Acetate Salts Research Articles

Cadmium(II) compounds of the bis-cyanoethyl derivative (LCX) of Me8[14]aneC (LC): characterization and antibacterial studies

The isomeric ligand LC, a saturated analogue of 2,9-C-meso-Me8[14]diene, on reflux with excess acrylonitrile afforded 1,8-N-pendant cyanoethyl derivative LCX. Interaction of LCX with cadmium(II) perchlorate, nitrate, acetate, and chloride salts produced six coordinated octahedral compounds, [Cd(LCX) (ClO4)2]∙2H2O, [Cd(LCX) (NO3)2], [Cd(LCX) (CH3COO)2], and [Cd(LCX)Cl2], respectively. Further, axial substitution reactions between [Cd(LCX) (ClO4)2]∙2H2O and KI, KBr, KCl, KSCN, and NaNO2 in a 1:2 ratio yielded six coordinated octahedral compounds, [Cd(LCX)I2]∙H2O, [Cd(LCX)Br2]∙2H2O, [Cd(LCX)Cl(ClO4)]∙2H2O, [Cd(LCX) (NCS)2]∙H2O, and [Cd(LCX) (NO2) (ClO4)]∙2H2O, respectively. All of the newly prepared compounds have been characterized by analytical, spectroscopic, molar conductivity, and magnetochemical data. The crystal structure of the ligand LCX was determined by x-ray crystallography which showed the 14-membered ring to adopt an extended chair conformation. Antibacterial activities of the newly formed cadmium(II) complexes against selected bacteria showed these to exhibit moderate and selective activity with 1-4 and 8 exhibiting greatest potency against the gram negative bacterium Salmonella typhi, and 5, 6, and 7 against the gram positive bacterium Bacillus wiedmannii.

Synthesis of novel of Mn(II), Co(II), and Cu(II) Schiff base complexes and their high catalytic effect on bleaching performance with H2O2

Oxidation catalysts are used in a wide range of industrial processes. For instance, stain bleaching in detergents, bleaching of raw cotton and wood pulp, and drying of alkyd-based paint can be given as examples of oxidation catalysts. In this study, methyl 2-(((3-hydroxynaphthalene -2-yl) methylene) amino) benzoate synthesized as the structure of a new Schiff base ligand by carrying out over 2-hydroxy-1-naphthaldehyde and methyl 2-aminobenzoate. By the reactions of the synthesized Schiff base ligand and Cu(II), Mn(II), and Co(II) acetate salts, their ML2 type complexes were obtained. The structural characterizations of obtained metal ion-Schiff base complexes were performed using FT-IR, 1H-NMR, 13C-NMR, UV-Vis, MALDI-TOF, elemental analysis and melting point methods. The bleaching performances of the prepared Schiff base complexes were examined by the degradation of morin as a hydrophilic dye that characterizes the wine stains. The bleaching processes of Schiff base complexes in the presence of catalyst and H2O2 in an aqueous solution buffered with Na2CO3/ NaHCO3 at pH: 10.5 were investigated using the online spectrophotometric method. It was found that the prepared catalysts exhibited better bleaching performance at 25 °C than that of tetraacetylethylenediamine (TAED) as a bleach activator commercially used in powder detergent formulations.

Minimizing the initial burst of octreotide acetate from glucose star PLGA microspheres prepared by the solvent evaporation method

Sandostatin long-acting release (SLAR) depot for 1-month controlled release of octreotide is a somatostatin analogue product that has been used extensively in the pharmacological treatment of acromegaly. The complexities in the SLAR coacervation manufacturing processes and the use of a unique glucose-starpoly(lactic-co-glycolic acid) (PLGA-glu) may have contributed to the lack of US FDA-approved generic products referencing SLAR in the USA. To address this challenge, we encapsulated octreotide acetate by the commonly used solvent evaporation method in microspheres of a similar composition to SLAR, including the use of a comparable PLGA-glu. Based on our previous study that identified key formulation variables to prepare octreotide acetate/PLGA-glu microspheres, including lowering initial peptide pH and introducing an annealing step post loading, here we added NaCl to the external water phase to further improve the formulation. The resulting microspheres exhibited highly similar release and stability performance in vitro to SLAR, including an exceptionally low initial burst. The very low initial burst was also confirmed by pharmacokinetics in rats. Full erosion behavior analysis (polymer MW, water uptake and mass loss) revealed a slightly faster degradation of SLAR than the solvent evaporation formulations. Analysis of kinetics of dry Tg of the formulations reflected (a) the elevated residual solvent in SLAR and was not duplicated in the solvent evaporation formulations, and (b) the slightly higher Tg of peptide loaded formulations relative to than blank microspheres, consistent with the interaction of the acetate salt of octreotide with linear PLGA chains in the PLGA-glu. These data indicate that it is possible to prepare peptide loaded microspheres by the solvent evaporation method with extraordinarily similar performance to microspheres, such as those in SLAR, that are prepared by the low-burst release coacervation method.

Structural, thermal, and electrochemical studies of biodegradable gel polymer electrolyte for electric double layer capacitor

A quasi-solid-state supercapacitor is fabricated using a biodegradable gel polymer electrolyte (GPE), and graphene nano-platelets (GNPs) capacitive electrodes. The GPE film comprises biodegradable polymer cellulose acetate (CA), ionic liquid, 1-ethyl-3-methylimidazolium thiocyanate (EMImSCN) and dopant salt potassium thiocyanate (KSCN). The polymeric gel films are prepared using the standard “solution cast technique” and characterized by using X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Thermogravemetric analysis (TGA), Impedance spectroscopy, and Linear sweep voltammetry techniques. The synthesized GPE exhibits maximum room temperature ionic conductivity ∼1.2 x 10−3 S cm−1 and an electrochemical stability window of ∼2.4 V. The electrical double layer capacitor (EDLC) is configured by sandwiching the GPE film between two graphene nanoplatelets (GNPs) electrodes. The performance of the EDLC cell is evaluated in terms of specific capacitance, rate, and pulse power by using cyclic voltammetry, and electrochemical impedance measurement techniques.

Discovery of Novel Drug Candidates for Alzheimer's Disease by Molecular Network Modeling.

To identify the molecular mechanisms and novel therapeutic agents of late-onset Alzheimer’s disease (AD), we performed integrative network analysis using multiple transcriptomic profiles of human brains. With the hypothesis that AD pathology involves the whole cerebrum, we first identified co-expressed modules across multiple cerebral regions of the aging human brain. Among them, two modules (M3 and M8) consisting of 1,429 protein-coding genes were significantly enriched with AD-correlated genes. Differential expression analysis of microarray, bulk RNA-sequencing (RNA-seq) data revealed the dysregulation of M3 and M8 across different cerebral regions in both normal aging and AD. The cell-type enrichment analysis and differential expression analysis at the single-cell resolution indicated the extensive neuronal vulnerability in AD pathogenesis. Transcriptomic-based drug screening from Connectivity Map proposed Gly-His-Lys acetate salt (GHK) as a potential drug candidate that could probably restore the dysregulated genes of the M3 and M8 network. Pretreatment with GHK showed a neuroprotective effect against amyloid-beta-induced injury in differentiated human neuron-like SH-SY5Y cells. Taken together, our findings uncover a dysregulated network disrupted across multiple cerebral regions in AD and propose pretreatment with GHK as a novel neuroprotective strategy against AD.

First electrochemical study of a potent antifungal drug caspofungin: Application to its enhanced voltammetric sensing based on the performance of boron-doped diamond electrode in CTAB-mediated measurements

This present study describes the first electrochemical investigation of caspofungin, which is a semisynthetic echinocandin class of antifungal drug. For this purpose, an electrochemically pretreated (anodically and subsequently cathodically) boron-doped diamond (BDD) electrode was used. The cyclic voltammetric scans showed a single oxidation step that is irreversible and controlled by a dual mechanism of adsorption and diffusion. For the optimization of experimental conditions, the influence of the electrode pretreatment, pH of the supporting electrolyte, concentration of cationic surfactant cetyltrimethylammonium bromide (CTAB), accumulation variables, and instrumental parameters was examined on the current response of caspofungin. The improved sensitivity of the voltammetric measurements was observed due to the synergistic effect of CTAB on the adsorption capacity of BDD electrode in alkaline pH conditions. Employing square-wave adsorptive stripping voltammetry (using open-circuit accumulation for 60 s), the oxidation signal at around +0.45 V allowed to the determination of caspofungin in Britton-Robinson buffer at pH 11.0 containing 1 × 10−4 M CTAB. The process could be used in the concentration range from 2.06 × 10−7 to 1.03 × 10−5 M (from 0.25 to 12.5 μg mL−1 as acetate salt) with a detection limit of 5.27 × 10−8 M (0.064 μg mL−1 as acetate salt). A technique developed here was used successfully to determine caspofungin concentration in commercial parenteral dosage formulations.

Influence of different salts of alkali and alkaline earth metals on the pyrolysis of Prosopis juliflora

AbstractThis study explores the effect of acetate, oxide and chloride salts of alkali and alkaline earth metals (AAEMs) on the pyrolysis of lignocellulosic biomass. Prosopis juliflora samples were infused using 2% acetate and chloride salts of potassium (CH3COOK, KCl) and the oxide and chloride salts of magnesium (MgO, MgCl2). Dry impregnation technique was employed for the infusion of salts into the biomass matrix. The AAEM salt‐infused biomass was pyrolyzed using a semi‐batch pyrolysis reactor, and the bio‐oils were characterized for variation in chemical composition using gas chromatography–mass spectroscopy. The AAEM salts significantly influenced the pyrolysis process by catalyzing different degradation pathways. Potassium salts catalyzed the ring fission reactions of carbohydrates, resulting in an increase in carboxylic acid yield. On the other hand, magnesium salts promoted the cyclization of the fragmented radicals of the ring fission, resulting in enhanced furan and cycloketone yield. AAEM salts were most effective in catalyzing carbohydrate degradation pathways over the lignin degradation reactions owing to their ability to easily influence polysaccharide C–C bond cleavage over those of lignin aromatic rings. This study also revealed that the anions of AAEM salts also play a major role in biomass pyrolysis. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd

Role of cobalt precursors in the synthesis of Co3O4 hierarchical nanostructures toward the development of cobalt‐based functional electrocatalysts for bifunctional water splitting in alkaline and acidic media

AbstractThe precursors have significant influence on the catalytic activity of nonprecious electrocatalysts for effective water splitting. Herein, we report active electrocatalysts based on cobalt oxide (Co3O4) hierarchical nanostructures derived from four different precursors of cobalt (acetate, nitrate, chloride, and sulfate salts) using the low‐temperature aqueous chemical growth method. It has been found that the effect of precursor on the morphology of nanostructured material depends on the synthetic method. The Co3O4 nanostructures exhibited cubic phase derived from these four precursors. The Co3O4 nanostructures obtained from chloride precursor have demonstrated improved oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) compared to other precursors due relatively higher content of Co3O4 nanostructures at the surface of material. An overpotential of 400 mV versus reversible hydrogen electrode (RHE) at 10 mA cm−2 was observed for HER. The Co3O4 nanostructures derived from the chloride precursor have shown favorable reaction kinetics via 34 mV dec−1 value of the Tafel slope for HER reaction. The Co3O4 nanostructures derived from chloride precursor have also shown an excellent HER durability for 15 hr in alkaline media. Furthermore, the OER functional characterization was carried out onto Co3O4 nanostructures derived from chloride precursor exhibited 220 mV overpotential at 10 mA cm−2 and Tafel slope of 56 mV dec−1. Importantly, the reason behind the favorable catalytic activity of Co3O4 nanostructures derived from chloride precursor was linked to one order of magnitude smaller charge transfer resistance and higher amount of Co3O4 content at the surface of nanostructures than the Co3O4 nanostructures derived from other precursors. The performance of Co3O4 nanostructures derived from chloride precursor via the wet chemical method suggests that cobalt chloride precursor could be of great interest for the development of efficient, stable, nonprecious, and environmentally friendly electrocatalysts for the chemical energy conversion and storage devices.

Эффективность использования в кормлении молодняка крупного рогатого скота органического кобальта

Aim. The study of the regularities of metabolism in the body when feeding various types of trace elements. Materials and Methods. The studies were carried out using generally accepted and modern biotechnological, biochemical and mathematical methods and certified laboratory equipment. All digital material obtained in the course of the research work was processed using the Microsoft Excel software package and the method of variation statistics, taking into account the Student's probability criterion. Results. Studies have found that the use of 1 mg/ kg of cobalt acetic acid compound feed in feeding young bulls aged 3-6 months had a positive effect on the physiological state of animals, expressed in an increase in the content of erythrocytes in the blood by 2.4%, hemoglobin – by 2.1, total protein – by 1.1, calcium and phosphorus – by 1.4 and 1.3%, respectively. At the same time, the glucose level decreased by 1.8%, urea – by 1.9%. it did not have a significant effect on the processes of cicatricial digestion. All indicators were within the limits of physiological norms. The animals of the experimental group showed a tendency to decrease the ammonia content in the scar fluid by 4.1%. At the same time, in the experimental group, the level of volatile fatty acids increased by 3.0%. Feeding the bulls with cobalt acetic acid salt provided an increase in the average daily live weight gain by 3.1%. The increase in productivity had a positive effect on the efficiency of the transformation of nutrients in the diet into products. Thus, feed costs for products decreased by 2.8%. Conclusion. The adding of cobalt acetic acid in the diet of young bulls had a positive effect to decrease the ammonia content in the rumen fluid, increasing the average daily gain and, in general, the productivity of animals.

Nanomodification of polyester fabric surface: Higher performances of synthesized CuFe2O4 comparing with CuO and Fe3O4 NPs

This paper is focused on introducing a nano-modified polyester fabric with copper ferrite nanoparticles as a composite of metal oxides and compares it with treated polyester fabrics with oxide of copper and iron nanoparticles. The nanoparticles of metal oxide were created on the fabric surface with the in-situ synthesis of copper acetate and ferrous sulfate salts in alkaline conditions. The analytical techniques (XRD, FTIR, XPS, SEM, and EDX), the rate of dye solution discoloring, the reduction colonies, cell viability, released ions into the water, and also, the response to the magnetic field and the color coordinates of treated fabrics were investigated. The copper ferrite nanoparticle was synthesized on the polyester fabric with an irregular shape and crystal size of 17 nm. The copper ferrite treated sample with dye degradation of 80.77%, colonies reduction of 100%, and saturation magnetic of 9.81 emu/g displayed better results regarding photocatalytic, antibacterial, and magnetic activity than other samples. Also, the copper ferrite treated sample with the highest cell viability and the least release of ions into the water has the least risk to the environment and human life. The polyester fabric containing copper ferrite nanoparticles had more desirable properties and fewer disadvantages.

Facile synthesis of electrospun transition metallic nanofibrous mats with outstanding activity for ethylene glycol electro-oxidation in alkaline solution

Electrospinning technique was exploited to prepare a series of nickel-manganese alloy on carbon nanofibers [NiMn@CNFs] in various Ni:Mn wt.% ratios by using the corresponding acetate salts at 20 kV, followed by a calcination process for the obtained metallic fibrous mats at 850 °C for 5 h. The crystalline structure, morphology and chemical constituents of formed nanocomposites were determined by using X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analyses. The electrocatalytic activity of different NiMn@CNFs nanomaterials for oxidizing ethylene glycol molecules was evaluated in NaOH solution through cyclic voltammetry and steady state polarization measurements. The presence of increased content of manganese in NiMn@CNFs nanocomposite significantly affected its electrochemical performance. Adding 40 wt.% Mn in the synthesized nanomaterial was sufficient to achieve the optimum oxidation current density with the best stability when compared to that of Ni@CNFs. The present work opens a new route for fabricating many binary and ternary transition metals-based fibrous mats by using the electrospinning technique and examining their electrochemical activity for renewable energy applications.

Acetic Acid as Processing Aid Dramatically Improves Organic Solvent Solubility of Weakly Basic Drugs for Spray Dried Dispersion Manufacture.

Many active pharmaceutical ingredients (APIs) in the pharmaceutical pipeline require bioavailability enhancing formulations due to very low aqueous solubility. Although spray dried dispersions (SDDs) have demonstrated broad utility in enhancing the bioavailability of such APIs by trapping them in a high-energy amorphous form, many new chemical entities (NCEs) are poorly soluble not just in water, but in preferred organic spray drying solvents, e.g., methanol (MeOH) and acetone. Spraying poorly solvent soluble APIs from dilute solutions leads to low process throughput and small particles that challenge downstream processing. For APIs with basic pKa values, spray solvent solubility can be dramatically increased by using an acid to ionize the API. Specifically, we show that acetic acid can increase API solubility in MeOH:H2O by 10-fold for a weakly basic drug, gefitinib (GEF, pKa 7.2), by ionizing GEF to form the transient acetate salt. The acetic acid is removed during drying, resulting in a SDD of the original GEF free base having performance similar to SDDs sprayed from solvents without acetic acid. The increase in solvent solubility enables large scale manufacturing for these challenging APIs by significantly increasing the throughput and reducing the amount of solvent required.

Green Synthesis and Evaluation of Zinc Oxide Nanoparticles from Manilkara Zapota Leaf Extract

Background: Zinc oxide Nanoparticles can be prepared by various chemical, physical, and biological methodologies. But biological approach is easier than the other methods and also eco-friendly. 
 Purpose of study: Plant-mediated amalgamation of Zinc oxide nanoparticles is promising contrast to traditional method of physical and chemical synthesis. 
 Method: In the current research work, Zinc oxide nanoparticles are synthesized by using Leaf extracts of Manilkara Zapota plant. Green synthesis was done utilizing the aqueous solution of Manilkara Zapota leaf extract as reducing agent and Zinc acetate salts along with Sodium hydroxide. Morphological, Structural and Antimicrobial properties of synthesized Zinc oxide nanoparticles were characterized using Scanning electron microscope, Fourier transform infrared analysis, Differential scanning calorimetry and Disc diffusion method. '
 Results: Biologically synthesized nanoparticles of Manilkara Zapota leaf extract revealed significant Anti-bacterial and Anti-fungal activities. 
 Cocnclusion: The organically incorporated nanoparticles by Manilkara Zapota can be utilized as antimicrobial agent against various pathogenic organisms.

A general guide for adsorption of cadmium sulfide (CdS) quantum dots by successive ionic layer adsorption and reaction (SILAR) for efficient CdS-sensitized photoelectrochemical cells

Using CdS quantum dots grown on the surface of mesoscopic TiO2 film through SILAR deposition as a model semiconductor-sensitizer, common but not well understood parameters in the deposition process such as precursor compound & its concentration, solvent, and dipping time of the substrate electrode are systematically checked for suggesting a general guideline to make efficient CdS-sensitized mesoporous TiO2 electrode for photovoltaic and photocatalytic applications. Among many variables, the electrostatic interaction between intrinsic (+)-charge of metal cation (Cd2+) and induced (−)-charge of TiO2 surface, which is generated by the degree of solution’s pH above the point of zero charge (pzc) of TiO2, is observed to be the most critical for controlling the extent of CdS adsorption by taking absorbance and TEM images after a defined SILAR process. The acetate salt is the best one for faster and more adsorption of as-grown CdS due to its role of increasing the pH value in solution as a weak base. The highest pH of ∼ 9.5 obtained by adding a weak base, triethanolamine (TEA) to any Cd2+-dissolved solution induces the most adsorption of CdS within the least cycle optimized for better photovoltaic conversions efficiency and photoelectrochemical H2 evolution than those from any other conditions.

Synthesis, structural elucidation, in vitro antibacterial activity, DFT calculations, and molecular docking aspects of mixed-ligand complexes of a novel oxime and phenylalanine

An oxime ligand (HL) was synthesized by the condensation of 4-biphenylhydroxymoyl chloride with 2-amino-5-bromopyridine. The oxime ligand was reacted with l-phenylalanine and metal(II) acetate salts (Co(II), Ni(II), and Cu(II)) to synthesize mixed-ligand complexes. Structural elucidation of the newly synthesized ligand and complexes was performed by elemental analysis, 13C NMR, 1H NMR, FT-IR, ICP-OES, the measurements of molar conductivity and magnetic susceptibility. The thermal properties of the compounds were characterized by TG/DTA analyses. The antibacterial activities of the compounds were evaluated in vitro by the resazurin-aided broth microdilution method. Optimized molecular geometries of the HL and its metal complexes were calculated using the density functional theory (DFT) of the B3LYP method with 6-311G (d, p) and LANL2DZ basis sets. The NMR chemical shift values, vibrational frequencies, and HOMO-(LUMO or SOMO) energies were also computed using the mentioned level. A molecular docking study was performed to demonstrate the interactions of the synthesized compound with beta-ketoacyl-ACP synthase III (KAS III), an enzyme that has a key role in bacterial survival. Based on the MIC values and binding energy scores, both in vitro and in silico studies showed that the antibacterial activity of the Cu(II) complex was better than the other studied molecules.

Effect of Pre-Treatment on the Quality of Smoked Baltic Sprats

Abstract Baltic sprats (Sprattus sprattus balticus) are a good source of protein, vitamins D3, B12, minerals, and unsaturated fats. In response to consumer demand, various types of fish products of stable quality are available all year round. Pre-treatment with brine containing acetic acid, salt (NaCl), and/or granulated CaCl2 in various concentrations and proportions can be used to stabilise quality. The aim of the study was to evaluate the effect of various pre-treatment methods on smoked Baltic sprat sensory and technological parameters. Prior to smoking, fish was treated in a solution of additives in various proportions for 30 min. Untreated sprats were used as a control sample. The use of pre-treatment allowed reduction of the smoking losses; the combination of NaCl and acetic acid resulted in about 26% smoking loss. If no pre-treatment was applied, the drying losses after 24-hour storage were 1.6%, while using the solution of NaCl and CaCl2 it decreased to 0.3%. Both the pre-treatment method and freezing affected fish pH. The pH of smoked fresh sprats was 6.73 and for smoked frozen sprats, it was 6.38. Sensory testing using the Just About Right (JAR) method demonstrated that the use of acetic acid made smoked fish texture firmer.

Synthesis, Characterization and Bioactivity Studies of S-Allyl-β-N-(1-(4-methoxyphenyl)- ethylidene)dithiocarbazate and its Bis-chelated Cu(II), Ni(II) and Zn(II) Complexes

The general formula M(mAp-sadtc)2 type of metal complexes (where M = Cu2+, Ni2+, Zn2+) were synthesized by reaction of S-allyl-β-N-(1-(4-methoxyphenyl)ethylidene)dithiocarbazate ligand [H-(mAp-sadtc)] with metal(II) acetate salts (M = Ni2+, Cu2+ or Zn2+). The bis-chelated metal complexes were synthesized by subsequent reaction of metal(II) acetate salts and dithiocarbazate ligand in 1:2 proportion, respectively. The metal complexes and dithiocarbazate Schiff base were characterized by available methods like elemental analysis, 1H NMR, UV-Vis spectroscopy, 13C NMR, FT-IR spectroscopy, molar conductance and magnetic moments. Both nitrogen atoms of azomethine moiety (C=N) and deprotonated thiolate sulfur of dithiocarbazate ligand coordinated to the central metal ion formed five-membered rings on chelation. The synthesized dithiocarbazate ligand [H-(mAp-sadtc)] (1) and its bis-chelated M(mAp-sadtc)2 complexes (2-4) were screened for bioactivity against bacterial strains. The antibacterial results show that the metal(II) complexes exhibited significantly prominent antibacterial activity than dithiocarbazate ligand. Among the synthesized bis-chelated metal complexes, Ni-complex exhibited prominent antibacterial and antifungal activity as compared to other metal(II) complexes and ligand.

Structure and morphology effects on sensing properties Cd-=SUB=-x-=/SUB=-Pb-=SUB=-1-x-=/SUB=-S films

Polycrystalline films of CdxPb1-xS (0.021≤x≤0.090) supersaturated substitutional solid solutions with a cubic structure B1 (Fm3m space group) have been obtained with varying cadmium acetate salt Cd(CH3COO)2 in the reaction mixture within 0.01-0.10 mol/l on the sitall substrates. Their thickness changed from ~0.4 to ~1.0 microns. A correlation has been established between the structural-morphological and functional properties of CdxPb1-xS thin-film layers. The extreme character of the voltage sensitivity dependence on the cadmium salt concentration in the reaction bath is associated with the nonmonotonic introduction of cadmium into the PbS crystal lattice. It is shown that the maximum photocurrent is possessed by CdxPb1-xS thin-film layers formed from crystallites with pronounced faceting. We have found the surface sensitivity of the CdxPb1-xS films to the presence of ~0.02 mg/m3 NO2 in the air, which is significantly lower than the maximum allowable concentration. Keywords: chemical bath deposition, film morphology, structural properties, CdxPb1-xS solid solution, photosensitivity, sensing properties.

Effects of tea polyphenols on UVA-induced melanogenesis via inhibition of α-MSH-MC1R signalling pathway.

IntroductionUltraviolet (UV) irradiation is a major environmental factor affecting photoaging, which is characterized by skin wrinkle formation and hyperpigmentation. Although many factors are involved in the melanogenesis progress, UV is thought to play a major role in tanning. The pathway of α-melanocyte-stimulating hormone (α-MSH)-melanocortin receptor 1 (MC1R) is associated with UV-induced melanogenesis. Thus, α-MSH antagonists may have applications in the prevention of melanogenesis.AimTo investigate the effects of tea polyphenols (TPS) on pigmentation, and further explore the underlying mechanism.Material and methodsHuman keratinocyte cell line (HaCaT) cells and Human epidermal melanocytes (HEM) were exposed to UVA and treated with different concentrations of TPS or Nonapeptide-1 acetate salt (N-1A). Then, cell viability, melanin content, and tyrosinase activity of both kinds of cells were detected. Quantification of α-MSH in HaCaT cells and HEM cells determined by ELISA assays. Immunohistochemistry of HEM cells was employed to further investigate the expression of melanogenesis-related proteins.ResultsThe different concentrations of TPS were found to decrease the melanin content, tyrosinase activity and melanogenesis-related proteins such as microphthalmia-associated transcription factor (MITF), tyrosinase-related protein (TRP)1, and TRP2. Besides, TPS inhibited α-MSH-MC1R signalling through directly suppressed α-MSH expression rather than the down-regulated expression level of MC1R.ConclusionsOur findings indicate that TPS may be a potential whitening agent for use in cosmetics and the medical treatment of hyperpigmentation disorders.

Synthesis, Characterization, and Spectroscopic Studies of Bis-(meso-4-methoxyphenyl)-Benziporphyrin and Its Pd-Metal Complex

Benziporphyrin systems are widely explored, yet alternative improved synthetic routes towards these systems are needed. Here, a fairly and efficient synthesis of the free base and its metal complex is well designed. Dimethoxybenzene dicarbinol intermediate was prepared in excellent yields by reacting 4-methoxyphenylmagnesium bromide with isophthaladehyde in diethyl ether. Reaction with equivalent pyrrole and pentafluorobenzaldehyde in the presence of trifluoroacetic acid (TFA), followed by oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), provided good yields of bis-(meso-4-methoxyphenyl)-benziporphyrin. Metalation of the free base was performed using palladium(II) acetate salt in acetonitrile. All intermediates and the final products are fully characterized using NMR, HMRS, and UV-Vis spectroscopies and briefly discussed.