nm laser, it can kill many types of cell, in addition, TDPC–PDT can destroy ECA-109 tumor in nude mice and a necrotic scab was formed eventually. The expression levels of many genes which regulated cell growth and apoptosis were determined by RT-PCR following TDPC–PDT. The results showed that it either increased or decreased, among which, the expression level of TNFSF13, a member of tumor necrosis factor superfamily, increased significantly. In general, TDPC is an effective antitumor PS in vitro and in vivo and is worthy of further study as a new drug candidate. TNFSF13 will be an important molecular target for the discovery of new PSs.

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