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The impact of double bonds in fatty acyl tails of unsaturated lipids on the photodynamic inactivation of ion channels formed by the pentadecapeptide gramicidin A in a planar bilayer lipid membrane was studied. The presence of unsaturated acyl tails protected gramicidin A against photodynamic inactivation, with efficacy depending on the depth of a photosensitizer in the membrane. The protective effect of double bonds was maximal with membrane-embedded chlorin e-monoethylenediamine monoamide dimethyl ester, and minimal - in the case of water-soluble tri-sulfonated aluminum phthalocyanine (AlPcS) known to reside at the membrane surface. By contrast, the protective effect of the hydrophilic singlet oxygen scavenger ascorbate was maximal for AlPcS and minimal for amide of chlorin e dimethyl ester. The depth of photosensitizer position in the lipid bilayer was estimated from the quenching of photosensitizer fluorescence by iodide. Thus, the protective effect of a singlet oxygen scavenger against photodynamic inactivation of the membrane-inserted peptide is enhanced upon location of the photosensitizer and scavenger molecules in close vicinity to each other. [ABSTRACT FROM AUTHOR]

C2-Acylated indoles have been synthesized in good yields through palladium-catalyzed dehydrogenative coupling of N-pyrimidine- protected indoles using aldehydes as the source of acyl reagent and tert-butyl hydroperoxide as the oxidant. 2-Indole carboxylates can be synthesized when aldehydes are substituted by ethyl glyoxylate. [ABSTRACT FROM AUTHOR]

Using a methanol assisted thermal decomposition approach, sphere shaped NaYGdF:Yb/Er upconversion nanoparticles (UCNPs) were successfully synthesized. The chemical, spectroscopic and fluorescence properties of the UCNPs were fully characterized. Characteristic upconversion fluorescence emissions were produced by the NPs in the green, red and NIR regions and the NPs were also shown to possess paramagnetic properties. The influence of the UCNPs on the spectroscopic and fluorescence properties of an aluminium octacarboxy phthalocyanine AlOCPc was investigated. Covalent conjugation to an AlOCPc resulted in a large blue shift of the phthalocyanine's Q band, which was accompanied by a decrease in the Pc's fluorescence lifetime in DMSO. By combining the phthalocyanine and upconversion nanoparticle, we present a system capable of multimodal imaging, using both the upconversion nanoparticle's and phthalocyanine's emission, and magnetic resonance imaging (as a result of doping the upconversion nanoparticles with Gd ions). [ABSTRACT FROM AUTHOR]

Gas-liquid interfaces are reaching a particular interest in biomedicine. Microbubbles, ultrasound contrast agents of clinical routine, gained increasing attention as theranostic platforms due to the preserved acoustic response, drug conjugation capabilities, and applicability in biological barrier opening. A combination of microbubbles and photodynamic therapy agents can enhance the photodynamic effect, yet the evaluation of agent conjugation on microbubble stabilization and photodynamic effect is needed. Hence, two commercially available phthalocyanine photosensitizers — Holosens® (ZnPc) and Photosens® (AlPc) — were coupled with bovine serum albumin before microbubble synthesis. We demonstrated an albumin: phthalocyanine ratio of 1:1 and covalent attachment for ZnPc, a ratio of 1:3 with electrostatic binding for AlPc. Submicron-sized microbubbles (air- and SF 6 - filled) had a diameter of 0.8 µm. Albumin-phthalocyanine conjugates increased the microbubble concentration and shelf-life stability compared to plain ones. We hypothesized that phthalocyanine fluorescence lifetime values decreased after conjugation with microbubbles due to narrow distance between conjugates in the shell. Agents based on AlPc demonstrated higher photodynamic activity than agents based on ZnPc, and microbubbles preserved acoustic stability in human blood plasma. The biodistribution of AlPc-conjugated microbubbles was evaluated. We conclude that our microbubble platforms demonstrate greater photodynamic activity and prolonged stability for further applications in photodynamic therapy. [Display omitted] • Zinc and aluminum phthalocyanines were conjugated to bovine serum albumin. • Albumin-phthalocyanine conjugates increased concentration of submicron microbubbles. • Phthalocyanine fluorescence lifetime values decreased after microbubble conjugation. • Phthalocyanine-conjugated microbubble enhanced photodynamic activity comparing dye. • Aluminum phthalocyanine conjugated agents biodistribution was demonstrated in vivo. [ABSTRACT FROM AUTHOR]

Semiconductor nanocrystals (CdSe/ZnS quantum dots, QDs) were used as inorganic focusing antenna, allowing for the enhancement of fluorescence and photosensitizing activity of polycationic aluminum phthalocyanines (PCs). It was found that QDs form stable complexes with PCs in aqueous solutions due to electrostatic interactions. In such hybrid complexes, we observed highly efficient nonradiative energy transfer from QD to PC, leading to a sharp increase in the effective absorption cross section of PC in the absorption bands of the CdSe/ZnS quantum dots. When hybrid complexes are excited within these bands, the intensity of PC fluorescence and the rate of photosensitized singlet oxygen generation increases significantly (up to 500 and 350%, correspondingly) compared to free PC at the same concentration. The observed effect is of interest for modeling primary stages of photosynthesis and increasing photosensitizing activity of dyes used in photodynamic therapy. [ABSTRACT FROM AUTHOR]

An aluminum phthalocyanine complex covalently bonded to the silica surface of mesoporous MCM-4I molecular sieve was successfully applied as a catalyst fo r hydrophosphorylation of various imines. The immobilized catalyst exhibited a high catalytic activity, stability, and reusability under various conditions for the synthesis of the wide range of a-aminophosphonates based on amino acid ket imines, azines, hydrazones, semicarbazones, and oximes. The immobilization of the phthalocyanine to the walls of MCM-41 was performed by the reaction of phthalocyanine tetracarboxylic acid chloroanhydride with MCM-41 premodified by 3-(aminopropyl)-triethoxysilane (APTES).The catalytic performance of the novel AlPc-MCM-4! for hydrophosphorylation was compared with that of the same unsupported complexes. [ABSTRACT FROM AUTHOR]

A procedure that converts a series of structurally diverse, readily available indole derivatives to their corresponding indolequinones is described. The three-step route commences with an iridium catalyzed C--H borylation to give a 7-borylindole that upon oxidation-hydrolysis affords the 7-hydroxyindole. Subsequent oxidation provides the indolequinone. [ABSTRACT FROM AUTHOR]

By means of Sonogashira reaction, a series of 2-alkynyl- and 2,7-dialkynyl derivatives of 1,8-bis(dimethylamino)naphthalene ("proton sponge") have been obtained from the corresponding iodides. It was disclosed that changing the reaction conditions and isolation protocol or conducting the model experiments with the authentic acetylenes results in several types of palladium- and copper-assisted heterocyclizations with the participation of the C≡C bond and 1-NMe2 group. These include: (i) a cyclization into isomeric 1H-benzo[g]indoles with [1,3] migration of the N-methyl group into the newly formed pyrrole ring; (ii) a similar cyclization with a loss of the methyl group; (iii) a tandem process of cyclization into benzo[g]indoles and their subsequent 3,3'-dimerization; and (iv) a copper-catalyzed oxidative transformation into 3-aroylbenzo[g]indoles. In most cases, the reactions occur in parallel, but under certain conditions, one of the above products becomes predominant or even the only one. Remarkably, in Pd-catalyzed cyclizations i-iii, the acetylenic bond behaves as an electrophile being attacked at the β-position by the amine nitrogen atom. In contrast, in transformation iv, the C≡C bond attacks by its Cα atom on the aminomethyl radical functionality N(Me)-CH2 presumably arising at copper oxidation/deprotonation of the 1-NMe2 group. Studying rearrangement i, some evidence for the porcelain catalysis was obtained. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (spheres, rods and bipyramids) were synthesized. The nanocrystals were characterized by UV–visible spectrometry, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The as prepared gold nanoparticles were then conjugated to a quaternized 2,(3)-tetra [2-(dimethylamino) ethanethio] substituted Al(OH) phthalocyanine (complex 1 ). The conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields and lifetimes. Conversely, an increase in the singlet oxygen quantum yields was observed for the conjugated complex 1 in the presence of AuNPs. [ABSTRACT FROM AUTHOR]

Abstract: Semiconducting molecular materials based on aluminum phthalocyanine chloride (AlPcCl) and bidentate amines have been successfully used to prepare thin films by using a thermal evaporation technique. The morphology of the deposited films was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Studies of the optical properties were carried out on films deposited onto quartz and (100) monocrystalline silicon wafers and films annealed after deposition. The absorption spectra recorded in the UV–vis region for the as-deposited and annealed samples showed two absorption bands, namely the Q- and B-bands. In addition, an energy doublet in the absorption spectra of the monoclinic form at 1.81 and 1.99eV was observed. A band-model theory was employed in order to determine the optical parameters. The fundamental energy gap (direct transitions) was determined to be within the 2.47–2.59 and 2.24–2.44eV ranges, respectively, for the as-deposited and annealed thin films. [Copyright &y& Elsevier]

An efficient formal synthesis of (±)-cycloclavine is achieved in seven steps and 27% overall yield from the known 2-(4-bromo-1-tosyl-1H-indol-3-yl)acetaldehyde. Key features include an iron(III)-catalyzed aza-Cope--Mannich cyclization and an intramolecular Heck reaction or a self-terminating 6-exo-trig aryl radical--alkene cyclization. [ABSTRACT FROM AUTHOR]

Abstract: A series of phosphonate analogues related to perindopril and ramipril were prepared and tested to estimate their ability to inhibit angiotensin converting enzyme. These new synthesized compounds were active ACE inhibitors with a promising activity. [Copyright &y& Elsevier]

As previous studies have shown, the photocatalytic reduction of Cr(vi) to Cr(iii) in the presence of 4-chlorophenol can be carried out efficiently under visible irradiation using TiO2 modified with hydroxoaluminum-tricarboxymonoamide phthalocyanine (AlTCPc) in spite of the high aggregation tendency of the dye. In the present work, photocurrent and absorption spectra of AlTCPc modified TiO2 films are studied together with absorption and fluorescence of the dye in solution as a function of the concentration of the dye to clarify (a) the role of aggregates and the nature of the species responsible for electron injection into the semiconductor and (b) the reasons why, as reported earlier, the photocatalytic activity is nearly independent of dye loading at constant TiO2 mass. Results are consistent with the presence of AlTCPc clusters with similar properties both on the TiO2 surface and in H2O–DMSO solution. The actual photoactive species is the monomeric dye electronically coupled to the semiconductor. Monomer concentration depends only slightly on AlTCPc analytical concentration, in a way similar to surfactant monomers in micellar equilibrium, thus explaining the independence of photocatalytic activity on dye concentration. [ABSTRACT FROM AUTHOR]

This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride (AlPcCl) thin films. To fabricate the sensors, 50-nm-thick electrodes with 50-μm gaps between them are deposited on glass substrates. AlPcCl thin films with thickness of 50–100 nm are deposited in the gap between electrodes by thermal evaporation. The resistance of the sensors decreases with increasing thickness and the annealing at 100 °C results in an increase in the initial resistance of sensors up to 24%. The sensing mechanism is based on the change in resistance with temperature. For temperature varying from 25 °C to 80 °C, the change in resistance is up to 60%. Simulation is carried out and results obtained coincide with experimental data with an error of ±1%. [ABSTRACT FROM AUTHOR]

Highlights: [•] AlPcCl as an anode buffer layer was introduced in OLED. [•] The performance of OLED with AlPcCl is superior to that of the device without AlPcCl. [•] The enhanced performance is explained by energy level and thermionic emission model. [•] The effect of the deposition rate of AlPcCl on the device performance was examined. [•] The optimal deposition rate of AlPcCl is 0.05nm/s. [ABSTRACT FROM AUTHOR]

In this paper, effects of post-deposition annealing on morphology and optical properties of electron beam evaporated Bromoaluminium phthalocyanine thin films have been investigated. Surface morphology of the films have been characterized by field emission scanning electron microscopy (FESEM). The FESEM micrographs have shown densely packed nanoparticles and nanorod-like structures for the films annealed at different temperatures. Conditions leading to β-phase have been identified by monitoring post-deposition annealing using optical absorption spectroscopy (UV-Vis). The optical absorption measurements on the as-deposited and annealed films shows that the absorption mechanism is due to direct transition. Also, it is found that the optical band gap decreases with increase in annealing temperature. [ABSTRACT FROM AUTHOR]

Abstract: Targeting cancer vasculature is an emerging field in cancer treatment. Photochemical internalization (PCI) is a drug delivery technology based on photochemical lysis of drug-bearing endocytic vesicles originally designed to target cancer cells. Recent investigations have revealed a lower PCI efficacy in vascular endothelial cells (HUVECs) in vitro than in HT1080 fibrosarcoma cells. This manuscript aims to explore the limiting factor for the PCI effect in HUVECs. Cellular uptake of the photosensitizers AlPcS2a and TPPS2a, and a model compound for macromolecular drugs taken up by fluid phase endocytosis, Alexa488-dextran, was explored by flow cytometry. The uptake of AlPcS2a and TPPS2a was 3.8-fold and 37-fold higher in HUVECs than in HT1080 cells, respectively, while the Alexa488-dextran uptake was 50% lower. AlPcS2a (but not TPPS2a) was shown to reduce Alexa488-dextran uptake in a concentration-dependent manner, resulting in 66% and 33% attenuation of Alexa488-dextran uptake at 20μg/ml AlPcS2a in HUVECs and HT1080 cells respectively. Studies of intracellular localization of Alexa488-dextran and AlPcS2a by confocal microscopy in HUVECs uncovered a concentration-dependent AlPcS2a-induced inhibition of Alexa488-dextran trafficking into AlPcS2a-stained and acidic vesicles. The localization of Alexa488-dextran to AlPcS2a-localizing compartments was reduced by 40% when the AlPcS2a concentration was increased from 5 to 20μg/ml. The treatment dose of AlPcS2a was found to influence on the efficacy of PCI of saporin, but to a lesser extent than expected considering the data from cellular uptake and intracellular trafficking of Alexa488-dextran. The implications of these results for further development of vascular targeting-PCI are discussed. [Copyright &y& Elsevier]

Environment polarity can cause changesin absorbance or emissionmaxima, for a given fluorophore. This is termed solvatochromism. Inthis study semiempirical models of solvatochromic shifts are usedto predict their lipid bilayer location. Four reaction field modelsare analyzed and compared, to provide the most accurate predictionof fluorophore solvatochromic shifts using a modified version of theLippert equation. For curcumin, the reaction field of Block and Walkergave the strongest agreement between experimental and predicted values(r= 0.978, p< 0.0001). Foraluminum phthalocyanine disulfonic acid (AlPcS2), the reactionfield of Wertheim, based on statistical mechanics, gave the best agreement(r= 0.951, p= 0.001) only whendispersion forces and solute polarizability are considered. The resultsof these models are correlated to the Dimroth–Reichardt ET(30) solvent polarity scale used by Frimer and colleagues.Using the model predicted values, curcumin is estimated to be 1–1.2nm from the phospholipid–water interface, in the acyl chainregion of the lipid bilayer. AlPcS2is predicted to be0.7–0.9 nm from the interface, at the fatty acid carbonyl.This investigation provides semiempirical methods to efficiently linkfluorophore solvatochromic shifts to a location in the lipid bilayervia reaction field models. [ABSTRACT FROM AUTHOR]

The efficacy of transfersomes (flexible liposomes) as a novel technique for topical delivery of the hydrophilic tetra-anionic photodynamic sensitizer aluminum (III) phthalocyanine tetrasulfonate (AlPcS4) was investigated, on mammalian fibroblasts and on Balb/c mice dorsal skin. AlPcS4 was loaded in transfersomes composed of phosphatidylcholine/sodium deoxycholate (5:1, 10:1, and 15:1 w/ w, ratios), resulting in 110-, 160-, and 200-nm mean size vesicles with encapsulation efficiencies of 16, 25, and 30 %, respectively. In vitro studies on baby hamster kidney-21 fibroblasts revealed twofold enhancement of the photocytotoxicity of AlPcS4 loaded in transfersomes (Trans-AlPcS4), compared to free AlPcS4 dissolved in culture medium. The photocytotoxicity of Trans-AlPcS4 was less dependent on the incubation time with cells, compared to free AlPcS4. Topical application on the dorsal skin of Balb/c mice revealed that both free AlPcS4 and Trans-AlPcS4 exhibited evident photosensitization towards mice skin, but acquiring different regions of skin. [ABSTRACT FROM AUTHOR]

The efficiency of the sensitizing action of photocatalysts prepared from montmorillonite modified by a cationic surfactant and treated with aluminum and zinc phthalocyanines was studied. The rates and quantum yields of acceptor (9,10-diphenylanthracene) consumption upon irradiation with the visible light of poly(methyl methacrylate) films and dispersions in toluene containing the photocatalysts were determined. The quantum yields of singlet oxygen generation were estimated on the basis of these data. The influence of the medium and concentration of phthalocyanines on the spectral characteristics of the photocatalysts was considered. [ABSTRACT FROM AUTHOR]

Bis(indol)alkaloid ‐ Analoga wurden unter milden Reaktionsbedingungen in hohen Ausbeuten durch eine Gold ‐ katalysierte Cycloisomerisierung von 1,1 ‐ Bis(indolyl) ‐ 5 ‐ alkinen hergestellt (siehe Schema). Die enantioselektive Version dieser Reaktion ergab die entsprechenden Produkte in mäßigen bis sehr guten Ausbeuten (55 – 90 %), mit mäßigen bis guten ee ‐ Werten (48 – 96 %) und Regioselektivitäten von 3.5:1 bis 20:1. [ABSTRACT FROM AUTHOR]

Abstract: In this work we have developed nanocapsules containing chloroaluminum phthalocyanine (ClAlPc) and assessed their phototoxic action on WM1552C, WM278, and WM1617 human melanoma cell lines. The ClAlPc-loaded nanocapsules were prepared by the nanoprecipitation method and optimized by means of a 23 full factorial design. The ClAlPc nanocapsules were characterized by particle size and distribution, zeta potential, morphology, encapsulation efficiency, singlet oxygen production, stability, and phototoxic action on melanoma cells. Both the development and optimization studies revealed that stable colloidal formulations could be obtained by using 1.75% (w/v) soybean lecithin, 1.25% (w/v) Poloxamer 188, 2.5% (v/v) soybean oil, and 0.75% (w/v) poly(D,L-lactide-co-glycolide). The nanocapsules had a mean diameter of 230nm, homogeneous size distribution (polydispersity index<0.3), and negative zeta potential (about −30mV). Their morphology was spherical, with evident polymer membrane coating droplet. The encapsulation efficiency was 70%, as expected for hydrophobic drugs, and the nanoencapsulated ClAlPc was able to produce high singlet oxygen quantum yield. ClAlPc nanocapsules exhibited good physical stability over a 12-month period. WM1552C primary melanoma cells were more sensitive (p <0.05) to the phototoxic effect elicited by ClAlPc nanocapsules (0.3μgml−1) under light irradiation at 20mJcm−2. On the other hand, the cell survival percentage for all the melanoma cell lines treated with the highest light dose (150mJcm−2) was lower than 10%. In summary, ClAlPc nanoencapsulation could enable application of this hydrophobic photosensitizer in the treatment of malignant melanoma with the use of both low sensitizer drug concentration and light dose. [Copyright &y& Elsevier]

Phthalocyanine photosensitizers are effective in anticancer photodynamic therapy (PDT) but suffer from limited solubility, limited cellular uptake and limited selectivity for cancer cells. To improve these characteristics, we synthesized isopropylidene-protected and partially deprotected tetra β-glycosylated zinc (II) phthalocyanines and compared their uptake and accumulation kinetics, subcellular localization, in vitro photocytotoxicity and reactive oxygen species generation with those of disulfonated aluminum phthalocyanine. In MCF-7 cancer cells, one of the compounds, zinc phthalocyanine {4}, demonstrated 10-fold higher uptake, 5-fold greater PDT-induced cellular reactive oxygen species concentration and 2-fold greater phototoxicity than equimolar (9 μ m) disulfonated aluminum phthalocyanine. Thus, isopropylidene-protected β-glycosylation of phthalocyanines provides a simple method of improving the efficacy of PDT. [ABSTRACT FROM AUTHOR]

Abstract: The combination of chemotherapy and photodynamic therapy was investigated by the synthesis and characterisation of phthalocyanine conjugates with Pt complexes. The complexes synthesized are: hydroxoaluminum trikis(diaquaplatinum) octacarboxyphthalocyanine (OHAlOCPc(Pt)3) and hydroxoaluminum tetrakis(diaquaplatinum) octacarboxyphthalocyanine (OHAlOCPc(Pt)4). The platinated phthalocyanine complexes gave long triplet lifetimes of 577 and 526 μs for OHAlOCPc(Pt)3 and OHAlOCPc(Pt)4, respectively. The triplet quantum yields were found to be 0.45 for OHAlOCPc(Pt)3 and 0.57 OHAlOCPc(Pt)4 while the singlet oxygen quantum yields were found to be 0.38 and 0.48, respectively. [Copyright &y& Elsevier]

Abstract: In present paper, the fabrication and humidity sensing properties of aluminum phthalocyanine chloride (AlPcCl) thin film based sensors have been presented. AlPcCl thin films with nominal thickness of 50–100nm are deposited on glass substrates between pre-deposited 50nm thick aluminum electrodes. The gap between the electrodes is 50μm. It is observed that the sensing mechanism is based on the variation of resistance with change in humidity. For change in relative humidity (RH) from 20% to 92%, the change in resistance is 22.2×102 and 13.3×102 times respectively for the sensors having 50nm and 100nm thick AlPcCl films, while the 1h annealing of these samples at 100°C results in increase in average sensitivity up to 30% and 40% respectively. The consequence of measuring frequency and absorption–desorption behavior of the humidity sensor are also discussed in detail. It is also observed that annealing results in minimization of hysteresis and reduction of recovery time (τ rec) up to 63% and 70% in sensors with 50nm and 100nm thick organic film respectively, while the response (τ res) time is 10s for both the sensors. [Copyright &y& Elsevier]

Photodynamic therapy (PDT) has been the subject of several clinical studies. Evidence to date suggests that direct cell death may involve apoptosis. T24 cells (bladder cancer cells, ATCC-Nr. HTB-4) were subjected to PDT with aluminum phthalocyanine tetrasulfonate chloride (AlS4Pc-Cl) and red laser light at 670 nm. Morphological changes after PDT were visualized under confocal microscopy. Raman microspectroscopy is considered as one of the newly established methods used for the detection of cytochrome c as an apoptotic marker. Results showed that PDT treated T24 cells seem to undergo apoptosis after irradiation with 3 J cm−2. Cytochrome c could not be detected from cells incubated with AlS4Pc-Cl using Raman spectroscopy whereas AlS4Pc-Cl seems to interfere with the Raman spectrum of cytochrome c. [ABSTRACT FROM AUTHOR]

Leishmania were previously shown to undergo photolysis when their transgenic mutants were induced endogenously to accumulate cytoplasmic uroporphyrin or when loaded exogenously with aluminum phthalocyanine chloride. A combinational use of both is reported here, which renders Leishmania far more susceptible to photolysis. Fluorescence microscopy of cells loaded with the two photosensitizers localized them to different subcellular sites. Pre-exposure of Leishmania to both synergistically sensitized them for photolysis as extracellular promastigotes and intracellular amastigotes in infected macrophages in vitro when illuminated at specific wavelengths to excite the respective photosensitizers for production of reactive oxygen species. Both Leishmania stages lost their viability completely when doubly photosensitized optimally and illuminated at low intensity, the host cells being left unscathed. Inoculation of mice with photoinactivated Leishmania produced no lesions, which invariably developed in the control groups during a period of observations for 8 weeks. Pretreatment of Leishmania with both photosensitizers rendered these cells susceptible to clearance from the ear dermis by white light illumination. The results suggest that double photosensitization for synergistic activity enhances the efficacy and safety of photodynamic therapy in general and for Leishmania in particular. [ABSTRACT FROM AUTHOR]

Leishmania were previously shown to undergo photolysis when their transgenic mutants were induced endogenously to accumulate cytoplasmic uroporphyrin or when loaded exogenously with aluminum phthalocyanine chloride. A combinational use of both is reported here, which renders Leishmania far more susceptible to photolysis. Fluorescence microscopy of cells loaded with the two photosensitizers localized them to different subcellular sites. Pre-exposure of Leishmania to both synergistically sensitized them for photolysis as extracellular promastigotes and intracellular amastigotes in infected macrophages in vitro when illuminated at specific wavelengths to excite the respective photosensitizers for production of reactive oxygen species. Both Leishmania stages lost their viability completely when doubly photosensitized optimally and illuminated at low intensity, the host cells being left unscathed. Inoculation of mice with photoinactivated Leishmania produced no lesions, which invariably developed in the control groups during a period of observations for 8 weeks. Pretreatment of Leishmania with both photosensitizers rendered these cells susceptible to clearance from the ear dermis by white light illumination. The results suggest that double photosensitization for synergistic activity enhances the efficacy and safety of photodynamic therapy in general and for Leishmania in particular. [ABSTRACT FROM AUTHOR]

Abstract: A photosensitive capsule consisting of aluminum phthalocyanine tetrasulfonate chloride (AlPcS4Cl) and polyelectrolytes was fabricated by assembling of oppositely charged poly(allylamine hydrochloride) (PAH) and AlPcS4Cl onto the preformed capsules composed of poly(styrene sulfonate) (PSS) and PAH. UV–visible absorption spectra, EDX spectrum and AFM images confirmed the successful deposition of AlPcS4Cl onto as-prepared hollow capsules. The assembled photosensitive capsules were found to remain intact and spherical morphology in the deposition process. The generation of cytotoxic singlet oxygen (1O2) of photosensitive capsules under visible light irradiation (670 ± 10 nm) was evidenced by ESR measurements and the oxidative reaction between the generated 1O2 and a detector. In vitro cellular experiments showed that photosensitive capsules exhibited a good biocompatibility in the dark and a higher killing efficacy against MCF-7 cancer cells under visible light irradiation as compared with free AlPcS4Cl, which implies that the assembled photosensitive capsules might be potentially applicable in photodynamic therapy. [Copyright &y& Elsevier]

Abstract: Nitric oxide (NO) is an extremely toxic compound formed during combustion, predominantly at high temperatures, and it is among the most important atmospheric pollutants. However, this compound has interesting biological activities, since it can control important biological processes in living organisms. With the aim of developing new materials that can be used as selective chemical sensors or as biomedical NO delivery agents we carried out a quantum mechanical study of the interaction of NO with aluminum phthalocyanine (AlPc) at B3LYP/6-31G* level. The calculation results show clearly that the complexation of NO with AlPc depends on the latter''s oxidation state. NO is more strongly bonded to AlPc in the reduced state (−33.77kcal/mol) than in the oxidized state (−4.96kcal/mol). By applying the Fukui function and analysis of the Frontier molecular orbital, it was possible to explain the situation within which nitric oxide interacts with AlPc. [Copyright &y& Elsevier]

Abstract: Glycerol is a byproduct produced in great quantity by biodiesel industries in transesterification reactions. Finding new applications for glycerol is a current concern of many research groups around the world. This work focuses on a theoretical investigation, at the B3LYP/6-31G* level of theory, into the possibility of using aluminum phthalocyanine (AlPc) and magnesium phthalocyanine (MgPc) in the modelling of catalysts to convert glycerol into alcohol, which has wider industrial applicability. According to our calculations there are strong interactions between the O-terminus of glycerol and the central metal atom of AlPc and MgPc. By applying the Fukui function, HSAB theory and analysis of the frontier molecular orbital, it was possible to explain the way in which glycerol interacts with AlPc and MgPc. As a result of these interactions, there is a considerable change in both electronic and geometric parameters of glycerol, which can be used in designing new strategies to convert glycerol into alcohol. [Copyright &y& Elsevier]

An efficient method has been developed for the synthesis of new aza-substituted indoles. The methodology involves a two-step synthesis. The first step involves the Michael addition of indoline with various Michael acceptors. The other includes the oxidation of the indoline ring in the Michael adducts to an indole [ABSTRACT FROM AUTHOR]

Abstract: Sodium salts of sulfonated hydroxyaluminum phthalocyanines [Al(OH)Pc(SO3Na) i ] containing various numbers of sulfonate groups (i =1–4), were studied by spectroscopic techniques. The lifetimes of the singlet states were found to range between 5 and 8ns, experimentally determined fluorescence quantum yields ranging between 0.45 and 0.74. Both parameters depend on the number of sulfonate groups, the singlet lifetime depending additionally on concentration. The triplet lifetime was indirectly estimated for aqueous solutions of Al(OH)Pc(SO3Na)3 to amount to ca. 0.6μs. The decay time of singlet oxygen in the same system was also found to be close to 0.6μs. The molecules were found to dimerize in acidic and neutral solutions, the second order rate constants of the dimerization being of the order of 10mol−1 dm3 s−1, and the equilibrium constants of the order of 104. The experiments were supplemented with quantum chemical calculations allowing us to assign electronic transitions in monomers and dimers. [Copyright &y& Elsevier]

The intramolecular Friedel-Crafts reaction of indole-2-carboxylic acid β-oxoamides catalyzed by trifluoroacetic acid or InCl3, is a convenient method for the synthesis of 3-aryl-, 4-aryl-, and 4-alkyl-β-carbolin-1-ones. [ABSTRACT FROM AUTHOR]

Abstract: The effect of magnetic fluid (MF) on the photophysical and photochemical parameters of zinc and aluminum phthalocyanines are reported. The complexes studied are zinc (II) phthalocyanine (ZnPc), chloroaluminum phthalocyanine ((Cl)AlPc) and tetrasulfonated aluminum phthalocyanine ((Cl)AlTSPc). The parameters are studied in dimethylsulfoxide (DMSO) for all complexes and also in aqueous media for (Cl)AlTSPc. The triplet lifetimes for (Cl)AlTSPc and ZnPc decreased while the triplet quantum yields increased in the presence of MF. For (Cl)AlPc, the triplet lifetimes were found to increase with decrease in laser energy while there was photoreduction to the Pc−3 species. Singlet oxygen and photodegradation quantum yields decreased in the presence of MF, suggesting quenching. [Copyright &y& Elsevier]

Abstract: One-dimensional aluminum phthalocyanine nanomaterials were prepared by electrochemical deposition method and characterized by means of AFM, SEM, UV–vis, and XRD measurements. The effects of solution concentration and deposition voltage on aluminum phthalocyanine nanomaterials preparation were studied. The resulting one-dimensional aluminum phthalocynine nanomaterials showed enhanced conductivity compared to that of bulk aluminum phthalocyanine. Furthermore, the growth mechanism of depositing one-dimensional aluminum phthalocyanine nanomaterials by electrochemical deposition method was put forward. [Copyright &y& Elsevier]

Abstract: A lithium phthalocyanine radical and the analogous aluminum phthalocyanine radical were synthesized as part of an investigation of isostructural dopants. An improved synthesis of the free base of octa(pentoxy)phthalocyanine (H2Pc*) involves the reduction of 1,2-dicyano-4,5-dipentoxybenzene with hydroquinone. Deprotonation with lithium bis(trimethylsilyl)amide leads to the dilithium derivative Li2Pc* and subsequent oxidation with ferrocenium yields the radical LiPc*. Treatment of H2Pc* with Et2AlCl gives ClAlPc* and reduction with sodium amalgam yields AlPc*, the first reported aluminum phthalocyanine radical. In the solid state LiPc* and AlPc* are electrical conductors with pressed-pellet conductivities of 8×10−11 Ω−1 cm−1 and 5×10−7 Ω−1 cm−1, respectively. [Copyright &y& Elsevier]

A new third-order nonlinear optical polyimide with aluminum phthalocyanine unit as a side-chain (APSPI) has been developed. The poly(hydroxyimide) (PHI) was prepared by the ring-opening polyaddition of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride with 4,4′-diamino-4″-hydroxytriphenylmethane, followed by thermal imidization. The resulting PHI had number- and weight-average molecular weights (Mn, Mw) of 34,000 and 64,000, respectively. The introduction of aluminum phthalocyanine unit (AlPc) to PHI was carried out by the reaction of PHI with chloroaluminum phthalocyanine in the presence of silver triflate. The third-order nonlinear susceptibility χ(3) of APSPI film with approximately 60 mol% content of AlPc at 1064 nm wavelength was 5.3×10−9 esu. This was measured using the closed Z-scan technique. [Copyright &y& Elsevier]

Photodynamic therapy of cancer is a promising treatment based on the tumor-specific accumulation of photosensitizers followed by irradiation with visible light which induces tumor cell death. The effect of different preincubation times on the photosensitization efficiency of the phthalocyanines AlPc and AlPcS4 was investigated in lymphoblastoid CCRF-CEM cells under conditions that allow maximal uptake of the sensitizers. First, the time course for the uptake of AlPcS4 and AlPc by CCRF-CEM cells and by the pheochromocytoma PC12 cells was compared. The uptake of AlPcS4 by CCRF-CEM cells was not significantly different after 6 h or 24 h incubation, but the photosensitization efficiency of the phthalocyanine was much higher when a 24 h preincubation period was used, with a fluence rate of 5 mW/cm2. However, for a fluence rate of 10 mW/cm2, the photosensitization efficiency of AlPcS4 was almost completely independent of the preincubation time (6 h vs. 24 h) with the phthalocyanine. When the cells were preincubated with 1 μmol/L AlPc for 10 min or 6 h, which allows the same accumulation of sensitizer by the cells, no significant effect of the incubation time on the photodynamic inactivation of CCRF-CEM cells was observed, with fluence rates of 5 mW/cm2 or 10 mW/cm2, for different light doses. Confocal fluorescence microscopy studies did not reveal differences in the localization of the phthalocyanines after maximal uptake was reached. The results show that the preincubation time with AlPcS4, after the maximal uptake is reached, affects cell growth to an extent depending on the fluence rate used, and this effect was not due to a major redistribution of the sensitizer during incubation. However, this was not observed when AlPc was used. [ABSTRACT FROM AUTHOR]

[Display omitted] Tetra- tert -butylphthalocyanine aluminum (III) chloride was studied by voltammetric and potential-resolved spectroelectrochemical methods in a non-coordinating solvent o -dichlorobenzene. Five redox transitions were found including two oxidation waves at 0.18 and 0.90 V and three reduction waves at −1.28, −1.65, and −2.63 V vs. Fc+/Fc. Electrochemical reversibility of the first oxidation and reduction processes was assessed by using the diagnostic criteria of cyclic voltammetry. First comprehensive spectroelectrochemical characterization of oxidation of the aluminum phthalocyanine is reported. Moreover, potential-resolved spectroelectrochemical titration revealed strong influence of aggregation on the UV–vis spectra and the half-wave potentials of the first oxidation transition and disclosed the presence of the partially oxidized complex in the initial solution, which noticeably affected the spectrum of the neutral form. [ABSTRACT FROM AUTHOR]

A gold-catalyzed formal [4+2] cycloaddition of vinyl indoles and N-allenamides leading to tetrahydrocarbazoles is described. Moreover, new multicomponent reactions of vinyl indoles with two allene molecules are reported. [ABSTRACT FROM AUTHOR]

Oncological photodynamic therapy (PDT) relies on photosensitizers (PSs) to photo-oxidatively destroy tumor cells. Currently approved PSs yield satisfactory results in superficial and easy-to-access tumors but are less suited for solid cancers in internal organs such as the biliary system and the pancreas. For these malignancies, second-generation PSs such as metallated phthalocyanines are more appropriate. Presently it is not known which of the commonly employed metallated phtahlocyanines, namely aluminum phthalocyanine (AlPC) and zinc phthalocyanine (ZnPC) as well as their tetrasulfonated derivatives AlPCS4 and ZnPCS4, is most cytotoxic to tumor cells. This study therefore employed an attritional approach to ascertain the best metallated phthalocyanine for oncological PDT in a head-to-head comparative analysis and standardized experimental design. ZnPC and AlPC were encapsulated in PEGylated liposomes. Analyses were performed in cultured A431 cells as a template for tumor cells with a dysfunctional P53 tumor suppressor gene and EGFR overexpression. First, dark toxicity was assessed as a function of PS concentration using the WST-1 and sulforhodamine B assay. Second, time-dependent uptake and intracellular distribution were determined by flow cytometry and confocal microscopy, respectively, using the intrinsic fluorescence of the PSs. Third, the LC 50 values were established for each PS at 671 nm and a radiant exposure of 15 J/cm2 following 1-h PS exposure. Finally, the mode of cell death as a function of post-PDT time and cell cycle arrest at 24 h after PDT were analyzed. In the absence of illumination, AlPC and ZnPC were not toxic to cells up to a 1.5-μM PS concentration and exposure for up to 72 h. Dark toxicity was noted for AlPCS4 at 5 μM and ZnPCS4 at 2.5 μM. Uptake of all PSs was observed as early as 1 min after PS addition to cells and increased in amplitude during a 2-h incubation period. After 60 min, the entire non-nuclear space of the cell was photosensitized, with PS accumulation in multiple subcellular structures, especially in case of AlPC and AlPCS4. PDT of cells photosensitized with ZnPC, AlPC, and AlPCS4 yielded LC 50 values of 0.13 μM, 0.04 μM, and 0.81 μM, respectively, 24 h post-PDT (based on sulforhodamine B assay). ZnPCS4 did not induce notable phototoxicity, which was echoed in the mode of cell death and cell cycle arrest data. At 4 h post-PDT, the mode of cell death comprised mainly apoptosis for ZnPC and AlPC, the extent of which was gradually exacerbated in AlPC-photosensitized cells during 8 h. ZnPC-treated cells seemed to recover at 8 h post-PDT compared to 4 h post-PDT, which had been observed before in another cell line. AlPCS4 induced considerable necrosis in addition to apoptosis, whereby most of the cell death had already manifested at 2 h after PDT. During the course of 8 h, necrotic cell death transitioned into mainly late apoptotic cell death. Cell death signaling coincided with a reduction in cells in the G 0 /G 1 phase (ZnPC, AlPC, AlPCS4) and cell cycle arrest in the S-phase (ZnPC, AlPC, AlPCS4) and G 2 phase (ZnPC and AlPC). Cell cycle arrest was most profound in cells that had been photosensitized with AlPC and subjected to PDT. Liposomal AlPC is the most potent PS for oncological PDT, whereas ZnPCS4 was photodynamically inert in A431 cells. AlPC did not induce dark toxicity at PS concentrations of up to 1.5 μM, i.e. , > 37 times the LC 50 value, which is favorable in terms of clinical phototoxicity issues. AlPC photosensitized multiple intracellular loci, which was associated with extensive, irreversible cell death signaling that is expected to benefit treatment efficacy and possibly immunological long-term tumor control, granted that sufficient AlPC will reach the tumor in vivo. Given the differential pharmacokinetics, intracellular distribution, and cell death dynamics, liposomal AlPC may be combined with AlPCS4 in a PS cocktail to further improve PDT efficacy. Unlabelled Image • Zinc phthalocyanine (ZnPC) and aluminum phthalocyanine (AlPC) are lipophilic photosensitizers. • ZnPC and AlPC tetrasulfonate (S4) are hydrophilic derivatives. • Which of these is most optimal to treat cancer cells by photodynamic therapy?. • A head-to-head comparative analysis was performed; liposomal AlPC performed best. • Liposomal AlPC can be combined with AlPCS4 for multi-locus photosensitization. [ABSTRACT FROM AUTHOR]