Antioxidant capacity of simplified oxygen heterocycles and proposed derivatives by theoretical calculations.

CONTEXT: Some structural properties can be involved in the antioxidant capacity of several polyphenol derivatives, among them their simplified structures. This study examines the contribution of simplified structure for the antioxidant capacity of some natural and synthetic antioxidants. The resonance structures were related to the π-type electron system of carbon-carbon double bonds between both phenyl rings. Trans-resveratrol, phenyl-benzofuran, phenyl-indenone, and benzylidene-benzofuranone are the best basic antioxidant templates among the simplified derivatives studied here. Additionally, the stilbene moiety was found on the molecules with the best antioxidant capacity. Furthermore, our investigation suggests that these compounds can be used as antioxidant scaffold for designing and developing of new promising derivatives. METHODS: To investigate the structure-antioxidant capacity for sixteen simplified natural and proposed derivatives we have employed density functional theory and used Gaussian 09. Our DFT calculations were performed using the B3LYP functional and the 6-31+G(d,p) basis set. All electron transfer mechanisms were investigated by using values of HOMO, ionization potential, energy affinity, stabilization energies, and spin density distributions.

Estimated polyphenol intake and major food sources of the Brazilian population: changes between 2008-2009 and 2017-2018.

Assessing the dietary intake of polyphenols and their major food sources is the first step towards documenting the associations with health outcomes. Considering recent changes in dietary patterns of the Brazilian population, continuous monitoring of polyphenol intake is important. Thus, the present study was conducted to estimate the polyphenol intake and major food sources in the diet of the Brazilian population using data from the most recent National Dietary Survey (NDS, 2017-2018), to characterise the intake changes according to demographic characteristics and to compare the intake over the past decade in Brazil. Data from two cross-sectional population-based surveys were analyzed in the study. Trends in polyphenol intake and major food sources were estimated using food consumption data from NDS 2008-2009 (n 34 003) and 2017-2018 (n 46 164). The median (25-75th percentiles) of energy-adjusted polyphenol intake in 2017-2018 was 216·3 mg (125·3-495·2 mg) per 1000 kcal/d (4184 kJ/d), representing an increase of 12·3 mg/d from 2008-2009. However, unadjusted polyphenol intakes were similar between the surveys (medians: 364·3 mg/d in 2008-2009 and 366·9 mg/d in 2017-2018). The main food sources of total and polyphenol intake classes presented some variations between 2008-2009 and 2017-2018, with greater contribution of beans preparations, salads and tea to polyphenol intake, and decrease of orange contribution. Our study provided an updated information on polyphenol intake and its major food sources. The median intake remains lower than the reported by other populations. Furthermore, the results may contribute to future studies investigating temporal trends in polyphenol intake and disease risk.

Temperature and light conditions affect stability of phenolic compounds of stored grape cane extracts.

This study aimed to determine the stability of PCs in grape canes extracts stored at different temperatures and light conditions. The PCs composition was monitored every-two weeks during three months by liquid chromatography coupled to diode array and fluorescence detectors (LC-DAD-FLD). Initially, stilbenes represented 87 % of total PCs. Storage at -20 and 5 °C reduced PCs 8 and 6 %, respectively. When extracts were exposed to 25 and 40 °C, the degradation of (+)-catechin and (-)-epicatechin was faster than under lower temperatures, and light accelerated the degradation kinetics. trans-piceatannol showed particularly sensitive to temperature increase, being mostly degraded after two weeks stored at 40 °C. Conversely, degradation of trans-resveratrol and ε-viniferin was mostly catalyzed by light, since nearly 70 % of them were degraded at 40 °C under light, in comparison with a 23 % reduction of trans-resveratrol and no changes of ε-viniferin at 40 °C in darkness.

Pilot project. Resveratrol intake by physical active and sedentary older adult women and blood pressure.

OBJECTIVE: Although the use of resveratrol is widespread, there is a lack of studies concerning its use in older adults who practice regular physical activity. The present study aimed to evaluate how resveratrol influenced anthropometric parameters, heart measures, blood analytes in women participants, aged 60 to 80 years old, distributed in four groups consisting of those who regularly exercise or not, and those who were under resveratrol treatment or not. The older adult women exercised in a Community Center. METHODS: A prospective, comparative clinical pilot study was carried out based on convenience non-probability sampling. Resveratrol 300 mg/daily/60 days was orally-administered to 43 participants that were regularly accompanied and checked for anthropometrical parameters, heart measures, blood analytes, leukogram, and plaquetogram indices. RESULTS: The effect of resveratrol and exercise was not significant in most of the parameters evaluated in the study. Nonetheless, both systolic (p = 0.0120) and diastolic (p = 0.0241) blood pressures (BP) were elevated in sedentary older adult women in comparison with older women that regularly exercised. However, they remained within the normal BP range considered for the age. Mean corpuscular volume (MCH; p = 0.0198) and red blood cell distribution width (RDW; p < 0.0001) were improved in the groups receiving resveratrol and exercises compared to the sedentary group receiving resveratrol. The sedentary group receiving resveratrol showed diminished segmented cells (p = 0.0459), basophils (p < 0.0001), and lymphocytes (p < 0.0001). CONCLUSIONS: Present findings showed that resveratrol consumption for sedentary older women could lead to dysregulated blood pressure. Although resveratrol consumption is indicated to treat inflammation, its use must be discussed with a health professional and not be inadvertently self-administered due to significant alterations in blood pressure in older adult women, primarily if not related to exercise practice.

Pilot-plant scale extraction of phenolic compounds from grape canes: Comprehensive characterization by LC-ESI-LTQ-Orbitrap-MS.

Grape canes, also named vine shoots, are well-known viticultural byproducts containing high levels of phenolic compounds, which are associated with a broad range of health benefits. In this work, grape canes (Vitis vinifera cv. Pinot noir) were extracted in a 750 L pilot-plant reactor under the following conditions: temperature 80 °C, time 100 min, solid/liquid ratio 1:10. The comprehensive characterization of grape cane phenolic compounds was performed by liquid chromatography coupled to high-resolution/accurate mass measurement LTQ-Orbitrap mass spectrometry. A total of 44 compounds were identified and, 26 of them also quantified, consisting of phenolic acids and aldehydes (17), flavonoids (12), and stilbenoids (15). The most abundant class of phenolics were stilbenoids, among which (E)-ε-viniferin predominated. The phenolic profile of grape canes obtained using pilot plant extraction differed significantly from the results of laboratory-scale studies obtained previously. Additionally, we observed a high antioxidant capacity of grape cane pilot-plant extract measured by the radical antioxidant scavenging potential (ABTS+) (2209 ± 125 µmol TE/g DW) and oxygen radical absorbance capacity using fluorescein (ORAC-FL) (4612 ± 155 µmol TE/g DW). Grape cane pilot-plant extract for their phenolic profile may be used as a by-product for the development of novel nutraceutical and pharmaceutical products, improving the value and the sustainability of these residues.

Rational Design of Resveratrol O-methyltransferase for the Production of Pinostilbene.

Pinostilbene is a monomethyl ether analog of the well-known nutraceutical resveratrol. Both compounds have health-promoting properties, but the latter undergoes rapid metabolization and has low bioavailability. O-methylation improves the stability and bioavailability of resveratrol. In plants, these reactions are performed by O-methyltransferases (OMTs). Few efficient OMTs that monomethylate resveratrol to yield pinostilbene have been described so far. Here, we report the engineering of a resveratrol OMT from Vitis vinifera (VvROMT), which has the highest catalytic efficiency in di-methylating resveratrol to yield pterostilbene. In the absence of a crystal structure, we constructed a three-dimensional protein model of VvROMT and identified four critical binding site residues by applying different in silico approaches. We performed point mutations in these positions generating W20A, F24A, F311A, and F318A variants, which greatly reduced resveratrol's enzymatic conversion. Then, we rationally designed eight variants through comparison of the binding site residues with other stilbene OMTs. We successfully modified the native substrate selectivity of VvROMT. Variant L117F/F311W showed the highest conversion to pinostilbene, and variant L117F presented an overall increase in enzymatic activity. Our results suggest that VvROMT has potential for the tailor-made production of stilbenes.

Estimated dietary polyphenol intake and major food sources of the Brazilian population.

Epidemiological studies have suggested an inverse association between polyphenol intake and the risk of chronic diseases. However, the lack of comprehensive data on population-level intakes, especially in Latin American countries, has limited research on this topic. We aimed to estimate total and individual polyphenol intakes and determine the major dietary contributors in a representative sample of the Brazilian population. Data were obtained from the Brazilian Household Budget Survey, a cross-sectional survey which included data on individual food intake of 34 003 subjects aged 10 years and over collected using two 24-h dietary records. Polyphenol content of foods was identified using the Phenol-Explorer database and Brazilian Food Composition Database. Total and individual polyphenol intake was calculated, as well as the intake distribution by socio-demographic factors. The median and 25-75th percentiles of polyphenol intake were 364·3 and 200·9-1008 mg/d, respectively. After energy adjustment, the median and 25-75th percentiles of polyphenol intake were 204 and 111·4-542·1 mg/1000 kcal/d (4184 kJ/d), respectively. Non-alcoholic beverages and fruits were the major polyphenol suppliers, and coffee and orange juice the main individual food contributors to polyphenol intake. The individual compounds most consumed were isomers of chlorogenic acid (5-caffeoylquinic acid, 4-caffeoylquinic acid, 3-caffeoylquinic acid), naringenin and hesperetin. The present study provides, for the first time, data on dietary intake of total and individual polyphenols by the Brazilian population and illustrates the low quality of their diet. These results will facilitate the study of associations between polyphenol class intake and health outcomes, and will also be useful for future dietary intake recommendations.

Physico-Chemical and Antiadhesive Properties of Poly(Lactic Acid)/Grapevine Cane Extract Films against Food Pathogenic Microorganisms.

The aim of this study was evaluation of the physico-chemical properties and adhesion of microorganisms on poly(lactic acid) (PLA)-based films loaded with grapevine cane extract (5-15 wt%). The films were processed in a compression molding machine and characterized by mechanical, thermal, water vapor barrier and microbiological tests. The best physical-chemical properties for PLA film containing 10 wt% of extract were obtained. The addition of 10 wt% of extract into PLA films led to decrease of tensile strength for 52% and increase in elongation at break for 30%. The water vapor barrier of this film formulation was enhanced for 55%. All films showed thermal stability up to 300 °C. The low release of the active compounds from films negatively influenced their antimicrobial and antifungal activity. Botrytis cinerea growth inhibition onto PLA containing extracts (PLA-E) films was in the range between 15 and 35%. On the other side, PLA/extract films exhibited the antiadhesive properties against Pseudomonas aeruginosa, Pectobacterium carotovorum, Saccharomyces pastorianus, and Listeria monocytogenes, which could imply their potential to be used as sustainable food packaging materials for preventing microbial contamination of food.

Sorting and cryopreservation of goat sperm with or without phenolic compounds / Seleção e criopreservação de espermatozoides caprinos com ou sem compostos fenólicos

The objectives of this study were to evaluate goat sperm sorting in continuous Percoll® density gradients and gamete freezability, in the presence or absence of phenolic antioxidants. For this, semen pools were sorted, frozen, and evaluated. The non-selected group (NSg) presented lower progressive motility (PM), linearity (LIN), straightness (STR), and wobble (WOB) than the selected groups, and straight line velocity (VSL) compared to those with catechin or resveratrol. The amplitude of lateral head displacement (ALH) was higher in NSg, and quercetin reduced the mitochondrial membrane potential (MMP). After thawing, the NSg presented lower PM than the selected groups, VSL and VAP (average path velocity) than the selected group with or without catechin, LIN and WOB than the selected with or without catechin or resveratrol, and STR than the selected with catechin. Moreover, NSg presented higher ALH and BCF than the samples selected with or without catechin. Plasma membrane integrity and intact and living cells were higher in the selected groups, and MMP was lower in the NSg and the selected group with quercetin. Thus, centrifugation in Percoll® continuous density gradients is a viable methodology to select goat sperm compatible with the freezing, especially in the presence of catechin or resveratrol.(AU)

Objetivou-se avaliar a separação de espermatozoides caprinos em gradientes de densidade contínuos de Percoll® e a congelabilidade espermática, com ou sem antioxidantes fenólicos. Para tal, pools seminais foram selecionados, congelados e avaliados. O grupo não selecionado (gNS) apresentou menor motilidade progressiva (MP), linearidade (LIN), retilinearidade (STR) e oscilação (WOB) do que os selecionados, bem como menor velocidade linear progressiva (VSL) do que os com catequina ou resveratrol. A amplitude de deslocamento lateral de cabeça (ALH) foi maior no gNS e a quercetina reduziu o potencial de membrana mitocondrial (PMM). Após a descongelação, o gNS manifestou menor MP do que os selecionados, menor VSL e VAP (velocidade média da trajetória) do que os com ou sem catequina, menor LIN e WOB do que os com ou sem catequina ou resveratrol, e menor STR do que os com catequina, além de maior ALH e BCF do que os com ou sem catequina. A integridade da membrana plasmática e as células intactas e vivas foram maiores nas amostras selecionadas e o PMM foi inferior no gNS e no selecionado com quercetina. Portanto, a centrifugação em gradientes contínuos de densidade de Percoll® é uma metodologia viável para selecionar espermatozoides caprinos compatíveis com a congelação, especialmente na presença de catequina ou resveratrol.(AU)

Sorting and cryopreservation of goat sperm with or without phenolic compounds / Seleção e criopreservação de espermatozoides caprinos com ou sem compostos fenólicos

The objectives of this study were to evaluate goat sperm sorting in continuous Percoll® density gradients and gamete freezability, in the presence or absence of phenolic antioxidants. For this, semen pools were sorted, frozen, and evaluated. The non-selected group (NSg) presented lower progressive motility (PM), linearity (LIN), straightness (STR), and wobble (WOB) than the selected groups, and straight line velocity (VSL) compared to those with catechin or resveratrol. The amplitude of lateral head displacement (ALH) was higher in NSg, and quercetin reduced the mitochondrial membrane potential (MMP). After thawing, the NSg presented lower PM than the selected groups, VSL and VAP (average path velocity) than the selected group with or without catechin, LIN and WOB than the selected with or without catechin or resveratrol, and STR than the selected with catechin. Moreover, NSg presented higher ALH and BCF than the samples selected with or without catechin. Plasma membrane integrity and intact and living cells were higher in the selected groups, and MMP was lower in the NSg and the selected group with quercetin. Thus, centrifugation in Percoll® continuous density gradients is a viable methodology to select goat sperm compatible with the freezing, especially in the presence of catechin or resveratrol.(AU)

Objetivou-se avaliar a separação de espermatozoides caprinos em gradientes de densidade contínuos de Percoll® e a congelabilidade espermática, com ou sem antioxidantes fenólicos. Para tal, pools seminais foram selecionados, congelados e avaliados. O grupo não selecionado (gNS) apresentou menor motilidade progressiva (MP), linearidade (LIN), retilinearidade (STR) e oscilação (WOB) do que os selecionados, bem como menor velocidade linear progressiva (VSL) do que os com catequina ou resveratrol. A amplitude de deslocamento lateral de cabeça (ALH) foi maior no gNS e a quercetina reduziu o potencial de membrana mitocondrial (PMM). Após a descongelação, o gNS manifestou menor MP do que os selecionados, menor VSL e VAP (velocidade média da trajetória) do que os com ou sem catequina, menor LIN e WOB do que os com ou sem catequina ou resveratrol, e menor STR do que os com catequina, além de maior ALH e BCF do que os com ou sem catequina. A integridade da membrana plasmática e as células intactas e vivas foram maiores nas amostras selecionadas e o PMM foi inferior no gNS e no selecionado com quercetina. Portanto, a centrifugação em gradientes contínuos de densidade de Percoll® é uma metodologia viável para selecionar espermatozoides caprinos compatíveis com a congelação, especialmente na presença de catequina ou resveratrol.(AU)

Bioactive compounds and total antioxidant capacity of cane residues from different grape varieties.

BACKGROUND: Every year, the viticulture activity generates considerable amounts of underused lignocellulosic residues as grape cane, which are generally composted or burned despite their potential value as a source of bioactive compounds. Determination of their phytochemical composition and total antioxidant capacity (TAC) may be a useful way of exploiting different high-added value applications. RESULTS: Twenty-one phenolic compounds (PC) and two carotenoids (Car) were quantified by high performance-liquid chromatography-diode array detection in eight grape varieties from different locations in Mendoza, Argentina. The maximum concentrations corresponded to the stilbene ϵ-viniferin [10 552 µg g-1 dry weight (DW)], followed by the flavanols (+)-catechin (3718 µg g-1 DW) and (-)-epicatechin (2486 µg g-1 DW). In addition, lutein and ß-carotene were quantified at levels ranging between 350 and 2400 ng g-1 DW. The TAC of the extracts was assessed by oxygen radical absorbance capacity, 2,20-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl assays, with a good correlation between TAC and total PC for each sample (r ≥ 0.82). CONCLUSION: Samples of cv. Malbec, the most representative variety of Argentina's winemaking industry, presented high contents of PC, particularly ϵ-viniferin, (+)-catechin and (-)-epicatechin. Quercetin-3-galactoside, OH-tyrosol and Car were reported for the first time in grape canes of the eight varieties. The results add to the existing knowledge related to this inexpensive source of high-value bioactive compounds, which could be used as functional ingredients. © 2019 Society of Chemical Industry.

Trellis systems, rootstocks and season influence on the phenolic composition of 'Chenin Blanc' grape

The biosynthesis of phenolic compounds might be influenced by environmental factors, such as solar radiation, temperature and relative air humidity, and production system. Some components of the production system, particularly the trellis system and rootstock, might change the phenolic composition of grapes due to microclimate of the cultivation region. In this study, the phenolic profile of Chenin Blanc grapes was characterized with different trellis systems and rootstocks in two consecutive production cycles by using high-performance liquid chromatography under tropical semi-arid conditions. In the second production cycle (Jan-May/2016), accumulation of (-) - epicatechin gallate and (-) - epigallocatechin gallate was higher when vigorous rootstocks were trellised to the lyre system, whereas the lyre system associated to rootstock SO4 resulted in higher rutin accumulation in the same cycle. There was little influence of the factors studied on trans-resveratrol and piceatannol accumulation. However, a higher accumulation of piceatannol was observed in the second productive cycle compared to cis-resveratrol and trans-resveratrol. This study highlights that accumulation of phenolic compounds is influenced not only by environmental factors typical of the production year season, but also by the trellis system and rootstock adopted. The identification of phenolic compounds in the accumulation stimulated by the combination of trellis system, rootstock, and production season allows to differentiate grape quality and add value to products derived from such combination in a tropical semi-arid region.

Trellis systems, rootstocks and season influence on the phenolic composition of 'Chenin Blanc' grape

The biosynthesis of phenolic compounds might be influenced by environmental factors, such as solar radiation, temperature and relative air humidity, and production system. Some components of the production system, particularly the trellis system and rootstock, might change the phenolic composition of grapes due to microclimate of the cultivation region. In this study, the phenolic profile of Chenin Blanc grapes was characterized with different trellis systems and rootstocks in two consecutive production cycles by using high-performance liquid chromatography under tropical semi-arid conditions. In the second production cycle (Jan-May/2016), accumulation of (-) - epicatechin gallate and (-) - epigallocatechin gallate was higher when vigorous rootstocks were trellised to the lyre system, whereas the lyre system associated to rootstock SO4 resulted in higher rutin accumulation in the same cycle. There was little influence of the factors studied on trans-resveratrol and piceatannol accumulation. However, a higher accumulation of piceatannol was observed in the second productive cycle compared to cis-resveratrol and trans-resveratrol. This study highlights that accumulation of phenolic compounds is influenced not only by environmental factors typical of the production year season, but also by the trellis system and rootstock adopted. The identification of phenolic compounds in the accumulation stimulated by the combination of trellis system, rootstock, and production season allows to differentiate grape quality and add value to products derived from such combination in a tropical semi-arid region.(AU)

Piceatannol Increases Antioxidant Defense and Reduces Cell Death in Human Periodontal Ligament Fibroblast under Oxidative Stress.

Piceatannol is a resveratrol metabolite that is considered a potent antioxidant and cytoprotector because of its high capacity to chelate/sequester reactive oxygen species. In pathogenesis of periodontal diseases, the imbalance of reactive oxygen species is closely related to the disorder in the cells and may cause changes in cellular metabolism and mitochondrial activity, which is implicated in oxidative stress status or even in cell death. In this way, this study aimed to evaluate piceatannol as cytoprotector in culture of human periodontal ligament fibroblasts through in vitro analyses of cell viability and oxidative stress parameters after oxidative stress induced as an injury simulator. Fibroblasts were seeded and divided into the following study groups: control, vehicle, control piceatannol, H2O2 exposure, and H2O2 exposure combined with the maintenance in piceatannol ranging from 0.1 to 20 µM. The parameters analyzed following exposure were cell viability by trypan blue exclusion test, general metabolism status by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method, mitochondrial activity through the ATP production, total antioxidant capacity, and reduced gluthatione. Piceatannol was shown to be cytoprotective due the maintenance of cell viability between 1 and 10 µM even in the presence of H2O2. In a concentration of 0.1 µM piceatannol decreased significantly cell viability but increased cellular metabolism and antioxidant capacity of the fibroblasts. On the other hand, the fibroblasts treated with piceatannol at 1 µM presented low metabolism and antioxidant capacity. However, piceatannol did not protect cells from mitochondrial damage as measured by ATP production. In summary, piceatannol is a potent antioxidant in low concentrations with cytoprotective capacity, but it does not prevent all damage caused by hydrogen peroxide.

Effects of Quercetin and Resveratrol on in vitro Properties Related to the Functionality of Potentially Probiotic Lactobacillus Strains.

The ability of probiotics to exert benefits on host has been associated with different physiological functionalities in these microorganisms, namely cell surface hydrophobicity, autoaggregation, coaggregation with pathogens, antagonistic activity against pathogens and ability to survive the exposure to gastrointestinal conditions. This study assessed the effects of different concentrations of quercetin (QUE) and resveratrol (RES) on the ability of six potentially probiotic Lactobacillus strains to tolerate different pH values and bile salt concentrations, to autoaggregate, coaggregate with and antagonize pathogens and survive the exposure to simulated gastrointestinal conditions. QUE and RES presented low inhibitory effects on all tested Lactobacillus strains, with minimum inhibitory concentration (MIC) ranging from 512 to >1024 µg/mL. In most cases, QUE and RES at all tested concentrations (i.e., MIC, 1/2 MIC, and 1/4 MIC) did not affect the tolerance of the Lactobacillus strains to acidic pH and bile salts. QUE increased cell surface hydrophobicity of most of the tested Lactobacillus strains and increases or decreases in cell surface hydrophobicity varied in the presence of different RES concentrations among some strains. QUE and RES increased the ability of tested Lactobacillus strains to autoaggregate and coaggregate with pathogens. QUE and RES did not negatively affect the antagonistic activity of the tested Lactobacillus strains against pathogens and did not decrease their survival rates when exposed to in vitro gastrointestinal conditions. In a few cases, the ability of some tested Lactobacillus strains to antagonize pathogens, as well as to survive specific steps of the in vitro digestion was increased by QUE and RES. QUE exerted overall better protective effects on the measured in vitro properties of tested Lactobacillus strains than RES, and L. fermentum and L. plantarum strains presented better responses when treated with QUE or RES. These results showed that probiotic Lactobacillus strains could present low susceptibility to QUE and RES. Combined use of QUE and RES with probiotic Lactobacillus could improve their functionalities on the host; however, the concentration of these polyphenols should be carefully selected to achieve the desirable effects and vary according to the selected probiotic strain.

Can we conserve trans-resveratrol content and antioxidant activity during industrial production of chocolate?

BACKGROUND: Cocoa exhibits high content of phenolic compounds, among which trans-resveratrol stands out, associated with several bioactive activities such as antioxidant properties. Chocolate contains reduced amounts of these bioactive compounds due to losses during the production process. Therefore, this study aimed to assess changes in total phenolic content, and specifically trans-resveratrol, as well as changes in the antioxidant activity of cocoa and its products during industrial production of chocolate. RESULTS: A total of ten different cocoa products were analyzed. The processes of fermentation and roasting caused significant loss of total phenolic compounds and antioxidant activity. The high temperature of roasting had a major influence on this loss (71% for total phenolic compounds and 53-77% for antioxidant activity), except for trans-resveratrol. The trans-resveratrol content formed after fermentation (9.8 µg kg-1 ) showed little variation during the processes, and it was detected in higher concentrations both in natural (11.4 µg kg-1 ) and in alkalized cocoa powder (13.5 µg kg-1 ). Alkalization of cocoa products led to loss of capacity of deactivating superoxide radical. CONCLUSION: These findings contribute to the optimization of the production process of chocolate and other food products containing cocoa and its derivatives, aiming to better preserve their bioactive compounds. © 2018 Society of Chemical Industry.

Multiresidue Determination of the Anabolic-Agent Residues Steroids, Stilbenes, and Resorcylic Acid Lactones in Bovine Urine by GC-MS/MS with Microwave-Assisted Derivatization.

In this work, a GC-MS/MS method was developed for the determination of anabolic-agent residues in bovine urine. The optimized sample preparation was as follows: enzymatic hydrolysis by ß-glucuronidase-sulfatase enzyme from Helix pomatia for 16 h at 37.5 °C, liquid-liquid extraction with diethyl ether, solid-phase extraction with HLB and aminopropylsilane cartridges, and microwave-assisted derivatization using 25 µL of MSTFA/NH4I/ethanethiol and full microwave power for 2 min. The method was validated according to Decision 657/2002/EC, Codex Alimentarius, and Manual da Garantia da Qualidade Analítica guidelines. The acceptability criteria for quantitative analysis were met for α-ethinylestradiol, α-nandrolone, ß-estradiol, ß-zearalanol, ß-zearalenol, drostanolone, ethisterone, dienestrol, diethylstilbestrol, hexestrol, megestrol, methyltestosterone, and zearalenone. The analytes α-zearalenol, α-zearalanol, and norethandrolone were validated for qualitative analysis.

Increasing pinosylvin production in Escherichia coli by reducing the expression level of the gene fabI-encoded enoyl-acyl carrier protein reductase

Background: The plant secondary metabolite pinosylvin is a polyphenol from the stilbene family, which have positive effects on human health. Biotechnological production is an attractive alternative for obtaining this stilbene. In Escherichia coli, malonyl-CoA is the precursor for both stilbene and fatty acid syntheses. In this study, with the aim of increasing pinosylvin production, we evaluated a novel approach that is based on reducing the expression of the gene fabI, which encodes the enzyme enoyl-acyl carrier protein reductase that is involved in fatty acid synthesis. Results: A recombineering method was employed to eliminate the chromosomal -35 promoter sequence and the upstream region of the gene fabI in E. coli strain W3110. Analysis, employing RT-qPCR, showed that such modification caused a 60% reduction in the fabI transcript level in the mutant strain W3110Δ-35fabI::Cm compared to the wild type W3110. Synthetic genes encoding a mutant version of 4-coumaroyl-CoA ligase from Streptomyces coelicolor A3 with improved catalytic activity employing cinnamic acid as substrate and a stilbene synthase from Vitis vinifera were cloned to generate the plasmid pTrc-Sc4CL(M)-VvSTS. The production performance of strains W3110Δ-35fabI::Cm/pTrc-Sc4CL(M)-VvSTS and W3110/pTrc-Sc4CL(M)- VvSTS was determined in shake flask cultures with Luria-Bertani medium supplemented with 10 g/L glycerol and 3 mM cinnamic acid. Under these conditions, the strain W3110Δ-35fabI::Cm/pTrc-Sc4CL(M)-VvSTS produced 52.67 mg/L pinosylvin, a level 1.5-fold higher than that observed with W3110/pTrc-Sc4CL(M)-VvSTS. Conclusion: A reduction in the transcript level of fabI caused by the elimination of the -35 and upstream promoter sequences is a successful strategy to improve pinosylvin production in E. coli.

Estimated dietary intake and major food sources of polyphenols in elderly of Viçosa, Brazil: a population-based study.

PURPOSE: Epidemiological studies have remarked the beneficial role that polyphenols may have in the elderly population such as cancer and cardiovascular disease prevention. This is particularly relevant considering the global tendency of population aging. Data on polyphenol intake in the elderly population are scarce and usually provide partial information-only for some polyphenol classes. The aim of this study was to estimate the intake of polyphenols and its major dietary contributors in the population of Viçosa. METHODS: A cross-sectional population-based survey including 620 elderly was conducted in Viçosa, Brazil. Food intake was estimated by recall of habitual consumption (RHC). Polyphenol intake was calculated by matching food consumption data from the RHC with the polyphenol content in foods listed in the Phenol-Explorer database. RESULTS: The average total polyphenol intake was 1198.6 mg/day (533.7 mg/day as aglycone). The main polyphenol classes were phenolic acids (729.5 mg/day) and flavonoids (444.7 mg/day). The main dietary contributors for total polyphenols were coffee (45.8%), beans (32.8%) and polenta (1.3%). A total of 292 polyphenols divided in 14 classes and 23 subclasses were found. The individual compounds with the highest intake were isomers of chlorogenic acid (i.e., 5-caffeoylquinic acid, 4-caffeoylquinic acid and 3-caffeoylquinic acid) among hydroxycinnamic acids that largely originated from coffee. CONCLUSIONS: The data reported here can be used to evaluate the association between the amount and type of ingested polyphenols and health outcomes in epidemiological studies in order to eventually establish nutritional recommendations.

Diarylethenes Display In Vitro Anti-TB Activity and Are Efficient Hits Targeting the Mycobacterium tuberculosis HU Protein.

Tuberculosis continues to be a great source of concern in global health because of the large reservoir of humans infected with the bacilli and the appearance of clinical isolates resistant to a wide array of anti-tuberculosis drugs. New drugs with novel mechanisms of action on new targets are urgently required to reduce global tuberculosis burden. Mycobacterium tuberculosis nucleoid associated protein (NAP) HU has been shown to be druggable and essential for the organism's survival. In this study, four diarylethenes were synthesized using a one-pot decarboxylated Heck-coupling of coumaric acids with iodoanisoles. The prepared compounds 1-4 were tested for their in vitro growth inhibition of M. tuberculosis H37Rv using the spot culture growth inhibition assay, displaying minimum inhibitory concentrations between 9 and 22 µM. Their cytotoxicity against BHK-21 cell line showed half inhibition at concentrations between 98 and 729 µM. The most selective hit (SI = 81), demonstrated inhibition of M. tuberculosis HU protein involved in maintaining bacterial genome architecture.