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Inhibitory Compounds (inhibitory + compound)
Selected AbstractsIsolation of eriocitrin (eriodictyol 7- O -rutinoside) as an arachidonate lipoxygenase inhibitor from Lumie fruit (Citrus lumia) and its distribution in Citrus speciesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2007Yoichi Nogata Abstract An inhibitory compound acting against rat platelet 12-lipoxygenase was isolated from the peel of Lumie fruit (Citrus lumia) by activity-guided separation. It was identified as eriocitrin (eriodictyol 7- O -rutinoside) by spectroscopic analyses. Eriocitrin inhibited 5-lipoxygenase (IC5029.1 µmol L,1) from rat peritoneal polymorphonuclear leukocytes in addition to 12-lipoxygenase (IC5022.3 µmol L,1). Its aglycone, eriodictyol (5,7,3,, 4,-tetrahydroxyflavanone), was a much more potent inhibitor of both 12-lipoxygenase (IC500.07 µmol L,1) and 5-lipoxygenase (IC500.20 µmol L,1). It also inhibited the production of leukotriene B4 in intact peritoneal polymorphonuclear leukocytes stimulated with calcium ionophore A23187 (IC5012.7 µmol L,1). The distribution of eriocitrin in 39 citrus fruits was investigated by high-performance liquid chromatography analysis. Lumie, eureka lemon (Citrus limon), Sambokan (Citrus sulcata), Sudachi (Citrus sudachi) and Koji (Citrus leiocarpa) fruits were found to contain high levels of eriocitrin in both peel and juice vesicles. Copyright © 2006 Society of Chemical Industry [source] An inhibitory compound produced by Pseudomonas with effectiveness on Vibrio harveyiAQUACULTURE RESEARCH, Issue 10 2010Radhakrishnan Preetha Abstract Persistence of the antivibrio property of the potential antagonistic probiotics, Pseudomonas MCCB 102 and 103, at different temperatures, pH and in organic solvents was studied. The antivibrio compound was extracted, purified and characterized using thin-layer chromatography, high-pressure liquid chromatography, liquid chromatography-mass spectroscopy, UV,Vis and nuclear magnetic resonance spectroscopy and identified as N -methyl-1-hydroxyphenazine, a phenazine antibiotic. The toxicity of the compound was tested in Penaeus monodon haemocyte culture and the IC50 value was found to be 1.4 ± 0.31 mg L,1. The compound was found to be bacteriostatic at 0.5 mg L,1. Its stability to varying temperature, pH, organic solvents, prolonged shelf-life and vibriostatic nature point to its suitability for prophylatic aquaculture application. [source] Switchgrass leaching requirements for solid-state fermentation by Acidothermus cellulolyticusBIOTECHNOLOGY PROGRESS, Issue 3 2010Jean S. VanderGheynst Abstract Growth of Acidothermus cellulolyticus in solid-state fermentation and its required growth conditions were investigated in this study. Extraction of switchgrass was required for growth. Under the experimental conditions, extraction ratio had the most significant effect on the growth of A. cellulolyticus. Heat treatment (in the form of autoclaving) of switchgrass did not have a significant effect on the growth rate; however, longer heat treatment times had a negative effect on the total growth. Moisture content adjustment had no effect on the release of inhibitors into extracts. Our results showed that leaching at a minimum 40:1 (gram water: gram dry biomass) removed inhibitory compound(s) from switchgrass. Upon extraction A. cellulolyticus colonized switchgrass in solid fermentation without exogenous addition of carbon and nitrogen sources. It is the first demonstration of growth of A. cellulolyticus in solid fermentation. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Methane oxidation kinetics differ in European beech and Norway spruce soilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2009D. M. Degelmann Summary Coniferous forest soils often consume less of the greenhouse gas methane (CH4) than deciduous forest soils. The reasons for this phenomenon have not been resolved. It might be caused by differences in the diffusive flux of CH4 through the organic layer, pH or different concentrations of potentially inhibitory compounds. Soil samples were investigated from three adjacent European beech (Fagus sylvatica) and Norway spruce (Picea abies) stands in Germany. Maximal CH4 oxidation velocities (Vmax(app)) and Michaelis Menten constants (KM(app)), retrieved from intact soil cores at constant CH4 concentrations, temperature and matric potential, were twice as great in beech as in spruce soils. Also atmospheric CH4 oxidation rates measured in homogenized soil samples displayed the same trend. Greatest atmospheric CH4 oxidation rates were detected in the Oa horizon or in the upper 5 cm of the mineral soil. In contrast to the beech soils, the Oa horizon of the spruce soils consumed no CH4. A differential effect due to divergent diffusive flux through the litter layer was not found. pH and ammonium concentration were similar in samples from both forest soil types. Ethylene accumulation in all soils was negligible under oxic conditions. These collective results suggest that the different atmospheric CH4 uptake by beech and spruce soils is caused by different CH4 oxidizing capacities of methanotrophic communities in the Oa horizon and top mineral soil. [source] Selection and identification of anaerobic lactobacilli producing inhibitory compounds against vaginal pathogensFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2006Jasadee Kaewsrichan Abstract Two strains of Lactobacillus crispatus (15L08 and 21L07) and one strain of Lactobacillus jensenii (5L08) were selected from amongst 100 isolates from the vaginas of healthy premenopausal women for properties relevant to mucosal colonization and the production of H2O2 and/or bacteriocin-like compound. All three strains self-aggregated and adhered to vaginal epithelial cells, displacing well-known vaginal pathogens, such as Gardnerella vaginalis and Candida albicans. Lactobacillus crispatus 15L08 was characterized as a potential H2O2 producer. A high level of bacteriocin-like compound was synthesized by L. jensenii 5L08, with a bactericidal mode of action for G. vaginalis, C. albicans and Escherichia coli. However, H2O2 -dependent activity alone was not sufficient to inhibit the growth of C. albicans. Simultaneous actions of H2O2 and bacteriocin-like compound produced by lactobacilli may be important for antagonizing pathogenic bacteria. These strains of lactobacilli may be excellent candidates for eventual use as probiotics to restore the normal microbial communities in the vaginal ecosystem. [source] Novel inhibitors targeted to methionine aminopeptidase 2 (MetAP2) strongly inhibit the growth of cancers in xenografted nude modelINTERNATIONAL JOURNAL OF CANCER, Issue 1 2005Eunyoung Chun Abstract Inhibition of angiogenesis is emerging as a promising strategy for the treatment of cancer. In our study reported here, the effects of 4 highly potent methionine aminopeptidase 2 (MetAP2) inhibitors, IDR-803, IDR-804, IDR-805 and CKD-732 (designed by structure-based molecular modeling), on angiogenesis and tumor growth were assessed. Concentrations of these inhibitors as low as 2.5 nM were able to inhibit the growth of human umbilical vein endothelial cells (HUVEC) by as much as 50%, arresting growth in the G1 stage of mitosis. An intracellular accumulation of p21WAF1/Cip1 protein was also observed. Furthermore, at higher concentrations (25 nM) of these 4 MetAP2 inhibitors, a significant induction of apoptosis was apparent in the same HUVEC cultures. As a result of these findings, the possible anticancer effects of these inhibitors were examined, utilizing the SNU-398 hepatoma cell line. Interestingly, pretreatment with these inhibitors led to an increased number of apoptotic cells of up to 60% or more, compared to untreated controls. Moreover, utilizing an in vivo xenografted murine model, these inhibitors suppressed the growth of engrafted tumor. In conclusion, these 4 inhibitory compounds potently exert an antiangiogenic effect to inhibit the growth of cancers in vivo and could potentially be useful for the treatment of a variety of cancers. © 2004 Wiley-Liss, Inc. [source] Effect of inhibitory compounds on the anaerobic digestion performance of diluted wastewaters from the alimentary industryJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2009Rafael Camarillo Abstract BACKGROUND: Up to now the effect of inhibitory compounds on the anaerobic digestion performance of urban and industrial wastewaters has been mostly studied in fluidized bed and upflowing anaerobic sludge blanket (UASB) bioreactors but not in upflow packed-bed biodigesters. RESULTS: In this paper, response surface methodology (RSM) was used to quantify the effect of various inhibitory compounds (olive oil, ethanol and phenol) on chemical oxygen demand (COD) removal and biogas production rate from synthetic solutions and real industrial wastewaters by anaerobic digestion. The synthetic solutions possessed the same composition in these inhibitory compounds as diluted effluents from olive oil mill and winery industries. The process was performed in a laboratory scale digester containing anaerobic sludge from the Urban Reclamation Station of Toledo (Spain). The comparison of both individual factors and interactions between factors showed that the addition of olive oil at moderate concentrations (up to 0.5% w/w) did not change the performance of the process in comparison with that observed when feeding to the system a model solution (51.5% COD removal, 0.65 L biogas day,1). However, low concentrations of ethanol or phenol (250 and 150 mg L,1, respectively) almost completely inhibited the methanogenic phase. Moreover, a strong interaction between ethanol and phenol concentrations on COD removal was observed. CONCLUSION: The experimental results showed quantitatively the importance of some inhibitory compounds on anaerobic treatment of both synthetic solutions and real wastewaters from olive oil mill and winery industries. Inhibitory effects are closely related to both the organic loads and the anaerobic bioreactor used. Copyright © 2009 Society of Chemical Industry [source] Characterization of the ,-Glucosidase Activity Produced by Enological Strains of Non-Saccharomyces YeastsJOURNAL OF FOOD SCIENCE, Issue 8 2003R. R. Cordero Otero ABSTRACT: The ,-glucosidase activities of 20 wine-related non- Saccharomyces yeasts were quantified, characterized, and assessed for their efficiency in releasing aroma-enhancing compounds during the winemaking process. Of these enzymatic activities, the ,-glucosidase activity of Debaryomyces pseudopolymorphus revealed the most suitable combination of properties in terms of functionality at wine pH, resistance to wine-associated inhibitory compounds (glucose, ethanol, and sulfur dioxide), high substrate affinity, and large aglycone-substrate recognition. Its potential as a wine aroma-enhancing enzyme was confirmed by the significantly increasing concentrations of free volatiles (citronellol, nerol, and geraniol) during the fermentation of Chardonnay juice inoculated with both D. pseudopolymorphus and a widely used commercial starter culture strain of Saccharomyces cerevisiae, VIN13. [source] Effect of varying monoterpene concentrations on the response of Ips pini (Coleoptera: Scolytidae) to its aggregation pheromone: implications for pest management and ecology of bark beetlesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2003Nadir Erbilgin Abstract 1,Host plant terpenes can influence attraction of conifer bark beetles to their aggregation pheromones: both synergistic and inhibitory compounds have been reported. However, we know little about how varying concentrations of individual monoterpenes affect responses. 2,We tested a gradient of ratios of ,-pinene, the predominant monoterpene in host pines in the Great Lakes region of North America, to Ips pini's pheromone, racemic ipsdienol plus lanierone. 3,Ips pini demonstrated a parabolic response, in which low concentrations of ,-pinene had no effect on attraction to its pheromone, intermediate concentrations were synergistic and high concentrations were inhibitory. These results suggest optimal release rates for population monitoring and suppression programmes. 4,Inhibition of bark beetle attraction to pheromones may be an important component of conifer defences. At terpene to pheromone ratios emulating emissions from trees actively responding to a first attack, arrival of flying beetles was low. This may constitute an additional defensive role of terpenes, which are also toxic to bark beetles at high concentrations. 5,Reduced attraction to a low ratio of ,-pinene to pheromone, as occurs when colonization densities become high and the tree's resin is largely depleted, might reflect a mechanism for preventing excessive crowding. 6,Thanasimus dubius, the predominant predator of I. pini, was also attracted to ipsdienol plus lanierone, but its response differed from that of its prey. Attraction increased across all concentrations of ,-pinene. This indicates that separate lures are needed to sample both predators and bark beetles effectively. It also provides an opportunity for maximizing pest removal while reducing adverse effects on beneficial species. This disparity further illustrates the complexity confronting natural enemies that track chemical signals to locate herbivores. [source] Development of a PCR test to detect the downy mildew causal agent Plasmopara halstedii in sunflower seedsPLANT PATHOLOGY, Issue 2 2007R. Ioos Plasmopara halstedii, the causal agent of downy mildew of sunflower, is an obligate parasite but viable sporangia and oospores of the pathogen may be found in a quiescent state in seeds of sunflower and therefore may be transported with sunflower seeds in international commercial exchanges. In order to prevent the spread of this pathogen, especially the introduction of potentially new races, an efficient method to analyse sunflower seed samples is required. In this study, a P. halstedii -specific polymerase chain reaction (PCR) test was developed based on the ribosomal large sub unit (LSU) DNA. The forward (PHAL-F) and reverse (PHAL-R) PCR primers were designed from two polymorphic regions of LSU. After screening 22 isolates of P. halstedii corresponding to different races and countries and 32 other oomycete, deuteromycete and ascomycete isolates, the PHAL-F/R primers amplified only a single PCR band of c. 310 bp from P. halstedii. The PHAL-F/R PCR test could detect as little as 3 pg of P. halstedii genomic DNA per 20 µL reaction volume and enabled the direct detection of P. halstedii in 35 g sunflower seed samples without the need for any prior biological baiting step. An internal amplification control (IAC) was developed to help discriminate against false negative samples due to the potential presence of inhibitory compounds in DNA extracts. The test was successfully used on samples of naturally contaminated seeds. These new molecular tools should be of great interest for quarantine seed testing purposes. [source] Modélisation de la cinétique de biodégradation de phénol par granules aérobiesTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2008Claudia Calvario-Rivera Abstract Ce travail est consacré à la modélisation de la cinétique de biodégradation de phénol par granules aérobies. Ceux-ci ont été obtenus à partir de la culture à alimentation séquentielle d'un surnageant de boues activées sur une eau usée synthétique,; puis ils ont été acclimatés au phénol (100 mg/L). La biodégradation de différentes concentrations de phénol (40,1112 mg/L) a été étudiée en fioles agitées ensemencées avec des granules acclimatés. Un modèle de type Haldane a été sélectionné, qui permet de décrire de manière adéquate l'évolution de la concentration de phénol avec un seul jeu de paramètres. Ce modèle pourrait permettre de mieux comprendre la biodégradation de molécules toxiques telles que le phénol dans des réacteurs granulaires aérobies. This work describes a model of the biodegradation of phenol carried out by aerobic granules. These granules were obtained by culturing an activated sludge supernatant in a sequencing batch reactor fed with a synthetic waste water and subsequently, by acclimation to phenol (100 mg/L). The kinetics of phenol biodegradation by the aerobic granules was investigated over a wide range of initial phenol concentrations (40,1112 mg/L) in shake-flask cultures. A Haldane-type model was adjusted to the experimental results, which depicts successfully the phenol biodegradation profiles in the entire range of initial concentrations studied by using only one set of parameters. It is our view that the proposed model could contribute to the knowledge about the ability of aerobic granular systems to biodegrade toxic, inhibitory compounds such as phenol. [source] Purification of bioethanol effluent in an UASB reactor system with simultaneous biogas formationBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2003M. Torry-Smith In this study, the prospect of using an Upflow Anaerobic Sludge Blanket (UASB) reactor for detoxification of process water derived from bioethanol production has been investigated. The bioethanol effluent (BEE) originated from wet oxidized wheat straw fermented by Saccharomyces cerevisiae and Thermoanaerobacter mathranii A3M4 to produce ethanol from glucose and xylose, respectively. In batch experiments the methane potential of BEE was determined to 529 mL-CH4/g-VS. In batch degradation experiments it was shown that the presence of BEE had a positive influence on the removal of the inhibitors 2-furoic acid, 4-hydroxyacetophenone, and acetovanillone as compared to conversion of the inhibitors as sole substrate in synthetic media. Furthermore, experiments were carried out treating BEE in a laboratory-scale UASB reactor. The results showed a Chemical Oxygen Demand (COD) removal of 80% (w/w) at an organic loading rate of 29 g-COD/(L · d). GC analysis of the lignocellulosic related potentially inhibitory compounds 2-furoic acid, vanillic acid, homovanillic acid, acetovanillone, syringic acid, acetosyringone, syringol, 4-hydroxybenzoic acid, and 4-hydroxybenzaldehyde showed that all of these compounds were removed from the BEE in the reactor. Implementation of a UASB purification step was found to be a promising approach to detoxify process water from bioethanol production allowing for recirculation of the process water and reduced production costs. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 7,12, 2003. [source] Sugar Recovery and Fermentability of Hemicellulose Hydrolysates from Steam-Exploded Softwoods Containing BarkBIOTECHNOLOGY PROGRESS, Issue 5 2001Abdel Boussaid The hemicellulose sugar recovery and ethanol production obtained from SO2 -catalyzed steam explosion of a mixed white fir (70%) and ponderosa pine (30%) feedstock containing bark (9% dry weight/dry weight) was assessed. More than 90% of the available hemicellulose sugars could be recovered in the hydrolysate obtained after steam explosion at 195 °C, 2.38 min, and 3.91% SO2, with 59% of the original hemicellulose sugars detected in a monomeric form. Despite this high sugar recovery, this hydrolysate showed low ethanol yield (64% of theoretical yield) when fermented with a spent sulfite liquor-adapted strain of Saccharomyces cerevisiae. In contrast, most hydrolysates prepared at higher steam explosion severity showed comparable or higher ethanol yields. Furthermore, the hydrolysates prepared from bark-free feedstock showed better fermentability (87% of theoretical yield) despite containing higher concentration of known inhibitors. The ethanol yield from the hydrolysate prepared from a bark-containing wood sample could be improved to 81% by an extra stage acid hydrolysis (121 °C for 1 h in 3% sulfuric acid). This extra stage acid hydrolysis and steam explosion at higher severity conditions seem to improve the fermentability of the hydrolysates by transforming certain inhibitory compounds present in the hydrolysates prepared from the bark-containing feedstock and thus lowering their inhibitory effect on the yeast used for the ethanol fermentation. [source] Development and Biological Evaluation of a Novel Aurora A Kinase InhibitorCHEMBIOCHEM, Issue 3 2009Teresa Sardon Dr. Abstract Stop dividing: In the quest for antitumorigenic compounds, aurora A kinase has recently emerged as a potential drug target. In this paper three novel aurora inhibitors (shown in the illustration) have been tested for their biological activity in cultured cells. One of them (TC-28) appears to be a promising specific aurora A inhibitor in vivo. The aurora kinase family groups several serine/threonine kinases with key regulatory functions during cell division. The three mammalian members, aurora A, B and C, are frequently over-expressed in human tumors and the aurora A gene is located in a genomic region frequently amplified in breast and colon cancer. All these data have fuelled the idea that aurora kinases are promising targets for anticancer therapy. Indeed some inhibitory compounds are currently being evaluated in clinical trials. However, it was recently shown that mutations in the targeted kinase can confer resistance to a broad range of inhibitors and render patients resistant to treatments. Moreover, aurora A over-expression results in increased resistance to antimitotic agents. The development of new compounds targeting aurora A is therefore highly relevant. We describe here the synthesis of three novel aurora kinase inhibitors, TC-28, TC-34 and TC-107. We report their properties as aurora inhibitors in vitro and their effect on human tissue culture cell lines. Interestingly, our results show that TC-28 has properties compatible with the specific inhibition of aurora A, in vivo. [source] The use of small molecule high-throughput screening to identify inhibitors of the proteinase 3-NB1 interactionCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2010M. Choi Summary Anti-neutrophil cytoplasmic antibodies (ANCA) to proteinase 3 (PR3) are found in patients with small-vessel vasculitis. PR3-ANCA bind strongly to membrane PR3 (mPR3) that is presented by the NB1 receptor. We performed high-throughput screening using a small molecule library to identify compounds that inhibit PR3-NB1 binding. We established a human embryonic kidney (HEK293) cell-based system, where approximately 95 ± 2% of the NB1-transfected cells expressed the NB1 receptor on the cell surface. Addition of 0·1 µg/ml human PR3 to 104 NB1-expressing HEK293 cells resulted in PR3 binding that was detected by immunofluorescence using a fluorescence plate reader assay. We identified 13 of 20 000 molecules that inhibited PR3 binding by >70%. Seven of 13 substances showed reproducible inhibition in four additional validation experiments. Two selected compounds (27519 and 27549) demonstrated a dose-dependent inhibition over a range from 6·25 to 100 µM as measured by the plate reader assay. We used flow cytometry as a second assay, and found that both compounds reproducibly inhibited PR3 binding to NB1-transfected HEK293 cells at 50 µM (inhibition to 42 ± 4% with compound 27519 and to 47 ± 6% with compound 27549 compared to the dimethylsulphoxide control). Furthermore, compounds 27519 and 27549 also inhibited binding of exogenous PR3 to human neutrophils. In contrast, the compounds did not decrease mPR3 expression on resting neutrophils, but reduced the tumour necrosis factor-,-mediated mPR3 increase on NB1pos neutrophils when present continuously during the assay. The findings suggest that small inhibitory compounds provide a potential therapeutic tool to reduce mPR3 by preventing its binding to NB1. [source] | |||||||||||||||||||||||||||||||