Water-soluble Zinc Research Articles

Synthesis, aggregation and spectroscopic studies of novel water soluble metal free, zinc, copper and magnesium phthalocyanines and investigation of their anti-bacterial properties

In this study, novel phthalonitrile derivative (3) was synthesized by the reaction between 4-nitrophthalonitrile (2) and a triazole derivative (1) containing pyridine moiety. Crystal structure of compound (3) was characterized by X-ray diffraction. New metal free and metallo-phthalocyanine complexes (Zn, Cu, and Mg) were synthesized using the phthalonitrile derivative (3). Cationic derivatives of these phthalocyanines (5, 7, 9, and 11) were prepared from the non-ionic phthalocyanines (4, 6, 8, and 10). All proposed structures were supported by instrumental methods. The aggregation behaviors of the phthalocyanines (4–11) were investigated in different solvents such as dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), chloroform and water. Water soluble cationic Pcs (5, 7, 9, and 11) aggregated in water and sodium dodecyl sulfate was used to prevent the aggregation. The second derivatives of the UV–Vis spectra of aggregated Pcs were used for analyzing the Q and B bands of aggregated species. Thermal behaviors of the phthalocyanines were also studied. In addition, anti-bacterial properties of the phthalocyanines were investigated. We used four gram negative and two gram positive bacteria to determine antibacterial activity of these compounds. Compound 7 has the best activity against the all bacteria with 125μg/mL of MIC value. Compounds 4, 6, and 10 have the similar effect on the bacteria with 250μg/mL of MIC value.

The contribution of zinc ions to the antimicrobial activity of zinc oxide

Zinc ions (Zn2+) exhibit antimicrobial activity against various bacterial and fungal strains. The partial dissolution of zinc oxide (ZnO) particles releases Zn2+ ions in aqueous suspension that contributes to the antimicrobial activity of ZnO. In addition to the activity of the soluble zinc species that is common with water-soluble zinc salts, ZnO combines two additional mechanisms of antimicrobial activity that supplement its activity as preservative in topical formulations: generation of reactive oxygen species and by direct contact to the cells walls. The present study aims at the evaluation of the contribution of the soluble zinc species to the antimicrobial activity of ZnO on microbial cultures in broth medium and the investigation of the dissolution of zinc from ZnO suspensions. The antimicrobial activities against the five microorganisms of the Challenge Tests were measured for suspensions of three ZnO grades in broth, and for the isolated liquid phase of the suspensions containing soluble zinc species. The Zn2+ released in the broth brought about a significant contribution to the overall antimicrobial activity of ZnO. The complexation of Zn2+ ions by the components of the broth increased the solubility of the zinc in the liquid medium. The respective activities of the soluble zinc species and ZnO particles showed specificity with respect to the microbial strains. Dissolution was faster for high concentrations of ZnO and for ZnO powders of larger specific area. Such conditions led to a better antimicrobial efficacy of ZnO powders. ZnO appears an advantageous alternative to soluble zinc salts such as zinc gluconate.

Synthesis, Characterization and Antibacterial Activity of Chlorophyllin Functionalized Graphene Oxide Nanostructures

ABSTRACTTo enhance the antimicrobial effect of graphene oxide against Escherichia coli, water soluble chlorophyllinand zinc metal ions were used to prepare two types of functionalized GO nanomaterials, namely, grapheneoxide-chlorophyllin and graphene oxide-chlorophyllin-Zn. Functionalized graphene oxide were characterizedusing Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, ultra violet-visible spec-troscopy, and field emission scanning electron microscopy. Under similar concentration and incubation condi-tions, graphene oxide-chlorophyllin-Zn dispersion had the highest antibacterial activity, followed by grapheneoxide-chlorophyllin and graphene oxide. Changes in the bacterial cell membrane were also investigated by fieldemission scanning electron microscopy. The incubation of bacteria with functionalized graphene oxide nanoma-terials caused the loss of cellular integrity and consequently, cell death. The results suggested that the surfacechemistry and metal toxicity played a major role in making graphene oxide-chlorophyllin-Zn a strong antibacte-rial agent. Antibacterial mechanisms of the functionalized graphene oxide nanomaterials are proposed.KEYWORDS:

Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide1–3

The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov> as NCT01576627.

Photocatalytic hydrogen production from a noble metal free system based on a water soluble porphyrin derivative and a cobaloxime catalyst

A combination of noble-metal free components, a water soluble porphyrin photosensitizer zinc meso-tetrakis(1-methylpyridinium-4-yl)porphyrin chloride [ZnTMPyP(4+)]Cl4 (1) with cobaloxime complex [Co(III)(dmgH)2(py)Cl] (2) as a catalyst, creates an efficient system for photochemical hydrogen production acting under visible light with 280 TONs. This is the first example of a water soluble porphyrin acting as a photosensitizer for cobaloxime catalysed H2 production.

Spray Pyrolyzed ZnSnO3 Nanostructured Thin Films for Hydrogen Sensing

Nanostructured ZnSnO3 thin films were prepared onto preheated glass substrate by a spray pyrolysis technique using water soluble Zinc chloride and Stannic chloride as precursors. The crystallinity of the prepared samples was analyzed by X-ray diffraction spectroscopy. The X-ray diffractogram of as prepared thin film clearly indicated the stichiometric and pervoskite nanostructured nature of ZnSnO3. The TEM image shows few nanorods along with fine particles of pervoskite ZnSnO3. The band gap energy of thin film sample was observed to be 4.13eV. The band gap energy was found to be enhanced as compare to the reported value. The sample showed selective response to H2 gas among the various gases such as LPG, hydrogen, ethanol, chlorine, carbon dioxide and ammonia. The dynamic response of ZnSnO3 pervoskite thin film sample is presented. The pervoskite oxides were used as potential gas sensing material for their stability in thermal and chemical atmospheres.

New Hybrid Materials Based on the Water Soluble Zinc Phthalocyanines and V2O5·nH2O

New Hybrid Materials Based on the Water Soluble Zinc Phthalocyanines and V2O5·nH2O

Photophysical properties of a new water soluble tetra thiamine substituted zinc phthalocyanine conjugated to gold nanorods of different aspect ratios

A water soluble zinc phthalocyanine substituted with thiamine is reported in this work. The aggregation of this compound in aqueous solutions causes quenching of the fluorescence quantum yields. Gold nanospheres and nanorods were linked to the phthalocyanine. X-ray photoelectron spectroscopy showed that both the amine and the sulphur groups on the thiamine substituent of the zinc phthalocyanine were involved in the linking to gold nanoparticles. The Pc showed an increase in the fluorescence quantum yields in the presence of the nanoparticles. The singlet oxygen quantum yield increased when the Pc was conjugated to the nanoparticles and even higher for larger aspect ratio gold nanorods.

New water soluble cationic zinc phthalocyanines as potential for photodynamic therapy of cancer

The novel phthalonitrile derivatives (2 and 3) bearing 2-[3-(dimethylamino)phenoxy]ethanol substituents on the 3 and 4 positions have been synthesized. The novel peripherally and non-peripherally tetra-{2-[3-(dimethylamino)phenoxy]} substituted zinc phthalocyanines (2a and 3a) were also synthesized by cyclotetramerization of phthalonitrile derivatives (2 and 3). The obtained new zinc phthalocyanines (2a and 3a) were converted into water-soluble quaternized products (2b and 3b). The new compounds have been characterized by combination of spectroscopic data including UV–Vis, IR, 1H NMR, 13C NMR, MS spectroscopic data and elemental analysis as well. The photophysical and photochemical properties of newly synthesized zinc phthalocyanines were investigated in DMSO for non-ionic and in both DMSO and phosphate buffer solution (PBS) for ionic compounds. The obtained ionic complexes (2b, 3b) show excellent solubility in both organic and aqueous solutions which is very useful for the treatment of cancer by photodynamic therapy (PDT).

Synthesis of water-soluble cobalt and zinc phthalocyanines with cationic substituents

Hexadecasubstituted CoPc and ZnPc containing different number of N-methylpyridiniumoxy groups and chlorine atoms were synthesized. It was shown that increasing number of cationic groups leads both to increased solubility of complexes in dipolar aprotic organic solvents and in water, and to increased contribution of monomeric form in aggregation equilibrium in water up full disaggregation.

Synthesis of a novel water-soluble zinc phthalocyanine and its CT DNA-damaging studies

A novel 3-(4-methoxybenzylamino) propanoic acid substituted water-soluble zinc phthalocyanine (CNPcZn) was synthesized. The interaction between CNPcZn with calf thymus DNA (CT DNA) was studied using spectroscopic methods. The studies indicated that CNPcZn has strong affinity to CT DNA, and furthermore, CNZnPc showed excellent photodamaging activity to CT DNA. Above results indicated that such CNPcZn has great potential to be used as an effective photosensitizer in the field of photodynamic therapy.

Spectroscopic properties of zinc porphyrin-functionalized poly(4-vinylporphine) derivatives in the solutions, solid powders and doped PMMA films

Polymeric zinc porphyrin derivatives were prepared through an axial coordination reaction of a charged water-soluble zinc porphyrin (ZnTMPyP) with poly(4-vinylpyridine) (PVP). Molar ratios of the porphyrin substituents relative to the pyridine monomers of PVP in the as-prepared polymeric porphyrins were about 1:30, 1:250 and 1:1000. Moreover, ZnTMPyP and ZnTMPyP–PVP doped poly(methylmethacrylate) (PMMA) composites and their optically transparent thin films were prepared. Compositions and spectroscopic properties of these porphyrins were investigated by using UV–vis absorption, infrared, X-ray electron and fluorescence spectroscopy as well as time-resolved fluorescence spectroscopy. The Soret absorption band of the porphyrins appeared at 438nm in the methanol solutions, which red shifted to 456nm in the doped PMMA films. Although the ZnTMPyP solid powders gave off very weak luminescent emission, its functionalized polymers and doped PMMA thin films gave off strong emissions at around 640nm. It was revealed that emission lifetime of the zinc porphyrin was about 0.2ns in the solid powders and 0.6–1.5ns in the polymeric porphyrins and the doped composite thin films.

Amino-functionalized water-soluble zinc phthalocyanines: Synthesis, photophysical, photochemical and protein binding properties

Abstract Tetra-peripherally substituted symmetrical and low symmetrical Zn (II) phthalocyanines containing 2-[2-(2-ethoxyethoxy)ethoxy]-1-[2-((2-ethoxyethoxy)-ethoxy)ethoxymethyl] ethyloxy and [2-(tert-butoxycarbonyl)amino]ethoxy groups, as well as their deprotected amino-functionalized derivatives were synthesized for the first time. These novel zinc phthalocyanines were characterized by elemental analysis and spectroscopic methods including FT-IR, 1 H and 13 C NMR, MALDI-TOF, UV–vis. Their photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen and photodegradation quantum yields) properties were investigated in DMSO, in water and in water + triton X-100 solutions for comparison of solvents and aggregation effects. Effects of symmetries of the phthalocyanine molecules on these properties were also revealed. The fluorescence quenching of these Zn (II) phthalocyanines upon addition of 1,4-benzoquinone were examined in DMSO. Binding study of these phthalocyanine photosensitizers to bovine serum albumin one of the blood carrier proteins, was also examined in this study.

A mitochondria-targeted zinc(ii) phthalocyanine for photodynamic therapy

A water-soluble zinc(II) phthalocyanine (ZnPc1) substituted with 1-(3-methyl) imidazoliumylethyloxy on the periphery was synthesized, and its subcellular localization and photodynamic activities were studied. ZnPc1 exhibited an almost exclusive mitochondrial-localizing property in human cervical carcinoma (HeLa) cells. Remarkable photocytotoxicity but low dark cytotoxic properties were observed for ZnPc1 in four different cancer cell lines. Photodynamic treatment (PDT) with ZnPc1 resulted in the generation of reactive oxygen species, a collapse of the mitochondrial membrane potential and chromatin condensation, all important hallmarks of apoptosis. The results are consistent with its mitochondrial localization property and qualify ZnPc1 as a promising PDT agent.

Texaphyrins and water-soluble zinc(II) ionophores: development, mechanism of anticancer activity, and synergistic effects.

Texaphyrins, first prepared by Sessler and coworkers in the 1980s, represent early examples of expanded porphyrins. This class of pentaaza, oligopyrrolic macrocycles demonstrates excellent tumor localization and metal-chelating properties. In biological milieus, texaphyrins act as redox mediators and are able to produce reactive oxygen species. Furthermore, texaphyrins have been shown to upregulate zinc in vivo, an important feature that inspired us to develop new zinc ionophores that might allow the same function to be elicited but via a simpler chemical means. In this review, the basic properties of texaphyrins and the zinc ionophores they helped spawn will be discussed in the cadre of developing an understanding that could lead to the preparation of new, redox-active anticancer agents.

Non-classical anticancer agents: on the way to water soluble zinc(ii) heteroleptic complexes

Two new heteroleptic Zn(II) complexes of the 4,4'-bis(hydroxymethyl)-2,2'-bipyridine have been synthesized by using different stoichiometric ratios of tropolone. In an attempt to induce the formation of metal complex co-crystals, liquid assisted solid state reaction followed by solvent crystallization has been conducted by using the new Zn(II) tropolonate derivatives 1 and 2 with saccharin. The novel Zn(II) species obtained exhibits different structures and properties with respect to their precursors, due to a hydrogen exchange between saccharin and the tropolonate coordinated ligand.

Dye encapsulation and release by a zinc–porphyrin pincer system through morphological transformations

A novel water soluble zinc–porphyrin pincer system exhibits vesicular structures in methanol and nanofibers in the aqueous medium. The vesicular structures encapsulate the guest molecules, which can be released on demand through morphological transformations induced by time and the solvent.

Effects of gold nanoparticle shape on the aggregation and fluorescence behaviour of water soluble zinc phthalocyanines

The absorption and fluorescence response as well as the fluorescence quantum yields and lifetimes of sulfonated phthalocyanines and alkyl carboxylic acid substituted zinc phthalocyanines in the presence of differently shaped water soluble gold nanoparticles were studied. The respective phthalocyanines are known to be highly aggregated in water, which is reported to markedly reduce the excited state lifetimes. This paper shows that in the presence of star shaped gold nanoparticles, the degree of phthalocyanine aggregation in water is greatly reduced, but the aggregation status of the phthalocyanines does not change for spherical Au nanoparticles. Since gold nanoparticles have already proven to be useful in numerous nanomedicinal and nanomedical applications, the disaggregation of phthalocyanines is an added advantage.

A soft supramolecular carrier with enhanced singlet oxygen photosensitizing properties

Herein we report the self-assembly of a supramolecular singlet oxygen photosensitizing system from an adamantane-functionalized, hexaanionic water-soluble zinc(II) phthalocyanine (PC) and β-cyclodextrin vesicles (CDV). Characterisation of the designed PC, which was synthesized by an asymmetric statistical condensation, was carried out by several analytical techniques such as MALDI-HRMS, NMR, IR, UV/vis as well as steady state and time resolved fluorescence spectroscopy. The influence of the docking of the PC to the CDVs on the PC photoluminescence as well as on the singlet oxygen photoproduction quantum yields was investigated. The results indicate that the host–guest interaction of the photosensitizer and the CDVs significantly prevents the formation of inactive aggregates, and enhances the photosensitizing ability of the PC. The supramolecular assembly constitutes a biocompatible photoactive platform for the design of phototherapeutic agents.

Thermal analysis and mechanism of α-Zn2SiO4:Mn2+ formation from zinc oxalate dihydrate under hydrothermal conditions

Reaction of zinc oxalate dihydrate in high-temperature water at 200–400 °C was investigated to understand the mechanism of α-Zn2SiO4:Mn2+ formation and specifically why zinc oxalate dihydrate forms α-Zn2SiO4 crystalline phase at a higher rate compared with other water soluble and insoluble zinc sources studied in our previous works. From experiments under hydrothermal conditions, it was determined that the dehydration of zinc oxalate dihydrate became suppressed as the temperature and pressure increased. From thermal analyses, zinc oxalate dihydrate, which dehydrates at 160 °C in air, was stable at conditions up to 300 °C in water and this resulted in the lack of formation of the intermediate phase, hemimorphite, which forms at 150–175 °C from other zinc compounds (e.g. ZnO). The stability of the zinc oxalate dihydrate under hydrothermal conditions can possibly be attributed to changes in the chemical equilibrium with temperature and pressure which leads to the compound having less reactivity with silica so that reaction paths to form hemimorphite and β-Zn2SiO4 become unfavorable. Zinc oxalate dihydrate as starting material provided α-Zn2SiO4 at a higher formation rate than other starting materials.