Ethyl (S)-3-hydroxybutyrate is a crucial chiral intermediate for the synthesis of pharmaceuticals, fine chemicals, liquid crystals and natural products. In a search for novel biocatalytic methods for their production, a whole seed screening was carried out to try to identify new and more efficient biological catalysts, able to reduce ethyl acetoacetate stereoselectively. This study showed seeds of Lupinus albus L. (Fabaceae) to be a very efficient and stereoselective biocatalyst. A Box-Behnken experimental design - Response Surface Methodology was used to analyze the effect on the conversion of reaction and enantiomeric excess of the following five independent variables: substrate concentration, temperature, pH, agitation speed and reaction time. Statistical analysis confirmed the model's strong significance (R-2 approximate to 0.92; p-value approximate to 0.006). Optimal conditions were established by the model and experimentally confirmed as follows: substrate concentration, 35 mM; temperature, 30 degrees C; pH 5.0; agitation, 100 rpm; and reaction time, 48 h. Under these conditions, large-scale bioreduction afforded a product with 100% conversion, >99.9% enantiomeric excess, and 73% isolated yield, representing an effective productivity of 3.38 g L-1 (70.37 mg L-1 h(-1)) for the synthesis of ethyl (S)-3-hydroxybutyrate. These results demonstrate that L. albus seeds are a highly efficient and stereoselective biocatalyst, offering a novel and ecofriendly use for whole seeds of this plant. In addition, the scope and advantages of this methodology are discussed and compared with other similar procedures that describe the use of plant parts as biocatalysts.

Metallic nanoparticles (NPs) have gained interest due to their practical applications in various areas. The synthesis of NPs from biomass proposes a simple, economical and environmentally friendly alternative. In this work, gold NPs (AuNPs) and silver NPs (AgNPs) were synthesized from aqueous extracts of dried Ligustrum lucidum fruits. The biomolecules of the extract, in addition to acting as a reducing agent, are absorbed on the surface of the NPs giving excellent colloidal stability, increasing their catalytic capacity reflected in their recyclability. The TON and TOF values obtained for the reduction reaction of 4-nitrophenol in the presence of NaBH4, are 1.4 105 and 500 s−1 respectively. Minimum inhibitory concentrations (MICs) were established for AgNPs using pathogens from certified collections (E. coli MIC = 25 µg/mL; S. aureus MIC = 100 µg/mL). Fractional inhibitory concentration indices (FICIs) in the presence of gentamicin showed synergistic effects (FICI = 0.5). The results demonstrate that the aqueous extract of L. lucidum allows the synthesis of AuNPs and AgNPs, which have attractive catalytic and antimicrobial activities, in a simple and environmentally friendly way.

Son escasos los estudios científicos acerca de competencias y trabajos finales de grado. Con ese propósito, se procedió a estudiar un período de diez años de dictado de la asignatura Trabajo Final de la Carrera de Farmacia de la Facultad de Ciencias Químicas de la Universidad Católica de Córdoba, para identificar campos de acción emergentes, competencias desarrolladas y cómo estas se asocian con las específicas que requiere el entorno actual. Se estudiaron, además, los procesos de generación y el afianzamiento de competencias que utilizan la teoría de la actividad como marco teórico-metodológico de dicho estudio. La aplicación metodológica de los conceptos aportados por la teoría de la actividad arrojó resultados que ayudan a interpretar el sistema de actividad dinámico en el que se insertan estudiantes y docentes. Gracias al análisis de sus componentes, se pudo describir cómo estos interactúan en un marco temporal y culturalmente situado para desarrollar y afianzar competencias.

Abstract Whole seeds of Bauhinia variegata L. (Fabaceae) were utilized as a biological reducer to transform benzaldehyde into benzyl alcohol. The effects of some variables such as temperature, the load of substrate and co-solvent, were established to optimize the reductive process. Utilizing the optimal reaction conditions, a laboratory-scale reaction (final concentration of the substrate: 21.2 mM) was performed to obtain benzyl alcohol (conversion: 95%; isolated yield: 49%; productivity: 1.11 g L−1 or 0.046 g L−1h−1 of benzyl alcohol). In addition, using these optimal conditions, fourteen substituted benzaldehydes were reduced, with a conversion achieved to their corresponding benzyl alcohols ranging from 62% to >99% (isolated yields from 7% to 70%). Moreover, useful building blocks by the synthesis of the drugs and important commercial products were also obtained. The scope, limitations and advantages of this new biocatalytic synthetic method are also discussed.

The acetophenone stereoselective reduction reactions carried out by different chemical or biochemical methodologies reported in the literature were analyzed. This study showed the importance of evaluation in each reaction step, both holistically and quantitatively, even if the amounts used are at the mmol level. It is clear that the use of catalysts does not guarantee that the chemical process is environmentally friendly, as well as that the benefits of bio-driven processes can be diminished due to the complications of product purification. This work shows that the development of tools to determine the sustainability of a process is extremely important.

The fruits ofLigustrum lucidumwere used as an efficient biological reducer of carbonyl compounds, and trials were carried out to optimise the reductive process using acetophenone as the model substrate. In order to try to eliminate the dependence on the seasonal production of the fruits, a study was carried out to find ways to conserve them. The results reported here show that it is possible to store the dehydrated fruits of glossy privet at room temperature over a prolonged period of time, during which time they can be used as a common chemical reagent. On the other hand, studies performed on different parts of the fruits established that the seeds are responsible for the bioreduction process, with the best reduction conditions found being isolated seeds from the fruits of glossy privet at 25 degrees C, in a 100 mM phosphate buffer pH 6.0, using 0.67% w/v of DMSO as co-solvent with an acetophenone charge of 2.67 g/L (22 mM). Moreover, seed reuse studies showed that it is possible to recycle them, providing almost the same activity and enantioselectivity from the first to the fifth cycle, without any loss of biocatalytic properties. Finally, using whole seeds of glossy privet in optimal reaction conditions, important alcohols useful as key intermediates in the synthesis of industrial products were obtained on a laboratory scale through the reduction of specially selected ketones and aldehydes.

With the aim of finding new methods for environmentally friendly synthesis of chiral phenylethanols, a screening was carried out to identify seeds that could be used as a biocatalyst capable of reducing stereoselectively prochiral ketones. As a result, seeds ofBauhinia variegataL. (Fabaceae) were identified as being an efficient and stereoselective biological reducer of acetophenone to produce (S)-1-phenylethanol (conversion of 98% and 99e.e.%). Then, to optimise the reductive process, the effects of some variables such as temperature, load of substrate, pH, co-solvent, and reuse and storability of the seeds as a function of time were established. Utilising the optimal reaction conditions, nineteen substituted acetophenones were reduced to their corresponding chiral alcohols with a conversion ranging from 30% to 98% and enantiomeric excess of between 65% and >99%, and in addition, useful key intermediates were also obtained by the synthesis of drugs. The scope and advantages of this new biocatalytic synthetic method are also discussed.

En la era de la sociedad del conocimiento, la educación se ubica como un elementoclave del sistema productivo. Este modelo requiere sinergia y articulación entre laadquisición del conocimiento y el practicum laboral entendido como el espacio de socializacióne iniciación profesional. Además, plantea como un componente central que,en su período de formación, el estudiante adquiera competencias que lo posicionencomo idóneo para la resolución autónoma de situaciones problemáticas con las que seenfrentará en su ejercicio profesional.En ese sentido, la información disponible da cuenta de numerosos estudios en el campode las competencias, pero existe una vacancia en la búsqueda de un agrupamiento y posterior clasificación que sirva como estructura organizativa de planes de estudiosde educación basada en competencias. El presente artículo propone establecer, conbase en las fuentes consultadas, un modelo de clasificación de competencias comoherramental para planificaciones educativas.

Introduction: The appearance and color of the teeth are common concerns for patients and are associated with an increased need for treatments that can improve dental aesthetics. For this reason, in the past 20 years, dental science has been searching for new techniques and materials able to reduce dental discoloration. Method: Gummy candies containing two different concentrations (7% and 14% w/v) of hydrogen peroxide microencapsulated by ionic gelation were prepared. In vitro tooth whitening treatment was carried out for 30 days to test the bleaching action of these formulations. The surface color of the treated teeth was measured using a colorimetric technique. Results: Significant differences were found on comparing the whitening treatments for the two formulations with a control group, with two daily treatments using the formulation with 7% hydrogen peroxide being more effective for whitening than a daily single treatment using the formulation with 14 %. Conclusions: The two formulations developed had an in vitro higher bleaching effect in comparison with the control group, and in addition, better results were achieved if the daily dose was provided by more applications at a lower concentration of hydrogen peroxide.

El enfoque por competencias surgió como potencial respuesta a una necesidad de transformación metodológica en el ámbito educativo, ya no centrado en el docente y sus saberes transmisibles, sino en el estudiante y sus capacidades puestas en acción hacia un mundo profesional cambiante. En este sentido, la implementación de una educación basada en competencias (EBC) en las universidades requiere de estudios científicos sobre los entornos educativos de aprendizaje que propicien el desarrollo de las mismas, de los procesos en que se construyen y la dinámica que se perfila entre los actores y los campos disciplinares objeto de estudio. Una opción posible en este contexto es el estudio de los procesos de investigación conducentes a los Trabajos de Fin de Grado (TFG). Por ello, este trabajo pretende mostrar un mapa retrospectivo sobre 10 años de desarrollo de TFG en el área de farmacia, llevados a cabo por estudiantes de la Facultad de Ciencias Químicas de la Universidad Católica de Córdoba (UCC), Argentina. En ellos se identificaron los principales campos de acción, las disciplinas específicas que involucraron, las competencias que se desarrollaron y cómo se asocian estas con las competencias profesionales específicas que requiere el entorno actual. ARK: http://id.caicyt.gov.ar/ark:/s18511562/5d5tkdh7m

The aim of the present work was to optimize the main experimental variables of a procedure using HS-SPME/GC-MS as the analytical methodology to establish the profile of the volatile compounds present in aerial parts of Hedeoma multiflorum Benth.The influence of the type of fiber, equilibrium time, extraction time and extraction temperature on the composition of the volatile compounds was determined using response surface methodology (RSM), and the parameters of the models were corroborated by multiple linear regressions.The results showed that the regression models generated adequately explained the data variation and represented the relationships between the parameters and their responses.The optimal analysis conditions from the contour plots were established (DVB/CAR/PDMS fiber, with a 10 min equilibrium time, 10 min extraction time, and 40°C).Under these conditions, 41 volatile components in the whole plant were determined, which represents more than those reported using hydrodistillation.

A mechanistic interpretation of the kinetic profiles obtained for the stereoselective reduction of acetophenone promoted by Galactomyces candidus GZ1 under aerobic and anaerobic conditions was made. Based on experimental and bibliographical data, a mechanism which may involve the participation of two alcohol dehydrogenases with opposite stereoselectivities and alcohol oxidase is discussed. Due to the stereoselectivity of the reduction of acetophenone being changed when anaerobic conditions were used, this microorganism also permitted (S)-1-phenylethanol to be obtained in the absence of oxygen. Moreover, the kinetic profiles of the reactions of a racemic mixture of (R,S)-1-phenylethanol and pure (S)-1-phenylethanol with Gal. candidus were analyzed, which corroborated that there existed a reaction step where (S)-1-phenylethanol was oxidized to acetophenone. The results presented here show that not only is it possible to resolve racemic mixtures of phenylethanols when Gal. candidus is used as a biocatalyst, but that this is also efficient in causing the complete stereoinversion of pure (S)-1-phenylethanol to (R)-1-phenylethanol.

Twenty strains of fungi isolated from food samples were screened for the asymmetric reduction of acetophenone. A dimorphic fungus denominated initially as GZ1 and isolated from a carrot sour rot showed very high reduction activities, and based on phenotypic and genetic characteristics was identified as Galactomyces candidus. The only product of the reduction was confirmed to be (R)-1-phenylethanol. The bioreduction conditions mediated by Gal. candidus GZ1 were investigated, and the optimal conditions in terms of acetophenone concentration, temperature, pH media, co-solvent, the charge of inoculum and shaking speed were established. Under the optimal conditions of 1.875 g/L of acetophenone dissolved in DMSO (1.25% v/v), 112.5 g/L of microorganism cells in 100 mM sterile phosphate buffer solution at pH 7.0, 25 degrees C and 150 rpm, the conversion and enantiomeric excess values after 48 h reaction were 99% and > 99.9%, respectively. A preparative scale reaction of (R)-1-phenylethanol was made and the isolated yield was 82% with > 99.9 e.e.%. Additionally, a study using several substituted acetophenones was carried out, and the advantages and scope of GZ1 in the production of chiral 1-phenylethanols were established. In this sense, good results were obtained with 3'-hydroxyacetophenone and a preparative scale reaction was performed which give (R)-1-(3'-hydroxyphenyl) ethanol (key intermediate of Rivastigmine) with 53% of isolated yield and > 99.9 e.e.%.

Context Coriandrum sativum L. (Apiaceae) (coriander) is an herb grown throughout the world as a culinary, medicinal or essential crop. In traditional medicine, it is used for the relief of anxiety and insomnia. Systemic hydro-alcoholic and aqueous extract from aerial parts and seeds had anxiolytic and sedative action in rodents, but little is known about its central effect in chicks.Objective To study the effects of intracerebroventricular administration of essential oil from coriander seeds and its major component linalool on locomotor activity and emotionality of neonatal chicks.Materials and methods The chemical composition of coriander essential oil was determined by a gas-chromatographic analysis (> 80% linalool). Behavioural effects of central administration of coriander oil and linalool (both at doses of 0.86, 8.6 and 86 mu g/chick) versus saline and a sedative diazepam dose (17.5 mu g/chick, standard drug) in an open field test for 10 min were observed.Results Doses of 8.6 and 86 mu g from coriander oil and linalool significantly decreased (p < 0.05) squares crossed number, attempted escapes, defecation number and distress calls, and significantly increased (p < 0.05) the sleeping posture on an open field compared with saline and were similar to the diazepam group.Discussion and conclusion The results indicate that intracerebroventricular injection of essential oil from Coriandrum sativum seeds induced a sedative effect at 8.6 and 86 mu g doses. This effect may be due to monoterpene linalool, which also induced a similar sedative effect, and, therefore, could be considered as a potential therapeutic agent similar to diazepam.

In the present research, an analytical methodology to micro scale based on the use of the HS-SPME/GC-MS to determine volatile compounds present in Clinopodium gilliesii (Benth.) Kuntze (Lamiaceae) was employed, and settled differences and similarities with its essential oil obtained by hydrodistillation. A systematic description of the volatile components of flowers, stems, leaves and combined aerial parts (whole plant) was constructed via GC-MS analyses of HS-SPME adsorbed compounds and of essential oils obtained through hydrodistillation of the same tissues. Piperitenone oxide and piperitone oxide were the main components of both the HS-SPME analysis and essential oil analysis. The HS-SPME method can achieve comparable results to those obtained by essential oil analysis, by using very fewer samples, a shorter extraction time and a much simpler procedure. Para citar este artículo Vázquez, A., Aimar, M.,Decarlini, M., Demmel, G., Cantero, J y Ruiz, G. (2016). Volatile Organic Constituents of Clinopodium gilliesii (Benth.) Kuntze: Analysis by HS-SPME and classic hydrodistillation. Rev. Colomb. Investig. Agroindustriales, 3(1), 91-100. DOI: http://dx.doi.org/10.23850/24220582.351

This paper describes the search for novel vegetal biocatalysts for the stereoselective reduction of prochiral phenylketones. In this study, twenty native weeds were tested and Eryngium horridum Malme (Apiaceae) was proven to be an effective biocatalyst for the stereoselective reduction of acetophenone to (S)-1-phenylethanol (96% conversion, >99.9 e.e.%). Using this biocatalyst, fourteen chiral (S)-phenylethanols with excellent enantiomeric excesses (>98%) and variable conversions (30–100%) were obtained.

En el presente trabajo se ha optimizado una metodologia analitica a micro-escala basada en HS-SPME/GC-MS para determinar los compuestos volatiles presentes en Clinopodium odorum (Griseb.) Harley (Lamiaceae), y se establecieron diferencias y similitudes con su aceite esencial. Se realizo una descripcion sistematica de los componentes volatiles de flores, tallos, hojas y partes aereas combinadas (planta entera) a partir de los analisis por GC-MS a traves del sistema HS-SPME y de los aceites esenciales. Pulegona fue el componente principal tanto del analisis por HS-SPME, como del aceite esencial. Ademas, el oxido de piperitenona y el oxido de piperitona eran los otros componentes principales en el aceite esencial mientras que en el analisis por HS-SPME, prevalecieron cis-isopulegona y mentona. El metodo de HS-SPME puede lograr resultados comparables a los obtenidos por el analisis de aceite esencial, mediante el uso de muestras de menor tamano, un tiempo de extraccion mas corto y un procedimiento mas simple

El concepto de calidad ha evolucionado en los ultimos anos adquiriendo un extraordinario protagonismo. Un alimento puede ser descripto mediante una serie de parametros o variables que se transforman en atributos de calidad por la percepcion y preferencias de un usuario. Los valores que deben alcanzar los atributos para que la adecuacion sea positiva, son las especificaciones de calidad. Entre los atributos de calidad de un alimento se encuentra la organoleptica o sensorial, que puede ser definida, medida y ponderada, estableciendose niveles de confianza para el cumplimiento de las especificaciones de calidad acordadas. Los componentes quimicos volatiles del alimento, estimulan las terminales sensitivas de boca y nariz, afectando a los atributos olor, aroma, fragancia, gusto y flavor. Por lo tanto, identificar dichos componentes y determinar su proporcion en el producto es de vital importancia para establecer correlaciones con las respuestas sensoriales. En el presente proyecto se desarrollaran metodologias analiticas basadas en Microextraccion en Fase Solida del Espacio de Cabeza seguida de Cromatografia Gaseosa (HS-SPME/GC) y en aceptabilidad sensorial para su aplicacion en la caracterizacion de plantas aromaticas y productos alimenticios, con la finalidad de identificar los compuestos volatiles responsables de la aceptacion o rechazo de los productos investigados, de evaluar el efecto del almacenamiento sobre las caracteristicas de los mismos, y establecer similitudes y diferencias entre los perfiles quimicos de diferentes productos del mismo tipo. Ademas, se realizaran protocolos de control de calidad para las muestras estudiadas.