Quantitation of chiral amino acids from microalgae by MEKC and LIF detection.

In this work, chiral and nonchiral MEKC methods have been combined with LIF detection (MEKC-LIF) to identify and quantify a group of D- and L-amino acids (D/L-aa) in different microalgae samples. The combination of the nonchiral and chiral-MEKC-LIF methods made the identification of the microalgae amino acids easier, previously derivatized with FITC, providing a double proof on the correct detection of these analytes. Three microalgae species, Spirulina platensis, Dunaliella salina, and Tetraselmis suecica, were compared in terms of their content in D-Arg, L-Arg, D-Lys, L-Lys, D-Ala, L-Ala, D-Glu, L-Glu, D-Asp, and L-Asp.

Analysis of chiral amino acids in conventional and transgenic maize.

In this work, a new chiral micellar electrokinetic chromatography with laser-induced fluorescence detection (chiral-MEKC-LIF) method is proposed to identify and quantify D- and L-amino acids in three lines of transgenic maize and their corresponding nontransgenic parental lines grown under identical conditions. The optimized procedure includes amino acids extraction, derivatization with FITC and chiral-MEKC-LIF separation in a background electrolyte composed of 100 mM sodium tetraborate, 80 mM SDS, and 20 mM beta-CD at pH 10.0.

Characterization by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry of the lipid fraction of Spirulina platensis pressurized ethanol extract.

Microalgae have been suggested as a potential source for new functional ingredients, making possible the development of new functional foods from natural origin. Among the natural ingredients, polyunsaturated fatty acids (PUFAs) have generally been identified as an interesting group of compounds with biological activity, mainly related to their anti-inflammatory properties. In this regard, the use of environmentally friendly extraction procedures (e.

Purification of lactulose from mixtures with lactose using pressurized liquid extraction with ethanol-water at different temperatures.

The viability of the purification of lactulose from a mixture with lactose [70:30 (w/w)] using pressurized liquid extraction (PLE) at 1500 psi for 30 min was studied. Different temperatures (from 40 to 130 degrees C) and proportions of ethanol:water (70:30, 80:20, 90:10, 95:5, and 100:0) as the extraction solvent were assayed. Lactose and lactulose were measured by gas chromatographic analysis as their trimethylsilyl derivatives.

Use of compressed fluids for sample preparation: food applications.

This review attempts to provide an updated overview (including works published till June 2006) on the latest applications of compressed fluids as sample preparation techniques for food analysis. After a general review of the principles of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE; also called accelerated solvent extraction, ASE or subcritical water extraction, SWE, when water is employed as extraction solvent), the principal applications of such techniques in the mentioned fields of food and natural products are described, discussing their main advantages and drawbacks.

[Affect and gender].

Unlabelled: Studies about affect and differences with regards to gender and age throw little conclusive results. There is a certain agreement on stablishing a bifactorial structure that would integrate the different dimensions of affect.

Objective: the aim is to analyze the distinguishing characteristics of affect in normal populations as a function of gender and age.

Differences in the frequency and distribution of BRCA1 and BRCA2 mutations in breast/ovarian cancer cases from the Basque country with respect to the Spanish population: implications for genetic counselling.

The prevalence of unique and recurrent BRCA1 and BRCA2 pathogenic mutations and unclassified variants varies among different populations. Two hundred and thirty-six breast and/or ovarian cancer patients were analysed to clarify the role of these genes in the Basque Country. We also studied 130 healthy women from the general population from the same region.

Use of specially designed columns for antioxidants and antimicrobials enrichment by preparative supercritical fluid chromatography.

A new, specially designed column has been developed for fractionation of supercritical fluid extract of rosemary by using a preparative supercritical fluid chromatography system (Prep-SFC). The column evaluated in this work was prepared using a new packing method consisting of a combination of slurry and supercritical CO2 with commercial silica particles coated with a stationary phase commonly used in gas chromatography, such as SE-54 (5% phenyl-, 95% methylsilicone). The new packing procedure provided columns with reasonable efficiencies, with high stability and useful at high-pressure range.

Cultural factors in decision-making about child physical abuse: identifying reporter characteristics influencing reporting tendencies.

Objective: This study examined cultural factors that may influence child physical abuse reporting. Relevant cultural factors such as the respondents' ethnic identity and corporal punishment acceptability were investigated as proximal variables of ethnicity that affect child physical abuse reporting tendencies.

Method: Participants consisted of 378 Caucasian, Hispanic, and African American college students.

Dunaliella salina microalga pressurized liquid extracts as potential antimicrobials.

In the present work, the antimicrobial activity of different pressurized liquid extracts obtained from Dunaliella salina microalga was tested against several microorganisms of importance for the food industry (Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus niger). Different solvents (hexane, petroleum ether, hexane, and water) and extraction conditions (40, 100, and 160 degrees C) were tested. Results showed that the best antimicrobial activity was obtained for each solvent at the highest extraction temperature (160 degrees C).

Selective recovery of tagatose from mixtures with galactose by direct extraction with supercritical CO2 and different cosolvents.

A selective fractionation method of carbohydrate mixtures of galactose/tagatose, using supercritical CO(2) and isopropanol as cosolvent, has been evaluated. Optimization was carried out using a central composite face design and considering as factors the extraction pressure (from 100 to 300 bar), the extraction temperature (from 60 to 100 degrees C), and the modifier flow rate (from 0.2 to 0.

Expression of recombinant human follicle-stimulating hormone in the mammary gland of transgenic mice.

In this article, we describe the use of a caprine beta-lactoglobulin (betaLG) expression cassette previously obtained by our group to target the expression of the human follicle-stimulating hormone (hFSH) to the mammary gland of transgenic mice. The hFSH is a pituitary glycoprotein composed of two subunits (alpha and beta). At present, this protein is obtained from mammalian cellular fermentors, and it is extensively used in the treatment of human infertility.

Optimization of the extraction of antioxidants from Dunaliella salina microalga by pressurized liquids.

In this work, extraction of antioxidant compounds from Dunaliella salina microalga is optimized by combining pressurized liquid extraction (PLE) and experimental design (three-level factorial design) with three different solvents (hexane, ethanol, and water). Two main factors were considered, the extraction temperature (40, 100, and 160 degrees C) and the extraction time (5, 17.5, and 30 min).

Isolation of functional ingredients from rosemary by preparative-supercritical fluid chromatography (Prep-SFC).

A supercritical fluid extract of rosemary has been fractionated under supercritical conditions by using a preparative-SFC system. In this work, the optimum conditions have been evaluated to achieve a selective isolation of the compounds responsible for both, antioxidant and antimicrobial activities. A 25 cm x 10 mm i.

Supercritical carbon dioxide extraction of compounds with antimicrobial activity from Origanum vulgare L.: determination of optimal extraction parameters.

Oregano leaves were extracted using a pilot-scale supercritical fluid extraction plant under a wide range of extraction conditions, with the goal of determining the extraction and fractionation conditions to obtain extracts with optimal antimicrobial activity. In this investigation, the essential oil-rich fractions were selectively precipitated in the second separator, and their chemical composition and antimicrobial activity were investigated. Gas chromatography-mass spectrometry analysis of the various fractions resulted in the identification of 27 compounds of the essential oil.

Subcritical water extraction of nutraceuticals with antioxidant activity from oregano. Chemical and functional characterization.

In the present work, oregano leaves (Origanum vulgare L.) are explored as natural source of nutraceuticals with antioxidant activity. To do this, subcritical water extraction (SWE), a new environmentally friendly technique, is employed as extraction procedure and HPLC coupled to DAD is used for the chemical characterization of the extracts.

A mutant pyruvate dehydrogenase E1 subunit allows survival of Escherichia coli strains defective in 1-deoxy-D-xylulose 5-phosphate synthase.

The 2-C-methyl-D-erythritol 4-phosphate pathway has been proposed as a promising target to develop new antimicrobial agents. However, spontaneous mutations in Escherichia coli were observed to rescue the otherwise lethal loss of the first two enzymes of the pathway, 1-deoxy-D-xylulose 5-phosphate (DXP) synthase (DXS) and DXP reductoisomerase (DXR), with a relatively high frequency. A mutation in the gene encoding the E1 subunit of the pyruvate dehydrogenase complex was shown to be sufficient to rescue the lack of DXS but not DXR in vivo, suggesting that the mutant enzyme likely allows the synthesis of DXP or an alternative substrate for DXR.

Genetic strain variations in the metaphase-II phenotype of mouse oocytes matured in vivo or in vitro.

The interplay between genetic and epigenetic factors plays a central role in mammalian embryo production strategies that superimpose ex vivo or in vivo manipulations upon strain background characteristics. In this study, we examined the relationship between genetic background and the phenotypic properties of mouse metaphase-II (M-II) oocytes that were matured under in vivo (IVO) or in vitro conditions, either in a basal (IVM) or a supplemented (IVM + ) medium. Differences existed amongst inbred (C57BL/6), outbred (CF-1, Black Swiss, NU/NU) and hybrid lines (B6D2F1) induced to superovulate with regard to cytoplasmic microtubule organizing center (MTOC) number but not spindle size or shape, except for larger and asymmetrical spindles in Black Swiss oocytes.

Separation and characterization of antioxidants from Spirulina platensis microalga combining pressurized liquid extraction, TLC, and HPLC-DAD.

A new procedure has been developed to separate and characterize antioxidant compounds from Spirulina platensis microalga based on the combination of pressurized liquid extraction (PLE) and different chromatographic procedures, such as TLC, at preparative scale, and HPLC with a diode array detector (DAD). Different solvents were tested for PLE extraction of antioxidants from S. platensis microalga.

Capillary electrophoresis-mass spectrometry of Spirulina platensis proteins obtained by pressurized liquid extraction.

In this work, the usefulness of CE-MS to monitor and optimize the pressurized liquid extraction (PLE) of proteins from Spirulina platensis microalga is demonstrated. Crude and purified PLE extracts from microalga were analyzed by CE-MS. It was observed that the use of purification protocols of phycobiliproteins (namely, ultrafiltration or precipitation-dialysis-freeze drying) resulted in better CE resolution and MS signals, demonstrating that sample matrix plays an important role in CE-MS of proteins in real samples.

Pressurized liquid extraction-capillary electrophoresis-mass spectrometry for the analysis of polar antioxidants in rosemary extracts.

A method based on capillary electrophoresis-electrospray-mass spectrometry (CE-ESI-MS) was developed to qualitatively characterize natural antioxidants from rosemary (Rosmarinus officinalis L.) in different fractions obtained by pressurized liquid extraction (PLE) using subcritical water. The parameters of CE-ESI-MS were adjusted allowing the separation and characterization of different compounds from rosemary in the PLE fractions.

Activated bovine cytoplasts prepared by demecolcine-induced enucleation support development of nuclear transfer embryos in vitro.

Demecolcine-induced enucleation (IE) of mouse oocytes has been shown to improve development to term of cloned mice. In this study, we characterized the kinetics and morphological progression of bovine oocytes subjected to IE, and evaluated their ability to support embryo development to the blastocyst stage after nuclear transfer (NT). In vitro matured bovine oocytes were parthenogenetically activated and subsequently exposed to demecolcine at various times post-activation.

Characterization of proteins from Spirulina platensis microalga using capillary electrophoresis-ion trap-mass spectrometry and capillary electrophoresis-time of flight-mass spectrometry.

In this work, a new capillary electrophoresis-mass spectrometry (CE-MS) procedure is developed to analyze proteins in Spirulina platensis microalgae. It is demonstrated that a fine optimization of several separation parameters is essential in order to achieve suitable CE-MS analysis of these proteins in natural extracts from microalgae. Namely, optimization of the composition of the separation buffer, electrospray conditions, and washing routine between runs are required in order to obtain reliable and reproducible CE-MS analyses of the main proteins found in this microalga (namely, allophycocyanin-alpha chain, allophycocyanin-beta, c-phycocyanin-alpha, and c-phycocyanin-beta).

Chemical composition and antimicrobial activity of Rosmarinus officinalis L. essential oil obtained via supercritical fluid extraction.

The chemical composition and antimicrobial activity of essential oil-rich fractions obtained by supercritical CO2 extraction from Rosmarinus officinalis L. were investigated. Gas chromatography-mass spectroscopy analysis of these fractions resulted in the identification of 33 compounds of the essential oil.