Effects of Myrcia pubipetala Miq (Myrtaceae) extract on innate inflammatory response

Myrcia is a genus widespread in South America with many species presenting anti-inflammatory and biological properties. We investigated the anti-inflammatory activity of crude hydroalcoholic extract of Myrcia pubipetala leaves (CHE-MP) using macrophages (RAW 264.7), and the air pouch model in mice to evaluate leukocyte migration and mediator's release. Adhesion molecule expression, CD49 and CD18, was evaluated in neutrophils. In vitro, the CHE-MP significantly reduced nitric oxide (NO), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF) levels in the exudate and the supernatant culture. CHE-MP did not present cytotoxicity and modulated the percentage of positive neutrophils for CD18 and its expression per cell, without modifying the expression of CD49, which corroborated with significantly reduced neutrophil migration to inflammatory exudate and subcutaneous tissue. Taken together, the data demonstrate that CHE-MP presents a potential activity on innate inflammatory.

An opportunity for acerola pulp (Malpighia emarginata DC) valorization evaluating its performance during the block cryoconcentration by physicochemical, bioactive compounds, HPLC-ESI-MS/MS, and multi-elemental profile analysis

The present study evaluated the effect of cryoconcentration of pulp blocks of acerola (Malpighia emarginata DC). The study evaluated cryoconcentration in three stages. The cryoconcentrated samples, the ice fractions, and the initial pulp were evaluated for physicochemical composition, bioactive composition, and multielement profile. The cryoconcentrated sample obtained in the third stage of cryoconcentration showed the best results for the concentration factor, process efficiency, total soluble solids content, red color intensity, and increasing of the macro and micronutrients: Cu, Ca, S, Sr, K, Mn, Na, P, Mg, Fe. All stages presented good performance in the total soluble solids content, increase in the titratable acidity of the concentrates, and progressive increase in the intensity of the red color. Generally, higher levels of total phenolic and antioxidant activity were found for the 2nd and 3rd concentrates. The phenolic activity showed an increase of 166.90% in the 3rd stage concentrate compared to fresh pulp, and the antioxidant activity was 112.10% by the ABTS method and 131.60% by the DPPH method, both in the 3rd stage concentrate. The major individual polyphenols were Ferulic acid, Protocatechuic acid, and Taxifolin, with significant increases in the concentration of the compounds in the 2nd and 3rd stage concentrates. In addition, the contents of potentially toxic metals were below detection limits. During the cryoconcentration process, there was a decrease in the values ​​of vitamin C content, moisture content, density, and elements Cu, Sr, and Zn.

Immobilized acetylcholinesterase in magnetic nanoparticles for in-line inhibition studies using a capillary electrophoresis system

Enzyme assays can be performed with the capillary electrophoresis technique (CE) in many approaches, such as the immobilized enzyme micro-reactor. Acetylcholinesterase is a promising enzyme to be used when pursuing such a method, as it has already been explored in the proposal of similar methods of miniaturizing enzyme assays. The present work proposes a novel enzyme micro-reactor, based on the anchorage of the enzyme on magnetic nanoparticles of MnFe₂O_4, with chitosan and glutaraldehyde as the cross-linker in the capillary by means of an arrange of neodymium magnets. The calculated K_m of the enzyme evaluated by this method was 1.12 mmol L^-1, comparable to other studies in the literature that utilizes immobilized enzymes. Also, IC₅₀ for neostigmine was assessed in 3 different micro-reactors, with an average of 29.42 ± 3.88 μmol L^-1. In terms of the micro-reactor stability, it was possible to perform at least 25 experiments with assembled micro-reactor. The method was applied to hydroalcoholic extracts of 7 plant species. Plinia cauliflora had the best result, with 42.31 ± 6.81% of enzyme inhibition in a concentration of 100 mg L^-1.

Kinetic Profile of Urine Metabolites after Acute Intake of a Phenolic Compounds-Rich Juice of Juçara (Euterpe edulis Mart.) and Antioxidant Capacity in Serum and Erythrocytes: A Human Study

The juçara palm tree produces a small spherical and black-purple fruit similar to açaí. It is rich in phenolic compounds, especially anthocyanins. A clinical trial evaluated the absorption and excretion of the main bioactive compounds in urine and the antioxidant capacity in serum and erythrocytes of 10 healthy subjects after juçara juice intake. Blood samples were collected before (0.0 h) and 0.5 h, 1 h, 2 h, and 4 h after a single dose (400 mL) of juçara juice, while urine was collected at baseline and 0-3 and 3-6 h after juice intake. Seven phenolic acids and conjugated phenolic acids were identified in urine deriving from the degradation of anthocyanins: protocatechuic acid, vanillic acid, vanillic acid glucuronide, hippuric acid, hydroxybenzoic acid, hydroxyphenylacetic acid, and ferulic acid derivative. In addition, kaempferol glucuronide was also found in urine as a metabolite of the parent compound in juçara juice. Juçara juice caused a decrease in the total oxidant status of serum after 0.5 h in comparison to baseline values (p < 0.05) and increased the phenolic acid metabolites excretion. This study shows the relationship between the production of metabolites of juçara juice and the total antioxidant status in human serum, indicating evidence of its antioxidant capacity.

A Rational Procedure to Increase Selectivity in the Determination of an Elicitor as Salicylic Acid in Polygala Extracts Using Capillary Electrophoresis

Considering the economic potential of secondary metabolites, researches have been focusing several strategies in order to explore and enhance the accumulation of these metabolites in plant matrices in a broad context. One of those strategies is the development of suitable methodologies for the determination of some elicitors, such as salicylic acid (SA). Since literature presents only a few analytical methods for the quantification of SA in plants, this study developed, validated and evaluated these metabolite contents in Polygala species using capillary zone electrophoresis with ultraviolet-visible detection. The background electrolyte (BGE) consisted of 15 mmol L−1 of hydroxymethyl-aminomethane and 30 mmol L−1 of 2-hydroxy-isobutyric acid, pH = 3.9. The BGE was chosen using a rational procedure to increase selectivity and reduce migration time. The method presented rapid performance, migration time less than 0.76 min for salicylic and phthalic acid (internal standard), precision results for peak area were better than 2.9% (intra-day) and 2.8% (inter-day) and the responses for the analytes were linear (range of 1-5 mg L−1), with limits of detection and quantification of 0.2 and 0.6 mg L−1, respectively. The developed method was applied for 39 samples of plant extracts.

Bayesian models to explain autistic traits in psychiatric population

Introduction

Studies on psychiatric patients have shown that the presence of autistic traits affects the effectiveness of the treatment, decreasing the likelihood of positive clinical outcomes.

Objectives

The aim of the present study is to investigate which are the areas of overlap between psychiatric symptoms and the traits of the autism spectrum using a bayesian approach.

Methods

A sample of 190 adult psychiatric patients, diagnosed with schizophrenia, bipolar disorder, major depression, and personality disorder participated in the study. The RAADS-R questionnaire was used to assess the presence of autistic traits. The severity of psychiatric symptoms was measured with the BPRS and PANSS scales, the perceived well-being and disability using the Whodas and Whoqol scales, the TOL and STROOP for the measurement of executive functions, the attentional matrices for visual-spatial attention, the Raven for general cognitive skills.

Results

No difference emerged between the diagnoses regarding the presence of symptoms of the autism spectrum, which affects 64% of subjects. Logistic regression showed that the severity of symptoms measured as BPRS and PANSS predicted the probability of having autistic traits. Bayesian regression showed that specific autistic traits are indicative of executive functions deficits. Namely, motor impairment severity measured at RAADS is strongly predicted by rule violation with number of correct moves measured at TOL. The other executive functions seemed to be only moderately linked to autistic traits.

Conclusions

These results provide new information about the expression of comorbidity with autism in psychiatric patients.

HPLC-ESI-MS/MS phenolic profile of ‟Nanicão Corupá” (Musa acuminata)

Abstract “Nanicão Corupá” (Musa acuminata) comes from Southern Brazil. The tropical climate in the region provides unique characteristics, including a sweeter flavor. This difference resulted in a Geographical Indication Recognition and Designation of Origin, recognized by the National Institute of Industrial Property (INPI) in Brazil. Considering that “Nanicão Corupá” has some peculiarities related to the climate and there are no studies evaluating this banana cultivars, the purpose of the present study was to investigate the qualitative and quantitative phenolic composition of the aerial parts of “Nanicão Corupá” by HPLC-ESI-MS/MS in comparison to 46 commercial standards of phenolic compounds. Aerial parts (flower, leaves, fruit and stem) of “Nanicão Corupá” were collected and macerated in methanolic extracts, which were partitioned with solvents of different polarities (dichloromethane and ethyl acetate). The HPLC-ESI-MS/MS analysis was performed using the sample pre-treatment, chromatographic and mass spectrometer parameters. Results demonstrated that a total of 11 phenolic compounds were identified in the analyzed samples. The majority of compounds was identified in the ethyl acetate fraction (BFEF) of banana flowers: rutin (36.06 ± 0.23) and isoquercetin (28.83 ± 5). The compounds isoquercetin, naringerin and myricitrin were identified for the first time in the Musa genus.

Phenolic compounds of Eugenia involucrata (Myrtaceae) extracts and associated antioxidant and inhibitory effects on acetylcholinesterase and α-glucosidase

Eugenia involucrata DC. (Myrtaceae), popularly known as "cereja-do-Rio-Grande", is a native tree from Brazil, popularly used as a hypoglycemiant. Crude hydroalcoholic extract (CHE) and fractions (insoluble (FI), dichloromethane (FDM), ethyl acetate (FEA) and butanol (FBu)) of leaves were assessed to determine the phenolic chemical composition by HPLC-ESI-MS/MS. 10 compounds were identified, being 7 new for this species: rutin, isoquercitrin, luteolin-7-O-rutinoside, mandelic acid, naringenin, luteolin-7-O-glucoside and salicylic acid. Extract and fractions showed inhibitory activity on acetylcholinesterase (AchE) enzyme (best result: IC₅₀ = 44.19 µg mL^-1, for FEA) and α-glucosidase (α-Glu) (best result: IC₅₀ = 31.25 ± 0.15 µg mL^-1, for CHE). The observed antioxidant and inhibitory activity on the AchE and α-Glu is due to, at least in part, the presence of phenolic compounds in the samples.

Dual electrophoretically-mediated microanalysis in multiple injection mode for the simultaneous determination of acetylcholinesterase and α-glucosidase activity applied to selected polyphenols

Acetylcholinesterase (AChE) and α-glucosidase (α-glu) are key target enzymes in the search for novel strategies in the treatment of Alzheimer's disease and type II diabetes. Therefore, methods to assess the enzyme inhibition are of great value in the research field. Here is proposed a novel a dual electrophoretically-mediated microanalysis for the simultaneous determination of both enzymes' activity. In order to do so, the various solutions required for both assays were introduced in the capillary electrophoresis system using the multiple injections approach. Enzymatic kinetic parameters were tested, K_m for AChE and α-glu were 3.81 and 0.43 mmol L^-1. K_i values were 4.27 μmol L^-1 for neostigmine (an AChE inhibitor) and 0.40 mmol L^-1 for acarbose (an α-glu inhibitor). Results of IC₅₀ (concentration for 50% of inhibition) were 5.11 ± 0.47 μmol L^-1 and 0.58 ± 0,02 mmol L^-1 for neostigmine and acarbose, respectively. All parameters (except for K_i of neostigmine) were comparable with the literature, indicating a good reliability of the proposed method to evaluate these enzymes activity. Total time analysis was approximately 10 min, being possible to perform around 12 enzymatic assays per hour, with low sample and reagent consumption, thus satisfying some of the principles of green chemistry. The method was applied to evaluate 10 phenolic compounds, of wich p-coumaric acid showed the best inhibitory activity for AChE (40.14 ± 4.75% at 10 mg L^-1); and quercetin for α-glu (46.53 ± 4.90% at 10 mg L^-1).

Sorocea guilleminiana Gaudich.: Wound healing activity, action mechanisms, and chemical characterization of the leaf infusion

ETHNOPHARMACOLOGICAL RELEVANCE

Sorocea guilleminina Gaudich. is a tree or shrub endemic to Brazil. Its leaves are used in Brazilian folk medicine for the healing of wounds, stomach problems, inflammation and as diuretic. The present study evaluates the activity and action mechanisms of the healing properties of the aqueous extract of S. guilleminiana leaves (AESg), in experimental models in vivo and in vitro, as well as performs a phytochemical analysis of the extract.

MATERIALS AND METHODS

The AESg was prepared by infusion: Ten g of dry leaves powder in 1 L hot water, soaked for 15 min, filtered, lyophilized, and stored at -30 °C. Phytochemical analyses were realized by colorimetry and HPLC/ESI/MS. Its' in vitro cytotoxicity was evaluated on fibroblastic N3T3 cells. The potential of the wound healing activity in vivo was evaluated using excision and incision wound rat models, by histopathology of the injured skin along with the determination of nitric oxide, cytokines (IL-1β, IL-10, and TNF-α), and antioxidant parameters (GSH, MPO and CAT). In vitro wound healing activity was also demonstrated in scratched N3T3 cells, by measuring the proliferation/migration rate.

RESULTS

The phytochemical analysis of the AESg revealed a strong presence of polar compounds, especially flavonoids (4 majoritarian), as well as terpenes and/or sterols (2 majoritarian). The AESg showed no toxicity in the N3T3 cell line (IC₅₀ > 800 μg/mL). Topical treatment with the AESg showed an increase (p < 0.05) in wound contraction with 2 mg/g cream on days 5 and 9 (43.56% and 6.70% increase, respectively), and with 50 mg/g on days 7 and 9 (10.88% and 7.91%, respectively), compared to the vehicle (non-ionic neutral cream). Topical application of AESg (2 or 50 mg/g non-ionic cream) in incised wounds caused an increase in the force necessary for the rupture of the wound when compared to the vehicle group. No changes in cytokines (IL-1β, IL-10, or TNF-α) or NO accumulation was found with up to 50 mg/g AESg treatment. For antioxidant activity on the incision wound, an increase in GSH levels was denoted with the AESg use, at the lowest and highest dose (2 and 50 mg/g) by 75.86% and 61.20% respectively, when compared to the vehicle. Also, the CAT activity was accentuated by AESg at the highest dose (50 mg/g) by 85.87%. Finally, the AESg at all doses attenuated MPO activity significantly in the incision wound by 71.35%, 73.21%, 78.08%, respectively. In the scratch test on N3T3 cells, the treatment with AESg resulted also in an increase in fibroblast proliferation/migration rate, compared to the vehicle.

CONCLUSION

AESg is not cytotoxic. The results confirm the popular use of the leaf infusion of S. guilleminiana for the treatment of cutaneous wounds, possibly by stimulating the proliferation of fibroblasts with a consequent deposition of collagen, fastening rearrangement of collagen fibers, and greater transformation into myofibroblasts, essential in the healing process. Preliminary chemical analyzes of AESg revealed the presence mainly of phenolic compounds, being salicylic acid, gallic acid, pinocembrin and isoquercitrin the majoritarian ones.

Dataset about Southern-Brazilian geopropolis: Physical and chemical perspectives

The dataset showed in this manuscript belongs to the investigation of the Southern-Brazilian geopropolis of stingless bees. Stingless bees are native species of insects from tropical areas; they produce honey, pollen and geopropolis that is composed of a mix of vegetal extracts, digestive enzymes, and mostly by soil. Used in folk medicine as antiseptic, antioxidant and antimicrobial agent, the composition is due to bee species, climate changes, local flora, and soil type. Moreover, the complex chemical content gives to the geopropolis a bioactive potential, with scavenging characteristics that is important to avoid free radical damages in the human health.

Regarding the importance of exploring new natural matrices sources with bioactive potential, the first approach of chemical characterization of geopropolis is indispensable. Thus, ten samples of Southern-Brazilian geopropolis were analyzed and the bioactive responses obtained were discussed in the accompanying article titled “Southern-Brazilian geopropolis: A potential source of polyphenolic compounds and assessment of mineral composition”. Furthermore, the physicochemical analysis of moisture and ash content, the yield of extraction, the reducing activity and free radical scavenging potential of ethanolic extracts, the antimicrobial activity, and the analysis of HPLC-ESI-MS/MS chromatograms are the main data presented in brief. The data can guide scientists in order to know methods and data for these samples.

Quantitative analysis of phenolic compounds in crude extracts of Myrcia splendens leaves by HPLC-ESI-MS/MS

Abstract Myrcia splendens is popularly known as “guamirim-de-folha-miúda”, and its occurrence ranges from Mexico to southern Brazil. The aim of this work was to identify and quantify phenolic compounds in the crude hydroalcoholic (EBH), ethyl acetate (EBAE) and dichloromethane (EBDM) extracts using the HPLC-ESI- MS/MS. In total, 15 compounds, including protocatecuic acid, syringic acid, p-coumaric acid, salicylic acid, isoquercetin, ellagic acid, ferulic acid, umbelliferone, coniferaldehyde, sinapaldehyde, carnosol, gallic acid, syringaldehyde, umbelliferone, coniferaldehyde, myricetin and kaempferol were identified. Ellagic acid was the major compound in all extracts.

Phenolic profile by HPLC-ESI-MS/MS of six Brazilian Eugenia species and their potential as cholinesterase inhibitors

Eugenia genus is known for its phenolic metabolites, which may influence the progression of the Alzheimer Disease. This study aimed to evaluate the anticholinesterase effects of six Eugenia species from Brazil. Leaves and stems were submitted to maceration (methanol) and partitioned with dichloromethane and ethyl acetate (EtOAc). Samples were screened (200 μg mL^-1) for the inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). HPLC-ESI-MS/MS analysis allowed the identification of twenty-eight phenolic compounds. Regarding the enzymatic activity, EtOAc fraction of E. mattosii exhibited the best results. Chemical and pharmacological aspects of seasonal E. mattosii extracts were evaluated. The extract from leaves collected in the winter was the most effective for AChE, and the extract from leaves collected in the spring was the most effective for BuChE. Correlating the enzymatic results with the chemical data, it was possible to associate these effects to isoquercitrin, quercetin, catechin, epicatechin, procatecuic acid and myricitrin content.

Bauhinia forficata link, a Brazilian medicinal plant traditionally used to treat cardiovascular disorders, exerts endothelium-dependent and independent vasorelaxation in thoracic aorta of normotensive and hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bauhinia forficata Link, commonly known as "cow's paw", is a native plant from South America. Its leaves are widely used in Brazilian folk medicine to treat diabetes and cardiovascular disorders. Although this species' biological potential has been extensively proven as an antidiabetic, anti-inflammatory and antioxidant agent, there is a lack of studies to evidence its action on the cardiovascular system.

AIM OF THE STUDY

This study was designed to investigate the vascular effects of B. forficata leaves preparations and its majority compound kaempferitrin, as well as its aglycone form kaempferol, in rat aortic rings of normotensive (NTR) and hypertensive (SHR) rats.

MATERIALS AND METHODS

Aorta rings from NTR and SHR precontracted with phenylephrine were exposed to cumulative concentrations of B. forficata extract, fractions (1-50 μg/mL) and compounds (0.001-0.3 μg/mL). The mechanisms involved in the vasorelaxant effect of ethyl-acetate plus butanol fraction (EAButF) were also evaluated.

RESULTS

Although kaempferitrin is the most abundant compound found in both methanolic extract and EAButF, 24 minor phenolic compounds were identified in B. forficata leaves, including kaempferol. EAButF was the only with endothelium-dependent and independent vasorelaxant properties in both NTR and SHR. The incubation with L-NAME or ODQ completely blocked EAButF-induced vasorelaxation. On the other hand, the incubation with propranolol, atropine, indomethacin, glibenclamide or barium chloride did not change the vasorelaxant activity of EAButF (50 μg/mL). Nevertheless, the incubation with tetraethylammonium and 4-aminopyridine significantly influenced the EAButF activity. It was also shown that Ca²⁺ influx or efflux is not related to EAButF vasorelaxation potential. Kaempferitrin and kaempferol were also able to relax the rat aortic rings in 34.70% and 40.54%, respectively.

CONCLUSIONS

This study shows, for the first time, the vasorelaxant effect of EAButF from B. forficata leaves, an effect that may be attributed to the modulation of vascular tone through nitric oxide/soluble guanylate cyclase pathway, and potassium channels. The bioactive kaempferitrin and kaempferol seem to be important for the effects observed with the fraction. Finally, preparations obtained from the leaves of B. forficata may be interesting candidates for new or complementary strategies regarding cardiovascular diseases.

Southern-Brazilian geopropolis: A potential source of polyphenolic compounds and assessment of mineral composition

Geopropolis is a stingless bee product compose mainly by soil, presenting complex composition geopropolis has bioactive compounds that will depend on geographical characteristics as well bee species, changing their chemical and biological properties. Thus the study aims to evaluate the solubility and chemical stability of geopropolis extracts, through radical capture capacity and reducing capacity. Besides, analysis of free and bonded phenolic compounds, and mineral composition. Geopropolis samples of Melipona mondury, Melipona quadrifasciata, Melipona scutellaris, Melipona seminigra and Tetragonisca angustula were analyzed. Both reducing compounds with a maximum of 2.96% GAE and free radical scavenging potential with a maximum of 5.84% AAE and 8.58% TE increases over 30 days of storage time. Also, methanolic extracts released at least 51% more reducing compounds and exhibited at least 27% more free radical scavenging potential in comparison to ethanolic extracts. The polyphenolic profile shows 31 compounds after acid and alkaline hydrolysis as cinnamic acid, ferulic acid, p-coumaric acid, aromadendrin, vanillin. For the mineral composition, sixteen minerals were found among essential and non-essential, differentiating each sample by chemometric PCA and HCA analysis according to geographic region. Geopropolis is a potential source of natural compounds that could enhance food quality, increasing the bioactive content and preventing oxygen damages in foods, likewise for pharmacological application for healthcare.

Supporting the improvement of air quality management practices: The "FAIRMODE pilot" activity

This paper presents the first outcomes of the "FAIRMODE pilot" activity, aiming at improving the way in which air quality models are used in the frame of the European "Air Quality Directive". Member States may use modelling, combined with measurements, to "assess" current levels of air quality and estimate future air quality under different scenarios. In case of current and potential exceedances of the Directive limit values, it is also requested that they "plan" and implement emission reductions measures to avoid future exceedances. In both "assessment" and "planning", air quality models can and should be used; but to do so, the used modelling chain has to be fit-for-purpose and properly checked and verified. FAIRMODE has developed in the recent years a suite of methodologies and tools to check if emission inventories, model performance, source apportionment techniques and planning activities are fit-for-purpose. Within the "FAIRMODE pilot", these tools are used and tested by regional/local authorities, with the two-fold objective of improving management practices at regional/local scale, and providing valuable feedback to the FAIRMODE community. Results and lessons learnt from this activity are presented in this paper, as a showcase that can potentially benefit other authorities in charge of air quality assessment and planning.

Neuroprotective effect of juçara (Euterpe edulis Martius) fruits extracts against glutamate-induced oxytosis in HT22 hippocampal cells

This study investigated the neuroprotective effect of juçara fruit extracts against glutamate-induced oxytosis in HT22 cells. Potential relationships between the extracts' polyphenolic composition and their protective/antioxidant capacities were also investigated. Experiments with the addition of either the crude methanolic extract or hexane, dichloromethane, ethyl acetate and butanol fractions 24 h before glutamate (pretreatment) and together with glutamate (co-treatment) were performed. At the concentration of 10 μg ml^-1, the hexane and dichloromethane fractions were able to protect cells, both in pretreatment and co-treatment. These fractions presented the highest number of quantified polyphenolics (24 and 21, respectively) although the total levels were 63-fold higher in the dichloromethane fraction. Syringaldehyde, vanillin and 4-aminobenzoic, cinnamic, salicylic and syringic acids were found only in these fractions. The dichloromethane fraction presented higher 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, while the butanol and ethyl acetate fractions showed higher ferric reducing antioxidant power. These results suggest juçara fruits extracts as promising for the reduction of the risk of neurodegenerative diseases.

Determination of acetylcholinesterase and α-glucosidase inhibition by electrophoretically-mediated microanalysis and phenolic profile by HPLC-ESI-MS/MS of fruit juices from Brazilian Myrtaceae Plinia cauliflora (Mart.) Kausel and Eugenia uniflora L

Alzheimer's disease and diabetes mellitus are contemporary diseases of great concern. Phenolic compounds are linked to several health benefits and could lead to novel strategies to combat these ailments. The objective of this study was to evaluate by electrophoretically-mediated microanalysis the potential inhibitory activity of the fruit juices from Plinia cauliflora ("jaboticaba") and Eugenia uniflora ("pitanga") toward acetylcholinesterase (AChE) and α-glucosidase, target enzymes in strategies for the treatment of these diseases. The phenolic profiles of the samples were also investigated. Jaboticaba and pitanga juices inhibited 85.90 ± 1.73 and 52.67 ± 1.24% of AChE activity at 5 mg mL^-1, and 57.91 ± 2.60 and 69.47 ± 2.89% of α-glucosidase activity at 1 mg mL^-1, respectively. Total phenolic content of the juices were 303.54 ± 28.28 and 367.00 ± 11.42 mgGA L^-1, respectively. The observed inhibitory activity can be explained, at least in part, by the presence of the phenolic compounds.

Ultrasonic-assisted extraction combined with sample preparation and analysis using LC-ESI-MS/MS allowed the identification of 24 new phenolic compounds in pecan nut shell [Carya illinoinensis (Wangenh) C. Koch] extracts

Ultrasonic-assisted extraction combined with statistical tools (factorial design, response surface methodology and kinetics) were used to evaluate the effects of the experimental conditions of temperature, solid-to-solvent ratio, ethanol concentration and time for the extraction of the total phenolic content from pecan nut shells. The optimal conditions for the aqueous and hydroalcoholic extract (with 20% v/v of ethanol) were 60 and 80 °C; solid to solvent ratio of 30 mL·g^-1 (for both) and extraction time of 35 and 25 min, respectively. Using these optimize extraction conditions, 426 and 582 mg GAE·g^-1 of phenolic compounds, from the aqueous and hydroalcoholic phases respectively, were obtained. In addition, the analysis of the phenolic compounds using the LC-ESI-MS/MS system allowed the identification of 29 phenolic compounds, 24 of which had not been reported in literature for this raw material yet.

Strain-induced effects in the electronic and spin properties of a monolayer of ferromagnetic GdAg2

We report on the structural, electronic and magnetic properties of a monolayer of GdAg₂, forming a moiré pattern on Ag(111). Combining scanning tunneling microscopy and ab initio spin-polarized calculations, we show that the electronic band structure can be shifted linearly via thermal controlled strain of the intra-layer atomic distance in the range of 1-7%, leading to lateral hetero-structuring. Furthermore, the coupling of the incommensurable GdAg₂ alloy layer to the Ag(111) substrate leads to spatially varying atomic relaxation causing subsurface layer buckling, texturing of the electronic and spin properties, and inhomogeneity of the magnetic anisotropy energy across the layer. These results provide perspectives for control of electronic properties and magnetic ordering in atomically-thin layers.

High Temperature Ferromagnetism in a GdAg2 Monolayer

Materials that exhibit ferromagnetism, interfacial stability, and tunability are highly desired for the realization of emerging magnetoelectronic phenomena in heterostructures. Here we present the GdAg2 monolayer alloy, which possesses all such qualities. By combining X-ray absorption, Kerr effect, and angle-resolved photoemission with ab initio calculations, we have investigated the ferromagnetic nature of this class of Gd-based alloys. The Curie temperature can increase from 19 K in GdAu2 to a remarkably high 85 K in GdAg2. We find that the exchange coupling between Gd atoms is barely affected by their full coordination with noble metal atoms, and instead, magnetic coupling is effectively mediated by noble metal-Gd hybrid s,p-d bands. The direct comparison between isostructural GdAu2 and GdAg2 monolayers explains how the higher degree of surface confinement and electron occupation of such hybrid s,p-d bands promote the high Curie temperature in the latter. Finally, the chemical composition and structural robustness of the GdAg2 alloy has been demonstrated by interfacing them with organic semiconductors or magnetic nanodots. These results encourage systematic investigations of rare-earth/noble metal surface alloys and interfaces, in order to exploit them in magnetoelectronic applications.

Determining the arsenic, cadmium, lead, copper and chromium contents by atomic absorption spectrometry in Pangasius fillets from Vietnam

BACKGROUND

Pangasius is a fish produced on a large scale in Vietnam and exported to many countries. Since river contamination from human activities can affect the safety of this food, fish consumption can cause exposure to potentially toxic elements for humans. The aim of this study, therefore, was to assess arsenic, cadmium, lead, copper and chromium contents by atomic absorption spectrometry in Pangasius fillet produced in the provinces of Dong Thap and Can Tho (Vietnam) and exported to Brazil.

RESULTS

The limits of detection were: arsenic 0.5443 µg kg(-1) , cadmium 0.0040 mg kg(-1) , chromium 0.0004 mg kg(-1) , copper 0.0037 mg kg(-1) and lead 0.0284 mg kg(-1) . Analysis of 20 samples showed results below the limit of detection for arsenic, chromium and lead, while copper average concentration was 0.0234 mg kg(-1) . Cadmium average concentration was 0.0547 mg kg(-1) , with no significant difference between the two regions studied.

CONCLUSION

The samples of Pangasius had no detectable concentrations of arsenic, chromium, copper and lead, and do not represent a hazard to public health. However, cadmium analysis revealed non-compliant samples, demonstrating the importance of monitoring the quality of imported Pangasius fish. © 2015 Society of Chemical Industry.

High-Throughput Analysis of Lidocaine in Pharmaceutical Formulation by Capillary Zone Electrophoresis Using Multiple Injections in a Single Run

This paper reports the development of a subminute separation method by capillary zone electrophoresis in an uncoated capillary using multiple injection procedure for the determination of lidocaine in samples of pharmaceutical formulations. The separation was performed in less than a minute leading to doing four injections in a single run. The cathodic electroosmotic flow contributed to reducing the analyses time. The background electrolyte was composed of 20 mmol L(-1) 2-amino-2-(hydroxymethyl)-1,3-propanediol and 40 mmol L(-1) 2-(N-morpholino)ethanesulfonic acid at pH 6.1. The internal standard used was benzylamine. Separations were performed in a fused uncoated silica capillary (32 cm total length, 23.5 cm effective length, and 50 μm internal diameter) with direct UV detection at 200 nm. Samples and standards were injected hydrodynamically using 40 mbar/3 s interspersed with spacer electrolyte using 40 mbar/7 s. The electrophoretic system was operated under constant voltage of 30 kV with positive polarity on the injection side. The evaluation of some analytical parameters of the method showed good linearity (r (2) > 0.999), a limit of detection 0.92 mg L(-1), intermediate precision better than 3.2% (peak area), and recovery in the range of 92-102%.

Sub-minute method for simultaneous determination of aspartame, cyclamate, acesulfame-K and saccharin in food and pharmaceutical samples by capillary zone electrophoresis

This paper reports the development of a sub-minute separation method by capillary zone electrophoresis for the determination of aspartame, cyclamate, acesulfame-K and saccharin in food products and pharmaceutical samples. Separations were performed in a fused uncoated silica capillary with UV detection at 220nm. Samples and standards were injected hydrodynamically using the short-end injection procedure. The electrophoretic system was operated under constant voltage of -30kV. The background electrolyte was composed of 45mmolL(-1) 2-amino-2-(hydroxymethyl)-1,3-propanediol and 15mmolL(-1) benzoic acid at pH 8.4. The separation time for all analytes was less than 1min. Evaluation of analytical parameters of the method showed good linearity (r(2)>0.9972), limit of detection of 3.3-6.4mgL(-1), intermediate precision better than 9.75% (peak area of sample) and recovery in the range of 91-117%.