Factors Associated with Serum Vitamin D Metabolites and Vitamin D Metabolite Ratios in Premenopausal Women

The most representative indicator of vitamin D status in clinical practice is 25(OH)D3, but new biomarkers could improve the assessment of vitamin D status and metabolism. The objective of this study is to investigate the association of serum vitamin D metabolites and vitamin D metabolite ratios (VMRs) with potentially influential factors in premenopausal women. This is a cross-sectional study based on 1422 women, aged 39-50, recruited from a Madrid Medical Diagnostic Center. Participants answered an epidemiological and a food frequency questionnaire. Serum vitamin D metabolites were determined using an SPE-LC-MS/MS platform. The association between participant's characteristics, vitamin D metabolites, and VMRs was quantified by multiple linear regression models. Mean 25(OH)D3 concentration was 49.2 + 18.9 nmol/L, with greater deficits among obese, nulliparous, dark-skinned women, and with less sun exposure. A lower R2 ratio (1,25(OH)2D3/25(OH)D3) and a higher R4 (24,25(OH)2D3/1,25(OH)2D3) were observed in nulliparous women, with high sun exposure, and those with low caloric intake or high consumption of calcium, vitamin D supplements, or alcohol. Nulliparous women had lower R1 (25(OH)D3/Vit D3) and R3 (24,25(OH)2D3/25(OH)D3), and older women showed lower R3 and R4. Vitamin D status modified the association of the VMRs with seasons. VMRs can be complementary indicators of vitamin D status and its endogenous metabolism, and reveal the influence of certain individual characteristics on the expression of hydroxylase enzymes.

Misused terms in analytical chemistry with emphasis on ultrasound application

A wide number of analytical terms have been applied erroneously for many years by analytical chemists, and they apply at present yet, by considering the time makes their use correct. The question is, may precedents validate the present use of incorrect scientific terms? Misused terms are found along the analytical process, starting with giving the name of the sample to the exiguous fraction of the original sample that reaches the detector or the high-resolution equipment after sample pretreatment and sample preparation. All the steps of the analytical process are considered in this article, with special emphasis on sample preparation and, within this, on the use of ultrasound, mainly for assisting extraction more unequivocally named as leaching or lixiviation. A call of attention in this respect is considered by the author to be of help to the analytical community.

Red and White Wine Lees Show Inhibitory Effects on Liver Carcinogenesis

SCOPE

Wine has shown anticarcinogenic benefits in hepatocarcinoma and polyphenols seem to be responsible for these effects. Wine lees are the sediments produced during fermentation and they endow wine with organoleptic and physicochemical properties. However, the anticarcinogenic role of these compounds is still unknown. Thus, the purpose of this work is to determine the phytochemical profiles of wine lees and then to analyze their anticarcinogenic effect and DNA methylation on a model of hepatocarcinogenesis.

METHODS AND RESULTS

The phytochemical composition of lees is determined by the Folin-Ciocalteu method and high-performance liquid chromatography. An in vivo study using a diethyl nitrosamine-hepatocarcinogenesis-induced model is performed to investigate the hepatoprotective properties of different doses of wine lees. For the DNA methylation analysis, a bisulfite-based method is used. Both types of lees mostly contain pyrogallol, gallic, and syringic acid with a high content of catechins in red lees. The carcinogen hypermethylates the Alu-M2 repetitive sequence and white lees decreases the hypermethylation at all tested concentrations. Low concentration of red and white lees and high concentration of white lees significantly improve the hepatocellular architecture and decrease the mitotic index in the murine model.

CONCLUSION

These findings suggest that wine lees are promising agents for chemoprevention of hepatocarcinoma.

Quantitative proteomic analysis of Pseudomonas pseudoalcaligenes CECT5344 in response to industrial cyanide-containing wastewaters using Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS)

Biological treatments to degrade cyanide are a powerful technology for cyanide removal from industrial wastewaters. It has been previously demonstrated that the alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to use free cyanide and several metal−cyanide complexes as the sole nitrogen source. In this work, the strain CECT5344 has been used for detoxification of the different chemical forms of cyanide that are present in alkaline wastewaters from the jewelry industry. This liquid residue also contains large concentrations of metals like iron, copper and zinc, making this wastewater even more toxic. To elucidate the molecular mechanisms involved in the bioremediation process, a quantitative proteomic analysis by LC-MS/MS has been carried out in P. pseudoalcaligenes CECT5344 cells grown with the jewelry residue as sole nitrogen source. Different proteins related to cyanide and cyanate assimilation, as well as other proteins involved in transport and resistance to metals were induced by the cyanide-containing jewelry residue. GntR-like regulatory proteins were also induced by this industrial residue and mutational analysis revealed that GntR-like regulatory proteins may play a role in the regulation of cyanide assimilation in P. pseudoalcaligenes CECT5344. The strain CECT5344 has been used in a batch reactor to remove at pH 9 the different forms of cyanide present in industrial wastewaters from the jewelry industry (0.3 g/L, ca. 12 mM total cyanide, including both free cyanide and metal−cyanide complexes). This is the first report describing the biological removal at alkaline pH of such as elevated concentration of cyanide present in a heterogeneous mixture from an industrial source.

The role of ultrasound in pharmaceutical production: sonocrystallization

Objectives

The main aim of this review was to develop a critical discussion of the key role ultrasound (US) can play on the production of active pharmaceutical ingredients (APIs) by discussing the versatile effect this type of energy produces.

Methods

The different crystallization techniques that can be assisted and improved by US are discussed in the light of the available US devices and the effect pursued by application of US energy. Simple and complex analytical methods to monitor API changes are also discussed.

Key findings

The countless achievements of API US-assisted production are summarized in a table, and outstanding effects such as narrower particle size distribution; decreased particle size, induction time, metastable zone and supersaturation levels; or a solubility increase are critically discussed.

Conclusions

The indisputable advantages of sonocrystallization over other ways of API production have been supported on multiple examples, and pending goals in this field (clarify the effect of US frequency on crystallization, know the mechanism of sonocrystallization, determine potential degradation owing to US energy, avoid calculation of the process yield by determining the concentration of the target drug remaining in the solution, etc.) should be achieved.

Composition of fatty acids in virgin olive oils from cross breeding segregating populations by gas chromatography separation with flame ionization detection

BACKGROUND

Recent technological advances to improve the quality of virgin olive oil (VOO) have been focused on olive breeding programs by selecting outstanding cultivars and target progenies. Fatty acid (FA) composition, with special emphasis on oleic acid (C18:1) and palmitic acid (C16:0), is one of the most critical quality factors to be evaluated in VOO. For this reason, the profile of FAs is frequently used as a decision tool in olive breeding programs.

RESULTS

A method based on gas chromatography with flame ionization detection (GC-FID) was used to study the influence of genotype on the concentration of ten of the most important FAs in VOOs from target crosses Arbequina × Arbosana, Picual × Koroneiki and Sikitita × Arbosana and their corresponding genitors Arbequina, Arbosana, Koroneiki, Picual and Sikitita. For this purpose, a targeted approach was selected for determination of esterified FAs (EFAs) and non-esterified FAs (NEFAs) in a dual analysis by the same chromatographic method. A Pearson analysis revealed correlations between pairs of FAs, which allowed detecting metabolic connections through desaturation and elongation enzymes. An ANOVA test (with P < 0.01) led to identification of C16:0 EFA, C16:1 EFA and C18:1 EFA and also C16:1 NEFA and C18:0 NEFA as the FAs more influenced by cross breeding. Statistical analysis was carried out by unsupervised analysis using principal component analysis (PCA) and cluster analysis (CA) to look for variability sources.

CONCLUSION

Crosses with a common genitor (Arbequina × Arbosana and Sikitita × Arbosana) were partially overlapped in the PCAs using the profile of FAs. The CA results revealed clear differences between Sikitita × Arbosana and Picual × Koroneiki crosses in the composition of the most significant FAs, while Arbequina × Arbosana was not properly discriminated from the other crosses.

Determination of fatty acids and stable carbon isotopic ratio in subcutaneous fat to identify the feeding regime of Iberian pigs

Discrimination among the types of feeding regimes for Iberian pigs is currently a highly demanded challenge by the Iberian pig sector. In the present research, discrimination among feeding regimes has been achieved by the combination of two analytical methods (based on FAMEs analysis by GC-FID and determination of δ(13)C by IRMS) previously used independently without success. In the present study, 80 samples of adipose tissue from Iberian pigs subjected to four different feedings were analyzed. The study of the variables more influenced by the feeding regime has allowed us to configure panels of markers with predictive power for the studied feedings by multivariate ROC analysis. The results provided values of specificity and sensitivity higher than 85% in most cases. The statistical combination of results from different analytical methods could be the key to develop models for the correct discrimination of Iberian pigs according to the feeding regime.

High-resolution mass spectrometry to evaluate the influence of cross-breeding segregating populations on the phenolic profile of virgin olive oils

BACKGROUND

The growing demand for high-quality virgin olive oils (VOOs) has increased the interest in olive breeding programs. Cross-breeding is considered, within these programs, the best strategy to generate new cultivars as an attempt to improve the present cultivars. In this research, the phenolic profile of VOOs from target crosses (Arbequina × Arbosana, Picual × Koroneiki and Sikitita × Arbosana) and their corresponding genitors (Arbequina, Arbosana, Koroneiki, Picual and Sikitita) has been evaluated using a targeted metabolomics approach.

RESULTS

The phenolic profiles were obtained by liquid chromatographic-hybrid quadrupole time-of-flight mass spectrometric targeted analysis of 37 phenols or compounds involved in the main pathways for their biosynthesis. Statistical multivariate analysis by principal component analysis was applied to study the influence of genotype on phenol composition. Phenolic compounds with the highest contribution to explain the observed variability associated to genotype were identified through fold change algorithms (cut-off > 2.0) and t-test analysis.

CONCLUSION

A total of nine phenols (viz. quercetin, ligstroside aglycon (p-HPEA-EA), demethyl oleuropein aglycon, oleuropein aglycon (3,4-DHPEA-EA), hydroxypinoresinol, hydroxytyrosol and phenolic acids such as p-coumaric acid, ferulic acid and protocatechuic acid) contributed to explain the observed variability with 99% confidence (P<0.01).

Characterization of monovarietal virgin olive oils by phenols profiling

The phenolic profiles of seven monovarietal virgin olive oils (VOOs) - viz. Arbequina, Arbosana, Cornicabra, FS-17, Hojiblanca, Picual and Sikitita - were characterized by using a quantitative strategy based on LC-MS/MS and the selected reaction monitoring (SRM) mode. Data dependent methods, based on precursor ion scanning, product ion scanning and neutral loss scanning, were developed for confirmatory analysis of secoiridoid derivatives. The observed phenolic profiles were used to find correlation between pairs of phenols and similarity trends among the monovarietal VOOs. A Pearson analysis revealed several correlations among phenols with p-value<0.01 and correlation coefficient (R)>0.75 in the seven monovarietal VOOs. Cluster analysis showed two main clusters between VOOs, formed by Arbequina/Hojiblanca/Cornicabra/Picual and Sikitita/Arbosana/FS-17. High correlations (R>0.7) were observed for the following pairs of VOOs: Arbequina/Hojiblanca (R=0.77), essentially supported on levels of hydroxytyrosol acetate (3,4-DHPEA-AC) and dialdehydic forms of secoiridoids; Cornicabra/FS-17 (R=0.81) and Picual/FS-17 (R=0.79), by correlation of flavonoids and secoiridoid derivatives in general. The highest correlation was observed for the pair Picual/Cornicabra (R=0.99). This preliminary study allowed setting similarities and dissimilarities between monovarietal VOOs by analysis of the phenolic profile. The observed connections between phenols for different varieties have been tentatively interpreted according to the main pathways for phenols biosynthesis.

Ultrasound-assisted extraction with LC-TOF/MS identification and LC-UV determination of imazamox and its metabolites in leaves of wheat plants

INTRODUCTION

imazamox is a herbicide used in many legominous and cereal crops. There are few methods in the literature for determination of imazamox and its metabolites in plants because of the lack of commercial standards or owing to expensive and/or complex synthesis.

OBJECTIVE

To develop a method based on liquid chromatography and ultraviolet absorption detection for simultaneous determination of imazamox and its metabolites in plants.

METHODS

Sample preparation was based on ultrasound-assisted extraction (70 W power and duty cycle of 0.7 s/s for 10 min) with subsequent filtration of the extracts and clean-up and concentration prior to chromatographic separation and detection at 240 nm. The chromatographic analysis was completed in 30 min using a Luna® HILIC column. Identification and confirmatory analysis of the presence of imazamox and its metabolites in extracts from treated plants was performed by LC-TOF/MS in high resolution mode for precursor ions. The metabolites were quantified using a surrogate approach based on an imazamox standard. The method was validated by analysing wheat samples treated with 200 g per hectare of active ingredient imazamox.

RESULTS

The linear dynamic range of the calibration curve was within 0.27-600 µg/mL, with a correlation coefficient of 0.998 and precision--studied at 0.1 and 2 µg/mL--of 2.9% and 5.0% for repeatability, and 4.7% and 6.9% for reproducibility, respectively.

CONCLUSION

The analytical characteristics of the method make it recommendable for evaluating the metabolism of imazamox in plants.

Targeted analysis of omega-6-derived eicosanoids in human serum by SPE-LC-MS/MS for evaluation of coronary artery disease

A targeted approach has been applied to quantitative analysis of eicosanoids derived from omega-6 fatty acids in serum from individuals diagnosed with coronary artery disease (CAD). The target metabolites were series-2 prostaglandins, thromboxane B2, hydroxyeicosatetraenoic acids, and hydroxyoctadecadienoic acids. The method was based on SPELC-MS/MS in selected reaction monitoring mode for highly selective and sensitive determination of the target eicosanoids. The combination of SPE and LC-MS/MS involved the benefits from both direct analysis of serum without a step for protein precipitation and fully automation of the analysis. The method allowed comparison of omega-6-derived eicosanoids in serum from patients diagnosed with CAD and from control individuals. The effect of treatment with aspirin on the profile of the target compounds was evaluated through its incidence on the different pathways. Finally, the serum levels of the target metabolites in patients diagnosed with CAD were also statistically examined according to the severity of the coronary lesion stratified as stable angina, non-ST-elevation acute coronary syndrome, and acute myocardial infarction.

Liquid chromatography-diode array detection to study the metabolism of glufosinate in Triticum aestivum T-590 and influence of the genetic modification on its resistance

The resistance to glufosinate of two lines-genetically modified (GM) and unmodified (T-590 and T-549, respectively)-of Triticum aestivum has been studied. In the GM line, the bar gene was introduced to increase the resistance to glufosinate. Experiments in a controlled growth chamber showed that line T-590 presented a high resistance to glufosinate with an ED50 value of 478.59 g active ingredient per hectare (g ai ha(-1)) versus 32.65 g ai ha(-1) for line T-549. The activity of glutamine synthetase (GS) in leaf extracts from both lines was investigated. The I50 for line T-590 was 694.10 μM glufosinate versus 55.46 μM for line T-549, with a resistance factor of 12.51. Metabolism studies showed a higher and faster penetration of glufosinate in line T-549 than in line T-590. LC-TOF/MS analysis of glufosinate metabolism at 48 h after herbicide treatment (300 g ai ha(-1)) revealed an 83.4% conversion of the herbicide (66.5% in N-acetyl-glufosinate metabolite), while in line T-549 conversion of the herbicide was about 40% (0% to N-acetyl-glufosinate). These results suggest that metabolism of glufosinate by the bar gene is a key mechanism of resistance in line T-590 that explains such high levels of herbicide tolerated by the plant, together with other mechanisms due to unmodified pathway, absorption and loss of glufosinate affinity for its target site.

Lower vitamin E serum levels are associated with osteoporosis in early postmenopausal women: a cross-sectional study

The aim of this study was to evaluate the relationship between vitamin E status and osteoporosis in early postmenopausal women. Anthropometric data, osteoporosis risk factors, vitamin E serum levels, bone mineral density (BMD) and other serum parameters which may influence bone mineral density in postmenopausal women were analyzed in a cross-sectional study. The association between osteoporosis and age, age of menopause, body mass index, osteocalcin, calcium, vitamin D, vitamin E (measured as 25 hydroxyvitamin D and as α-tocopherol:lipids ratio, respectively), bone alkaline phosphatase, smoking status, leisure physical activity and alcohol intake were modeled by a multivariate logistic regression and multi-linear regression analysis in 232 early postmenopausal women. A lower vitamin E:lipid ratio was associated with osteoporosis in multivariate logistic regression. In a multivariate linear model with BMD of the lumbar spine as a dependent variable, the vitamin E:lipid ratio was clearly related with BMD of the lumbar spine (F ratio = 6.30, p = 0.002). BMD of the lumbar spine was significantly higher in the highest tertile of the vitamin E:lipid ratio than in the lowest tertile. The mean vitamin E:lipid ratio was significantly lower in osteoporotic postmenopausal women (T score ≤-2.5) (3.0 ± 0.6 μmol/mmol) than normal (neither osteoporotic nor osteopenic) postmenopausal women (T score >-1) (3.5 ± 0.7 μmol/mmol) using multivariable-adjusted BMD. These findings highlight that vitamin E may increase BMD in healthy postmenopausal women.

Tentative identification of phenolic compounds in olive pomace extracts using liquid chromatography-tandem mass spectrometry with a quadrupole-quadrupole-time-of-flight mass detector

The reuse of agronomical residues is a pending goal for sustainable agriculture. Particular residues in olive-oil-producing countries are leaves, wastewater, and olive pomace. Olive leaves and wastewaters have been previously characterized by isolation of the phenolic fraction. However, olive pomace has not yet been qualitatively characterized as a source of phenols. Olive pomace extracts were obtained using superheated solvent extraction using 50:50 (v/v) water/ethanol as a leaching mixture at 160 °C. The extracts were analyzed by liquid chromatography coupled to tandem mass spectrometry using a quadrupole-quadrupole-time-of-flight (QqTOF) hybrid mass analyzer (R = 25,000-45,000). Qualitative analysis was supported upon measurement of accurate masses for precursor and product ions as well as their isotopic distribution. Identification was focused on the main families of phenolic compounds present in extra virgin olive oil. The potential of this residue as a rich source of phenols with antioxidant properties has been proven.

Virgin olive oil phenolic profile and variability in progenies from olive crosses

BACKGROUND

The progressive transformation of olive growing and the increasing demands for high-quality monovarietal virgin olive oil (VOO) have triggered interest in olive breeding programs, in which the evaluation of the new genotypes is the basis for obtaining new olive cultivars. In this work, the phenolic composition of VOOs from two progenies from crosses between 'Arbequina', 'Arbosana' and 'Sikitita' has been evaluated along two years.

RESULTS

A higher degree of variation was observed in segregating population as compared to genitors. The results also showed that the variability within crosses constitutes the major contribution to total variance for all considered parameters (>92% of total sum of squares). All compounds under study were present in oils obtained in both years; however, clear differences in their concentrations were observed between years.

CONCLUSION

Olive breeding can indeed provide genotypes that produce oils with improved phenolic profiles as compared to traditional cultivars. In addition, the data showed that selection as a function of tyrosol content could be achieved in only one crop year. Finally, p-coumaric acid was the unique component able to discriminate between both crop years under study.

Evaluation of the composition of vine shoots and oak chips for oenological purposes by superheated liquid extraction and high-resolution liquid chromatography-time-of-flight/mass spectrometry analysis

Vine shoots are characterized in this research and compared to oak chips, frequently employed in the aging of wine or spirits. For this purpose, liquid chromatography-diode array detection and liquid chromatography-time-of-flight/mass spectrometry (LC-TOF/MS) analyses of hydroalcoholic extracts from vine shoots pertaining to 18 different vine varieties and from five varieties of oak chips have been carried out. The concentrations of a representative panel of interesting compounds from an oenological point of view have been compared in the extracts, finding similarity patterns for many of them. The analysis by LC-TOF/MS in high accuracy mode has led to the identification of numerous compounds in the hydroalcoholic extracts. The statistical analysis has enabled identification of the vine-shoot varieties providing extracts with more similar composition to that given by extracts from oak chips. Therefore, these vine-shoots varieties are suitable to be presented as an alternative to the use of oak barrels or oak chips in the aging process of wine and spirits.

Comparison of accelerated methods for the extraction of phenolic compounds from different vine-shoot cultivars

Most research on the extraction of high-priced compounds from vineyard/wine byproducts has traditionally been focused on grape seeds and skins as raw materials. Vine-shoots can represent an additional source to those materials, the characteristics of which could depend on the cultivar. A comparative study of hydroalcoholic extracts from 18 different vineyard cultivars obtained by superheated liquid extraction (SHLE), microwave-assisted extraction (MAE), and ultrasound-assisted extraction (USAE) is here presented. The optimal working conditions for each type of extraction have been investigated by using multivariate experimental designs to maximize the yield of total phenolic compounds, measured by the Folin-Ciocalteu method, and control hydroxymethylfurfural because of the organoleptic properties of furanic derivatives and toxicity at given levels. The best values found for the influential variables on each extraction method were 80% (v/v) aqueous ethanol at pH 3, 180 °C, and 60 min for SHLE; 140 W and 5 min microwave irradiation for MAE; and 280 W, 50% duty cycle, and 7.5 min extraction for USAE. SHLE reported better extraction efficiencies as compared to the other two approaches, supporting the utility of SHLE for scaling-up the process. The extracts were dried in a rotary evaporator, reconstituted in 5 mL of methanol, and finally subjected to liquid-liquid extraction with n-hexane to remove nonpolar compounds that could complicate chromatographic separation. The methanolic fractions were analyzed by both LC-DAD and LC-TOF/MS, and the differences in composition according to the extraction conditions were studied. Compounds usually present in commercial wood extracts (mainly benzoic and hydroxycinnamic acids and aldehydes) were detected in vine-shoot extracts.

Pool of resistance mechanisms to glyphosate in Digitaria insularis

Digitaria insularis biotypes resistant to glyphosate have been detected in Brazil. Studies were carried out in controlled conditions to determine the role of absorption, translocation, metabolism, and gene mutation as mechanisms of glyphosate resistance in D. insularis. The susceptible biotype absorbed at least 12% more (14)C-glyphosate up to 48 h after treatment (HAT) than resistant biotypes. High differential (14)C-glyphosate translocation was observed at 12 HAT, so that >70% of the absorbed herbicide remained in the treated leaf in resistant biotypes, whereas 42% remained in the susceptible biotype at 96 HAT. Glyphosate was degraded to aminomethylphosphonic acid (AMPA), glyoxylate, and sarcosine by >90% in resistant biotypes, whereas a small amount of herbicide (up to 11%) was degraded by the susceptible biotype up to 168 HAT. Two amino acid changes were found at positions 182 and 310 in EPSPS, consisting of a proline to threonine and a tyrosine to cysteine substitution, respectively, in resistant biotypes. Therefore, absorption, translocation, metabolism, and gene mutation play an important role in the D. insularis glyphosate resistance.

Limited uptake, translocation and enhanced metabolic degradation contribute to glyphosate tolerance in Mucuna pruriens var. utilis plants

Velvet bean (Mucuna pruriens, Fabaceae) plants exhibits an innate, very high resistance (i.e., tolerance) to glyphosate similar to that of plants which have acquired resistance to this herbicide as a trait. We analyzed the uptake of [(14)C]-glyphosate by leaves and its translocation to meristematic tissues, and used scanning electron micrographs to further analyze the cuticle and 3D capillary electrophoresis to investigate a putative metabolism capable of degrading the herbicide. Velvet bean exhibited limited uptake of glyphosate and impaired translocation of the compound to meristematic tissues. Also, for the first time in a higher plant, two concurrent pathways capable of degrading glyphosate to AMPA, Pi, glyoxylate, sarcosine and formaldehyde as end products were identified. Based on the results, the innate tolerance of velvet bean to glyphosate is possibly a result of the combined action of the previous three traits, namely: limited uptake, impaired translocation and enhanced degradation.

Quality and stability of edible oils enriched with hydrophilic antioxidants from the olive tree: the role of enrichment extracts and lipid composition

Phenolic extracts from olive tree leaves and olive pomace were used to enrich refined oils (namely, maize, soy, high-oleic sunflower, sunflower, olive, and rapeseed oils) at two concentration levels (200 and 400 μg/mL, expressed as gallic acid). The concentration of characteristic olive phenols in these extracts together with the lipidic composition of the oils to be enriched influenced the mass transfer of the target antioxidants, which conferred additional stability and quality parameters to the oils as a result. In general, all of the oils experienced either a noticeable or dramatic improvement of their quality-stability parameters (e.g., peroxide index and Rancimat) as compared with their nonenriched counterparts. The enriched oils were also compared with extra virgin olive oil with a natural content in phenols of 400 μg/mL. The healthy properties of these phenols and the scarce or nil prices of the raw materials used can convert oils in supplemented foods or even nutraceuticals.

Qualitative and quantitative sugar profiling in olive fruits, leaves, and stems by gas chromatography-tandem mass spectrometry (GC-MS/MS) after ultrasound-assisted leaching

Qualitative and quantitative profiling of sugars in vegetal materials from Olea europaea cultivars is here reported. Vegetal tissues from olive fruits, leaves, and stems have been characterized by determination of 22 compounds belonging to monosaccharides, disaccharides, trisaccharides, sugar carboxylic acids and alcohols, cyclic polyols, and derived compounds. Sugar isolation was carried out by leaching into a 2:1 dichloromethane/methanol extraction solution under ultrasonic assistance. Multivariate optimization made possible complete isolation of the target fraction in 10 min with an efficiency similar to that provided by a conventional protocol based on 24 h maceration of the vegetal samples. An aliquot of the extract was dried and reconstituted for silylation prior to GC-MS/MS analysis for selective and sensitive identification/quantitation of sugars. Monitoring the target product ions generated after isolation of the precursor ions for each analyte increases the selectivity of the method. The proposed approach is of particular interest for characterization of the sugar fraction in O. europaea, which is of great relevance because of the role of sugars in the metabolism of lipids, proteins, and antioxidants.

Determination of glyphosate and its metabolites in plant material by reversed-polarity CE with indirect absorptiometric detection

A simple CE method for simultaneous determination of glyphosate and its metabolites (i.e. aminomethylphosphonic acid, glyoxylate, sarcosine and formaldehyde) in plants is reported here. A BGE of pH 7.5, 10% ACN, 7.5 mM phthalate, containing 0.75 mM hexadecyltrimethylammonium bromide as an electro-osmotic flow modifier, an applied voltage of -20 kV and absorptiometric monitoring at 220 nm were the optimal chemical and instrumental parameters. The method, with development time 20 min, shows linear calibrations within the range 5-500 microg/mL (for all target analytes) with correlation coefficients between 0.999 and 0.998. It has been validated by application to samples of Lolium spp. The electroinjection mode hinders most interferents to enter the capillary, thus providing a clean electropherogram and making unnecessary long sample-preparation steps.

Temporal metabolomic analysis of o-glucoside phenolic compounds and their aglycone forms in olive tree and derived materials

INTRODUCTION

Maturity is one of the most important factors associated with evaluation of the quality of fruit and vegetables. In olive oil, maturation plays a key role in the kinetics of biosynthetic pathways of the secondary metabolism. One of the most relevant pathways is that catalysed by beta-glucosidases, which are involved in olive oil debittering. Therefore, the knowledge of this influence can be of particular interest for olive oil industry.

OBJECTIVE

To monitor the profile of O-glucoside phenols and their aglycone forms in olive oil, alperujo (the semisolid residue resulting in the production of olive oil), stones, leaves and branches in order to interpret its evolution according to the sample and the period of the season (October, when olive drupes are green; December, when these drupes are green-purple; and February, when they are mostly black).

METHODOLOGY

Targeted phenols were extracted by previously optimised methods assisted by auxiliary energies (i.e. ultrasound, microwaves or superheated liquids) according to the characteristics of the sample. The analysis was carried out by liquid chromatography-tandem mass spectrometry with a triple quadrupole mass detector. Highly selective identification and sensitive determination of metabolites was performed in multiple-reaction monitoring mode. Statistical analysis to evaluate differences in the profile of the target compounds was based on principal compounds analysis.

RESULTS

The evolution of the analytes concentration is strongly related to the role of beta-glucosidases. An explanation for this evolution in olive oil, alperujo and stones is given by relation to the industrial process for olive oil production. For leaves and small branches, the concentration was practically constant over the season, which was foreseeable because of the perennial character of olive trees. Leaves and branches were found to be highly concentrated in O-glucoside derivatives, demonstrating their capacity for phenolic compounds storage.

CONCLUSIONS

Targeted metabolomic profiling has proved a useful tool to monitor O-glucoside phenolic compounds and their aglycone forms in olive materials. The profile of target compounds enables interpretion of their evolution according to the olive material and the period of the season.

Dependence of fatty-acid composition of edible oils on their enrichment in olive phenols

Olive phenol extracts from waste from olive-oil production (alperujo) have been obtained by microwave-assisted extraction and used for edible oil enrichment. The extracts as such or after extractant removal were used to enrich edible oils of different fatty acid composition by liquid-liquid or solid-liquid extraction, respectively. The distribution ratios of the phenols in the different oils [olive-orujo (the waste of milled olives from which low-quality oil is obtained), sunflower, high oleic-acid content sunflower, coconut, and linseed] showed a given order as a function of phenol polarity and molecular weight, with higher distribution factors for more polar and lower molecular-weight phenols. Concerning oil composition, those oils with higher concentration of polyunsaturated fatty acids yielded higher phenol distribution factors; oils with higher concentrations of saturated fatty acids yielded lower distribution factors.

Solid-liquid transfer of biophenols from olive leaves for the enrichment of edible oils by a dynamic ultrasound-assisted approach

A continuous approach assisted by ultrasound for direct enrichment of edible oils (olive, sunflower, and soya) with the main phenols in olive leaves (i.e., oleuropein, verbascoside, apigenin-7-glucoside, and luteolin-7-glucoside) has been developed. Multivariate methodology was used to carry out a detailed optimization of the enrichment, and quantitation of the transferred compounds was based on LC-MS-MS in multiple reaction monitoring optimizing the most sensitive transition for each biophenol. Under the optimal working conditions, only 20 min is necessary to enrich the edible oils with 14.45-9.92 microg/mL oleuropein, 2.29-2.12 microg/mL verbascoside, 1.91-1.51 microg/mL apigenin-7-glucoside, and 1.60-1.42 microg/mL luteolin-7-glucoside. The enrichment method is carried out at room temperature and is organic-solvent-free; thus, the healthy properties of the edible oils improve as does their quality. Also, the low acquisition and maintenance costs of an ultrasound source and its application in a dynamic system make advisable the industrial implementation of the proposed method.

Liquid chromatography/triple quadrupole tandem mass spectrometry with multiple reaction monitoring for optimal selection of transitions to evaluate nutraceuticals from olive-tree materials

Optimal transitions have been selected for the identification and quantitation of the most interesting hydrophilic biophenols in extracts from olive-tree materials, which are of interest because of their nutraceutical properties. The tested materials were extra virgin olive oil, waste from oil production (known as alperujo), and olive-tree materials such as leaves, small branches and fruit stones. The identification and determination steps of the target biophenols are based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) with a triple quadrupole (QQQ) mass detector. The interface between the chromatograph and the QQQ was an electrospray ionization source operated in the negative ion mode. Highly selective identification of the biophenols was confirmed by multiple reaction monitoring (MRM) using the most representative transitions from the precursor ion to the different product ions. Quantitative MS/MS analysis was carried out by optimization and selection of the most sensitive transition for each analyte, which resulted in estimated detection limits of 5.10 to 11.65 ng/mL for the extracts. The biophenols were extracted from the tested samples by different methods: liquid-liquid extraction for virgin olive oil, microwave-assisted leaching for olive leaves, branches and stones, and pressurized liquid leaching for alperujo. This study provides valuable information about the most suitable source for the isolation of each nutraceutical biophenol and enables us to obtain a complete profile of them in Olea Europaea.

Static-dynamic superheated liquid extraction of hydroxytyrosol and other biophenols from alperujo (a semisolid residue of the olive oil industry)

Hydroxytyrosol and other olive biophenols (OBPs) such as tyrosol, verbascoside, apigenin-7-glucoside, and alpha-taxifolin have been extracted from alperujo by using static-dynamic superheated liquids. Multivariate methodology has been used to carry out a detailed optimization of the extraction. Under the optimal working conditions no further extraction of the target analytes was achieved after 27 min (up to 2800 and 1500 mg/kg of hydroxytyrosol and tyrosol, respectively), so complete removal of them within this interval was assumed. The extract was injected into a chromatograph-photodiode array detector assembly for individual separation-quantification. The efficacy of ethanol/water mixtures to extract OBPs from alperujo has been demonstrated and compared with that of a conventional stirring-based method. These less toxic extractant mixtures are of interest with a view to future human uses of OBPs.

On-line preparation of microsamples prior to CE

An experimental setup is presented here for the automated analysis of microsamples, based on the on-line coupling of a capillary SPE module and a CE unit using a two-position six-port valve, an open-closed valve to isolate electrically the sample preparation from the CE unit and a "T" interface. A C18 trapping microcolumn (dimensions 2.5 cm x 100 microm id x 360 microm od) was used for the SPE step. The utility of the proposed experimental setup was demonstrated by applying it to the determination of quinolone antibiotics in serum microsamples, which was efficiently carried out in less than 20 min (4 min for protein denaturation and 15 min for analytes preconcentration and CE-UV separation-determination). A complete optimization study was performed for preconcentration and cleanup of quinolones, the coupling of sample preparation module to the CE unit and electrophoretic separation of quinolones. A preconcentration factor of 10.4 was achieved. The volume injected with the proposed method was 125 nL versus 160 nL introduced by hydrodynamic injection. The volume required for the analysis was 2 microL, which makes the proposed experimental setup very useful for the analysis of microsamples in fields of current interest such as metabolomics or proteomics.

Identification and determination of fat-soluble vitamins and metabolites in human serum by liquid chromatography/triple quadrupole mass spectrometry with multiple reaction monitoring

A method for determination of fat-soluble vitamins K(1), K(3), A, D(2), D(3) and E (as alpha- and delta-tocopherol) and metabolites 25-hydroxyvitamin D(2) and D(3) and 1,25-dihydroxyvitamin D(3) in human serum by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) in positive mode is proposed. Highly selective identification of the target compounds in serum was confirmed by the most representative transitions from precursor ion to product ion. Quantitative MS/MS analysis was carried out by multiple reaction monitoring optimizing the most sensitive transition for each analyte in order to achieve low detection limits (from 0.012 to 0.3 ng/mL estimated with serum). The analysis was performed with 1 mL of serum, which was subjected to protein precipitation, liquid-liquid extraction to an organic phase, evaporation to dryness and reconstitution with methanol. The precision of the overall method ranged from 3.17-6.76% as intra-day variability and from 5.07-11.53% as inter-day variability. The method, validated by the standard addition method, provides complete information on the fat-soluble vitamins profile, which is of interest in clinical and metabolomics studies.

Determination of phenolic compounds in grape skin by capillary electrophoresis with simultaneous dual fluorescence and diode array absorption detection after dynamic superheated liquid leaching

A fast method for the analysis of 10 of the characteristic compounds of the phenolic fraction in grape skin is proposed here. The method is based on a leaching step by superheated ethanol-water at 120 degrees C and 80bar, which enables to maintain the leachant in liquid state and wide the range of leachable compounds (polar, mid-polar and relatively non-polar compounds) by decrease of the dielectric constant; thus, allowing high leaching efficiencies to be achieved in 30min. After leaching, the target analytes were separated by capillary electrophoresis using a 50mM sodium tetraborate with 10% methanol (pH 8.4) solution as background electrolyte. Determination was performed by simultaneous dual diode array absorption and fluorescence detection, the combination of which increased the selectivity of the overall method, particularly interesting taking into account the complexity of the leachate as no additional concentration and/or clean-up steps were required prior to electrophoretic separation, which lasted only 10min. The short time of the electrophoretic step makes it useful as a screening tool of the target analytes in commercial and non-commercial extracts belonging to the pharmaceutical, cosmetic, nutraceutical or food fields.