Polychloronaphthalenes and other dioxin-like compounds in Arctic and Antarctic marine food webs

Here we report accumulation patterns of polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and pesticides (HCB, p,p'DDE) in polar organisms (polar bear from Alaskan Arctic and krill, sharp-spined notothen, crocodile icefish, Antarctic silverfish, Adélie penguin, South polar skua, and Weddell seal from the Ross Sea, Antarctica). PCNs, found in most of the samples, ranged from 1.5 pg/g in krill to 2550 pg/g in South polar skua on a wet weight basis. Lower chlorinated PCNs were the predominant congeners in organisms except skua and polar bear that showed similar PCN homologue patterns. PCDD/F concentrations were <90 pg/g wet wt in polar organisms; PCDD congeners showed peculiar accumulation patterns in different organisms. Correlation existed between PCN and PCB concentrations. PCB, HCF, and p,p'DDE levels were the highest in skua liver (11,150 ng/g wet wt, 345 ng/g wet wt, and 300 ng/g wet wt, respectively). Contribution of PCNs to 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ) was negligible (<0.1%) because of the lack of most toxic congeners. The highest TEQ was found in South polar skua liver (45 pg/g, wet weight). This is the first study to document the occurrence of PCNs in Antarctic organisms. High levels of dioxin-like chemicals in skua suggest the importance of intake via diet and migration habits, thus POP detection can be useful to trace migration behavior. Moreover, POP concentrations in penguin and skua eggs prove their transfer from the mother to eggs.     

Detection and analysis of triterpenic compounds in apple extracts

A new technique for the rapid detection and analysis of triterpenic compounds in apple extracts using HPLC was developed and validated. The main advantage of this technique is the short duration of the analysis – this makes this technique superior to others currently applied for the routine HPLC analysis of triterpenic compounds. The developed, optimized, and validated technique was used for the evaluation of triterpenic compounds in samples of different cultivars of apples, their peels, and flesh. In total, four triterpenic compounds were isolated and identified. Ursolic acid was the dominant compound in all the tested apple samples. The highest amounts of triterpenic compounds were detected in the peels of the ‘Lodel’ apple cultivar, and thus apples of this cultivar may be potentially useful for the isolation of individual compounds and the production of functional food and dietary supplements.     

Quantification of antidiabetic extracts and compounds in bitter gourd varieties

Several studies have shown blood glucose lowering effects of bitter gourd compounds. Previous experiments with db/db mice revealed that the lipid and the saponin extracts are more effective in lowering glycated haemoglobin levels and excessive body weight gain than the hydrophilic extract or the whole fruit.     

高效液相色谱法同时测定绿原酸及其五种主要代谢产物

建立一种同时测定绿原酸、咖啡酸、3-羟基苯丙酸(3-hydroxyphenylpropionic acid,3-HPA)、p-香豆酸(p-coumaric acid,PA)、阿魏酸(ferulic acid,FA)和马尿酸(hippuricacid,HA)含量的高效液相色谱方法.色谱柱为美国Agilent Eclipse XDB-C18(250mm×4.6mm,5μm);流动相为甲醇和1％的冰醋酸水溶液,梯度洗脱;检测波长为320nm和253nm;流速为1mL/min 六种酚酸物质在一定范围内有良好的线性关系,相关系数为0.9979～0.9999,平均回收率为86.84％～101.56％,相对标准偏差为1.15％～2.29％ 结果表明该方法快速、准确、灵敏度高,可用于绿原酸及其代谢物的检测.     

Polar compounds dominate in vitro effects of sediment extracts

Sediment extracts from three polluted sites of the river Elbe basin were fractionated using a novel online fractionation procedure. Resulting fractions were screened for mutagenic, aryl hydrocarbon receptor (AhR)-mediated, transthyretin (TTR)-binding, and estrogenic activities and their potency to inhibit gap junctional intercellular communication (GJIC) to compare toxicity patterns and identify priority fractions. Additionally, more than 200 compounds and compound classes were identified using GC-MS/MS, LC-MS/MS, and HPLC-DAD methods. For all investigated end points, major activities were found in polar fractions, which are defined here as fractions containing dominantly compounds with at least one polar functional group. Nonpolar PAH fractions contributed to mutagenic and AhR-mediated activities while inhibition of GJIC and estrogenic and TTR-binding activities were exclusively observed in the polar fractions. Known mutagens in polar fractions included nitro- and dinitro-PAHs, azaarenes, and keto-PAHs, while parent and monomethylated PAHs such as benzo[a]pyrene and benzofluoranthenes were identified in nonpolar fractions. Additionally, for one sample, high AhR-mediated activities were determined in one fraction characterized by PCDD/Fs, PCBs, and PCNs. Estrone, 17β-estradiol, 9H-benz[de]anthracen-7-one, and 4-nonylphenol were identified as possible estrogenic and TTR-binding compounds. Thus, not only nonpolar compounds such as PAHs, PCBs, and PCDD/Fs but also the less characterized and investigated more polar substances should be considered as potent mutagenic, estrogenic, AhR-inducing, TTR-binding, and GJIC-inhibiting components for future studies.     

Lysosomal proteinases in muscle tissue and leukocytes of meat animals

Carboxypeptidases A and B, cathepsins B, D and E, dipeptidyl aminopeptidase 1 and collagenase were extracted from bovine and porcine leukocyte lysosomes and diaphragm muscle lysosomes with 4% n-butyl alcohol in dry ice and various chemical properties were studied. The enzymes were classified by their specific activities with different substrates, pH optima, energies of activation and the influence of inhibitors and stimulators. Cathepsins D and E were the most active proteases studied and all enzymes were more active in leukocytes than in sediments from muscle tissue. The properties of these enzymes, compared with enzymes from other sources, and their possible involvement in meat tenderness are discussed.     

Identification of inorganic pyrophosphate in alkaline extracts of soil

An acid-labile phosphate has been detected in alkaline extracts of four acid soils, and has been isolated and purified by ion-exchange and paper chromatography. Its chromatographic properties, its rate of hydrolysis in hydrochloric acid-and the infra-red spectrum of its barium salt show that it is inorganic pyrophosphate. In three of the soils the amount was in the range 2.1–2.6 ppm P, compared with only 0.5 in the fourth but the investigation was essentially qualitative and losses may have occurred during isolation. the phosphate may occur in the soil in inorganic form or alternatively as an ester which is mineralised during extraction.     

Selective androgen receptor modulators: in vitro and in vivo metabolism and analysis

For future targeted screening in National Residue Control Programmes, the metabolism of seven SARMs, from the arylpropionamide and the quinolinone classes, was studied in vitro using S9 bovine liver enzymes. Metabolites were detected and identified with ultra-performance liquid chromatography (UPLC) coupled to time-of-flight mass spectrometry (ToF-MS) and triple quadrupole mass spectrometry (QqQ-MS). Several metabolites were identified and results were compared with literature data on metabolism using a human cell line. Monohydroxylation, nitro-reduction, dephenylation and demethylation were the main S9 in vitro metabolic routes established. Next, an in vivo study was performed by oral administration of the arylpropionamide ostarine to a male calf and urine samples were analysed with UPLC-QToF-MS. Apart from two metabolites resulting from hydroxylation and dephenylation that were also observed in the in vitro study, the bovine in vivo metabolites of ostarine resulted in glucuronidation, sulfation and carboxylation, combined with either a hydroxylation or a dephenylation step. As the intact mother compounds of all SARMs tested are the main compounds present after in vitro incubations, and ostarine is still clearly present in the urine after the in vivo metabolism study in veal calves, the intact mother molecules were selected as the indicator to reveal treatment. The analytical UPLC-QqQ-MS/MS procedure was validated for three commercially available arylpropionamides according to European Union criteria (Commission Decision 2002/657/EC), and resulted in decision limits ranging from 0.025 to 0.05 µg l^–1 and a detection capability of 0.025 µg l^–1 in all cases. Adequate precision and intra-laboratory reproducibility (relative standard deviation below 20%) were obtained for all SARMs and the linearity was 0.999 for all compounds. This newly developed method is sensitive and robust, and therefore useful for confirmation and quantification of SARMs in bovine urine samples for residue control programmes and research purposes.     

Phenolic compounds in oak wood extracts used in the ageing of brandies

The oak wood extracts used in brandy production are extremely varied because of the different ways in which they are made: by infusion, by boiling or by maceration, with or without prior physical or chemical treatment of the wood. Such extracts release a large quantity of phenolic compounds and a very small amount of partially degraded lignin into the brandy, unlike spirits aged in oak barrels. Among monomer compounds derived from lignin, the presence of vanillic and syringic acids, vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde can be noted. In the wood extracts, phenolic compounds and aromatic acids frequently dominate the ligno-complex and aromatic aldehydes respectively, which is not the case in brandies. Two samples of liquid extracts of oak wood displayed statistically aberrant vanillin contents.     

Concentration of flavonoids and phenolic compounds in aqueous and ethanolic propolis extracts through nanofiltration

Propolis has a variable and complex chemical composition with high concentration of flavonoids and phenolic compounds present in the extract. The extract varies with the solvent used in extraction. Ethanol extracts more phenolic acid and polar compounds than water. Before their use in industry, extracts must be concentrated but the use of high temperatures can degrade some compounds. Membrane processes is an option that allows concentration at low temperatures. Nanofiltration was carried out with aqueous and ethanolic extracts and each extract results in two distinct fractions: permeate and retentate. The capacity of the membrane to retain the compounds was verified by spectrophotometric analysis: for aqueous solution, the membrane retained around 94% of the phenolic compounds and 99% of the flavonoids, while for the ethanolic solution these values were 53% and 90%, respectively. Ferulic acid retention index was 1.00 and 0.88 to aqueous and ethanolic solutions, respectively. Thus, the nanofiltration process showed high efficiency in the concentration of propolis extracts.     

Identification of bitter compounds in whole wheat bread

Bitterness in whole wheat bread can negatively influence product acceptability and consumption. The overall goal of this project was to identify the main bitter compounds in a commercial whole wheat bread product. Sensory-guided fractionation of the crust (most bitter portion of the bread sample) utilising liquid–liquid extraction, solid-phase extraction, ultra-filtration and 2-D offline RPLC revealed multiple bitter compounds existed. The compounds with the highest bitterness intensities were selected and structurally elucidated based on accurate mass-TOF, MS/MS, 1D and 2D NMR spectroscopy. Eight bitter compounds were identified: Acortatarins A, Acortatarins C, 5-(hydroxymethyl)furfural(HMF), 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP), N-(1-deoxy-d-fructos-1-yl)-l-tryptophan (ARP), Tryptophol (TRO), 2-(2-formyl-5-(hydroxymethyl-1H-pyrrole-1-yl)butanoic acid (PBA) and Tryptophan (TRP). Based on the structures of these compounds, two main mechanisms of bitterness generation in wheat bread were supported, fermentation and Maillard pathways.     

Antioxidant capacity and major phenolic compounds of spices commonly consumed in China

The antioxidant capacity, total phenolic content, and major phenolic compounds of a total of 19 commonly consumed spices in China were systematically investigated. Ultra performance liquid chromatography (UPLC) coupled with photodiode array detector (PDA) was used to identify and quantify the phenolic compounds in the spice extracts. Galangal exhibited the highest antioxidant capacity, associated with the highest total phenolic content. Furthermore, galangin was identified as the principal phenolic component and the main contributor to the highest antioxidant capacity of galangal. Spices in the family Rutaceae and Lauraceae possessed very high antioxidant capacity and high levels of phenolics. Generally, chlorogenic acid and rutin were identified as the dominant phenolic compounds in the spice extracts. This study might provide useful information not only for human health, but also for screening new economic natural antioxidants that could be used in foods.     

Antimicrobial effects of Finnish plant extracts containing flavonoids and other phenolic compounds

Plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. Antimicrobial screening of 13 phenolic substances and 29 extracts prepared from Finnish plant materials against selected microbes was conducted in this study. The tests were carried out using diffusion methods with four to nine microbial species (Aspergillus niger, Bacillus subtilis, Candida albicans, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Staphylococcus aureus and Staphylococcus epidermidis). Flavone, quercetin and naringenin were effective in inhibiting the growth of the organisms. The most active plant extracts were purple loosestrife (Lythrum salicaria L.) against Candida albicans, meadowsweet (Filipendula ulmaria (L.) Maxim.), willow herb (Epilobium angustifolium L.), cloudberry (Rubus chamaemorus L.) and raspberry (Rubus idaeus L.) against bacteria, and white birch (Betula pubescens Ehrh.), pine (Pinus sylvestris L.) and potato (Solanum tuberosum. L.) against gram-positive Staphylococcus aureus.     

Antimicrobial activity and bioactive compounds of Portuguese wild edible mushrooms methanolic extracts

The antimicrobial properties of phenolic extracts of Portuguese wild edible mushroom species (Lactarius deliciosus, Sarcodon imbricatus and Tricholoma portentosum) against pathogens were investigated. The minimal inhibitory concentrations (MICs) were evaluated for the entire mushroom, the cap and the stipe, separately; the portion of the mushroom used proved to be influenced in the results obtained, which are directly correlated with the content of total phenols and flavonoids in the extracts. The growth of Gram-positive bacteria (Bacillus cereus, B. subtilis,) was well inhibited by these mushrooms, while Escherichia coli (Gram-negative bacteria) was resistant. The study on the antifungal effect of these mushrooms revealed that Candida albicans and Cryptococcus neoformans were differently inhibited for the mushrooms used.     

Identification of the major yeasts isolated from high moisture corn and corn silages in the United States using genetic and biochemical methods

The objective of this study was to identify species of yeasts in samples of high moisture corn (HMC) and corn silage (CS) collected from farms throughout the United States. Samples were plated and colonies were isolated for identification using DNA analysis. Randomly selected colonies were also identified by fatty acid methyl esters (FAME) and by physiological substrate profiling (ID 32C). For CS, Candida ethanolica, Saccharomyces bulderi, Pichia anomala, Kazachstania unispora, and Saccharomyces cerevisiae were the predominant yeasts. Pichia anomala, Issatchenkia orientalis, S. cerevisiae, and Pichia fermentans were the prevalent species in HMC. The 3 identification methods were in agreement at the species level for 16.6% of the isolates and showed no agreement for 25.7%. Agreement in species identification between ID 32C and DNA analysis, FAME and ID 32C, and FAME and DNA analysis was 41.1, 14.4, and 2.2%, respectively. Pichia anomala and I. orientalis were able to grow on lactic acid, whereas S. cerevisiae metabolized sugars (galactose, sucrose, and glucose) but failed to use lactic acid. The yeast diversity in CS and HMC varied due to type of feed and location. Differences in species assignments were seen among methods, but identification using substrate profiling generally corresponded with that based on DNA analysis. These findings provide information about the species that may be expected in silages, and this knowledge may lead to interventions that control unwanted yeasts.     

Antioxidant activity and phenolic compounds of Holotrichia parallela Motschulsky extracts

Insects have been relatively unexplored as potential sources of natural antioxidants. We report the antioxidant activity of extracts of the adult large black chafer beetle Holotrichia parallela Motschulsky, a common crop pest in China. The antioxidant activity of the ethanolic extract (EE) and the water extract (WE) of adult H. parallela were evaluated by four different in vitro assays. EE showed potent metal-chelating activity and inhibition of lipid peroxidation. WE proved to be an excellent antioxidant in the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and metal-chelating activity. Catechin was identified in the ethanolic extract and proteins were the main components in the water extracts. Both compounds could contribute to the antioxidant activity of the species. These results suggest that adult H. parallela might be used as a nutraceutical to alleviate oxidate-induced diseases and as a natural antioxidant additive in the food industry.     

Development of a reversed-phase high performance liquid chromatography (RP-HPLC) procedure for the simultaneous determination of phenolic compounds in peanut skin extracts

A reversed-phase high performance liquid chromatography (RP-HPLC) procedure was developed for simultaneous determination of five phenolic acids, two stilbenes and eight flavonoids in peanut skin extract. A C₁₈ column fitted with diode array detection at 250 and 320, 280 and 370, and 306 nm for phenolic acids, flavonoids and stilbenes, respectively, with mobile phase consisting of 0.1% formic acid in water and 0.1% formic acid in 100% acetonitrile. Phenolic compounds were eluted with good resolution (Rs > 1.5) within 95 min as follows: gallic, protocatechuic, epigallocatechin, catechin, β-resorcylic (internal standard), caffeic, procyanidin B₂, epicatechin, epigallocatechin gallate, p-coumaric, ferulic, piceid, epicatechin gallate, catechin gallate, resveratrol and quercetin. The variation in recovery and reproducibility in peak area was <11 and <2.5%, respectively. The correlation coefficients, r, of calibration curves of the 15 compounds were >0.999. The method was used to quantify phenolic compounds in peanut skin extracts from Runner, Virginia and Spanish peanuts.     

Low-temperature thermal decomposition of dioxin-like compounds in fly ash: combination of chemical analysis with in vitro bioassays (EROD and DR-CALUX)

To investigate the dechlorination of fly ash during low-temperature treatment under oxygen-deficient conditions (thermocatalyic treatment or Hagenmaier process), six fly ash samples from six different incineration plants were treated in a laboratory experiment or in the actual plant, either under ideal (400 degrees C, 120 min) or intermediate (300 degrees C, 30 min) conditions. The aim of the present study was to confirm the decrease in the I-TEQ (international toxicity equivalency) of polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs) and coplanar polychlorinated biphenyls (co-PXBs) and, also for the first time, the decrease in the sum of dioxin-like toxicity (bioassay- or bio-TEQ) of all kinds of other dioxin-like Ah receptor agonists (such as PXDD/Fs, PXBs, PXN, X = Br, F) measured by two state-of-the-art cell-based Ah receptor-dependent bioassays: H4IIE-Ethoxy-Resorufin-o-Deethylase (EROD) and H4IIE-luc/DR-Chemical Activated Luciferase expression (DR-CALUX). The treatment efficiency was calculated on the basis of the reduction in the I-TEQ and bio-TED values. For these fly ash samples, the treatment efficiency, as measured by chemical analysis, was higher than 99%, and 85%-99%, in the case of the bio-TED values, indicating that these Ah receptor binding toxic compounds were sufficiently decomposed. Bio-TEQ values for untreated fly ash samples (n = 6) were on average 1.2 times (range 0.7-1.9), for the H4IIE-EROD assay, and 2.8 times (1.1-4.9), for the DR-CALUX assay, higher than I-TEQ values measured by chemical analyses (sum of PCDD/Fs and co-PCBs). In the case of these fly ash samples treated under ideal conditions and therefore low in contaminants, the bio-TEQ values were on average 1.4 times (range 0.9-1.8), for the H4IIE-EROD assay, and 5.1 times (range 1.2-12), for the DR-CALUX assay, higher than the I-TEQ values.     

Identification of bacteriocin genes in enterococci isolated from game animals and saltwater fish

Bacteriocins produced by enterococci, referred to as enterocins, possess great interest for their potential use as biopreservatives in food and feed, as well as alternative antimicrobials in humans and animals. In this context, the aim of the present study was to determine the antimicrobial activity and the presence of bacteriocin structural genes in fecal enterococcal isolates from animal origins. Evaluation of the direct antimicrobial activity of 253 isolates from wild boars (Sus scrofa, n = 69), mullets (Liza ramada, n = 117), and partridges (Perdix perdix, n = 67) against eight indicator bacterial strains (including Listeria monocytogenes, Pediococcus pentosaceus, and Enterococcus spp.) showed that 177 (70%) exerted antimicrobial activity against at least one indicator microorganism. From these isolates, 123 were further selected on the basis of their inhibition group, and 81 were found to be producers of bacteriocins active against Listeria monocytogenes. Analysis of the presence of enterocin structural genes in a subset of 36 isolates showed that 70% harbored one or more of the evaluated genes, those of enterocin P and hiracin JM79 being the most prevalent. These results show that wild animals constitute an appropriate source for the isolation of bacteriocinogenic enterococci.