Laccase-based biosensor for determination of acetaminophen

The use of biosensors based on laccase is an interesting alternative for monitoring phenolic compounds in pharmaceutical and environmental analysis. The detection and determination of acetaminophen in pharmaceutical samples, using a biosensor with carbon paste modified with laccase is described. The method showed good linearity (r = 0.9954) and low detection and quantification limits (2.4 x 10-6 mol.L-1 and 7.9 x 10-6 mol.L-1, respectively). Furthermore, the proposed methodology using an enzyme electrode showed appropriated reproducibility and selectivity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Electrochemical Behavior and Determination of Fluconazole

The electrochemical behavior of fluconazole showed an irreversible oxidation process, with the electrochemical - chemical mechanism being highly dependent on the electrode material. Adsorption of reagent at positive applied potential was observed at Pt electrode while preferential adsorption of the oxidation products was observed at Glassy Carbon surfaces. In pH below 7.0, the anodic current process was intensively decreased. At carbon paste electrode, the fluconazole oxidation current, recorded in phosphate buffer solution (pH 8.0), changed linearly with the fluconazole concentration, Ipa = 5.7×10-5 (mA) × 0.052 [Fluconazol] (μg mL-1), in the range of 48.0 to 250.0 μg mL-1. The detection limit obtained was 6.3 μg mL-1.O comportamento eletroquímico do fluconazol demonstrou oxidação irreversível com mecanismos eletroquímicos-químicos dependentes do material eletródico. Em eletrodos de Pt observou-se adsorção do reagente sob a aplicação de potenciais positivos, enquanto adsorção preferencial dos produtos foi observada em eletrodo de carbono vítreo. Em valores de pH inferiores a 7,0, a corrente do processo anódico é intensamente diminuída. Em eletrodo de pasta de carbono e tampão fosfato, pH 8,0, a corrente de oxidação variou linearmente com a concentração de fluconazol em solução, Ipa = 5,7×10-5 (mA) × 0,052 [Fluconazol] (μg mL-1), no intervalo de 48,0 a 250,0 μg mL-1. O limite de detecção obtido foi 6,3 μg mL-1.FAPES

Electroanalytical characterization of 4-nerolidylcatechol and its derivatives

4-Nerolidylcatechol (4-NRC) is the most abundant antioxidant product isolated from the roots of Pothomorphe umbellata (L) Miq. It displays important sunscreen protection and other pharmacological properties comprising analgesic, anti-inflammatory and antimicrobial activity. However, low water solubility and chemical instability has limited its use and analysis. Therefore, chemical modifications such as silylated derivatives and inclusion complexes have been proposed. Regarding antioxidants, electrochemical investigation techniques are important tools in comprehensive characterization of phenol molecules, showing higher selectivity than spectroscopic methods. In the present study, the 4-NRC and its derivatives are characterizated by voltammetric analysis in order to support physicochemical properties of 4-NRC inclusion-complex and catechol silylation products. It is observed that in both liquid- or solid-state the redox process of the 4-NRC is non-reversible and occurs in two stages, seen as two anodic peaks, respectively, at 0.75 and 1.12 V. The electrochemical techniques showed to be also a powerful tool to evaluate the efficiency of chemical modification on electroactive groups.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Electroanalytical method for the analysis of methyldopa in pharmaceutical tablets using a crude extract of laccase from Pycnoporus sanguineus as oxidizing agent

Several colorimetric and chromatographic methods have been used for the identification and quantification of methyldopa (MA) in pharmaceutical formulations and clinical samples. However, these methods are time- and reagent-consuming, which stimulated our efforts to develop a simple, fast, and lowcost alternative method. We carried out an electroanalytical method for the determination of MA in pharmaceutical formulations using the crude enzymatic extract of laccase from Pycnoporus sanguineus as oxidizing agent. This method is based on the biochemical oxidation of MA by laccase (LAC), both in solution, followed by electrochemical reduction on glassy carbon electrode surface. This method was employed for the determination of MA in pure and pharmaceutical formulations and compared with the results obtained using the official method. A wide linear curve from 2.5 x 10-5 to 1 x 10-4 mol L-1 was found with a detection limit calculated from 4.5 x 10-6 mol L-1.Colegio de Farmacéuticos de la Provincia de Buenos Aire

The Sloan Digital Sky Survey Quasar catalog : fourteenth data release

We present the data release 14 Quasar catalog (DR14Q) from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV). This catalog includes all SDSS-IV/eBOSS objects that were spectroscopically targeted as quasar candidates and that are confirmed as quasars via a new automated procedure combined with a partial visual inspection of spectra, have luminosities Mi [z = 2] < −20.5 (in a Λ CDM cosmology with H0 = 70 km s−1 Mpc−1, ΩM =0.3, and ΩΛ = 0.7), and either display at least one emission line with a full width at half maximum larger than 500 km s−1 or, if not, have interesting/complex absorption features. The catalog also includes previously spectroscopically-confirmed quasars from SDSS-I, II, and III. The catalog contains 526 356 quasars (144 046 are new discoveries since the beginning of SDSS-IV) detected over 9376 deg2 (2044 deg2 having new spectroscopic data available) with robust identification and redshift measured by a combination of principal component eigenspectra. The catalog is estimated to have about 0.5% contamination. Redshifts are provided for the Mg II emission line. The catalog identifies 21 877 broad absorption line quasars and lists their characteristics. For each object, the catalog presents five-band (u, g, r, i, z) CCD-based photometry with typical accuracy of 0.03 mag. The catalog also contains X-ray, ultraviolet, near-infrared, and radio emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra, covering the wavelength region 3610–10 140 Å at a spectral resolution in the range 1300 < R < 2500, can be retrieved from the SDSS Science Archiver Server.Publisher PDFPeer reviewe

The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra. \ua9 2015. The American Astronomical Society

Electrochemical methods used for evaluation of antioxidant activity of natural products

O presente artigo apresenta uma revisão sobre as aplicações dos métodos eletroquímicos na identificação e quantificação da atividade antioxidante. Trabalhos descrevendo o uso de técnicas voltamétricas (cíclica e de pulso diferencial), coulometria e sistemas de separação com detecção eletroquímica, utilizando diferentes tipos de eletrodos (ex. Pt, carbono vítreo, pasta de carbono), assim como técnicas combinadas (CRAC, biossensor de DNA) foram compilados. Uma breve leitura sobre grande quantidade de trabalhos descritos demonstra que é necessário estabelecer critérios de medida bem definidos que permitam comparações entre diferentes resultados. Sobre este aspecto, a padronização dos procedimentos de medida é ainda necessária.This article presents a review about the application of electrochemical methods in the identification and quantification of antioxidant activity. Reports describing the utilization of voltammetry (cyclic and differential pulse), coulometry and amperometric detection systems, using the most different types of electrodes such as Pt, glassy carbon, pyrolitc graphite, carbon paste, chemical modified electrodes and biosensors, as well combined techniques (CRAC, DNA biosensor) were compiled. A brief reading over the enormous quantity of the reported data makes possible to conclude that it is necessary to get a measure criterion which allows the comparison between different results. Under this aspect, the standardization of the measurement procedures still is necessary.Colegio de Farmacéuticos de la Provincia de Buenos Aire

The importance of inorganic compounds in leishmaniasis treatment

La leishmaniasis, infección por protozoarios tripanosomátidos del género Leishmania sp, es una enfermedad endémica que abarca mas de 80 países incluyendo algunos del continente europeo y principalmente los países en vías de desarrollo. En esta revisión son mostradas las opciones terapéuticas usuales enfocando principalmente sus mecanismos de acción y de resistencia, farmacocinética y toxicidad. Asimismo, son presentados los intentos de aplicación de agentes quimioterápicos, en especial los compuestos organometálicos derivados de ligandos potencialmente activos.Leishmaniasis is a parasitic disease caused by protozoan genus Leishmania. It is an endemic illness that encloses 80 countries, including some of the European continent and especially in development countries. In this revision the usual therapeutical options, focusing mechanisms of action and resistance, pharmacokinetics and toxicity are discussed . Additionally, the attempts for application of other chemotherapeutical drugs, especially organometalic substances derivatives of potencial active ligands, are also cited .Colegio de Farmacéuticos de la Provincia de Buenos Aire

Measurement of the anodic potential in solid state: a tool for determination of the antioxidant potential of phytomedicine

Las técnicas electroanalíticas se muestran bastante promisorias para el control de calidad de materias-primas vegetales. La determinación del potencial anódico en estado sólido es una alternativa rápida, práctica y de bajo costo, además de ser un parámetro de identificación, puede ser utilizado para determinar también su actividad antioxidante. El sistema desarrollado consiste básicamente en el empleo de un electrodo modificado, compuesto por electrodo de pasta de carbono modificado con la materia-prima vegetal pulverizada (EMF). Los ensayos fueron hechos en una celda electroquímica conteniendo electrodos de trabajo (EMF), referencia (Ag/AgCl, KCl ) y auxiliar (Pt).The electroanalytical techniques are very promissing to perform the quality control of crude vegetable. Solid State Differential Pulse Voltammetry in the supporting electrolyte is able to detect the oxidation signals of the active material, which can be used as a parameter to identify the type of crude vegetable and its antioxidant activity. The working electrode consisted in a carbon paste electrode modified with the pow- der of vegetable raw material (EMF). The electrochemical measurements were performed in a cell containing the working (EMF), reference (Ag/AgCl, KCl ) and auxiliary (Pt) electrodes.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Studies on the bioavailability of zinc in rats supplementated with two different zinc-methionine compounds

Se han estudiado los efectos de los complejos zinc-metionina con la relación molar 1:1 y 1:2 como suplementación alimentaria de zinc en ratones. La obtención y la caracterización de dos complejos de zinc fueron evaluadas por análisis elemental y FTIR. El efecto de la biodisponibilidad de zinc fue estudiado por la retención en el contenido del metal en los tejidos de ratones alimentados con diversas fuentes. El compuesto 1:1 era un complejo del catión de fórmula [Zn(C5H10NO2S)(H2O)2]+ , muy soluble en agua, mientras que el compuesto 1:2 era un complejo neutro de fórmula [Zn(C5H10NO2S)2], solamente soluble debajo de pH 3. Los espectros de FTIR de ambos complejos demostraron franjas de absorción fuertes debido al estiramiento del C-O del grupo del aminoácido (extendiéndose de νs(C=O) 1638 cm–1 y νas(C-O) 1414 cm–1 , en ZnMet, a νs(C=O) 1608 cm–1 y νas(C-O) 1426 cm–1 , en Zn(Met)2, cambiados de posición perceptiblemente las frecuencias asimétricas aumentan y las frecuencias simétricas disminuyen con respecto a la metionina libre νs(COO) 1582 cm–1 y νas(COO) 1415 cm–1 , 1720 cm–1 El resultado de la alimentación fue observado claramente en la eliminación fecal del zinc de los animales del grupo de control perceptiblemente diferente (P < 0,05) que los tratados de los . animales con dietas suplementadas con zinc, pero no se observó en la eliminación urinaria. El estudio indica que el contenido del zinc en las heces recogidas en 14 días para toda la dieta del zinc era perceptiblemente diferente (P < 0,05) del grupo de control (tratamiento de los animales con prácticamente ausencia de zinc). La retención del zinc en los grupos a los que se administraron compuestos de metionina fue perceptiblemente más alta que la alimentación con dieta de ZnSO4 y de ZnO. En conclusión, estos datos indican que el uso del los complejos zincmetionina constituyen una herramienta valiosa a la biodisponibilidad del aumento del zinc, no obstante sin diferencias significativas entre ZnMet y la forma Zn(Met)2.The effects of zinc-methionine complexes with molar relation 1:1 and 1:2 have been examined as nutritional supplements in rats. The synthesis and characterization of two compounds were studied by elemental analysis and FTIR. The bioavailability effect was studied by zinc retention and its content in rat tissues in rats fed with different zinc-methionine complexes. The compound 1:1 was a cation complex of formula [Zn(C5H10NO2S)(H2O)2]+ , very water soluble, while the compound 1:2 was a neutral complex of formule [Zn(C5H10NO2S]2], only soluble in pH below 3. FTIR spectra of both complexes show strong absorption bands due to C-O stretching of the amino acid group (ranging from νs(C=O) 1638 cm–1 and νas(C-O) 1414 cm–1 , in ZnMet, to νs(C=O) 1608 cm–1 and νas(C-O) 1426 cm–1 , in Zn(Met)2) shifted significantly with respect to the ones observed for the free methionine (νas(COO) 1582 cm–1 and νs(COO) 1415 cm–1 ,1720 cm–1 ). The nutritional result in the zinc fecal elimination of the animals of the control group was significantly different (P < 0.05) to the ones observed for the animals treaties with zinc supplemented diets, though this was not observed during urinary elimination. This study indicates that the content of zinc in the feces collected in 14 days for all zinc diet were significantly different (P<0.05) from the control group (animals treaties with zinc practically absent). The retention of zinc in the groups treated with the methionine compounds was significantly higher than the ones fed with ZnSO4 and ZnO diet. In conclusion, these data indicate that the use of zinc-methionine chelates is a valuable tool to increase bioavailability of zinc, however without significant differences between ZnMet and Zn(Met)2.Colegio de Farmacéuticos de la Provincia de Buenos Aire