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1.
Top Curr Chem (Cham) ; 378(2): 30, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32124072

RESUMO

The non-covalent assemblies among multiple non-identical metal complexes have scopes to develop a new subject area. There are infinite numbers of ways for different combinations among inorganic neutral or ionic complexes. Each partnering species of those molecular complexes would also have diversities by changing metal ions, ligands, oxidation states of metal ions, and coordination numbers. Keeping a view of the emergence of framework materials and self-assembled nano-structures of metal complexes, the non-covalently linked assemblies of inorganic molecular complexes would have scopes for new nano-dimensional materials. This account provides a systematic description of the different inorganic molecular complexes for a concerted effort to develop a new area that would have importance in applied materials.


Assuntos
Complexos de Coordenação/química , Compostos Inorgânicos/química , Ligantes , Metais/química , Conformação Molecular
2.
Top Curr Chem (Cham) ; 378(2): 29, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32125542

RESUMO

The efficacy of photocatalysis strongly depends on the activity of the catalysts and the operational factors, especially factors associated with mass transfer and the possibility of catalyst deactivation. The use of ultrasound has great potential to enhance catalyst activity, during both the synthesis and actual oxidation processes due to the cavitational effects of turbulence and liquid streaming. This article presents an overview of the application aspects of ultrasound, both in the synthesis of the photocatalyst and applications for wastewater treatment. A review of the literature revealed that the use of ultrasound in the synthesis processes can result in a catalyst with a lower mean size and higher surface area as well as uniform size distribution. The application of ultrasound in the actual photocatalytic oxidation facilitates enhancement of the oxidation capacity, leading to higher degradation rates, sometimes synergistic results and definitely lower treatment times. This article also presents guidelines for the selection of the best operating conditions for the use of ultrasound in photocatalytic systems and includes a discussion on the possible reactor configurations suitable for large-scale operations. Overall, a combination of ultrasound with photocatalytic oxidation or the optimized application of ultrasound in catalyst synthesis can yield significant benefits.


Assuntos
Sonicação , Raios Ultravioleta , Catálise , Metais/química , Nanopartículas/química , Oxirredução , Óxidos/química , Fotólise/efeitos da radiação , Poluentes Químicos da Água/química
3.
Top Curr Chem (Cham) ; 378(1): 18, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32009187

RESUMO

DNA molecules with superior flexibility, affinity and programmability have garnered considerable attention for the controllable assembly of nanoparticles (NPs). By controlling the density, length and sequences of DNA on NPs, the configuration of NP assemblies can be rationally designed. The specific recognition of DNA enables changes to be made to the spatial structures of NP assemblies, resulting in differences in tailorable optical signals. Comprehensive information on the fabrication of DNA-driven NP assemblies would be beneficial for their application in biosensing and bioimaging. This review analyzes the progress of DNA-driven NP assemblies, and discusses the tunable configurations determined by the structural parameters of DNA skeletons. The collective optical properties, such as chirality, fluorescence and surface enhanced Raman resonance (SERS), etc., of DNA-driven NP assemblies are explored, and engineered tailorable optical properties of these spatial structures are achieved. We discuss the development of DNA-directed NP assemblies for the quantification of DNA, toxins, and heavy metal ions, and demonstrate their potential application in the biosensing and bioimaging of tumor markers, RNA, living metal ions and phototherapeutics. We hihghlight possible challenges in the development of DNA-driven NP assemblies, and further direct potential prospects in the practical applications of macroscopical materials and photonic devices.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Nanopartículas/química , Imagem Óptica/métodos , Biomarcadores Tumorais/análise , Grafite/química , Humanos , Metais/química , Análise Espectral Raman
4.
J Phys Chem Lett ; 11(5): 1697-1701, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32039604

RESUMO

Here we demonstrate sub-10 nm spatial resolution sampling of a volume of ∼360 molecules with a strong field enhancement at the sample-tip junction by implementing noble metal substrates (Au, Ag, Pt) in photoinduced force microscopy (PiFM). This technique shows the versatility and robustness of PiFM and is promising for application in interfacial studies with hypersensitivity and super spatial resolution.


Assuntos
Metais/química , Microscopia de Força Atômica/métodos , Animais , Bovinos , Ouro/química , Platina/química , Soroalbumina Bovina/química , Dióxido de Silício/química , Prata/química
5.
Phys Chem Chem Phys ; 22(10): 5584-5596, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32107511

RESUMO

The identity of metal ions surrounding DNA is key to its biological function and materials applications. In this work, we compare atomistic molecular dynamics simulations of double strand DNA (dsDNA) with four alkaline earth metal ions (Mg2+, Ca2+, Sr2+, and Ba2+) to elucidate the physical interactions that govern DNA-ion binding. Simulations accurately model the ion-phosphate distance of Mg2+ and reproduce ion counting experiments for Ca2+, Sr2+, and Ba2+. Our analysis shows that alkaline earth metal ions prefer to bind at the phosphate backbone compared to the major groove and negligible binding occurs in the minor groove. Larger alkaline earth metal ions with variable first solvation shells (Ca2+, Sr2+, and Ba2+) show both direct and indirect binding, where indirect binding increases with ion size. Mg2+ does not fit this trend because the strength of its first solvation shell predicts indirect binding only. Ions bound to the phosphate backbone form fewer contacts per ion compared to the major groove. Within the major groove, metal ions preferentially bind to guanine-cystosine base pairs and form simultaneous contacts with the N7 and O6 atoms of guanine. Overall, we find that the interplay among ion size, DNA-ion interaction, and the size and flexibility of the first solvation shell are key to predicting how alkaline earth metal ions interact with DNA.


Assuntos
DNA/química , Íons/química , Metais Alcalinoterrosos/química , Metais/química , Simulação de Dinâmica Molecular , Água/química
6.
Chem Soc Rev ; 49(4): 1090-1108, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32016270

RESUMO

Inorganic phosphate has numerous biomedical functions. Regulated primarily by the kidneys, phosphate reaches abnormally high blood levels in patients with advanced renal diseases. Since phosphate cannot be efficiently removed by dialysis, the resulting hyperphosphatemia leads to increased mortality. Phosphate is also an important component of the environmental chemistry of surface water. Although required to secure our food supply, inorganic phosphate is also linked to eutrophication and the spread of algal blooms with an increasing economic and environmental burden. Key to resolving both of these issues is the development of accurate probes and molecular receptors for inorganic phosphate. Yet, quantifying phosphate in complex aqueous media remains challenging, as is the development of supramolecular receptors that have adequate sensitivity and selectivity for use in either blood or surface waters. Metal-based receptors are particularly well-suited for these applications as they can overcome the high hydration enthalpy of phosphate that limits the effectiveness of many organic receptors in water. Three different strategies are most commonly employed with inorganic receptors for anions: metal extrusion assays, responsive molecular receptors, and indicator displacement assays. In this review, the requirements for molecular receptors and probes for environmental applications are outlined. The different strategies deployed to recognize and sense phosphate with metal ions will be detailed, and their advantages and shortfalls will be delineated with key examples from the literature.


Assuntos
Metais/química , Fosfatos/química , Quelantes/química , Complexos de Coordenação/química , Elementos da Série dos Lantanídeos/química , Metais/metabolismo , Fosfatos/metabolismo , Elementos de Transição/química , Água/química
7.
Chem Pharm Bull (Tokyo) ; 68(1): 1-33, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31902899

RESUMO

Novel reactions using hetero-heavy atoms (P, S, Si, Se, and Sn) were developed and applied to the synthesis of biofunctional molecules and some medicine-candidates, in which the following items are covered. 1) Development of introduction of C1-unit using cyanophosphates (CPs). 2) Carbene-generation under neutral condition from CPs and its application to organic synthesis. 3) [3,3]Sigmatropic rearrangement-ring expansion reactions of medium-sized cyclic thionocarbonates containing a sulfur atom and their application to natural product synthesis. 4) Stereoselective synthesis of novel ß-imidazole C-nucleosides via diazafulvene intermediates and their application to investigating ribozyme reaction mechanism. 5) Developments of novel histamine H3- and H4-receptor ligands using new synthetic methods involving Se or Sn atoms.


Assuntos
Produtos Biológicos/química , Metais/química , Animais , Produtos Biológicos/síntese química , Proliferação de Células/efeitos dos fármacos , Agonistas dos Receptores Histamínicos/síntese química , Agonistas dos Receptores Histamínicos/química , Agonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores Histamínicos/síntese química , Antagonistas dos Receptores Histamínicos/química , Antagonistas dos Receptores Histamínicos/farmacologia , Humanos , Metano/análogos & derivados , Metano/química , Metano/metabolismo , Nitrilos/química , Nucleosídeos/síntese química , Nucleosídeos/química
8.
Chem Soc Rev ; 49(3): 908-950, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31958107

RESUMO

Donor and donor-donor carbenes are two important kinds of carbenes, which have experienced tremendous growth in the past two decades. This review provides a comprehensive overview of the recent development of donor and donor-donor carbene chemistry. The development of this chemistry offers efficient protocols to construct a wide variety of C-C and C-X bonds in organic synthesis. This review is organized based on the different types of carbene precursors, including diazo compounds, hydrazones, enynones, cycloheptatrienes and cyclopropenes. The typical transformations, the reaction mechanisms, as well as their subsequent applications in the synthesis of complex natural products and bioactive molecules are discussed. Due to the rapidly increasing interest in this area, we believe that this review will provide a timely and comprehensive discussion of recent progress in donor and donor-donor carbene chemistry.


Assuntos
Metano/análogos & derivados , Compostos Azo/química , Catálise , Ciclopropanos/química , Hidrazonas/química , Metais/química , Metano/síntese química , Estrutura Molecular , Estereoisomerismo
9.
Top Curr Chem (Cham) ; 378(1): 16, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31942682

RESUMO

The cooperation between two orthogonal catalytic events during the formation of carbon-carbon and carbon-heteroatom bonds has emerged as an effective strategy for enantioselective chemical synthesis. In recent years, a number of pioneering investigations have described useful chemical synthesis methods whereby the reactivity or nucleophile-electrophile combinations can be fine-tuned or extended far beyond the effect and influence of a single catalyst. The recognition of this has had profound implications for the development cooperative catalysis as a field and has provided a foundation for the development of broadly useful chemical synthesis methods. This chapter focuses on the combination of tertiary amine Lewis base and transition metal catalysts, which the authors hope will simulate further developments and advances.


Assuntos
Compostos de Amônio/química , Bases de Lewis/química , Metais/química , Carbono/química , Catálise , Técnicas de Química Sintética/métodos , Estereoisomerismo , Elementos de Transição/química
10.
Environ Sci Pollut Res Int ; 27(8): 8418-8430, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31902074

RESUMO

Treatment efficiency of iron-rich acid mine drainage (AMD; pH 3, and 2 and 4 g/L Fe) was tested in a laboratory tri-unit pilot-scale reactor (2.65 m3) for 1 year. The first unit consisted of a passive biochemical reactor (PBR1), filled with reactive mixture (50% of manure, sawdust, maple chips, compost, urea, sediment, and sand; 50% of calcite), with the aim to neutralize acidity and to partially remove metals. The second unit contained wood ash and acted as neutralizer and iron retention filter (by sorption and precipitation). The last unit was a second polishing PBR2, filled with reactive mixture (98% of manure, sawdust, maple chips, compost, urea, sediment, and sand; 2% of calcite), which aim was to remove the residual metals. The results showed that pH increased to about 6 and redox potential decreased significantly (from 550 mV to -100 mV). Iron, the most challenging metal in the AMD, decreased from 4 g/L (the highest tested concentration) to approximately 100 mg/L. The performance of the multistep treatment system was controlled by the capacity of the wood ash to immobilize iron.


Assuntos
Ácidos/química , Ferro , Metais/química , Poluentes Químicos da Água , Concentração de Íons de Hidrogênio , Mineração
11.
Chemistry ; 26(9): 1906-1921, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-31693220

RESUMO

Metal-catalyzed allylic alkylation reactions between dual nucleophiles and dual electrophiles represent a powerful set of methods for the synthesis of small-, medium-, and even large-sized rings. Using this strategy, a handful of simple allylic diol derivatives can be transformed into a broad array of complex carbo- and heterocycles of varying ring sizes in just a single step. Because of their ability to rapidly generate complexity, annulative allylic alkylation reactions between dual nucleophiles and dual electrophiles have been extensively employed in the total synthesis of both natural products and pharmaceutical compounds.


Assuntos
Compostos Alílicos/química , Produtos Biológicos/síntese química , Preparações Farmacêuticas/síntese química , Alquilação , Produtos Biológicos/química , Carbono/química , Catálise , Ciclização , Metais/química , Preparações Farmacêuticas/química , Estereoisomerismo
12.
Chemistry ; 26(7): 1633-1639, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31724757

RESUMO

Convenient and sensitive detection of biomolecules is of great significance to disease diagnosis. In this work, a metal-free photoinduced atom transfer radical polymerization (photoATRP) by a reductive quenching pathway as a novel strategy is applied to achieve lung cancer DNA detection. Thiolated PNA is exploited to specifically recognize target DNA, and the initiator of photoATRP is linked to the electrode surface via phosphate-Zr4+ -carboxylate. Under the excitation of blue light, the reductive quenching pathway is activated with eosin Y (EY) as photoredox catalyst and N,N,N',N'',N'-pentamethyldiethylenetriamine (PMDETA) as electron donor, and numerous polymeric chains are formed. Under optimal conditions, the linear range of this strategy is from 0.1 pm to 10 nm (R2 =0.989) with a limit of detection (LOD) of 1.4 fm (14 zmol in 10 µL). The variety of possible light sources for photoATRP and simple operation endow this biosensor with great potential for practical applications.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Radicais Livres/química , Neoplasias Pulmonares/genética , Metais/química , Polímeros/química , Catálise , DNA/genética , Eletrodos , Humanos , Limite de Detecção , Neoplasias Pulmonares/química , Polimerização
13.
J Agric Food Chem ; 68(1): 77-87, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31794210

RESUMO

Soybeans (Glycine max) (V3 stage) were sprayed once with nanoparticles (NPs) of AgO, B, CeO, CuO, MnO, MoO3, SiO, TiO, or ZnO and exposed to Fusarium virguliforme, the cause of sudden death syndrome. Up to 80% root rot was observed in greenhouse experiments. However, NP CuO, B, MoO3, or ZnO reduced the root rot severity by 17-25%. Infected roots and shoots had significant changes in B, Mg, P, S, Si, and Zn, but NP treatment restored levels to that of the healthy control. For example, the increased root Mg and Mn contents induced by disease were reversed by NP B and Mn amendments. In vitro assays found that the NPs did not inhibit the pathogen. This, along with the restoration of altered nutrient levels in the plant tissue, suggests that modulated plant nutrition increased disease defense. Treatment of seedlings with nanoscale micronutrients may be a new tool in promoting soybean health.


Assuntos
Fungicidas Industriais/farmacologia , Nanopartículas Metálicas/análise , Metais/farmacologia , Óxidos/farmacologia , Doenças das Plantas/prevenção & controle , Soja/efeitos dos fármacos , Fungicidas Industriais/química , Fusarium/efeitos dos fármacos , Fusarium/fisiologia , Metais/química , Óxidos/química , Doenças das Plantas/microbiologia , Soja/fisiologia
14.
Chem Asian J ; 15(2): 214-230, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31714665

RESUMO

Catalysis by nucleic acids is indispensable for extant cellular life, and it is widely accepted that nucleic acid enzymes were crucial for the emergence of primitive life 3.5-4 billion years ago. However, geochemical conditions on early Earth must have differed greatly from the constant internal milieus of today's cells. In order to explore plausible scenarios for early molecular evolution, it is therefore essential to understand how different physicochemical parameters, such as temperature, pH, and ionic composition, influence nucleic acid catalysis and to explore to what extent nucleic acid enzymes can adapt to non-physiological conditions. In this article, we give an overview of the research on catalysis of nucleic acids, in particular catalytic RNAs (ribozymes) and DNAs (deoxyribozymes), under extreme and/or unusual conditions that may relate to prebiotic environments.


Assuntos
DNA Catalítico/química , RNA Catalítico/química , Sequência de Bases , Catálise , DNA Catalítico/efeitos da radiação , Concentração de Íons de Hidrogênio , Pressão Hidrostática , Metais/química , Origem da Vida , RNA Catalítico/efeitos da radiação , Temperatura Ambiente , Raios Ultravioleta
15.
Chemosphere ; 241: 125025, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31604190

RESUMO

Metals in atmospheric aerosols play potentially an important role in human health and ocean primary productivity. However, the lack of knowledge about solubility and speciation of metal ions in the particles or after solubilisation in aqueous media (sea or surface waters, cloud or rain droplets, biological fluids) limits our understanding of the underlying physico-chemical processes. In this work, a wide range of metals, their soluble fractions, and inorganic/organic compounds contained in urban particulate matter (PM) from Padua (Italy) were determined. Metal solubility tests have been performed by dissolving the PM in water and in solutions simulating rain droplet composition. The water-soluble fractions of the metal ions and of the organic compounds having ligand properties have been subjected to a multivariate statistical procedure, in order to elucidate associations among the aqueous concentrations of these PM components in simulated rain droplets. In parallel, a multi-dimensional speciation calculation has been performed to identify the stoichiometry and the amount of metal-ligand complexes theoretically expected in aqueous solutions. Both approaches showed that the solubility and the aqueous speciation of metal ions were differently affected by the presence of inorganic and organic ligands in the PM. The solubility of Al, Cr, and Fe was strongly correlated to the concentrations of oxalic acid, as their oxalate complexes represented the expected dominant species in aqueous solutions. Oxalates of Al represented ∼98% of soluble Al, while oxalates of Cu represented 34-75% of the soluble Cu, and oxalates of Fe represented 76% of soluble Fe. The oxidation state of Fe can strongly impact the speciation picture. If Fe is present as Fe(II) rather than Fe(III), the amount of Cr and Cu complexed with diacids can increase from 75% to 94%, and from 32% to 53%, respectively. For other metals, the solubility depended on the formation of soluble aquo-complexes, hence with a scarce effect of the organic ligands. An iron-oxalate complex was also directly detected in aerosol sample extracts.


Assuntos
Complexos de Coordenação/química , Metais/química , Ácido Oxálico/química , Material Particulado/análise , Aerossóis/análise , Humanos , Itália , Ligantes , Oxirredução , Solubilidade , Reforma Urbana , Água
16.
Food Chem Toxicol ; 135: 110889, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31629790

RESUMO

Tetramethyl bisphenol F (TMBPF) has been shown to impart unique physical properties critical for high performance of epoxy can coatings without the estrogenic activity concerns associated with other bisphenols. To further characterize the toxicological profile of TMBPF, additional endocrine-related endpoints including in vitro aromatase inhibition and steroidogenesis assays, and in vivo androgen agonism/antagonism were performed. Systemic toxicity was also assessed by a repeat dose 90-day dietary toxicity study followed by 28-day recovery period. TMBPF did not inhibit aromatase activity, and induced estradiol and testosterone at highest non-cytotoxic concentrations (10 µM) in the steroidogenesis assay. In the Hershberger assay, TMBPF showed no androgenic activity at any dose and equivocal anti-androgenic activity at the highest dose (1000 mg/kg-bw/d). In a 90-day dietary toxicity study with 28-day recovery period, observations including changes in clinical pathology, absolute and relative organ weights, and microscopic findings are discussed. In this current study, the no observed adverse effect level was considered to be 750 mg/kg-bw/d for female rats and 1000 mg/kg-bw/d for male rats with no biologically significant changes to endocrine endpoints at any dose level. Our findings provide further evidence that TMBPF is a low-toxicity substance with a toxicology profile distinct from some other bisphenols.


Assuntos
Compostos Benzidrílicos/química , Compostos Benzidrílicos/toxicidade , Embalagem de Alimentos , Metais/química , Fenóis/química , Fenóis/toxicidade , Animais , Compostos Benzidrílicos/administração & dosagem , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Feminino , Hormônios Esteroides Gonadais/antagonistas & inibidores , Humanos , Masculino , Nível de Efeito Adverso não Observado , Fenóis/administração & dosagem , Ratos , Ratos Sprague-Dawley
17.
Adv Exp Med Biol ; 1237: 121-134, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31802447

RESUMO

Metallic nanomaterials show tremendous applications in biomedical devices due to compatible integration into the most of the biological systems as they are nano- structured. Metallic nanomaterials are capable of mimicking all the three major antioxidant enzymes such as catalase (CAT), peroxidase and oxidase, to control the level of reactive oxygen species (ROS) inside the cell as an alternative strategy over conventional one which has biological toxicity and have several adverse effects, if accumulation takes places during the treatment. This anti-oxidant property of metallic nanomaterials demonstrates as a promising candidate for its biomedical application in disease conditions where the excessive level of ROS causes damage to DNA, lipids and protein in several conditions such as diabetes, cancer and neurodegenerative diseases. Tribology is the study of interacting surfaces in motion and the measurement of properties such as friction, wear-tear and abrasion. While designing nano-scale biomedical devices, the consideration of tribology is particularly important because the high surface area ratio enhances problems with friction and wear-tear which can further affects its function as well as longevity.


Assuntos
Nanopartículas Metálicas/química , Metais/química , Nanomedicina , Antioxidantes/química , Fricção , Humanos , Movimento (Física) , Espécies Reativas de Oxigênio/metabolismo
18.
Sci Total Environ ; 704: 135414, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31810693

RESUMO

Efficient conversion of food waste to value-added products necessitates the development of high-performance heterogeneous catalysts. This study evaluated the use of Al2O3 as a low-cost and abundant support material for fabricating Lewis acid catalysts, i.e., through the in-situ doping of Cu, Ni, Co, and Zr into Al2O3 followed by calcination. The characterisation results show that all catalysts were mainly amorphous. In particular, adding the transition metals to the Al2O3 matrix resulted in the increase of acidity and meso-/micro-pores. The catalysts were evaluated in the conversion of glucose, which can be easily derived from starch-rich food waste (e.g., bread waste) via hydrolysis, to fructose in biorefinery. The results indicate that the Ni-doped Al2O3 (Al-Ni-C) achieved the highest fructose yield (19 mol%) and selectivity (59 mol%) under heating at 170 °C for 20 min, of which the performance falls into the range reported in literature. In contrast, the Zr-doped Al2O3 (Al-Zr-C) presented the lowest fructose selectivity despite the highest glucose conversion, meaning that the catalyst was relatively active towards the side reactions of glucose and intermediates. The porosity and acidity, modified via metal impregnation, were deduced as the determinants of the catalytic performance. It is noteworthy that the importance of these parameters may vary in a relative sense and the limiting factor could shift from one parameter to another. Therefore, evaluating physicochemical properties as a whole, instead of the unilateral improvement of a single parameter, is encouraged to leverage each functionality for cost-effectiveness. This study provides insights into the structure-performance relationships to promote advance in catalyst design serving a sustainable food waste biorefinery.


Assuntos
Óxido de Alumínio/química , Alimentos , Eliminação de Resíduos/métodos , Resíduos , Glucose , Concentração de Íons de Hidrogênio , Hidrólise , Metais/química , Porosidade
19.
J Photochem Photobiol B ; 202: 111722, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31785445

RESUMO

Nowadays, the study of well-known sensitizers for photodynamic therapy and search for new ones are intensively conducted. In the present work supramolecular organization of crown-ether and phosphoryl-containing phthalocyanines ({Mgcr8Pc, I, and М[R4Pc] (M = Zn2+, R = -OPhP(O)(OH)(OC5H11), II; M = 2H+, R = -OPhP(O)(OH)(OC5H11), III; M = 2H+, -OPhP(O)(OH)2), IIIa}, respectively) was studied in microheterogeneous media. The role of a metal ion of a macrocycle in monomerization of phosphoryl-containing Pc in the presence of water-soluble poly(N-vinylpyrrolidone) was revealed. Some photobiological properties of compound I as possible photosensitizer with respect to human adenocarcinoma cells, HeLa, were analyzed. So, the light and dark cytotoxicity of I (IC50 dose) was 1.83 µÐœ and higher than 25 µÐœ, respectively. The reactive oxygen species (ROS) formation studied with use of fluorescent ROS detector DCFH2 revealed the plateau on the curves of fluorescence intensity vs time after 30 min of irradiation and ROS are almost not produced after the end of irradiation. In HeLa cells, accumulation of compounds I and II as well as fluorescent DCF presence were shown by confocal microscopic images. At concentration of 5 µM, compound I easily penetrates into the cell localizing primarily in the perinuclear region, whereas compound II mainly remains in the periphery of the cells in the fluorescent-active state. The results obtained allow us to continue the study of these interesting compounds.


Assuntos
Éteres de Coroa/química , Indóis/química , Metais/química , Fármacos Fotossensibilizantes/química , Polivinil/química , Pirrolidinas/química , Espécies Reativas de Oxigênio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Luz , Microscopia Confocal , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/farmacologia
20.
Crit Rev Anal Chem ; 50(1): 78-89, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30777442

RESUMO

The separation and purification techniques of chelates can improve the accuracy of detecting results of the chelation rate. As a quantitative indicator of metal ion chelates, the chelation rate can not only reflect the completion of chelation but also determine the amount of metal ions in different forms. The determination of chelation rate can help to determine the suitable chelating reaction conditions, make theoretical basis for the fertilizer efficiency, analyze the stability of chelating fertilizers and study the action mechanism of trace elements. In our study, the methods of separation free metal ions from mixture were reviewed first, including gel filtration chromatography, organic solvent precipitation, ion exchange chromatography, membrane separation and high performance liquid chromatography. Then, the qualitative analysis methods of chelates were introduced briefly, including chemical identification, infrared spectroscopy, ultraviolet spectroscopy. A detailed overview of the quantitative determination methods of chelates were also shown, such as ethylenediaminetetraacetic acid titration, chemical titration, atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry, spectrophotometric, chemical modified electrode. In addition, the merits and demerits of chelated rate determination methods of various determination methods were analyzed, and summarized the applicability of various methods, which provided a theoretical basis for optimizing chelating process, characterizing the structure of chelates and analyzing the mechanism of chelating fertilizer. The current methods of measuring chelation rate were also summarized and prospected.


Assuntos
Quelantes/química , Complexos de Coordenação/química , Metais/química , Cromatografia Líquida , Cinética , Espectrometria de Massas , Solventes/química , Espectrofotometria Atômica , Oligoelementos/análise
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