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  • A survey of acid catalysts in dipyrromethanecarbinol condensations leading to meso‐substituted porphyrins
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    G. Richard Geier, Jennifer B. Callinan, Polisetti Dharma Rao, Jonathan S. Lindsey

    The successful use of dipyrromethanecarbinols in rational routes to porphyrinic macrocycles requires catalysis conditions that enable irreversible condensation, thereby avoiding substituent scrambling and formation of undesired porphyrin products. Previously, successful conditions of trifluoroacetic acid (TFA) (30 mM) in acetonitrile were identified following a lengthy survey of TFA and BF3‐etherate catalysis in diverse solvents. In this study, focus was placed on the acid catalyst by examining 17 acids in CH2Cl2, the traditional solvent for two‐step, one‐flask porphyrin syntheses. In the self‐condensation of the carbinol derived from 1‐(4‐methylbenzoyl)‐5‐phenyldipyrromethane, porphyrin yields of 9–55% were obtained from the various acids, compared to 20% under TFA catalysis­in acetonitrile. A number of catalytic conditions that produce little to no porphyrin in reactions of pyrrole + benzaldehyde afforded good yields of porphyrin and the suppression of scrambling in reactions of dipyrromethanecarbinols. The four best acid catalysts (InCl3, Sc(OTf)3, Yb(OTf)3, and Dy(OTf)3) initially identified were then examined with dipyrromethanecarbinols bearing challenging substituents (alkyl, pyridyl, or no substituent). The greatest improvement was obtained with the pyridyl substrates. Selected reactions performed on a preparative scale (115 to 460 mg of isolated porphyrin) verified the results of the analytical‐scale experiments and revealed the more facile isolation of the porphyrin from reactions performed in CH2Cl2 rather than acetonitrile. This study provides alternatives to the use of TFA/acetonitrile that offer advantages in terms of yield and isolation of the porphyrin without sacrificing suppression of scrambling. Furthermore, the finding that poor catalysts for the benzaldehyde + pyrrole reaction can be excellent catalysts for dipyrromethanecarbinols provides guidance for the identification of other catalysts for use with reactive precursors in porphyrin‐forming reactions. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Evaluation studies of technetium‐99m‐porphyrin (T3,4BCPP) for tumor imaging
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Murugesan Subbarayan, S. J. Shetty, T. S. Srivastava, O. P. D. Noronha, A. M. Samuel

    A water‐soluble porphyrin, 5,10,15,20‐tetrakis[3,4‐bis(carboxymethyleneoxy)phenyl] porphyrin (T3,4BCPP), was successfully labeled with 99mTc and biodistribution studies were performed in Wistar rats. Scintiimaging and in vivo distribution studies were also carried out in C6‐gliomas and mammary tumor‐bearing animals using a gamma camera. Tumor‐to‐muscle (T/M) ratios were calculated and compared with those obtained with the known tumor‐seeking radiopharmaceuticals 99mTc(V)‐DMSA (DMSA = dimercaptosuccinic acid), 99mTc‐citrate and 201TlCl. In the case of C6‐gliomas, the ratios were 4.2, 2.2, 4.00 and 3.0; while in the case of C3H/J mammary tumor, the ratios were 9.4, 8.8, 8.1 and 8.5 for T3,4BCPP, 99mTc(V)‐DMSA, 99mTc‐citrate and 201TlCl, respectively. Similar studies were carried out in N‐methyl‐N‐nitrosourea (NMU)‐induced mammary tumor animals and the T/M ratios obtained were 5.9, 2.0, 5.3 and 3.3 for T3,4BCPP, 99mTc(V)‐DMSA, 99mTc‐citrate and 201TlCl, respectively. The radiolabeled photosensitizer could perhaps be used to detect cancer non‐invasively and could even prove useful in monitoring the progression/regression of tumors before, during, and after chemotherapy, radiation therapy or photodynamic therapy (PDT). Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Kinetics of zinc ion incorporation in base into a centrally aprotic beta‐octabrominated cationic water‐soluble porphyrin and its monolithium complex
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Sabrina L. Bailey, P. Hambright

    The kinetics of zinc incorporation from pH 12 to 13 into the centrally aprotic BrP(4)2+ form of beta‐octabromo‐meso‐tetrakis(N‐methyl‐4‐pyridyl)porphyrin and its monolithium complex were studied at 25.0 °C, ionic strength (I) = 0.10. The reactions were first order in porphyrin and total zinc concentrations. For BrP(4)2+, the specific rate constant was 5.1 × 105 M−1 s−1 for Zn(OH)2aq, 9.9 × 104 M−1 s−1 for , and was unreactive. The Li‐BrP(4)3+ complex had a formation constant with BrP(4)2+ of 1.1 × 103 M−1 from both kinetic and equilibrium measurements. In solutions containing both BrP(4)2+ and Li‐BrP(4)3+, zinc incorporation proceeded only through BrP(4)2+. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Synthesis of N‐phytochlorin‐substituted [60]fulleropyrrolidines
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Alexander Efimov, Nikolai V. Tkatchenko, Pirjo Vainiotalo, Helge Lemmetyinen

    A series of new phytochlorin–fullerene dyads was prepared. Synthetic pathway includes attachment of glycine to aldehyde‐containing phytochlorins via reductive amination, where 3‐ and 7‐carbonyl‐substituted pheophorbides exhibit surprisingly different reactivity. The appropriate conditions of reactions (e.g. solvents and reducing agents) were determined in each case. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Spectroscopic studies of the interaction of cobalt(II) N,N′,N″,N″′‐tetramethyltetra‐3,4‐pyridinoporphyrazine with amino acids and nitrogen oxides
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Mamothibe A. Thamae, Tebello Nyokong

    The interaction of histidine, cysteine, NO and nitrite with cobalt(II) N,N′,N″,N″′‐tetramethyltetra‐3,4‐tetrapyridinoporphyrazine ([CoIItmtppa]4+) is reported. Metal‐based autoreduction of [CoIItmtppa]4+ occurs with the formation of the [CoItmtppa(−2)]3+ species in the presence of histidine and cysteine. Kinetic data for the auto reduction of [CoIItmtppa]4+ in the presence of these amino acids gave the rate constants kf = 2.1 × 101 and 2.8 dm3 mol−1 s−1, for cysteine and histidine, respectively. One molecule of NO or nitrite was found to coordinate to the [CoIItmtppa]4+ species. The equilibrium and rate constants for the coordination of the nitric oxide were K = 2.3 × 104 dm3 mol−1 and kf = 7.5 dm3 mol−1 s−1, respectively. The coordination of nitrite to [CoIItmtppa]4+ occurred with an equilibrium constant of K = 2.0 × 102 dm3 mol−1 and a rate constant of kf = 4.0 × 10−3 dm3 mol−1 s−1. There was no evidence for the coordination of two molecules of nitrite to the [CoIItmtppa]4+ species. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • A non‐tetradecarboxylative synthesis of ­2,7,12,17‐tetraphenylporphycene
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Ana Gavalda, JosÉ I. Borrell, Jordi Teixido, Santiago Nonell, Ofir Arad, Roser Grau, Magdalena CaÑete, Angeles Juarranz, Angeles Villanueva, Juan C. Stockert

    A new synthetic method for 2,7,12,17‐tetraphenylporphycene (2e, TPPo) which avoids tetradecarboxylation by sublimation of the intermediate tetracarboxylic acid 8 is reported. Thus, the use of a pyrrol 13a bearing two orthogonal ester groups allows the synthesis of bipyrrol 12a, from which the benzyl ester groups are selectively removed to afford diester 11. The latter is transformed to dialdehyde 10 by using the McFayden–Stevens reaction, thus avoiding the unstable bipyrrol 9 formed during the tetradecarboxylation of 8. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • PDT‐related photophysical properties of conformationally distorted palladium(II) porphyrins
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    A. Wiehe, H. Stollberg, S. Runge, A. Paul, M. O. Senge, B. RÖder

    The photodynamic therapy (PDT) related photophysical properties of five palladium(II) porphyrins with increasing steric demand of the meso‐substituents were investigated by steady state and time‐resolved absorption and luminescence spectroscopy. The steric strain of the meso‐substituents is reflected in a bathochromic shift of the B‐band in the absorption spectra. In contrast to free‐base porphyrins, the palladium(II) complexes exhibit only a very weak fluorescence with ΦFl ∼10−4. Instead, the corresponding triplet states of the porphyrins are formed via inter system crossing (ISC) with a quantum yield ΦISC of nearly unity. A phosphorescence quantum yield ΦISC of 10−4 was determined assuming dynamic quenching. The triplet state of all compounds is efficiently quenched by molecular oxygen, generating singlet molecular oxygen with a quantum yield of ΦΔ ∼0.85. The various substitution patterns exerted no significant influence on the ISC rates or singlet oxygen quantum yields. Significant differences, on the other hand, were observed with respect to the triplet lifetimes, with a tendency of longer lifetimes for the porphyrins with sterically more demanding substituents (in air‐saturated solution). All porphyrins were successfully incorporated into liposomes. The phototoxic activity of three compounds was investigated in cell suspensions. The use of the new porphyrinato‐palladium(II) in PDT applications is discussed. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • 5,15‐Diaryl‐β‐substituted‐porphyrinato‐manganese(III) chlorides as probes for structure–activity relationships in porphyrin‐based epoxidation catalysts
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Abílio J. F. N. Sobral, António M. d'A. Rocha Gonsalves

    Manganese complexes of 5,15‐diaryl‐β‐substituted‐porphyrins were prepared and their behaviour as oxidation catalysts was studied. The role of the pyrrolic and meso‐substituents on the activity and selectivity of these catalysts was studied to reveal new structure–activity relationships in these porphyrin‐based epoxidation catalysts. The beneficial effect of the halogen atoms at the meso‐phenyls is still observed with these catalysts but, for the first time, a strong dependence on the selectivity of the epoxide production was found to be dependent on the nature of the non‐halogen substituents at the β‐pyrrolic positions of the porphyrin. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Synthesis of organo‐soluble metallophthalocyanines bearing electron‐withdrawing substituents
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Muriel Sanchez, Eric Fache, Didier Bonnet, Bernard Meunier

    The syntheses of organo‐soluble metallophthalocyanines having sulfo‐ and sulfonamido‐ electron‐withdrawing substituents are reported. The simple cation exchange of the readily available tetrasodium salt of metallo‐sulfophthalocyanines 1 (M = Ni, Co, Fe, Cr) by alkylammonium salts afforded the sulfophthalocyanines 2 and 3 in good yields. Complexes 2 featuring two long C18 alkyl chains are only soluble in organic solvents while tetrabutylammonium counter ions exhibit a dual solubility in both organic solvents and water for compounds 3. The tetrasulfonamidophthalocyanine complexes 5–7 with four C8, four C18 or eight C8 alkyl chains have been obtained after chlorination of the sulfophthalocyanines 1 leading to the chlorosulfonyl derivatives 4, followed by reaction with various substituted amines. The synthesis of the chromium precursors with tetrasulfo and tetrachlorosulfonyl substituents is also described. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Interactions of tetracationic mercury(II), cadmium(II) and lead(II) porphyrins with DNA and their effects on DNA cleavage
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Elvis Nyarko, Masaaki Tabata

    The effects of tetrakis(1‐methylpyridinium‐4‐yl)porphyrinatomercury(II) [Hg(TMPyP)]4+ (6) along with [Pb(TMPyP)]4+ (7), [Cd(TMPyP)]4+ (8), and [H2(TMPyP)]4+ (1) (free base porphyrin) on DNA cleavage by Haemophilus aegyptius (HaeIII) have been studied using gel electrophoresis, UV‐vis absorption spectroscopy, and circular dichroism (CD) spectroscopy. The gel electrophoresis results indicate that in the absence of 6, HaeIII restriction enzyme could not cleave plasmid DNA at a low concentration of 0.2 units µl−1 after 1 h incubation at 37 °C. However, DNA cleavage occurred in the presence of 6 at the concentrations of 1.0 × 10−6 and 1.0 × 10−7 M and 0.2 units µl−1 of HaeIII under the same conditions. In addition, acceleration of DNA cleavage occurred at a higher concentration of HaeIII (0.4 units µl−1) in the presence of a wider concentration range of 6 from 1.0 × 10−5 to 1.0 × 10−7 M. 8, 7, and 1 could not enhance DNA cleavage in the presence of HaeIII (0.2 units µl−1). However, when the concentration of HaeIII was increased to 0.4 units µl−1, only 8 inhibited DNA cleavage by HaeIII at higher concentrations (1.0 × 10−5–10−6 M) whereas 6, 7, and 1 did not. The UV‐vis and CD spectroscopic results indicate that these porphyrins interact differently with DNA based on their binding modes. 6 enhanced DNA cleavage due to the synergistic effect of the Hg2+ ions and the free base porphyrin 1 that dissociated from the mercury(II) porphyrin complex upon binding to DNA which resulted in the enhanced transformation of the DNA conformation from the original B‐form to a Z‐like conformation, while 8 inhibited HaeIII activity at higher concentrations and 7 and 1 neither enhanced nor inhibited DNA cleavage. A mechanism for this phenomenon is suggested. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Tetrakis(selenodiazole)porphyrazines. 2: Metal complexes with Mn(II), Co(II), Ni(II), and Zn(II)
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Silvia Angeloni, Elvira M. Bauer, Claudio Ercolani, Irina A. Popkova, Pavel A. Stuzhin

    The present report describes two series of new porphyrazine macrocycles derived from tetrakis(selenodiazole)porphyrazine, TSeDPzH2, having the formulae [TSeDPzM](CH3COOH)(H2O) x M = Mn(II), Co(II), Ni(II), Zn(II); x = 4–6) and [TSeDPzM(py)](CH3COOH)(H2O) x (M = Mn(II), Co(II), Ni(II); x = 1–5), obtained by reaction of the free ligand with the appropriate metal acetate in dimethyl (DMSO), and, respectively, pyridine. All the species isolated are stable‐to‐air substantially amorphous materials, almost completely insoluble in the usual organic solvents and N‐donors (pyridine etc.), and only slightly soluble in CF3COOH or 96% H2SO4. The complexes have been investigated by IR, Raman, and UV‐vis spectra, and magnetic susceptibility measurements. Their properties in terms of electronic structure and reactivity towards N‐bases are discussed in comparison with their S‐containing analogs and the class of the structurally similar metal phthalocyanines. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • The nature of the bonding between metalloporphyrins [Fe(II), Co(II), Mn(II)] and oxygen species (·O·, H2+O·/HO·, HOO·, ·O·)
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2001-12-31
    Donald T. Sawyer

    The interaction of reduced transition‐metal porphyrins [e.g. PMn(II), PFe(II), PCo(II)] with oxygen species (·O·, H2+O·/HO·, HOO·, ·O·) involves radical/radical coupling to form covalent bonds. Coordinately unsaturated iron(II) porphyrins form two sigma bonds with ·O·(−ΔGBF = 1–6 kcal mol−1) via two of the four unpaired d‐electrons of the iron center. The hydroxyl radical couples with an unpaired electron of the PM(II) porphyrins to form a single covalent bond . The bond energies (−ΔGBF) for and are 65 ± 4 and 58 kcal mol−1, respectively. Under neutral conditions the uncharged species [(Cl8TPP)MnIII–OH, (Cl8TPP)FeIII–OH, (Cl8TPP)CoIII–OH] have bond‐formation energies (−ΔGBF) of 70 ± 4, 63, and 61 kcal mol−1, respectively. In acetonitrile solutions atomic oxygen (·O·; derived from ozone, O3) couples with (Cl8TPP)MnIII[ClO4], (Cl8TPP)MnII, (Cl8TPP)FeIII[ClO4], and (Cl8TPP)FeII to form (Cl8TPP+)MnVO (−ΔGBF = 59 ± 4 kcal mol−1), (Cl8TPP)MnIVO (85 kcal mol−1), (Cl8TPP+·)FeIVO (68 kcal mol−1; model for compound I of horseradish peroxidase), and (Cl8TPP)FeIVO (78 kcal mol−1; model for compound II of horseradish peroxidase). The weakly bonded species [(Cl8TPP+)MnVO and (Cl8TPP+·)FeIVO] epoxidize olefins with near‐stoichiometric efficiency; the other two species are essentially unreactive with olefins. Copyright © 2001 John Wiley & Sons, Ltd.

    更新日期:2019-11-18
  • Susanna J. Shaw, Sakthitharan Shanmugathasan, Oliver J. Clarke, Ross W. Boyle, Alan G. Osborne and Christine Edwards, ‘A 13C NMR spectral examination of α‐ and β‐carbon signal peak heights in some disubstituted arylporphyrins’.Journal of Porphyrins and Phthalocyanines5(7)2001, 575‒581
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2002-01-03
    Susanna J. Shaw, Sakthitharan Shanmugathasan, Oliver J. Clarke, Ross W. Boyle, Alan G. Osborne, Christine Edwards

    The original article to which this Erratum refers was published in The Journal of Porphyrins and Phthalocyanines 5(7) 2001, 575–581

    更新日期:2019-11-18
  • Adventures in photodynamic therapy: 1976-2008.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2008-07-24
    David Kessel

    While the concept of photodynamic therapy dates from 1900, and there have been periodic re-discoveries, the clinical era really began with the studies by Dougherty and associates in the early 1970s. This report relates my encounter with the field of PDT, along with experimental approaches to the elucidation of pertinent phototoxic mechanisms.

    更新日期:2019-11-01
  • Targeting of the epidermal growth factor receptor with mesoporphyrin IX-peptide conjugates.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2016-10-16
    Krystal R Fontenot,Benson G Ongarora,Logan E LeBlanc,Zehua Zhou,Seetharama D Jois,M Graça H Vicente

    The synthesis and in vitro evaluation of four mesoporphyrin IX-peptide conjugates designed to target EGFR, over-expressed in colorectal and other cancers, are reported. Two peptides with known affinity for EGFR, LARLLT (1) and GYHWYGYTPQNVI (2), were conjugated to mesoporphyrin IX (MPIX, 3) via one or both the propionic side chains, directly (4, 5) or with a triethylene glycol spacer (7, 8). The conjugates were characterized using NMR, MS, CD, SPR, UV-vis and fluorescence spectroscopies. Energy minimization and molecular dynamics suggest different conformations for the conjugates. SPR studies show that conjugate 4, bearing two LARLLT with no PEG spacers, has the greatest affinity for binding to EGFR, followed by conjugate 7 with two PEG and two LARLLT sequences. Molecular modeling and docking studies suggest that both conjugates 4 and 7 can bind to monomer and dimer EGFR in open and closed conformations. The cytotoxicity and cellular targeting ability of the conjugates were investigated in human HEp2 cells over-expressing EGFR. All conjugates showed low dark- and photo-toxicities. The cellular uptake was highest for conjugates 4 and 8 and lowest for 7 bearing two LARLLT linked via PEG groups, likely due to decreased hydrophobicity. Among the conjugates investigated 4 is the most efficient EGFR-targeting agent, and therefore the most promising for the detection of cancers that over-express EGFR.

    更新日期:2019-11-01
  • Internal Spin Trapping of Thiyl Radical during the Complexation and Reduction of Cobalamin with Glutathione and Dithiothrietol.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2012-06-19
    Somasundaram Ramasamy,Tapan Kumar Kundu,William Antholine,Periakaruppan T Manoharan,Joseph M Rifkind

    The activation of cobalamin requires the reduction of Cbl(III) to Cbl(II). The reduction by glutathione and dithiothreitol was followed using visible spectroscopy and electron paramagnetic resonance. In addition the oxidation of glutathione was monitored. Glutathione first reacts with oxidized Cbl(III). The binding of a second glutathione required for the reduction to Cbl(II) is presumably located in the dimethyl benzimidazole ribonucleotide ligand cavity. The reduction of Cbl(III) by dithiothreitol, which contains two thiols, is much faster even though no stable Cbl(III) complex is formed. The reduction, by both thiol reagents, results in the formation of thiyl radicals, some of which are released to form oxidized thiol products and some of which remain associated with the reduced cobalamin. In the reduced state the intrinsic lower affinity for the benzimidazole base, coupled with a trans effect from the initial GSH bound to the β-axial site and a possible lowering of the pH results in an equilibrium between base-on and base-off complexes. The dissociation of the base facilitates a closer approach of the thiyl radical to the Co(II) α-axial site resulting in a complex with ferromagnetic exchange coupling between the metal ion and the thiyl radical. This is a unique example of 'internal spin trapping' of a thiyl radical formed during reduction. The finding that the reduction involves a peripheral site and that thiyl radicals produced during the reduction remain associated with the reduced cobalamin provide important new insights into our understanding of the formation and function of cobalamin enzymes.

    更新日期:2019-11-01
  • Effect of the Ruffled Porphyrin Ring on Electronic Structures: Structure and Characterization of [Fe(TalkylP)(OClO3)] and [Fe(TPrP)(THF)2]ClO4 (alkyl = Ethyl, Et and n-Propyl, Pr).
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2013-04-30
    Ming Li,Allen G Oliver,Teresa J Neal,Charles E Schulz,W Robert Scheidt

    We report the synthesis of Fe(TalkylP)(OClO3)] (alkyl = ethyl and propyl) and [Fe(TPrP)(THF)2]ClO4, which are characterized by UV-vis, EPR, X-ray crystallography, and solid-state magnetic susceptibilities. The macrocycles of all three complexes are ruffled, all of the structural features for [Fe(TEtP(OClO3)] and [Fe(TPrP)(OClO3)] are characteristic of the nearly pure S = 3/2 state, while the structural parameters for [Fe(TPrP)(THF)2]ClO4 feature a pure intermediate-spin (S = 3/2) state, which are all consistent with EPR and magnetic data. It is clear from these studies that the ruffled conformation plays a significant role in affecting the extent of S = 3/2 character.

    更新日期:2019-11-01
  • Synthetic protocols for the nitration of corroles.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2012-01-31
    Giuseppe Pomarico,Frank R Fronczek,Sara Nardis,Kevin M Smith,Roberto Paolesse

    The modification of peripheral positions of corroles by introduction of nitro groups is an important functionalization of this macrocycle. The nitro substituent strongly influences the corrole behavior leading to the preparation of macrocycles with different properties, which can be of interest for their exploitation as catalysts, sensing layers in chemical sensors or in the field of supramolecular chemistry. In the last few years we have developed different routes for the β-nitration of the corrole ring, and we report here novel synthetic protocols which can allow the formation of tri- and tetranitro derivatives, as demonstrated by X-ray analysis. In all of the methodologies used, the presence of isocorrole species as reaction intermediates was established, which regenerated the corresponding corrole by metal insertion.

    更新日期:2019-11-01
  • One-pot synthesis of meso-alkyl substituted isocorroles: the reaction of a triarylcorrole with Grignard reagent.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2010-12-18
    Sara Nardis,Giuseppe Pomarico,Federica Mandoj,Frank R Fronczek,Kevin M Smith,Roberto Paolesse

    The reaction of 5,10,15-tritolylcorrole with EtMgBr opens the way for novel functionalizations of the corrole ring. DDQ oxidation of the macrocycle, followed by addition of the Grignard reagent, led to the formation of 5- and 10-alkyl substituted isocorroles in satisfying yields. Together with the one-pot formation of these isocorrole isomers, the use of such a nucleophile evidenced the competitive reactivity of the macrocycle β-positions, leading to the formation of 2-bromo- and 3-bromo-5,10,15-tritolylcorrole. While the formation of these monobromocorrole derivatives is not unprecedented, this is the first time the isomers have been separated and fully characterized. Furthermore, the higher yields of the 2-substituted species highlight a useful regioselectivity for the substitution reaction.

    更新日期:2019-11-01
  • Inter-Ring Interactions in [Fe(TalkylP)(Cl)] (alkyl = ethyl, n-propyl, n-hexyl) Complexes: Control by meso-Substituted Groups.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2010-06-08
    Ming Li,Teresa J Neal,Noelle Ehlinger,Charles E Schulz,W Robert Scheidt

    Syntheses, molecular structures and magnetic susceptibilities of three meso-substituted high-spin iron(III) porphyrinate complexes ([Fe(TEtP)(Cl)], [Fe(TPrP)(Cl)], and [Fe(THexP)(Cl)]) are described. It was determined that the inter-ring interactions within each dimeric unit change upon alteration of the alkyl groups at the meso-positions. Magnetic exchange couplings between iron centers of the dimers are in accord with the trends in structural inter-ring geometries. Crystal data for [Fe(TEtP)(Cl)]: a = 10.1710(5) Å, b = 11.309(3) Å, c = 12.170(3) Å, α = 91.774(9) °, β = 113.170(14) °, γ = 112.149(9) °, V = 1165.2(4) Å(3), triclinic, P1̄, Z = 2, R(1) = 0.0844 and ωR(2) = 0.2073 for observed data. Crystal data for [Fe([Fe(TPrP)(Cl)])(Cl)]: a = 13.040(2) Å, b = 15.221(2) Å, c = 14.6681(9) Å, β = 109.997(11) °, V = 2735.9(7) Å(3), monoclinic, P2(1)/n, Z = 4, R(1) = 0.0477 and ωR(2) = 0.1176 for observed data. Crystal data for [Fe(THexP)(Cl)]: a = 10.246(7) Å, b = 12.834(4) Å, c = 17.420(15) Å, α = 69.74(3) °, β = 87.52(4) °, γ, = 84.89(3) °, V = 2140(2) Å(3), triclinic, P1̄, Z = 2, R(1) = 0.1024 and ωR(2) = 0.2659 for observed data.

    更新日期:2019-11-01
  • Explorations in metalloporphyrin stereochemistry, physical properties and beyond.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2008-01-01
    W Robert Scheidt

    A review of selected portions of our work in the area of porphyrin structure and physical characterization is presented. Topics covered include early work on periodic trends in first row transtion metalloporphyrins, a survey of electronic structure of iron derivatives including spin-state trends, ligand orientation effects and the elucidtion of unusual low-spin states for iron(II). A discussion of the different tlypes of high-spin iron(II) complexes and the effects of hydrogen bonding is given. A survey of nitric oxide (NO) derivatives is presented as well as a brief introduction into the use of nuclear resonance vibrational spectroscopy for the study of iron porphyrins and heme proteins.

    更新日期:2019-11-01
  • Design of Metalloporphyrin-Based Dendritic Nanoprobes for Two-Photon Microscopy of Oxygen.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2009-09-19
    Artem Y Lebedev,Thomas Troxler,Sergei A Vinogradov

    Metalloporphyrin-based phosphorescent nanoprobes are being developed for two-photon microscopy of oxygen. In these molecular constructs generation of porphyrin triplet states upon two-photon excitation is induced upon the intramolecular Förster-type resonance energy transfer from a covalently attached 2P antenna. In the earlier developed prototypes, electron transfer between the antenna and the metalloporphyrin strongly interfered with the phosphorescence, reducing the sensitivity and the dynamic range of the sensors. By tuning the distances between the antenna and the core and adjusting their redox potentials the unwanted electron transfer could be prevented. An array of phosphorescent Pt porphyrins (energy transfer acceptors) and 2P dyes (energy transfer donors) was screened using dynamic quenching of phosphorescence, and the FRET-pair with the minimal ET rate was identified. This pair, consisting of Coumarin-343 and Pt meso-tetra-(4-alkoxyphenyl)porphyrin, was used to construct a probe in which the antenna fragments were linked to the termini of G3 poly(arylglycine) (AG) dendrimer with PtP core. The folded dendrimer formed an insulating layer between the porphyrin and the antenna, simultaneously controlling the rate of oxygen quenching (Stern-Volmer oxygen quenching constant). Modification of the dendrimer periphery with oligoethyleneglycol residues made the probe's signal insensitive to the presence of proteins and other macromolecular solutes.

    更新日期:2019-11-01
  • Probing the heme-thiolate oxygenase domain of inducible nitric oxide synthase with Ru(II) and Re(I) electron tunneling wires.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2009-09-18
    Charlotte A Whited,Wendy Belliston-Bittner,Alexander R Dunn,Jay R Winkler,Harry B Gray

    Nitric oxide synthase (NOS) catalyzes the production of nitric oxide from L-arginine and dioxygen at a thiolate-ligated heme active site. Although many of the reaction intermediates are as yet unidentified, it is well established that the catalytic cycle begins with substrate binding and rate-limiting electron transfer to the heme. Here we show that Ru(II)-diimine and Re(I)-diimine electron tunneling wires trigger nanosecond photoreduction of the active-site heme in the enzyme. Very rapid generation of a reduced thiolate-ligated heme opens the way for direct observation of short-lived intermediates in the NOS reaction cycle.

    更新日期:2019-11-01
  • Copper β-trinitrocorrolates.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2013-11-02
    Manuela Stefanelli,Sara Nardis,Frank R Fronczek,Kevin M Smith,Roberto Paolesse

    The β-nitration reaction carried out on the corrole macrocycle has been shown to be extremely regioselective, although the reduced symmetry of the macrocycle could potentially lead to a huge number of possible regioisomers. We recently reported that the careful use of AgNO2/NaNO2 as a nitrating system enabled the achievement in good yields of mono- and dinitro-derivatives on both corrole free base and its copper complex, proving to be an efficient and cost-effective method. In this work, we present a detailed study of the scope of this method using TtBuCorrH3 as a model corrole. A further increase of the oxidant pushes the nitration up to the functionalization of three β-pyrrolic positions, although concomitant decomposition of the macrocycle is also observed. The application of the proven nitration method with a five-fold excess of both silver and sodium nitrites with respect to corrole, afforded the 2,3,17-(NO2)3-TtBuPCorrCu as the main product, in 25% yield, together with traces of another compound identified by X-ray crystallographic analysis as the 3,8,17-(NO2)3-TtBuPCorrCu isomer. In light of these recent results, we also reinvestigated the characterization of the nitration products obtained from bis-substitution reactions, allowing among others the identification of the copper 3,8-(NO2)2 corrolate.

    更新日期:2019-11-01
  • Synthesis and evaluation of cationic bacteriochlorin amphiphiles with effective in vitro photodynamic activity against cancer cells at low nanomolar concentration.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2013-08-21
    Sulbha K Sharma,Michael Krayer,Felipe F Sperandio,Liyi Huang,Ying-Ying Huang,Dewey Holten,Jonathan S Lindsey,Michael R Hamblin

    Bacteriochlorins are attractive candidates as photosensitizers for photodynamic therapy (PDT) due to their intense absorption in the near-infrared (NIR) region of the spectrum where light transmission through tissue is maximal. Many naturally occurring bacteriochlorins are inherently unstable due to adventitious atmospheric oxidation. A de novo synthesis affords bacteriochlorins that contain a geminal dimethyl group in each reduced pyrrole ring to increase stability against oxidation. Here, three new synthetic bacteriochlorins, each bearing a single side-chain containing one or two positive charges, were investigated for their in vitro PDT activity against HeLa human cancer cells. All bacteriochlorins were active at low nanomolar concentration when activated with NIR light; those bearing a single positive charge exhibited faster uptake and higher activity. The bacteriochlorins were localized in mitochondria, lysosomes and endoplasmic reticulum as shown by organelle specific fluorescent probes. Cell death was via apoptosis as shown by cell morphology and nuclear condensation. Taken together, the results show the importance of appropriate peripheral groups about a photosensitizer for effective PDT applications.

    更新日期:2019-11-01
  • Indium as a central metal enhances the photosensitizing efficacy of benzoporphyrin derivatives.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-11-01
    Courtney Saenz,Manivannan Ethirajan,Gary Iacobucci,Ankit Pandey,Joseph R Missert,Mahabeer P Dobhal,Ravindra K Pandey

    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.

    更新日期:2019-11-01
  • Syntheses, properties and cellular studies of metalloisoporphyrins.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2012-06-30
    Sandra C Mwakwari,Haijun Wang,Timothy J Jensen,M Graça H Vicente,Kevin M Smith

    b-Bilene hydrochlorides are shown to be improved intermediates for the synthesis of metallo-isoporphyrins in enhanced yields (28% vs. 6%). Several new diamagnetic zinc(II) and a novel paramagnetic copper(II) isoporphyrin salts were also obtained using this approach. Metal-free isoporphyrins were also isolated. In vitro studies using human carcinoma HEp2 cells show that all metallo-isoporphyrins accumulate within cells and localize partially in the mitochondria. The zinc-isoporphyrins were found to be moderately phototoxic while the copper complex showed the lowest phototoxicity, maybe as a result of its paramagnetic nature.

    更新日期:2019-11-01
  • Conformational Distortions of π-Cation Radical (β-Oxoporphyrin)copper(II) Derivatives: [Cu(2,7,12-TrioxoOEHP)][SbCl(6)] and [Cu(2,7-DioxoOEiBC)][SbCl(6)].
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-11-26
    Ilona Turowska-Tyrk,Seong-Joo Kang,W Robert Scheidt

    The preparation and characterization of two π-cation radical derivatives of copper β-oxo porphyrins is described. [3,3,8,8,13,13,17,18-Octaethyl-(3H,8H,13H)-porphine-2,7,12-trionato (2-)] copper π-cation radical, [Cu(2,7,12-trioxoOEHP(.))](+), and [3,3,8,8,12,13,17,18-octaethyl-(3H,8H)-porphine-2,7-dionato(2-)] copper π-cation radical, [Cu(2,7-dioxoOEiBC(.))](+), have been prepared and characterized by single-crystal X-ray determinations, UV/vis/NIR, and IR spectroscopies. Both molecules have modest distortion from the planarity and show monomeric units in the solid state. [Cu(2,7-dioxoOEiBC(.))](+) shows a concentration dependent near-IR band at 1410 nm. Crystal data for [Cu(2,7,12-trioxoOEHP(.))][SbCl(6)]: tetragonal, space group P4(2)/n, a = 31.085 (14) Å, c = 9.410 (4) Å, V = 9093 Å(3), Z = 8, T = 127 K. Crystal data for [Cu(2,7-dioxoOEiBC(.))][SbCl(6)]: monoclinic, space group P2(1)/n, a = 9.655 (4) Å, b = 20.592 (8) Å, c = 43.347 (17) Åβ = 89.97(1)(°), V = 8618. Å(3), Z = 8, T = 100 K.

    更新日期:2019-11-01
  • Crown ether functionalized texaphyrin monomers and dimers.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-10-26
    Christian Preihs,Darren Magda,Jonathan L Sessler

    The synthesis and characterization of two 18-crown-6 functionalized analogues of an extensively studied gadolinium texaphyrin derivative, motexafin gadolinium (1, MGd), are reported. These are the monomeric and dimeric species, compounds 2 and 3, respectively. Both crown ether functionalized species proved to be stable at physiological pH and revealed distinct shifts in the UV spectrum when treated with sodium-, potassium-, ammonium- or zinc(II)-salts. Zinc(II) is believed to play a major role regulating apoptosis mechanisms in cancerous cells. Therefore, cytotoxicity studies of 2 and 3 were carried out using Ramos cell lines in the presence and absence of zinc(II).

    更新日期:2019-11-01
  • Palladium(0) catalyzed 2,2'-bipyrrole syntheses.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-09-03
    Lijuan Jiao,Erhong Hao,Frank R Fronczek,M Graça H Vicente,Kevin M Smith

    Several 2-iodopyrroles are used in Pd(0) catalyzed homocoupling reactions at room temperature in the presence of water to efficiently synthesize 2,2'-bipyrroles. These 2,2'-bipyrroles are strongly luminous materials and have high fluorescence quantum yields.

    更新日期:2019-11-01
  • FERROCHELATASE: THE CONVERGENCE OF THE PORPHYRIN BIOSYNTHESIS AND IRON TRANSPORT PATHWAYS.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-08-20
    Gregory A Hunter,Salam Al-Karadaghi,Gloria C Ferreira

    Ferrochelatase (also known as PPIX ferrochelatase; Enzyme Commission number 4.9.9.1.1) catalyzes the insertion of ferrous iron into PPIX to form heme. This reaction unites the biochemically synchronized pathways of porphyrin synthesis and iron transport in nearly all living organisms. The ferrochelatases are an evolutionarily diverse family of enzymes with no more than six active site residues known to be perfectly conserved. The availability of over thirty different crystal structures, including many with bound metal ions or porphyrins, has added tremendously to our understanding of ferrochelatase structure and function. It is generally believed that ferrous iron is directly channeled to ferrochelatase in vivo, but the identity of the suspected chaperone remains uncertain despite much recent progress in this area. Identification of a conserved metal ion binding site at the base of the active site cleft may be an important clue as to how ferrochelatases acquire iron, and catalyze desolvation during transport to the catalytic site to complete heme synthesis.

    更新日期:2019-11-01
  • Efficient synthesis and reactions of 1,2-dipyrrolylethynes.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-08-09
    Hillary K Tanui,Erhong Hao,Moses I Ihachi,Frank R Fronczek,Kevin M Smith,M Graça H Vicente

    Various dipyrroles possess important motifs for construction of pyrrole-containing pigments. A series of 1,2-dipyrrolylethynes (4a-d) has been efficiently synthesized using an improved one-pot double Sonagashira coupling from trimethylsilylethyne and various 2-iodopyrroles. The resulting 1,2-dipyrrolylethynes were further transformed into novel indolyl-, ethenyl- and carboranyl-dipyrroles (5-7) using the Larock indole synthesis, stereoselective catalytic hydrogenation, or B(10)H(14). Indolyl-dipyrroles were found to selectively bind fluoride ions using one pyrrolic and the indolyl NHs, whereas the carboranyl- and ethenyl-dipyrroles are potentially valuable precursors for the synthesis of porphyrin isomers and expanded pigments.

    更新日期:2019-11-01
  • Resonance Raman Spectroscopic Examination of Ferrochelatase-induced Porphyrin Distortion.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2011-07-22
    Ricardo Franco,Salam Al-Karadaghi,Gloria C Ferreira

    Ferrochelatase, the terminal enzyme of the heme biosynthetic pathway, catalyzes the insertion of ferrous iron into protoporphyrin IX to give heme. Resonance Raman spectroscopy has been instrumental in defining the distortion (mode and extent) of the porphyrin substrate, which is a critical step in the catalytic mechanism of ferrochelatase. Saddling is the predominant porphyrin out-of-plane deformation induced upon binding to ferrochelatase. Our analysis demonstrated that the intensity of the γ(15) line, which is assigned to an out-of-plane porphyrin vibration, in resonance Raman spectra obtained for wild-type- and variant ferrochelatase-bound porphyrin, correlates with the saddling deformation undergone by the porphyrin substrate. Further analysis of the three dimensional X-ray structures of bacterial, human and yeast ferrochelatases and the type and extent of distortion of the protein-bound porphyrin substrate and inhibitors using normal structure decomposition, support the view that ferrochelatase catalysis involves binding of a distorted porphyrin substrate and releasing of a flatter, metalated porphyrin.

    更新日期:2019-11-01
  • Syntheses and PDT activity of new mono- and di-conjugated derivatives of chlorin e6.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2017-10-24
    Hui Chen,Stewart W Humble,R G Waruna Jinadasa,Zehua Zhou,Alex L Nguyen,M Graça H Vicente,Kevin M Smith

    Syntheses of three new chlorin e6 conjugates for PDT of tumors are reported. One of the new compounds 17 is conjugated with lysine at the 131-position, but the others are mono-conjugated 14 or diconjugated 15 with the non-amino acid species ethanolamine. Cellular experiments with the three new compounds and previously synthesized non-amino acid 152-conjugates (7-10), 131-monoconjugates 14, 16, and a 131,152-diconjugate 12 are reported. In vitro cytotoxicity experiments show that the 131-conjugates are more toxic than the 152-conjugates, and the most toxic derivative (dark- and photo-toxicity) is the 131-ethylenediamine conjugate 11. The most useful PDT photosentitizers appear to be the ethanolamine derivatives, conjugated at the 152- and the 131,152-positions; these show high phototoxicity but relatively low dark toxicity compared with 11, and also the highest dark/photo cytotoxicity ratios.

    更新日期:2019-11-01
  • Characterization of the mixed axial ligand complex (4-cyanopyridine)(imidazole)(tetramesitylporphinato)iron(iii) perchlorate. Stabilization by synergic bonding.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2016-08-31
    Judith A Serth-Guzzo,Ilona Turowska-Tyrk,Martin K Safo,F Ann Walker,Peter G Debrunner,W Robert Scheidt

    The reaction of [Fe(TMP)(OClO3)], where TMP is the dianion of tetramesitylporphyrin, with a combination of a strong π-acceptor ligand and a π-donating imidazole can lead to the preparation of mixed-ligand complexes [Fe(Porph)(4-CNPy)(L)]+ where L is imidazole itself or 1-acetylimidazole and 4-cyanopyridine is the strong π acceptor ligand. The stability of the new mixed-ligand pair is the presumed result of synergic bonding between the two axial ligands. The molecular structure and other characterization of the new mixed axial ligand complex, [Fe(TMP)(4-CNPy)(HIm)]ClO4 is described. The axial ligands have a relative perpendicular arrangement with Fe-N(imidazole) = 1.945 Å and Fe-N(pyridine) = 2.021 Å The average equatorial Fe-Np distance is 1.963 Å, which is consistent with the S4-ruffled TMP core. Despite the relative perpendicular arrangement of axial ligands, the EPR spectrum of the complex is a rhombic signal and not a large gmax signal. The EPR g-values are g1 = 3.05, g2 = 2.07, and g3 = 1.22. A quadrupole doublet was seen in the Mössbauer spectrum with an isomer shift of 0.197 mm/s and quadrupole splitting of 1.935 mm/s. Two crystalline forms of [Fe(TMP)(4-CNPy)(HIm)]ClO4 have been characterized; the two forms differ only in the solvent content of the lattice. Crystal data for form A: a = 15.432 (12) Å, b = 20.696 (2) Å, c = 19.970 (5) Å, and β = 99.256 (14)°, monoclinic, space group P21/n, V = 6295 (2) Å3, Z = 4, formula FeCl3O4N8C69H69, 8397 observed data, R1 = 0.086, wR2 = 0.210, refinement on F2. Crystal data for form B: a = 15.267 (3) Å, b = 20.377 (6) Å, c = 19.670 (4) Å, and β = 98.14 (1)°, monoclinic, space group P21/n, V = 6058 (4) Å3, Z = 4, formula C65.25H60.5Cl1.5FeN8O4, 5464 observed data, R1 = 0.096, wR2 = 0.112, refinement on F.

    更新日期:2019-11-01
  • Solid-state Porphyrin Interactions with Oppositely Charged Peripheral Groups.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2016-08-23
    W Robert Scheidt,Beisong Cheng,Allen G Oliver,John A Goodwin

    The crystallization and the crystal and molecular structure of a very slightly soluble electrostatically interacting pair of porphyrins is described. The tetra-anion 5,10,15,20-tetrakis-(4-sulfonatophenyl)-21,23H-porphyrin [H2TPPSO3]4- and the tetra-cation 5,10,15,20-tetra(N-methylpyridyl)21H,23H-porphyrin [H2TMePyP]4+ are found to form an alternating one-dimensional stack that is stabilised by electrostatic interactions between the porphyrin rings but also by π-π interactions between all substituted phenyl rings in the ensemble. The resulting interactions between the porphyrins is exceptionally tight.

    更新日期:2019-11-01
  • Photodynamic therapy: Promotion of efficacy by a sequential protocol.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2016-08-17
    David Kessel

    Photodynamic therapy (PDT) offers a new approach to selective tumor eradication. Modifications designed to increase and optimize efficacy continue to emerge. Selective photodamage to malignant cells and their environment can bring about tumor cell destruction, shutdown of the tumor vasculature, stimulation of immunologic anti-tumor effects and potentiation of other therapeutic effects. Current development of combination protocols may provide a better rationale for integration of PDT into clinical practice. An example described here is the ability of a sequential (two-sensitizer) PDT protocol to enhance the efficacy of photokilling. The first step involves low-level lysosomal photodamage that has been shown to promote the apoptotic response to subsequent photodynamic effects directed at mitochondria. In this report, we demonstrate the ability of Photofrin, an FDA-approved photosensitizing agent, to serve as either the first or second element of the sequential protocol.

    更新日期:2019-11-01
  • Structural characterization of the μ-Nitrido Complex {[Fe(OEP)]2N}
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2014-11-11
    Ming Li,W Robert Scheidt

    The molecular structure of the μ-nitrido dimer, μ-nitrido-bis(2,3,7,8,12,13, 17,18-octaethylporphyrinato)iron, is reported. The axial Fe-N distances average to 1.657 (11) Å and the equatorial distances average to 2.005(5) Å. Although not required by symmetry, the two iron centers appear equivalent and are consistent with an assignment of a low-spin state and a formal oxidation state of +3.5. A comparison of this structure with other nitrido-bridged species is given.

    更新日期:2019-11-01
  • Synthesis and biological investigations of a ZnPc-antiCEA bioconjugate for imaging of colorectal cancer.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2013-01-01
    Inder Sehgal,Hairong Li,Benson Ongarora,Daniel Devillier,M Graça H Vicente

    Two zinc(II) phthalocyanines (ZnPcs) were conjugated with a monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA), using an in situ activated carboxylic acid on the ZnPcs. The bioconjugate with the highest ZnPc/MAb ratio of 3 was investigated in vitro for its ability to target and fluorescently label human colorectal HT-29 cells. The ZnPc-CEA MAb 2 was observed to efficiently target HT-29 cells, about 37 times more than unconjugated ZnPc. Furthermore, in the presence of a 4-fold excess of unlabelled anti-CEA antibody, the fluorescence signal of 2 was reduced by ~90% showing that the targeting is CEA-mediated. These studies further confirm the high specificity of Pc-antibody conjugates for antigens over-expressed on tumor cells and warrant further investigations of these immunoconjugates and their derivatives for imaging of colorectal cancer.

    更新日期:2019-11-01
  • Progress Towards Synthetic Chlorins with Graded Polarity, Conjugatable Substituents, and Wavelength Tunability.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2015-12-08
    Doyoung Ra,Kelly A Gauger,Kannan Muthukumaran,Thiagarajan Balasubramanian,Vanampally Chandrashaker,Masahiko Taniguchi,Zhanqian Yu,Daniel C Talley,Melanie Ehudin,Marcin Ptaszek,Jonathan S Lindsey

    Advances in chlorin synthetic chemistry now enable the de novo preparation of diverse chlorin-containing molecular architectures. Five distinct molecular designs have been explored here, including hydrophobic bioconjugatable (oxo)chlorins; a hydrophilic bioconjugatable chlorin; a trans-ethynyl/iodochlorin building block; a set of chlorins bearing electron-rich (methoxy, dimethylamino, methylthio) groups at the 3-position; and a set of ten 3,13-disubstituted chlorins chiefly bearing groups with extended π-moieties. Altogether 23 new chlorins (17 targets, 6 intermediates) have been prepared. The challenge associated with molecular designs that encompass the combination of "hydrophilic, bioconjugatable and wavelength-tunable" chiefly resides in the nature of the hydrophilic unit.

    更新日期:2019-11-01
  • Synthesis, spectroscopic, and cellular properties of α-pegylated cis-A2B2- and A3B-types ZnPcs.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2015-06-13
    Benson G Ongarora,Zehua Zhou,Elizabeth A Okoth,Igor Kolesnichenko,Kevin M Smith,M Graça H Vicente

    A series of pegylated cis-A2B2- or A3B-type ZnPcs, substituted on the α-positions with tri(ethylene glycol) and hydroxyl groups, were synthesized from a new bis-phthalonitrile. A clamshell-type bis-phthalocyanine was also obtained as a byproduct. The hydroxyl group of one ZnPc was alkylated with 3-dimethylaminopropyl chloride to afford a pegylated ZnPc functionalized with an amine group. All mononuclear ZnPcs were soluble in polar organic solvents, showed intense Q absorptions in DMF, and had fluorescence quantum yields in the range 0.10-0.23. The clamshell-type bis-phthalocyanine adopts mainly open shell conformations in DMF, and closed clamshell conformations in chloroform. All ZnPcs were highly phototoxic to human carcinoma HEp2 cells, particularly the amino-ZnPc mainly protonated under physiological conditions, which showed the highest phototoxicity (IC50 = 0.5 μM at 1.5 J/cm2) and dark cytotoxicity (IC50 = 22 μM), in part due to its high cellular uptake. The ZnPcs localized in multiple organelles, including mitochondria, lysosomes, Golgi and ER.

    更新日期:2019-11-01
  • Reactions of a heme-superoxo complex toward a cuprous chelate and •NO(g): CcO and NOD chemistry.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2015-06-10
    Savita K Sharma,Patrick J Rogler,Kenneth D Karlin

    Following up on the characterization of a new (heme)FeIII-superoxide species formed from the cryogenic oxygenation of a ferrous-heme (PPy)FeII (1) (PPy = a tetraarylporphyrinate with a covalently tethered pyridine group as a potential axial base), giving (PPy)FeIII-O2•- (2) (Li Y et al., Polyhedron 2013; 58: 60-64), we report here on (i) its use in forming a cytochrome c oxidase (CcO) model compound, or (ii) in a reaction with nitrogen monoxide (•NO; nitric oxide) to mimic nitric oxide dioxygenase (NOD) chemistry. Reaction of (2) with the cuprous chelate [CuI(AN)][B(C6F5)4] (AN = bis[3-(dimethylamino) propyl]amine) gives a meta-stable product [(PPy)FeIII-([Formula: see text])-CuII(AN)][B(C6F5)4] (3a), possessing a high-spin iron(III) and Cu(II) side-on bridged peroxo moiety with a μ-η2:η2-binding motif. This complex thermally decays to a corresponding μ-oxo complex [(PPy)FeIII-(O2-)-CuII(AN)][B(C6F5)4] (3). Both (3) and (3a) have been characterized by UV-vis, 2H NMR and EPR spectroscopies. When (2) is exposed to •NO(g), a ferric heme nitrato compound forms; if 2,4-di-tert-butylphenol is added prior to •NO(g) exposure, phenol ortho-nitration occurs with the iron product being the ferric hydroxide complex (PPy) FeIII(OH) (5). The latter reactions mimic the action of NOD's.

    更新日期:2019-11-01
  • Synthesis and anti-cancer activities of a water soluble gold(III) porphyrin.
    J. Porphyr. Phthalocyanines (IF 1.292) Pub Date : 2015-04-29
    Aaron D Lammer,Melissa E Cook,Jonathan L Sessler

    Gold(III) compounds continue to be explored for their potential utility as anticancer agents. A recognized limitation is the reactivity of gold(III), which is typically reduced to the more labile gold(I) state under physiological conditions. The use of porphyrins can overcome this problem. However, to date the stabilization provided by the use a strongly chelating porphyrin is offset by the poor solubility of the resulting complex in aqueous media. In this work, we describe the synthesis and in vitro anti-cancer activity of a gold(III)porphyrin complex with relatively good aqueous solubility. As judged from standard antiproliferation assays, this complex displays an IC50 of 9 μM for the A2780 human ovarian cancer cell line. This is a higher level of potency than displayed by two related control systems.

    更新日期:2019-11-01
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