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Summary: In the current study, polyphenols were extracted from chestnut (Castanea sativa) shells (CSS) by two eco‐friendly techniques, namely microwave‐assisted extraction (MAE) and ultrasound‐assisted extraction (UAE). The bioaccessibility, phenolic composition and bioactivity of CSS extracts were explored upon in vitro gastrointestinal digestion considering a future nutraceutical use. The phenolic and flavonoid concentrations, bioaccessibility and antioxidant/antiradical properties of both extracts decreased during digestion. The bioaccessibility was 25% and 26%, respectively, for UAE and MAE extracts. The phenolic profile demonstrated that gallic acid, caftaric acid and catechin were the most bioaccessible compounds for both extraction techniques. The CSS extracts unveiled notable radicals scavenging efficiency, particularly against HOCl (18.32–75.44% inhibition) and ONOO− (16.78–86.11% inhibition), as well as hypoglycaemic (6.95–17.99% α‐amylase inhibition) and neuroprotective (16.44–54.66% AChE inhibition) properties upon digestion. Considering the undigested extracts, the UAE extract revealed better results than the MAE extract. Oppositely, among digested fractions the MAE digests disclosed the most promising outcomes. The remarkable contribution of phenolic compounds to the bioactivity of CSS extracts after in vitro digestion was proved by heatmap correlations, indicating that their pro‐healthy properties were modified after gastrointestinal digestion, being ascribed to the distinct phenolic composition. This study evaluates, for the first time, the impact of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolics‐rich CSS extracts prepared by UAE and MAE. [ABSTRACT FROM AUTHOR]

Screening and early diagnosis are crucial to increase the success of cancer patients' treatments and improve the survival rate. To contribute to this success, distinct electrochemical immunosensing platforms were developed for the analysis of the ExtraCellular Domain of the Human Epidermal growth factor Receptor 2 (HER2‐ECD) through sandwich assays on nanomaterial‐modified screen‐printed carbon electrodes (SPCEs). The most promising platforms showed to be SPCEs modified with (i) gold nanoparticles (AuNPs) and (ii) multiwalled carbon nanotubes combined with AuNPs. The antibody‐antigen interaction was detected using a secondary antibody labelled with alkaline phosphatase and 3‐indoxyl phosphate and silver ions as the enzymatic substrate. The electrochemical signal of the enzymatically generated metallic silver was recorded by linear sweep voltammetry. Under the optimized conditions, linear calibration plots were obtained between 7.5 and 50 ng/mL and the total assay time was 2 h 20 min, achieving LODs of 0.16 ng/mL (SPCE‐MWCNT/AuNP) and 8.5 ng/mL (SPCE‐AuNP), which are well below the established cut‐off value of 15 ng/mL for this cancer biomarker. [ABSTRACT FROM AUTHOR]

Nitric oxide radical (NO) is a signalling molecule involved in virtually all forms of life. Its relevance has been leading to the development of different analytical methodologies to assess the temporal and spatial fluxes of NO under the complex biological milieu. Third‐generation electrochemical biosensors are promising tools for in loco and in vivo NO quantification and, over the past years, heme proteins and porphyrins have been used in their design. Since there are some limitations with the biorecognition element directly adsorbed onto the electrode surface, nanomaterials (carbon nanotubes, gold nanoparticles, etc.) and polymers (cellulose, chitosan, nafion®, polyacrylamide, among others) have been explored to achieve high kinetics and better biosensor performance. In this review, a broad overview of the field of electrochemical third‐generation biosensors for NO electroanalysis is presented, discussing their main characteristics and aiming new outlooks and advances in this field. [ABSTRACT FROM AUTHOR]

This work describes a sensitive voltammetric immunosensor for label‐free electroanalysis of the prostate specific antigen (PSA), the main biomarker of prostate cancer. A gold electrode was firstly modified with the optimum self‐assembled monolayer (SAM), 1,6‐hexanedithiol, followed by the subsequent adsorption of gold nanoparticles (AuNPs) and, then, the monoclonal antibody to recognize PSA was immobilized. The influence of the most significant experimental variables (SAM type and incubation time, AuNPs deposition, antibody concentration and bovine serum albumin immobilization) on the biosensor response was studied by microscopy and voltammetry techniques. The electroanalytical detection was based on the interaction between PSA antibody and PSA via square‐wave voltammetry using ferrocyanide/ferricyanide as electrochemical redox indicator. Using the proposed immunosensor, PSA was specifically detected within the linear range between 0.2 and 200 ng mL−1 with 0.01 ng mL−1 as limit of detection. The immunosensor allows accurate, reproducible and sensitive (22.7 % reduction mL ng−1) detection in a concentration range useful for clinical purposes. [ABSTRACT FROM AUTHOR]

Abstract: In cancer, screening and early detection are critical for the success of the patient's treatment and to increase the survival rate. The development of analytical tools for non‐invasive detection, through the analysis of cancer biomarkers, is imperative for disease diagnosis, treatment and follow‐up. Tumour biomarkers refer to substances or processes that, in clinical settings, are indicative of the presence of cancer in the body. These biomarkers can be detected using biosensors, that, because of their fast, accurate and point of care applicability, are prominent alternatives to the traditional methods. Moreover, the constant innovations in the biosensing field improve the determination of normal and/or elevated levels of tumour biomarkers in patients’ biological fluids (such as serum, plasma, whole blood, urine, etc.). Although several biomarkers (DNA, RNA, proteins, cells) are known, the detection of proteins and circulating tumour cells (CTCs) are the most commonly reported due to their approval as tumour biomarkers by the specialized entities and commonly accepted for diagnosis by medical and clinical teams. Therefore, electrochemical immunosensors and cytosensors are vastly described in this review, because of their fast, simple and accurate detection, the low sample volumes required, and the excellent limits of detection obtained. The biosensing strategies reported for the six most commonly diagnosed cancers (lung, breast, colorectal, prostate, liver and stomach) are summarized and the distinct phases of the sensors’ constructions (surface modification, antibody immobilization, immunochemical interactions, detection approach) and applications are discussed. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Morus nigra (mulberry) fruit has been reported as a source of bioactive compounds, although information about their leaves is very limited. Usually, they are considered wastes and have been traditionally used only for tea preparation. The main objective of this work was to explore the valorization of mulberry leaves by polyphenols microwave‐assisted extraction (MAE) and characterization of their antioxidant activity and phenolic composition. A 23 factorial design combined with response surface methodology were applied to characterize the effect of main microwave parameters on total phenolic content (TPC). RESULTS: The optimized MAE conditions were 20 mL of ethanol:water (1:1; v/v), 120 °C, 28 min, 0.414 g and medium stirring speed. Under these conditions, TPC was 19.7 ± 2.0 mg gallic acid equivalents (GAE) g‐1 dry plant (DP), and antioxidant activity was 15.3 ± 1.0 mg ascorbic acid (AA) g‐1 DP (ferric reduction activity power –FRAP– assay), 18.6 ± 1.3 mg Trolox equivalents (TE) g‐1 DP (2,2‐diphenyl‐1‐picrylhydrazyl –DPPH– assay) and 186 ± 15 mg TE g‐1 DP (oxygen radical absorbance capacity –ORAC– assay). When compared with ultrasound extraction and Pharmacopeia reference method, MAE was more efficient, representing a valuable technology. Of the 13 compounds identified by HPLC, the most abundant were rutin, chlorogenic, β‐resorcylic and caffeic acids. CONCLUSION: These results indicate that mulberry leaves are of potential interest for agro‐food industries as a new source of natural antioxidants. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Sweet cherries (Prunus avium L.) and sour cherries (Prunus cerasus L.) contain substantial amounts of anthocyanins and polyphenolics, and their stems have been used in traditional medicine for centuries. However, comparative data on the composition of sweet and sour cherry stems using the same analytical methodologies are limited. Moreover, there is no data in terms of biological activity of subcritical water extracts of cherry stems. RESULTS AND DISSCUSION: Results obtained by using several assays that focused on different mechanisms showed that subcritical water extracts of sour and sweet cherry stems were powerful antiradicals and antioxidants. Anti‐proliferative properties measured by MTT (3‐[4,5‐ dimethylthiazol‐2‐yl]‐2,5 diphenyl tetrazolium bromide) test showed prominent cytotoxicity against different tumor cell lines. Inhibitory concentrations obtained were in the range 8.38–11.40 µg mL‐1. GC–MS (gas chromatography mass spectrometry) analysis showed the presence of alcohols, fatty acids, organic acids and other organic compounds. However, the chemical compositions of the two samples observed were similar, indicating similar chemical composition of sour and sweet cherry stems. CONCLUSION: Subcritical water extracts of cherry stem demonstrated excellent biological activity and the potential to be used for pharmaceuticals or supplements due to confirmed high antioxidant, antiradical and antitumor activity. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: To obtain bioactive fractions from plant material subcritical water is notably advantageous in comparison to any other technique. Excellent solvating properties and selectivity combined with finely tuned reactivity of subcritical water enable exploitation of the potential of plants. Herein subcritical water extraction was used for recovery of bioactive compounds from leaves, roots and fruits of Sambucus ebulus L. Extracts obtained were characterized in terms of biological and chemical fingerprints. RESULTS AND DISCUSSION: Results obtained by using several antioxidant assays that focused on different mechanisms showed that subcritical water extracts of Sambucus ebulus were powerful antioxidants. Enzyme inhibitory effects were tested against α‐amylase, α‐glucosidase and tyrosinase, and the results showed the anti‐diabetic potential of the extracts as well as its possible use with skin disorders. Antiproliferative properties were detected on three cell lines (A‐549; LS‐174 T; HeLa) and showed prominent cytotoxicity against all tumor cell lines. Inhibitory concentrations obtained were in the range 0.58–8.10 μg mL‐1. Generally, the SCW extracts from leaves exhibited stronger biological activities with higher levels of phenolic compounds compared with the roots and fruits of Sambucus ebulus. Gallic acid, catechin and caffeic acid were identified as major components in these extracts and these components seem to relate with observed biological activity. CONCLUSION: The results obtained suggest that Sambucus ebulus has great potential for preparing new phyto‐pharmaceuticals and functional food ingredients. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Psidium guajava L. have been reported to be a rich source of antioxidant compounds. Its carotenoids have been highlighted by their high antioxidant capacity, which offers several benefits for human health. In this sense, lycopene isomers need to be identified. In this work, the comprehensive chemical characterization, by HPLC‐DAD, MS/MS, and NMR, of lycopene isolated from P. guajava L., antioxidant and antimicrobial activity of lycopene extracts and isolated lycopene are evaluated. The FTIR results reported a structure with Z configuration, confirmed by UV‐Vis, with λmax = 448, 473, and 505 nm for 5‐Z lycopene. Furthermore, MS/MS positive ionization shows one fragment m/z 309 [M‐227]+, relatively abundant for isolated lycopene. Experimental and Theoretical NMR studies revealed that guava may contain 5‐Z lycopene because of the similarity found among the peaks. Lycopene extracts presented higher antioxidant activity than isolated lycopene, from both P. guajava L. and tomato, when measured by ABTS and ORAC (r2 = 0.9995 and r2 = 0.9992, respectively). In addition, lycopene extract shows antibacterial efficacy against E. coli, S. aureus, and L. innocua, presenting MBC values of 20 mg mL−1. These results suggest that lycopene extract have potential applicability for food, cosmetics, and pharmaceutical industry. Practical Applications: Lycopene from P. guajava L. is characterized by HPLC‐DAD, MS, NMR, FTIR, and X‐Ray, presented antioxidant capacity by ORAC and antibacterial efficacy against food pathogens. Lycopene is isolated from P. guajava L., and lycopene extracts produced are characterized by HPLC‐DAD and ESI‐MS/MS. Lycopene isolated from P. guajava L. following the process may be 5‐Z isomer of lycopene. [ABSTRACT FROM AUTHOR]

Controlled release of aromatic mixtures to the atmosphere is a requirement for scented systems for indoor applications. The product must smell nice, but also be able to last, slowly releasing the perfume over time. Several adsorption materials have been used, for this purpose. In this study, cork was investigated as a potential perfume adsorbent for application in scented drawer sachets and equivalent products. Cork was selected due to its adsorption properties and because it is a natural, renewable, sustainable material. Granulated cork is a significant by-product in cork industries and it was chosen for adsorption in this work. Linalool, an enantiomeric monoterpene alcohol and one of the main components of several essential oils, was selected as the model compound for adsorption studies. Activated carbon (AC) was used as the reference material. The sorption of linalool to granulated cork and AC was evaluated by HS-SPME-GC-FID. The linalool isotherm on cork was shown to follow a Brunauer-Deming-Deming and Teller, Type IV model. The isotherm data on AC can be adjusted to Langmuir and Freundlich models. A maximum adsorption capacity of 3.9x103μg/g was achieved for AC. Desorption studies were performed. Linalool was still released from granulated cork after three equilibrium stages of desorption, whereas only two desorption values were obtained for AC from the equilibrium with highest linalool concentration. Thus, AC demonstrated good adsorption but not good desorption properties. Sorption and desorption studies of linalool from granulated cork, showed that granulated cork could be an excellent material allowing controlled release of the aroma. [ABSTRACT FROM AUTHOR]

ABSTRACT Transgenic maize produced by the insertion of the Cry transgene into its genome became the second most cultivated crop worldwide. Cry gene from Bacillus thuringiensis kurstaki expresses protein derivatives of crystalline endotoxins which confer insect resistance onto the maize crop. Mandatory labeling of processed food containing or made by genetically modified organisms is in force in many countries, so, it is very urgent to develop fast and practical methods for GMO identification, for example, biosensors. In the absence of an available empirical structure of Cry1A(b)16 protein, a theoretical model was effectively generated, in this work, by homology modeling and molecular dynamics simulations based on two available homologous protein structures. Molecular dynamics simulations were carried out to refine the selected model, and an analysis of its global structure was performed. The refined models of Cry1A(b)16 showed a standard fold and structural characteristics similar to those seen in Bacillus thuringiensis Cry1A(a) insecticidal toxin and Bacillus thuringiensis serovar kurstaki Cry1A(c) toxin. After in silico analysis of Cry1A(b)16, two immunoreactive candidate peptides were selected and specific polyclonal antibodies were produced resulting in antibody-peptide interaction. Biosensing devices are expected to be developed for detection of the Cry1A(b) protein as a marker of transgenic maize in food. Proteins 2017; 85:1248-1257. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Pilocarpus microphyllus Stapf ex Wardlew (Rutaceae), popularly known as jaborandi, is a plant native to the northern and northeastern macroregions of Brazil. Several alkaloids from this species have been isolated. There are few reports of antibacterial and anthelmintic activities for these compounds. In this work, we report the antibacterial and anthelmintic activity of five alkaloids found in P. microphyllus leaves, namely, pilosine, epiisopilosine, isopilosine, epiisopiloturine and macaubine. Of these, only anthelmintic activity of one of the compounds has been previously reported. Nuclear magnetic resonance, HPLC and mass spectrometry were combined and used to identify and confirm the structure of the five compounds. As regards the anthelmintic activity, the alkaloids were studied using in vitro assays to evaluate survival time and damaged teguments for Schistosoma mansoni adult worms. We found epiisopilosine to have anthelmintic activity at very low concentrations (3.125 μg mL-1 ); at this concentration, it prevented mating, oviposition, reducing motor activity and altered the tegument of these worms. In contrast, none of the alkaloids showed antibacterial activity. Additionally, alkaloids displayed no cytotoxic effect on vero cells. The potent anthelmintic activity of epiisopilosine indicates the potential of this natural compound as an antiparasitic agent. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Although the mechanism of action of antimicrobial peptides (AMPs) is not clear, they can interact electrostatically with the cell membranes of microorganisms. New ocellatin-PT peptides were recently isolated from the skin secretion of Leptodactylus pustulatus. The secondary structure of these AMPs and their effect on Leishmania infantum cells, and on different lipid surface models was characterized in this work. The results showed that all ocellatin-PT peptides have an α-helix structure and five of them (PT3, PT4, PT6 to PT8) have leishmanicidal activity; PT1 and PT2 affected the cellular morphology of the parasites and showed greater affinity for leishmania and bacteria-mimicking lipid membranes than for those of mammals. The results show selectivity of ocellatin-PTs to the membranes of microorganisms and the applicability of biophysical methods to clarify the interaction of AMPs with cell membranes. [ABSTRACT FROM AUTHOR]

Quick, easy, cheap, effective, rugged, and safe extraction is a modern sample preparation method that involves a number of steps with a low susceptibility to error. The efficiency of a laboratory can be improved not only through labor reduction and consumable savings but also through the use of high-throughput methods and the reduction of wastes. In commercially available kits, different salts and buffers are mixed in anhydrous packages. The composition of these kits are optimized and fixed for particular applications by the suppliers. In this work three model compounds (ibuprofen and two of its main metabolites: hydroxyibuprofen and carboxyibuprofen) were chosen and the amount of each salt (magnesium sulfate, sodium chloride, sodium citrate, and disodium citrate sesquihydrate) in the quick, easy, cheap, effective, rugged, and safe content was optimized for three different soil samples (soils A, B, and C) with different organic carbon contents, using a 24 factorial design. The optimized extraction procedure was applied to 12 soil samples; ranging from river sediments to agricultural soils. Based on the analysis 100 samples, a price reduction of 5.1- (soil B), 5.7- (Soil C), and 6.1-fold (soil A) was achieved without compromising the performance of the method when compared to commercial kits. [ABSTRACT FROM AUTHOR]

Over the last few years, there has been a growing concern about the presence of pharmaceuticals in the environment. The main objective of this study was to develop and validate an SPE method using surface response methodology for the determination of ibuprofen in different types of water samples. The influence of sample pH and sample volume on the ibuprofen recovery was studied. The effect of each studied independent variable is pronounced on the dependent variable (ibuprofen recovery). Good selectivity, extraction efficiency, and precision were achieved using 600 mL of sample volume with the pH adjusted to 2.2. LC with fluorescence detection was employed. The optimized method was applied to 20 water samples from the North and South of Portugal. [ABSTRACT FROM AUTHOR]

ABSTRACT Scientific evidence has shown an association between organochlorine compounds (OCC) exposure and human health hazards. Concerning this, OCC detection in human adipose samples has to be considered a public health priority. This study evaluated the efficacy of various solid-phase extraction (SPE) and cleanup methods for OCC determination in human adipose tissue. Octadecylsilyl endcapped (C18-E), benzenesulfonic acid modified silica cation exchanger (SA), poly(styrene-divinylbenzene (EN) and EN/RP18 SPE sorbents were evaluated. The relative sample cleanup provided by these SPE columns was evaluated using gas chromatography with electron capture detection (GC-ECD). The C18-E columns with strong homogenization were found to provide the most effective cleanup, removing the greatest amount of interfering substance, and simultaneously ensuring good analyte recoveries higher than 70%. Recoveries > 70% with standard deviations (SD) < 15% were obtained for all compounds under the selected conditions. Method detection limits were in the 0.003-0.009 mg/kg range. The positive samples were confirmed by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The highest percentage found of the OCC in real samples corresponded to HCB, o, p′-DDT and methoxychlor, which were detected in 80 and 95% of samples analyzed respectively. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]