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1.
Molecules ; 27(22)2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36432023

RESUMEN

Cross contamination of ß-lactams is one of the highest risks for patients using pharmaceutical products. Penicillin and some non-penicillin ß-lactams may cause potentially life-threatening allergic reactions. The trace detection of ß-lactam antibiotics in cleaning rinse solutions of common reactors and manufacturing aids in pharmaceutical facilities is very crucial. Therefore, the common facilities adopt sophisticated cleaning procedures and develop analytical methods to assess traces of these compounds in rinsed solutions. For this, a highly sensitive and reproducible ultra-performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-MS/MS) method was developed for the analysis of Cephapirin and Ceftiofur. As per the FDA guidelines described in FDA-2011-D-0104, the contamination of these ß-lactam antibiotics must be regulated. The analysis was performed on an XBridge C18 column with 100 mm length, 4.6 mm diameter, and 3.5 µm particle size at an oven temperature of about 40 °C. The mobile phase was composed of 0.15% formic acid in water and acetonitrile as mobile phases A and B, and a flow rate was set to 0.6 mL/min. The method was validated for Cephapirin and Ceftiofur. The quantification precision and accuracy were determined to be the lowest limit of detection 0.15 parts per billion (ppb) and the lowest limit of quantification 0.4 ppb. This method was linear in the range of 0.4 to 1.5 ppb with the determination of coefficient (R2 > 0.99). This sensitive and fast method was fit-for-purpose for detecting and quantifying trace amounts of ß-lactam contamination, monitoring cross contamination in facility surface cleaning, and determining the acceptable level of limits for regulatory purposes.


Asunto(s)
Cefapirina , Humanos , Espectrometría de Masas en Tándem/métodos , Antibacterianos/análisis , Reproducibilidad de los Resultados , Cromatografía Liquida/métodos , beta-Lactamas , Monobactamas , Penicilinas
2.
Molecules ; 28(1)2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36615440

RESUMEN

Green syntheses of metallic nanoparticles using plant extracts as effective sources of reductants and stabilizers have attracted decent popularity due to their non-toxicity, environmental friendliness and rapid nature. The current study demonstrates the ecofriendly, facile and inexpensive synthesis of silver nanoparticles (AP-AgNPs) using the extract of aerial parts of the Anthemis pseudocotula Boiss. plant (AP). Herein, the aerial parts extract of AP performed a twin role of a reducing as well as a stabilizing agent. The green synthesized AP-AgNPs were characterized by several techniques such as XRD, UV-Vis, FT-IR, TEM, SEM and EDX. Furthermore, the antimicrobial and antibiofilm activity of as-prepared AP-AgNPs were examined by a standard two-fold microbroth dilution method and tissue culture plate methods, respectively, against several Gram-negative and Gram-positive bacterial strains and fungal species such as Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), multidrug-resistant Pseudomonas aeruginosa (MDR-PA) and Acinetobacter baumannii (MDR-AB), methicillin-resistant S. aureus (MRSA) and Candida albicans (C. albicans) strains. The antimicrobial activity results clearly indicated that the Gram-negative bacteria MDR-PA was most affected by AgNPs as compared to other Gram-negative and Gram-positive bacteria and fungi C. albicans. Whereas, in the case of antibiofilm activity, it has been found that AgNPs at 0.039 mg/mL, inhibit biofilms formation of Gram-negative bacteria i.e., MDR-PA, E. coli, and MDR-AB by 78.98 ± 1.12, 65.77 ± 1.05 and 66.94 ± 1.35%, respectively. On the other hand, at the same dose (i.e., 0.039 mg/mL), AP-AgNPs inhibits biofilm formation of Gram-positive bacteria i.e., MRSA, S. aureus and fungi C. albicans by 67.81 ± 0.99, 54.61 ± 1.11 and 56.22 ± 1.06%, respectively. The present work indicates the efficiency of green synthesized AP-AgNPs as good antimicrobial and antibiofilm agents against selected bacterial and fungal species.


Asunto(s)
Anthemis , Antiinfecciosos , Nanopartículas del Metal , Staphylococcus aureus Resistente a Meticilina , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Candida albicans , Escherichia coli , Bacterias Gramnegativas , Bacterias Grampositivas , Pruebas de Sensibilidad Microbiana , Componentes Aéreos de las Plantas , Extractos Vegetales/farmacología , Pseudomonas aeruginosa , Plata/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus
3.
Environ Res ; 170: 389-397, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30623886

RESUMEN

Inexpensive multi-walled carbon nanotubes (MCNTs) were prepared with 10-40 nm particle sizes and 9.0 m2g-1 surface area. Fenuron pesticide was removed in water using these CNTs with 100.0 µgL-1 concentration, 60 min contact time, 2.0 g L-1 dose, 7.0 pH, and 25 °C. 90% removal of fenuron pesticide was achieved. Adsorption data obeyed Tempkin, Freundlich, Langmuir and Dubinin-Radushkevich models. The standard free energies values of fenuron pesticide adsorption were -11.89, -11.59, -11.55 kJ mol-1. The values of enthalpy and entropy were -9.12 kJmol-1 and -26.61 × 10-3 kJ mol-1 K. The negative values of free energy showed speedy adsorption of fenuron pesticide on CNTs. The supramolecular mechanism of fenuron adsorption onto CNTs was fixed by simulation studies and the binding energy and binding affinity of fenuron with CNTs were - 6.5 kcal mol-1 and 5.85 × 104 M-1, respectively. There were one π-σ, seven π-π stacked, one π-π T-shaped, and three π-alkyl type of hydrophobic interactions between fenuron and carbon nanotube. These results clearly indicated the physical nature of the adsorption. The method is speedy, cost-effective, efficient and repeatable. Therefore, the established adsorption method is appropriate for adsorption of fenuron pesticide in waters.


Asunto(s)
Nanotubos de Carbono/química , Plaguicidas/química , Compuestos de Fenilurea/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Cinética , Termodinámica
4.
Environ Res ; 160: 353-357, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29055210

RESUMEN

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system is described. Both uptake and degradation processes of (-)-o,p-DDT were slightly higher than (+)-o,p-DDT enantiomer. The optimized parameters for uptake were 7.0µgL-1 concentration of o,p-DDT, 60min contact time, 5.0pH, 6.0gL-1 amount of reverine sediment and 25°C temperature. The maximum degradation of both (-)- and (+)-o,p-DDT was obtained with 16 days, 0.4µgL-1 concentration of o,p-DDT, pH 7 and 35°C temperature. Both uptake and degraded process followed first order rate reaction. Thermodynamic parameters indicated exothermic nature of uptake and degradation processes. Both uptake and degradation were slightly higher for (-)-enantiomer in comparison to (+)-enantiomer of o,p-DDT. It was concluded that both uptake and degradation processes are responsible for the removal of o,p-DDT from nature but uptake plays a crucial role. The percentage degradations of (-)- and (+)-o,p-DDT were 30.1 and 29.5, respectively. This study may be useful to manage o,p-DDT contamination of our earth's ecosystem.


Asunto(s)
DDT/química , Contaminantes Químicos del Agua/química , Sedimentos Geológicos , Concentración de Iones de Hidrógeno , Cinética , Simulación de Dinámica Molecular , Estereoisomerismo , Termodinámica
5.
Chirality ; 30(4): 491-497, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29315810

RESUMEN

The enantiomeric resolution of DL-alanine-DL-tryptophan dipeptide is described on amylose stationary phase. The eluent used was CH3 OH─CH3 COONH4 (10mM)─CH3 CN (50: 40, 10) at 0.8-mL/min flow, 230-nm detection, 25-minute run time, and 25°C ± 1°C temperature. The chiral phase was amylose [AmyCoat RP (15 cm × 0.46 cm × 5 micron)]. The magnitudes of the retention factors (k) were 2.71, 3.52, 5.11, and 7.75. The magnitudes of separation factor (α) were 1.19, 1.57, and 1.51 while the resolution factors (Rs) were 3.25, 14.84, and 15.76. The limits of detection and quantitation were of 2.5 to 5.4 and 12.8 to 27.5 µg/mL. The enantiomeric resolution is controlled by hydrogen, hydrophobic, π-π, steric, etc interactions. The elution order of the enantiomer was supported by the modeling data. The described method is fast, reproducible, precise, and selective, which can be used successfully for evaluating the enantiomers of the reported dipeptide.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Dipéptidos/química , Alanina/química , Amilosa/química , Dipéptidos/aislamiento & purificación , Hidrógeno/química , Límite de Detección , Reproducibilidad de los Resultados , Estereoisomerismo , Triptófano/química
6.
Chirality ; 29(7): 386-397, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28608452

RESUMEN

Chiral resolution of baclofen, bupropion, and etodolac profens was obtained with amylose derivatized chiral reversed stationary phase (carbamate groups). The eluent used for bupropion and etodolac was MeOH-water (20:80, v/v) and for baclofen was water-methanol (95:5, v/v). The eluent run rates, finding wavelength and temperature, were 1.0 mL/min, 220 nm and 27 ± 1 °C for all the eluents. The magnitude of the retardation factors for S- and R-enantiomers of baclofen, bupropion, and etodolac were 1.37, 2.62, 2.25, 3.25, 1.8, and 3.0. The magnitudes of separation and resolution factors were 1.90, 1.44, and 1.67 and 2.77, 2.35, and 2.04. Limits of detection and quantitation were 1.0-2.0 and 5.1-10.0 µg/mL. Chiral recognition mechanisms were recognized by simulation and high-performance liquid chromatography (HPLC) experiments. It was seen that hydrogen interactions, hydrophobic interactions, and π-π exchanges were the chief interactions for chiral recognition mechanisms. The described methods may be exploited for the chiral separation of baclofen, bupropion, and etodolac profens in any unknown sample.

7.
J Sep Sci ; 39(14): 2678-88, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27229265

RESUMEN

Iron nanoparticles were prepared by a green method following functionalization using 1-butyl-3-methylimidazolium bromide. 1-Butyl-3-methylimidazole iron nanoparticles were characterized using FTIR spectroscopy, energy dispersive X-ray fluorescence, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The nanoparticles were used in solid-phase membrane micro-tip extraction to separate vitamin B complex from plasma before high-performance liquid chromatography. The optimum conditions obtained were sorbent (15 mg), agitation time (30 min), pH (9.0), desorbing solvent [water (5 mL) + methanol (5 mL) + sodium hydroxide (0.1 N) + acetic acid (d = 1.05 kg/L, pH 5.5), desorbing volume (10 mL) and desorption time (30 min). The percentage recoveries of all the eight vitamin B complex were from 60 to 83%. A high-performance liquid chromatography method was developed using a PhE column (250 × 4.6 mm, 5.0 µm) and water/acetonitrile (95:5, v/v; pH 4.0 with 0.1% formic acid) mobile phase. The flow rate was 1.0 mL/min with detection at 270 and 210 nm. The values of the capacity, separation and resolution factor were 0.57-39.47, 1.12-6.00 and 1.84-26.26, respectively. The developed sample preparation and chromatographic methods were fast, selective, inexpensive, economic and reproducible. The developed method can be applied for analyzing these drugs in biological and environmental matrices.


Asunto(s)
Hierro/química , Nanopartículas del Metal/química , Microextracción en Fase Sólida , Complejo Vitamínico B/sangre , Cromatografía Líquida de Alta Presión , Humanos
8.
Biomed Chromatogr ; 30(5): 683-94, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26840015

RESUMEN

Enantiomeric resolution of multichiral centre racemates is an important area as some multichiral centre racemates are of great medicinal importance. However, enantioseparation of such types of racemates is a challenging task. Amongst many analytical techniques, capillary electrophoresis is a powerful technique and may be used to resolve such racemates. Only few papers are available describing enantiomeric resolution of such racemates. Therefore, efforts have been made to describe the enantiomeric resolution of multichiral centre racemates by capillary electrophoresis. This article discusses the importance of multichiral racemates, the need for capillary electrophoresis in enantiomeric resolution and chiral resolution of multichiral centre racemates using various chiral selectors. Further, attempts have been made to discuss the future challenges and prospects of enantiomeric resolution of multichiral racemates. The various chiral selectors used for the purpose are chiral crown ether, cyclodextrins, polysaccharides, macrocyclic glycopeptide antibiotics and ligand exchange.


Asunto(s)
Electroforesis Capilar/métodos , Preparaciones Farmacéuticas/análisis , Preparaciones Farmacéuticas/química , Ciclodextrinas/química , Estereoisomerismo
9.
Environ Monit Assess ; 187(8): 490, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26148690

RESUMEN

The chiral xenobiotics are very dangerous for all of us due to the different enantioselective toxicities of the enantiomers. Besides, these have different enantioselective bioaccumulations and behaviors in our body and other organisms. It is of urgent need to understand the enantioselective bioaccumulations, toxicities, and the health hazards of the chiral xenobiotics. The present article describes the classification, sources of contamination, distribution, enantioselective bioaccumulation, and the toxicities of the chiral xenobiotics. Besides, the efforts are also made to discuss the prevention and remedial measures of the havoc of the chiral xenobiotics. The challenges of the chiral xenobiotics have also been highlighted. Finally, future prospectives are also discussed.


Asunto(s)
Contaminantes Atmosféricos/análisis , Salud Ambiental , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Xenobióticos/análisis , Contaminantes Atmosféricos/química , Contaminantes Atmosféricos/farmacocinética , Animales , Biota/efectos de los fármacos , Salud Ambiental/métodos , Salud Ambiental/tendencias , Cadena Alimentaria , Humanos , Leche Humana/química , Plantas Comestibles/química , Estereoisomerismo , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/farmacocinética , Xenobióticos/química , Xenobióticos/farmacocinética
10.
Polymers (Basel) ; 15(16)2023 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-37631514

RESUMEN

Customer demand for natural packaging materials in the food industry has increased. Biocomposite films developed using boiled rice water could be an eco-friendly and cost-effective packaging product in the future. This study reports the development of bio-based films using waste materials, such as boiled rice water (matrix) and Pistacia vera shells (reinforcement material), using an adapted solution casting method. Several film combinations were developed using various concentrations of plasticizing agent (sorbitol), thickening agent (oil and agar), and stabilizing agents (Arabic gum, corn starch, and Pistacia vera shell powder). Various packaging properties of the film were analyzed and examined to select the best bio-based film for food packaging applications. The film fabricated with Pistacia vera shell powder in the biocomposite film exhibited a reduced water solubility, swelling index, and moisture content, as compared to polyethene packaging material, whereas the biocomposite film exhibited poor antimicrobial properties, high vapor transmission rate, and high biodegradability rate. The packaging properties and characterization of the film indicated that the boiled rice water film with Pistacia vera shell powder was suitable for packaging material applications.

11.
Analyst ; 137(18): 4309-17, 2012 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-22847179

RESUMEN

This work describes the preparation of polymer based monolithic materials and their use as stationary phases in capillary liquid chromatography. Multi-walled carbon nanotubes (MWCNT) were incorporated into a mixture containing benzyl methacrylate (BMA) and ethylene dimethacrylate (EDMA) as co-monomers. The optimized porogenic mixture was a ternary solution composed of cyclohexanol, 1,4-butandiol and butanol which resulted in a stable and homogeneous suspension. Six capillary columns with increasing amounts of MWCNT, from 0 to 0.4 mg mL(-1), were prepared by thermal polymerization in 0.32 mm (i.d.) and 150 mm length fused silica tubing. The chromatographic evaluation showed that the synthesized monolithic beds were mechanically stable while their porosity and permeability increased with the MWCNT content. The prepared capillary columns were tested for the separation of mixtures of ketones and phenols at an optimum flow rate of 2 µL min(-1). The results showed that incorporation of MWCNT slightly affected the retention while it enhanced the column efficiency by increasing the column efficiency by a factor of up to 9. This effect corresponded also to an improved resolution and full separation of the solutes.

12.
J Biochem Mol Toxicol ; 26(11): 469-76, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23132795

RESUMEN

An increase in the broad usage of Al2O3 nanoparticles (ANPs) in the food and agricultural sectors may produce rare hazards for human health. The objective of this study was to assess the acute toxicity of ANPs in human mesenchymal stem cells (hMSCs) in vitro. Cell viability, cellular uptake, morphology, and gene expression using quantitative real-time polymerase chain reaction (qRT-PCR) were analyzed. The results indicate that ANPs have a significant and dose-dependent effect on cytotoxicity. Control cells showed a characteristic, homogeneous nuclear staining pattern, whereas ANP-exposed cells showed abnormal nuclear morphological changes such as condensation or fragmentation. An early characteristic of apoptosis was observed in ANP-treated cells. Further confirmation of cell death in hMSCs was observed through increased expression of chosen signaling genes and also decreased expression of Bcl-2 during mitochondria-mediated cell death. Although they provide great advantages in food and agricultural products, the chronic and acute toxicity of ANPs still needs to be assessed carefully.


Asunto(s)
Óxido de Aluminio/toxicidad , Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/efectos de los fármacos , Células Madre Mesenquimatosas/efectos de los fármacos , Nanopartículas del Metal/toxicidad , Mitocondrias/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/agonistas , Proteínas Reguladoras de la Apoptosis/genética , Transporte Biológico , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Tecnología de Alimentos/tendencias , Humanos , Células Madre Mesenquimatosas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Mensajero/metabolismo , Transducción de Señal/efectos de los fármacos , Tecnología Farmacéutica/tendencias , Pruebas de Toxicidad Aguda
13.
ACS Omega ; 6(23): 15147-15155, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34151094

RESUMEN

Graphene nanocomposites have gained significant interest in a variety of biological applications due to their unique properties. Herein, we have studied the apoptosis-inducing ability and anticancer properties of functionalized highly reduced graphene oxide (HRG) and gold nanoparticles (Au NPs)-based nanocomposites (AP-HRG-Au). Samples were prepared under facile conditions via simple stirring and ultrasonication. All the samples were tested for their anticancer properties against different human cancer cell lines including lung (A549), liver (HepG2), and breast (MCF-7) cancer cells using doxorubicin as a positive control. In order to enhance the solubility and bioavailability of the sample, HRG was functionalized with 1-aminopyrene (1-AP) as a stabilizing ligand. The ligand also facilitated the homogeneous growth of Au NPs on the surface of HRG by offering chemically specific binding sites. The synthesis of nanocomposites and the surface functionalization of HRG were confirmed by UV-Vis, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The structure and morphology of the as-prepared nanocomposites were established by high-resolution transmission electron microscopy. Because of the functionalization, the AP-HRG-Au nanocomposite exhibited enhanced physical stability and high dispersibility. A comparative anticancer study of pristine HRG, nonfunctionalized HRG-Au, and 1-AP-functionalized AP-HRG-Au nanocomposites revealed the enhanced apoptosis ability of functionalized nanocomposites compared to the nonfunctionalized sample, whereas the pristine HRG did not show any anticancer ability against all tested cell lines. Both HRG-Au and AP-HRG-Au have induced a concentration-dependent reduction in cell viability in all tested cell lines after 48 h of exposure, with a significantly higher response in MCF-7 cells compared to the remaining cells. Therefore, MCF-7 cells were selected to perform detailed investigations using apoptosis assay, cell cycle analysis, and reactive oxygen species measurements. These results suggest that AP-HRG-Au induces enhanced apoptosis in human breast cancer cells.

14.
Sci Rep ; 10(1): 15012, 2020 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-32929130

RESUMEN

A series of La1-xCexCoO3 perovskite nanoparticles with rhombohedral phases was synthesized via sol-gel chemical process. X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Electron Diffraction Spectroscopy (EDS), Thermogravimetric Analysis (TGA), UV-Vis spectroscopy, Fourier Transform Infrared spectra (FTIR), Nitrogen Adsorption/desorption Isotherm, Temperature Program Reduction/Oxidation (TPR/TPO), X-ray Photoelectron Spectroscopy (XPS) techniques were utilized to examine the phase purity and chemical composition of the materials. An appropriate doping quantity of Ce ion in the LaCoO3 matrix have reduced the bond angle, thus distorting the geometrical structure and creating oxygen vacancies, which thus provides fast electron transportation. The reducibility character and surface adsorbed oxygen vacancies of the perovskites were further improved, as revealed by H2-TPR, O2-TPD and XPS studies. Furthermore, the oxidation of benzyl alcohol was investigated using the prepared perovskites to examine the effect of ceria doping on the catalytic performance of the material. The reaction was carried out with ultra-pure molecular oxygen as oxidant at atmospheric pressure in liquid medium and the kinetics of the reaction was investigated, with a focus on the conversion and selectivity towards benzaldehyde. Under optimum reaction conditions, the 5% Ce doped LaCoO3 catalyst exhibited enhanced catalytic activity (i.e., > 35%) and selectivity of > 99%, as compared to the other prepared catalysts. Remarkably, the activity of catalyst has been found to be stable after four recycles.

15.
Int J Biol Macromol ; 132: 244-253, 2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-30930264

RESUMEN

Many water bodies are being contaminated by atorvastatin, which has certain side effects and problems on healthy individuals through contaminated water. For this purpose, effective and selective carboxymethylcellulose macromolecule iron composite nanoparticles were synthesized by green methods, characterized and used for uptake of atorvastatin drug residue from water. Atorvastatin in water was analyzed by HPLC using Aqua C28 (250 mm × 46 mm id) column and buffer-ACN (35:65, v/v) as eluent. The maximum elimination of atorvastatin was 80% with 40 µg L-1 concentration; 40 min agitated time, 5.0 pH, 1.0 g L-1 dose and 298 K temp. The removal data obeyed Freundlich, Langmuir, Dubinin-Radushkevich and Temkin models. The values of free energy were -8.79, -8.73 and -8.65 kJ mol-1 at 20.0, 25.0 and 30.0 °C temperatures. Enthalpy value was -14.16 kJ mol-1; showing exothermic removal. Entropy was -18.74 × 10-3 kJ mol-1 K; presenting decrease in entropy in the process. The kinetics modeling showed pseudo-first-order and liquid film diffusion mechanisms of removal. The removal technology was quick, conservation pleasant and lucrative. It is because of it capability with little dose and interaction time. Hence, the reported technology is practical for the exclusion of atorvastatin in water resource.


Asunto(s)
Atorvastatina/química , Carboximetilcelulosa de Sodio/química , Hierro/química , Agua/química , Adsorción , Tampones (Química) , Concentración de Iones de Hidrógeno , Cinética , Modelos Químicos , Termodinámica
16.
Sci Rep ; 9(1): 7747, 2019 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-31123284

RESUMEN

Ce-doped LaMnO3 perovskite ceramics (La1-xCexMnO3) were synthesized by sol-gel based co-precipitation method and tested for the oxidation of benzyl alcohol using molecular oxygen. Benzyl alcohol conversion of ca. 25-42% was achieved with benzaldehyde as the main product. X-ray diffraction (XRD), thermogravimetric analysis (TGA), BET surface area, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (H2-TPR), temperature-programmed oxidation (O2-TPO), FT-IR and UV-vis spectroscopic techniques were used to examine the physiochemical properties. XRD analysis demonstrates the single phase crystalline high purity of the perovskite. The Ce-doped LaMnO3 perovskite demonstrated reducibility at low-temperature and higher mobility of surface O2-ion than their respective un-doped perovskite. The substitution of Ce3+ ion into the perovskite matrix improve the surface redox properties, which strongly influenced the catalytic activity of the material. The LaMnO3 perovskite exhibited considerable activity to benzyl alcohol oxidation but suffered a slow deactivation with time-on-stream. Nevertheless, the insertion of the A site metal cation with a trivalent Ce3+ metal cation led to an enhanced in catalytic performance because of atomic-scale interactions between the A and B active site. La0.95Ce0.05MnO3 catalyst demonstrated the excellent catalytic activity with a selectivity of 99% at 120 °C.

17.
RSC Adv ; 8(53): 30125-30147, 2018 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35546837

RESUMEN

TiO2 is a compound of great importance due to its remarkable catalytic and distinctive semiconducting properties. It is also a chemically stable, non-toxic and biocompatible material. Nano TiO2 is strong oxidizing agent with a large surface area and, hence, high photo-catalytic activities. With low production cost and a high dielectric constant, it is an inexpensive material. It can be prepared by diverse procedures such as solution and gas phase procedures. Nowadays, TiO2 is being used frequently for photo degradation of organic molecules and water splitting for hydrogen generation. Most important applications include purification, disinfection of waste water, self-cleaning coatings for buildings in urban areas and the production of the green currency of energy (hydrogen) by splitting water. The review describes the advances in the syntheses, properties and applications of TiO2 nano structures. Besides, efforts are also made to discuss the working mechanism and future challenges and perspectives.

18.
Colloids Surf B Biointerfaces ; 171: 606-613, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-30103149

RESUMEN

Second generation herbicide is applied for broad leaf weeds and yearly grasses in the growing fields of bananas, pineapple, sugarcane - polluting water sources. Cyanazine removal is described on functionalized iron nano particles (nano-adsorbent). The nano-adsorbent was developed via eco-friendly method, functionalized with 1-butyl-3-methylimidazolidium bromide followed by SEM, XRD and FT-IR characterization. Remaining cyanazine in water was examined by C18-HPLC method. The batch experimentation limits were 30.0 µg/L (concen.), 30.0 min. (time) 7.0 (pH), 2.5 g/L (dose) and 25.0 °C temperature. The experimentation data followed Freundlich, Temkin Dubinin-Radushkevich and Langmuir isotherms. The values of ΔG°, ΔH° and ΔS° were -7.41, -6.47 and -6.27 kJ/mol at 20, 25 and 30 °C temps.; -8.27 kJ/mol and -7.93 × 10-3 kJ/mol K. These observations shown removal process fast and exothermic. The removal obeyed pseudo-first-order and liquid film diffusion mechanism. The removal method was quick, eco-friendly, and cheap owing to be appropriate under usual situations of water assets. The removal method can be applied for cyanazine removal in different waters.


Asunto(s)
Hierro/química , Nanopartículas del Metal/química , Triazinas/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Cromatografía Líquida de Alta Presión , Tamaño de la Partícula , Propiedades de Superficie , Termodinámica , Triazinas/química , Agua/química , Contaminantes Químicos del Agua/química
19.
RSC Adv ; 8(66): 37905-37914, 2018 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-35558619

RESUMEN

Facile synthesis of micellar "nano" indole heterocyclic anti-cancer compounds is described. The synthesized compounds (11-23) were characterized by UV-VIS, 1H NMR, FT-IR and mass spectroscopy. The binding energies of DNA-compound adducts varied from -20.08 to -23.85 kJ mol-1, and they were stabilized by hydrophobic interactions and H-bonding. The synthesized compounds enter into minor grooves of DNA during adduct formation. The DNA binding constant of compounds 11-23 was 1.00 to 2.00 × 105 M-1. The drug-loading efficiency and drug-loading content in their micellar forms were recorded. Compounds 11, 12, 14 and 19 at a micellar concentration of 670 µL mL-1 displayed excellent anticancer activities against the HepG2/C3A line (25-50%). The potency of nano anticancer drugs was predicted by drug likeness using Lipinski's "rule of five". Taken together, compounds 11-23 could be used to treat cancers.

20.
Comb Chem High Throughput Screen ; 20(3): 208-214, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28000562

RESUMEN

AIM AND OBJECTIVE: The population of diabetic patients is rapidly increasing globally. The treatment of these patients is a complex phenomenon due to the use of the different drugs. The present article reports a synchronized fast SPE-UFLC separation of eight antidiabetic drugs in human plasma. Inexpensive solid phase extraction (SPE) and ultra fast liquid chromatography (UFLC) methods were presented for monitoring of eight antidiabetic drugs in human plasma. The separated drugs include metformin HCl, vildagliptin, gliclazide, linagliptin, sitagliptin, pioglitazone, glimepiride and repaglinide plasma sample. MATERIAL AND METHOD: The column used was a Sunshell C18 (150 x 4.6 mm, 2.6 µ) with eluent of acetate buffer (0.05% TEA in 0.05 M NH4Ac of pH 7.0 with H 3PO4) - ACN (60 : 40, v/v). The flow rate was 1.0 mL/min with a detection wavelength of 210 nm and column temp. of 45±1ºC. These drugs were extracted from human plasma using Sep-Pac C18 cartridge. Phosphate buffer (25 mM; pH 7.0) containing these drugs were allowed to pass through cartridge at 0.1 mL/min flow rate. The adsorbed drugs on C18 cartridge were eluted by methanol at 1.0 mL/min flow rate. RESULTS: The values for the retention, separation and resolution factors were ranged from 0.072 to 9.140, 1.443 to 4.208 and 2.147 to 18.652, correspondingly. The percent recoveries for these drugs in the standard laboratory samples prepared in water ranged from 77 to 88%. These values in plasma samples ranged from 10 to 22%. CONCLUSION: The validated method was fruitfully adopted to analyze these drugs in human plasma for the clinical monitoring of these drugs.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Hipoglucemiantes/sangre , Extracción en Fase Sólida/métodos , Monitoreo de Drogas/métodos , Diseño de Equipo , Humanos
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