Food industrial biowaste-based magnetic activated carbons as sustainable adsorbents for anthropogenic mercury emissions.

Bio-derived magnetic activated carbons from industrial chestnut shell waste have been obtained through a novel, optimized and sustainable methodology where impregnation, pyrolysis, acid washing or other intermediate steps commonly used in the activation process were eliminated saving time, energy and costs. The resulting materials (MACs) were obtained at 220-800 °C showed interesting properties: textural (SBET up to 568 m2 g-1) and magnetic (different iron species developed), depending on the activation temperature employed. Data showed outstanding results when MACs were tested for Hg removal in pollution emissions at 150 °C in lab-scale device. In MACs obtained at 500-600 °C, where the highest concentration of magnetite was found, the best Hg adsorption capacity was achieved, while it decreased when metallic iron or iron carbides were present (MACs obtained at 800 °C). Moreover, the difference of Hg0 removal/adsorption in N2+O2 and Simulated Flue Gas atmosphere between MACs obtained at 500 and 600 °C pointed out the influence on Hg removal of additional parameters, as surface chemistry and the existence of sulfur or chloride. The determination of Hg species in post-retention solids confirmed the mercury oxidation by high-valence iron ions (Fe3+) and the involvement of physisorption and chemisorption processes for the gas-solid interaction mechanism.

Exploitation of artichoke byproducts to obtain bioactive extracts enriched in inositols and caffeoylquinic acids by Microwave Assisted Extraction.

Byproducts from artichoke represent the majority of the mass collected from the plant and constitute an interesting source of bioactive compounds such as inositols and caffeoylquinic acids. In this work, a microwave assisted extraction (MAE) methodology was developed for the simultaneous extraction of these compounds from artichoke stalks, leaves, receptacles and external bracts. Optimal MAE conditions to maximize the extraction of these bioactives and the antioxidant activity were 97 °C, 3 min, ethanol:water (50:50, v/v). Moreover, a GC-MS methodology was also developed for the simultaneous determination of these compounds in a single run; optimal derivatization conditions were achieved using hexamethyldisilazane and N,O-bis(trimethylsilyl)trifluoroacetamide with 1% trimethylchlorosilane. Artichoke receptacle extracts were the richest in caffeoylquinic acids (28-35 mg g-1 dry sample), followed by the bracts (9-18 mg g-1 dry sample), while those from leaves showed the highest concentrations of inositols (up to 15 mg g-1 dry sample). Receptacle extracts also had the highest antioxidant activity (123 mg TE g-1 dry sample) and the greatest concentration of total phenolic compounds (47 mg GAE g-1 dry sample). Therefore, the developed methodology could be considered as a valuable procedure to obtain and characterize bioactive ingredients with industrial interest from artichoke byproducts, opening new routes of revalorization of artichoke agro-industrial residues.

Gas chromatographic-based techniques for the characterization of low molecular weight carbohydrates and phenylalkanoid glycosides of Sedum roseum root supplements.

An extensive characterization of low molecular weight carbohydrates (LMWC) and phenylalkanoid glycosides (PAG) of Sedum roseum root supplements has been carried out for the first time by gas chromatography coupled to mass spectrometry (GC-MS) and by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-ToF MS). Optimization of the required derivatization procedure for improved determination of PAG showed the combined use of trimethylsilylimidazole and trimethylchlorosilane as the most appropriate reagents. Up to 37 compounds were qualitative- and quantitatively characterized in different dietary supplements of S. roseum by GC-MS. In addition to the well-known rosin, rosarin, rosavin and salidroside, other carbohydrates, polyalcohols, acids, etc. were determined. Among them, several seven-carbon monosaccharides such as coriose and 2,7-anhydro-ß-d-altro-heptulose were detected for the first time in S. roseum root supplements. Sedoheptulose was found to be the most abundant compound (9-151 mg g-1), followed by rosiridin (20-81 mg g-1) and rosavin (11-56 mg g-1). The use of GC × GC-ToF MS allowed the detection and tentative assignation of 48 additional compounds mainly belonging to the phenylalkanoid glycoside, pentosyl-hexose and hexosyl-hexose families.

Pressurized liquid extraction of Aglaonema sp. iminosugars: Chemical composition, bioactivity, cell viability and thermal stability.

Pressurized liquid extraction of Aglaonema sp. iminosugars has been optimized. A single cycle under optimal conditions (80mg, 100°C, 2min) was enough to extract ⩾96% of most iminosugars. Further incubation with Saccharomyces cerevisiae for 5h removed coextracted interfering low molecular weight carbohydrates from extracts of different Aglaonema cultivars. A complete characterization of these extracts was carried out by gas chromatography-mass spectrometry: three iminosugars were tentatively identified for the first time; α-homonojirimycin and 2,5-dideoxy-2,5-imino-d-mannitol were the major iminosugars determined. α-Glucosidase inhibition activity, cell viability and thermal stability of Aglaonema extracts were also evaluated. Extracts with IC50 for α-glucosidase activity in the 0.010-0.079mgmL(-1) range showed no decrease of Caco-2 cell viability at concentrations lower than 125µgmL(-1) and were stable at 50°C for 30days. These results highlight the potential of Aglaonema extracts as a source of bioactives to be used as functional ingredients.

Analysis of iminosugars and other low molecular weight carbohydrates in Aglaonema sp. extracts by hydrophilic interaction liquid chromatography coupled to mass spectrometry.

A method by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS(2)) has been successfully developed for the simultaneous analysis of bioactive iminosugars and other low molecular weight carbohydrates in Aglaonema leaf extracts. Among other experimental chromatographic conditions, mobile phase eluents, additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry provided for target carbohydrates. In general, narrow peaks (wh: 0.2-0.6min) with good symmetry (As: 0.9-1.3) and excellent resolution (Rs>1.8) were obtained for iminosugars using an acetonitrile:water gradient with 5mM ammonium acetate in both eluents at 55°C. Tandem mass spectra were used to confirm the presence of previously detected iminosugars in Aglaonema extracts and to tentatively identify for the first time others such as miglitol isomer, glycosyl-miglitol isomers and glycosyl-DMDP isomers. Concentration of total iminosugars varied from 1.35 to 2.84mgg(-1) in the extracts of the different Aglaonema samples analyzed. To the best of our knowledge, this is the first time that a HILIC-MS(2) method has been proposed for the simultaneous analysis of iminosugars and other low molecular weight carbohydrates of Aglaonema sp. extracts.

Evaluation of different hydrophilic stationary phases for the simultaneous determination of iminosugars and other low molecular weight carbohydrates in vegetable extracts by liquid chromatography tandem mass spectrometry.

Iminosugars are considered potential drug candidates for the treatment of several diseases, mainly as a result of their α-glycosidase inhibition properties. A method by hydrophilic interaction liquid chromatography tandem mass spectrometry has been optimized for the first time for the simultaneous determination of complex mixtures of bioactive iminosugars and other low molecular weight carbohydrates (LMWC) in vegetable extracts. Three hydrophilic stationary phases (sulfoalkylbetaine zwitterionic, polyhydroxyethyl aspartamide and ethylene bridge hybrid (BEH) with trifunctionally bonded amide) were compared under both basic and acidic conditions. The best sensitivity (limits of detection between 0.025 and 0.28ngmL-1) and overall chromatographic performance in terms of resolution, peak width and analysis time were obtained with the BEH amide column using 0.1% ammonium hydroxide as a mobile phase additive. The optimized method was applied to the analysis of extracts of hyacinth bulbs, buckwheat seeds and mulberry leaves. Iminosugar and other LMWC structures were tentatively assigned by their high resolution daughter ions mass spectra. Several iminosugars such as glycosyl-fagomine in mulberry extract were also described for the first time. Among the extracts analysed, mulberry showed the widest diversity of iminosugars, whereas the highest content of them was found in hyacinth bulb (2.5mgg-1) followed by mulberry (1.95 mgg-1).

Characterization of trimethylsilyl ethers of iminosugars by gas chromatography-mass spectrometry.

A combination of gas chromatographic retention data (linear retention indices) on two different stationary phases (100% methyl- and 50% phenylmethylsilicone) and electron impact mass spectrometric relative abundances for characteristic m/z ratios of 12 trimethylsilylated piperidine and pyrrolidine iminosugars are reported. These results have been related to their structural features and applied to the characterization of iminosugar composition of an Aglaonema treubii root extract. Seven iminosugars were detected in this extract, two of them were described for the first time.

Optimization of pressurized liquid extraction of inositols from pine nuts (Pinus pinea L.).

Pressurized liquid extraction (PLE) has been used for the first time to extract bioactive inositols from pine nuts. The influence of extraction time, temperature and cycles of extraction in the yield and composition of the extract was studied. A quadratic lineal model using multiple linear regression in the stepwise mode was used to evaluate possible trends in the process. Under optimised PLE conditions (50°C, 18 min, 3 cycles of 1.5 mL water each one) at 10 MPa, a noticeable reduction in extraction time and solvent volume, compared with solid-liquid extraction (SLE; room temperature, 2h, 2 cycles of 5 mL water each one) was achieved; 5.7 mg/g inositols were extracted by PLE, whereas yields of only 3.7 mg/g were obtained by SLE. Subsequent incubation of PLE extracts with Saccharomyces cerevisiae (37°C, 5h) allowed the removal of other co-extracted low molecular weight carbohydrates which may interfere in the bioactivity of inositols.

Characterization by the solvation parameter model of the retention properties of commercial ionic liquid columns for gas chromatography.

For the first time, four commercial ionic liquid columns (SLB-IL59, SLB-IL76, SLB-IL82 and SLB-IL100) for gas chromatography have been comprehensively evaluated in terms of efficiency, polarity and solvation properties. Grob tests and McReynolds constants showed that they were all high-efficiency columns of high polarity, but with low inertness to compounds with hydrogen bonding capabilities. The solvation parameter model was used to characterize the solvation interactions of the four columns in the 80-160°C temperature range. Results revealed that all the ionic liquids studied can be considered moderately hydrogen-bond acid and highly cohesive stationary phases, on which the dominant contributions to retention were the dipolar-type and hydrogen-bond base interactions, while π-π and n-π interactions were barely significant. The SLB-IL59 column provided the best separation of homologs, while the SLB-IL76 and SLB-IL100 columns had the most basic and the most acidic phases, respectively. A principal component analysis for the commonly used stationary phases in capillary GC showed that these commercial ionic liquid columns fill an empty area of the available selectivity space, which clearly enhances the separation capacity of this technique.

Improvement of a gas chromatographic method for the analysis of iminosugars and other bioactive carbohydrates.

The analysis of derivatised iminosugars and other bioactive low molecular weight carbohydrates present at low concentrations in different vegetable extracts (hyacinth, mulberry and buckwheat) required the improvement of a previously developed gas chromatographic method. Among the different parameters optimized, the temperature of the injection port, evaluated for the first time, resulted to be the most important. Thus, 240 °C was chosen as a tradeoff to achieve the required volatility, to avoid degradation and to provide symmetric peaks for bioactive carbohydrates highly retained such as glycosyl inositols. GC-MS operating under selective ion monitoring (SIM) acquisition mode and GC-FID provided limits of detection and quantitation for the target compounds of 0.2 and 0.7 ng g(-1) and of 1 and 3 ng g(-1) on average, respectively. Therefore, both methodologies could be considered appropriate to extend the range of quantitation of these bioactives.

Derivatization of carbohydrates for GC and GC-MS analyses.

GC and GC-MS are excellent techniques for the analysis of carbohydrates; nevertheless the preparation of adequate derivatives is necessary. The different functional groups that can be found and the diversity of samples require specific methods. This review aims to collect the most important methodologies currently used, either published as new procedures or as new applications, for the analysis of carbohydrates. A high diversity of compounds with diverse functionalities has been selected: neutral carbohydrates (saccharides and polyalcohols), sugar acids, amino and iminosugars, polysaccharides, glycosides, glycoconjugates, anhydrosugars, difructose anhydrides and products resulting of Maillard reaction (osuloses, Amadori compounds). Chiral analysis has also been considered, describing the use of diastereomers and derivatives to be eluted on chiral stationary phases.

[Comparative study of the effectiveness two of hyperoxygenated fatty acids in the treatment of grade I ulcers in geriatric hospitalized patients]. / Estudio comparativo de efectividad de dos ácidos grasos hiperoxigenados en el tratamiento de úlceras de grado I en pacientes geriátricos hospitalizados.

OBJECTIVE: To evaluate whether there is equivalence between two treatments for grade I ulcers with a base of hyperoxygenated fatty acids, AGHO and Mepentol: AGHO and phytotherapy. METHOD: A randomized, controlled, triple blind clinical trial was conducted with patients admitted at the Elderly Ward at San Carlos Hospital in Madrid between November 2006 and January 2008. There were two treatment groups: Experimental and control. A theoretical limit of 15% was determined between both groups. We took a random sample of patients admitted to the Elderly Ward, which produced a sample of 151 sores. The control group received treatment with Mepentol and the experimental group received AGHO. The assignment to the group was at random. The output variable was healing of erythema within the first 72h. We calculated the absolute difference in the incidence of healing between both treatments with a level of confidence of 95%. RESULTS: The sample at the end of the study was 148 (72 control and 76 experimental). There was a healing incidence of 55.6% in the control group and 69.7% in the experimental group (p=0.074). The difference in the incidence of healing between both treatments was 14% (95% CI: 29% to -1%). The upper limit of the confidence interval of the difference is outside the margin of equivalence. CONCLUSIONS: We cannot conclude that the treatment with AGHO fatty acids is equivalent to Mepentol treatment. With both treatments the healing is clinically significant.