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Sample records for monoterpene acid glucose

  1. α,β-Unsaturated monoterpene acid glucose esters: structural diversity, bioactivities and functional roles.

    Science.gov (United States)

    Goodger, Jason Q D; Woodrow, Ian E

    2011-12-01

    The glycosylation of lipophilic small molecules produces many important plant secondary metabolites. The majority of these are O-glycosides with relatively fewer occurring as glucose esters of aromatic or aliphatic acids. In particular, monoterpene acid glucose esters have much lower structural diversity and distribution compared to monoterpene glycosides. Nevertheless, there have been over 20 monoterpene acid glucose esters described from trees in the genus Eucalyptus (Myrtaceae) in recent years, all based on oleuropeic acid, menthiafolic acid or both. Here we review all of the glucose esters containing these monoterpenoids identified in plants to date. Many of the compounds contain phenolic aglycones and all contain at least one α,β-unsaturated carbonyl, affording a number of important potential therapeutic reactivities such as anti-tumor promotion, carcinogenesis suppression, and anti-oxidant and anti-inflammatory activities. Additional properties such as cytotoxicity, bitterness, and repellency are suggestive of a role in plant defence, but we also discuss their localization to the exterior of foliar secretory cavity lumina, and suggest they may also protect secretory cells from toxic terpenes housed within these structures. Finally we discuss how the use of a recently developed protocol to isolate secretory cavities in a functional state could be used in conjunction with systems biology approaches to help characterize their biosynthesis and roles in plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Effects of salicylic acid on monoterpene production and antioxidant ...

    African Journals Online (AJOL)

    Salicylic acid (SA) plays important roles in plant defense responses. However, little is available about its effects on monoterpene responses. Therefore, monoterpene contents and antioxidant systems were measured three days after foliar application of SA with different concentrations in Houttuynia cordata. SA at low ...

  3. Synthesis and Biological Evaluation of Novel Phosphatidylcholine Analogues Containing Monoterpene Acids as Potent Antiproliferative Agents.

    Directory of Open Access Journals (Sweden)

    Anna Gliszczyńska

    Full Text Available The synthesis of novel phosphatidylcholines with geranic and citronellic acids in sn-1 and sn-2 positions is described. The structured phospholipids were obtained in high yields (59-87% and evaluated in vitro for their cytotoxic activity against several cancer cell lines of different origin: MV4-11, A-549, MCF-7, LOVO, LOVO/DX, HepG2 and also towards non-cancer cell line BALB/3T3 (normal mice fibroblasts. The phosphatidylcholines modified with monoterpene acid showed a significantly higher antiproliferative activity than free monoterpene acids. The highest activity was observed for the terpene-phospholipids containing the isoprenoid acids in sn-1 position of phosphatidylcholine and palmitic acid in sn-2.

  4. Evaluation of measurement uncertainty for purity of a monoterpenic acid by small-scale coulometry

    Science.gov (United States)

    Norte, L. C.; de Carvalho, E. M.; Tappin, M. R. R.; Borges, P. P.

    2018-03-01

    Purity of the perylic acid (HPe) which is a monoterpenic acid from natural product (NP) with anti-inflammatory and anticancer properties was analyzed by small-scale coulometry (SSC), due to the low availability of HPe on the pharmaceutic market and its high cost. This work aims to present the evaluation of the measurements uncertainty from the purity of HPe by using SSC. Coulometric mean of purity obtained from 5 replicates resulted in 94.23% ± 0.88% (k = 2.06, for an approximately 95% confidence level). These studies aim in the future to develop the production of certified reference materials from NPs.

  5. High-performance liquid chromatographic enantioseparation of monoterpene-based 2-amino carboxylic acids on macrocyclic glycopeptide-based phases.

    Science.gov (United States)

    Sipos, László; Ilisz, István; Pataj, Zoltán; Szakonyi, Zsolt; Fülöp, Ferenc; Armstrong, Daniel W; Péter, Antal

    2010-10-29

    The enantiomers of five monoterpene-based 2-amino carboxylic acids were directly separated on chiral stationary phases containing macrocyclic glycopeptide antibiotics such as teicoplanin (Astec Chirobiotic T and T2) and teicoplanin aglycone (Chirobiotic TAG) as chiral selectors. The effects of pH, the mobile phase composition, the structure of the analyte and temperature on the separations were investigated. Experiments were performed at constant mobile phase compositions in the temperature range 10-40°C to study the effects of temperature and thermodynamic parameters on separations. Apparent thermodynamic parameters and T(iso) values were calculated from plots of ln k or ln α versus 1/T. Some mechanistic aspects of the chiral recognition process are discussed with respect to the structures of the analytes. It was found that the enantioseparations were in most cases enthalpy driven. The sequence of elution of the enantiomers was determined in all cases. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Salvianolic acid B Relieves Oxidative Stress in Glucose Absorption ...

    African Journals Online (AJOL)

    Absorption and Utilization of Mice Fed High-Sugar Diet ... Salvianolic acid B, Blood glucose, Reactive oxygen species, Oxidative stress, Sugar diet. ... protein expression in human aortic smooth ... induced by glucose uptake and metabolism [8].

  7. Hydroxycitric acid delays intestinal glucose absorption in rats

    NARCIS (Netherlands)

    Wielinga, PY; Wachters-Hagedoorn, RE; Bouter, B; van Dijk, TH; Stellaard, F; Nieuwenhuizen, AG; Verkade, HJ; Scheurink, AJW; Nieuwenhuizen, Arie G.; Verkade, Henkjan J.

    In this study, we investigated in rats if hydroxycitric acid (HCA) reduces the postprandial glucose response by affecting gastric emptying or intestinal glucose absorption. We compared the effect of regulator HCA (310 mg/kg) and vehicle (control) on the glucose response after an intragastric or

  8. Fatty acid and amino acid modulation of glucose cycling in isolated rat hepatocytes

    NARCIS (Netherlands)

    Gustafson, LA; Neeft, M; Reijngoud, DJ; Kuipers, F; Sauerwein, HP; Romijn, JA; Herling, AW; Burger, HJ; Meijer, AJ

    2001-01-01

    We studied the influence of glucose/glucose 6-phosphate cycling on glycogen deposition from glucose in fasted-rat hepatocytes using S4048 and CP320626, specific inhibitors of glucose-6-phosphate translocase and glycogen phosphorylase respectively. The effect of amino acids and oleate was also

  9. Mechanocatalytic Production of Lactic Acid from Glucose by Ball Milling

    Directory of Open Access Journals (Sweden)

    Luyang Li

    2017-06-01

    Full Text Available A solvent-free process was developed for the direct production of lactic acid from glucose in a mechanocatalytic process in the presence of Ba(OH2, and a moderate lactic acid yield of 35.6% was obtained. Glucose conversion and lactic acid formation were favorable at higher catalyst/glucose mass ratios. However, at relatively lower catalyst/glucose mass ratios, they were greatly inhibited, and the promotion of fructose formation was observed. The mechanocatalytic process was applicable for various carbohydrates such as C5 sugars, C6 sugars, and disaccharides with 20–36% lactic acid yields achieved. This work provides a new pathway for the production of value-added chemicals from biomass resources.

  10. Glucose-Sensitive Hydrogel Optical Fibers Functionalized with Phenylboronic Acid.

    Science.gov (United States)

    Yetisen, Ali K; Jiang, Nan; Fallahi, Afsoon; Montelongo, Yunuen; Ruiz-Esparza, Guillermo U; Tamayol, Ali; Zhang, Yu Shrike; Mahmood, Iram; Yang, Su-A; Kim, Ki Su; Butt, Haider; Khademhosseini, Ali; Yun, Seok-Hyun

    2017-04-01

    Hydrogel optical fibers are utilized for continuous glucose sensing in real time. The hydrogel fibers consist of poly(acrylamide-co-poly(ethylene glycol) diacrylate) cores functionalized with phenylboronic acid. The complexation of the phenylboronic acid and cis-diol groups of glucose enables reversible changes of the hydrogel fiber diameter. The analyses of light propagation loss allow for quantitative glucose measurements within the physiological range. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Recent Advances in Fluorescent Arylboronic Acids for Glucose Sensing

    Directory of Open Access Journals (Sweden)

    Jon Stefan Hansen

    2013-12-01

    Full Text Available Continuous glucose monitoring (CGM is crucial in order to avoid complications caused by change in blood glucose for patients suffering from diabetes mellitus. The long-term consequences of high blood glucose levels include damage to the heart, eyes, kidneys, nerves and other organs, among others, caused by malign glycation of vital protein structures. Fluorescent monitors based on arylboronic acids are promising candidates for optical CGM, since arylboronic acids are capable of forming arylboronate esters with 1,2-cis-diols or 1,3-diols fast and reversibly, even in aqueous solution. These properties enable arylboronic acid dyes to provide immediate information of glucose concentrations. Thus, the replacement of the commonly applied semi-invasive and non-invasive techniques relying on glucose binding proteins, such as concanavalin A, or enzymes, such as glucose oxidase, glucose dehydrogenase and hexokinases/glucokinases, might be possible. The recent progress in the development of fluorescent arylboronic acid dyes will be emphasized in this review.

  12. Production of caffeoylmalic acid from glucose in engineered Escherichia coli.

    Science.gov (United States)

    Li, Tianzhen; Zhou, Wei; Bi, Huiping; Zhuang, Yibin; Zhang, Tongcun; Liu, Tao

    2018-07-01

    To achieve biosynthesis of caffeoylmalic acid from glucose in engineered Escherichia coli. We constructed the biosynthetic pathway of caffeoylmalic acid in E. coli by co-expression of heterologous genes RgTAL, HpaBC, At4CL2 and HCT2. To enhance the production of caffeoylmalic acid, we optimized the tyrosine metabolic pathway of E. coli to increase the supply of the substrate caffeic acid. Consequently, an E. coli-E. coli co-culture system was used for the efficient production of caffeoylmalic acid. The final titer of caffeoylmalic acid reached 570.1 mg/L. Microbial production of caffeoylmalic acid using glucose has application potential. In addition, microbial co-culture is an efficient tool for producing caffeic acid esters.

  13. An extremely sensitive monoboronic acid based fluorescent sensor for glucose

    International Nuclear Information System (INIS)

    Sun Xiangying; Liu Bin; Jiang Yunbao

    2004-01-01

    An extremely sensitive monoboronic acid based fluorescent sensor for glucose was developed. This was carried out by assembling a fluorescent monoboronic acid, 3-aminophenylboronic acid (PBA) indirectly onto gold surface via its electrostatic interaction with cysteine (Cys) that was directly assembled on the gold surface. The formation of self-assembled bilayers (SAB) was confirmed and primarily characterized by cyclic voltammetry and X-ray photoelectron spectra (XPS). The SAB containing PBA was found fluorescent and its fluorescence showed an extremely high sensitivity to the presence of glucose and other monosaccharides such as galactose and fructose with quenching constants at 10 8 M -1 order of magnitude compared to those at 10 2 M -1 in bulk solutions. The quenching constants were found to vary in the order of D-glucose>D-galactose>D-fructose>D-mannose that is different from that in bulk solution which shows the highest binding affinity toward D-fructose and very low sensitivity toward glucose. The reported monoboronic acid based SAB fluorescent sensor showed the highest sensitivity towards glucose with the capacity of detecting saccharides of concentration down to nanomolar level. It was also demonstrated that the fluorescence from PBA/Cys/Au can be easily recovered after each measurement event and therefore also represents a new reusable method for immobilizing reagent in fabricating chemosensors

  14. Heteropoly acid catalyzed hydrolysis of glycogen to glucose

    International Nuclear Information System (INIS)

    Klein, Miri; Pulidindi, Indra Neel; Perkas, Nina; Gedanken, Aharon

    2015-01-01

    Complete conversion of glycogen to glucose is achieved by using H 3 PW 12 O 40 ·nH 2 O (HPW) and H 4 SiW 12 O 40 ·nH 2 O (HSiW) as catalysts for the hydrolysis under optimized hydrothermal conditions (mass fraction of catalyst 2.4%, 373 K and 2 h reaction time). The reusability of the catalyst (HPW) was demonstrated. In addition to carrying out the glycogen hydrolysis in an autoclave, other novel methods such as microwave irradiation and sonication have also been investigated. At higher mass fraction of the heteropoly acids (10.5%), glycogen could be completely converted to glucose under microwave irradiation. Sonication of an aqueous solution of glycogen in the presence of HPW and HSiW also yielded glucose. Thus, heteropoly acids are efficient, environmentally friendly and reusable catalysts for the conversion of glycogen to glucose. - Highlights: • Hydrothermal, microwave and sonication based methods of hydrolysis. • Heteropoly acids are green catalysts for glycogen hydrolysis. • Glycogen from cyanobacteria is demonstrated as a potential feedstock for glucose

  15. Nanomolar Caffeic Acid Decreases Glucose Uptake and the Effects of High Glucose in Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Lucia Natarelli

    Full Text Available Epidemiological studies suggest that moderate and prolonged consumption of coffee is associated with a reduced risk of developing type 2 diabetes but the molecular mechanisms underlying this effect are not known. In this study, we report the effects of physiological concentrations of caffeic acid, easily achievable by normal dietary habits, in endothelial cells cultured in 25 mM of glucose (high glucose, HG. In HG, the presence of 10 nM caffeic acid was associated with a decrease of glucose uptake but not to changes of GLUT-1 membrane localization or mRNA levels. Moreover, caffeic acid countered HG-induced loss of barrier integrity, reducing actin rearrangement and FITC-dextran passage. The decreased flux of glucose associated to caffeic acid affected HG induced apoptosis by down-regulating the expression of initiator (caspase 8 and 9 and effector caspases (caspase 7 and 3 and by increasing the levels of phosphorylated Bcl-2. We also observed that caffeic acid in HG condition was associated to a reduction of p65 subunit nuclear levels with respect to HG alone. NF-κB activation has been shown to lead to apoptosis in HG treated cells and the analysis of the expression of a panel of about 90 genes related to NF-κB signaling pathway revealed that caffeic acid significantly influenced gene expression changes induced by HG. In conclusion, our results suggest that caffeic acid, decreasing the metabolic stress induced by HG, allows the activation of survival mechanisms mediated by a different modulation of NF-κB-related signaling pathways and to the activation of anti-apoptotic proteins.

  16. Glucose-stimulated acrolein production from unsaturated fatty acids.

    Science.gov (United States)

    Medina-Navarro, R; Duran-Reyes, G; Diaz-Flores, M; Hicks, J J; Kumate, J

    2004-02-01

    Glucose auto-oxidation may be a significant source of reactive oxygen species (ROS), and also be important in the lipid peroxidation process, accompanied by the release of toxic reactive products. We wanted to demonstrate that acrolein can be formed directly and actively from free fatty acids in a hyperglycemic environment. A suspension of linoleic and arachidonic acids (2.5 mM) was exposed to different glucose concentrations (5, 10 and 15 mmol/L) in vitro. The samples were extracted with organic solvents, partitioned, followed at 255-267 nm, and analysed using capillary electrophoresis and mass spectroscopy. The total release of aldehydes significantly (P products, acrolein (5% of total) and its condensing product, 4-hydroxy-hexenal, were identified. From the results presented here, it was possible to demonstrate the production of acrolein, probably as a fatty acid product, due to free radicals generated from the glucose auto-oxidation process. The results led us to propose that acrolein, which is one of the most toxic aldehydes, is produced during hyperglycemic states, and may lead to tissue injury, as one of the initial problems to be linked to high levels of glucose in vivo.

  17. Process of converting starch to glucose and glucose to lactic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

    1990-01-01

    This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

  18. A selective glucose sensor: the cooperative effect of monoboronic acid-modified poly(amidoamine) dendrimers.

    Science.gov (United States)

    Tsai, Ching-Hua; Tang, Yi-Hsuan; Chen, Hui-Ting; Yao, Yi-Wen; Chien, Tun-Cheng; Kao, Chai-Lin

    2018-05-01

    Selective glucose binding was identified through five generations of monoboronic acid-functionalized PAMAM dendrimers. The best selectivity obtained when using G3 dendrimers (1b) generated 71.1, 94.9, and 1309 times stronger binding than when using galactose, fructose, and lactose, respectively. Further experiments using dendrimer analogues and glucose derivatives suggested that two nearby monoboronic acids cooperatively bound one glucose.

  19. Effects of glucose, glucose plus branched-chain amino acids, or placebo on bike performance over 100 km

    DEFF Research Database (Denmark)

    Madsen, Klavs; MacLean, David A; Kiens, Bente

    1996-01-01

    This study was undertaken to determine the effects of ingesting either glucose (trial G) or glucose plus branched-chain amino acids (BCAA: trial B), compared with placebo (trial P), during prolonged exercise. Nine well-trained cyclists with a maximal oxygen uptake of 63.1 +/- 1.5 ml O2. min-1.kg-...

  20. Glucose and fatty acid metabolism in normal and diabetic rabbit cerebral microvessels

    International Nuclear Information System (INIS)

    Hingorani, V.; Brecher, P.

    1987-01-01

    Rabbit cerebral microvessels were used to study fatty acid metabolism and its utilization relative to glucose. Microvessels were incubated with either [6- 14 C]glucose or [1- 14 C]oleic acid and the incorporation of radioactivity into 14 CO 2 , lactate, triglyceride, cholesterol ester, and phospholipid was determined. The inclusion of 5.5 mM glucose in the incubation mixture reduced oleate oxidation by 50% and increased esterification into both phospholipid and triglyceride. Glucose oxidation to CO 2 was reduced by oleate addition, whereas lactate production was unaffected. 2'-Tetradecylglycidic acid, an inhibitor of carnitine acyltransferase I, blocked oleic acid oxidation in the presence and absence of glucose. It did not effect fatty acid esterification when glucose was absent and eliminated the inhibition of oleate on glucose oxidation. Glucose oxidation to 14 CO 2 was markedly suppressed in microvessels from alloxan-treated diabetic rabbits but lactate formation was unchanged. Fatty acid oxidation to CO 2 and incorporation into triglyceride, phospholipid, and cholesterol ester remained unchanged in the diabetic state. The experiments show that both fatty acid and glucose can be used as a fuel source by the cerebral microvessels, and the interactions found between fatty acid and glucose metabolism are similar to the fatty acid-glucose cycle, described previously

  1. Influence of free fatty acids on glucose uptake in prostate cancer cells

    DEFF Research Database (Denmark)

    Andersen, Kim Francis; Divilov, Vadim; Sevak, Kuntalkumar

    2014-01-01

    The study focuses on the interaction between glucose and free fatty acids (FFA) in malignant human prostate cancer cell lines by an in vitro observation of uptake of fluoro-2-deoxy-d-glucose (FDG) and acetate.......The study focuses on the interaction between glucose and free fatty acids (FFA) in malignant human prostate cancer cell lines by an in vitro observation of uptake of fluoro-2-deoxy-d-glucose (FDG) and acetate....

  2. Monoterpenes Support Systemic Acquired Resistance within and between Plants.

    Science.gov (United States)

    Riedlmeier, Marlies; Ghirardo, Andrea; Wenig, Marion; Knappe, Claudia; Koch, Kerstin; Georgii, Elisabeth; Dey, Sanjukta; Parker, Jane E; Schnitzler, Jörg-Peter; Vlot, A Corina

    2017-06-01

    This study investigates the role of volatile organic compounds in systemic acquired resistance (SAR), a salicylic acid (SA)-associated, broad-spectrum immune response in systemic, healthy tissues of locally infected plants. Gas chromatography coupled to mass spectrometry analyses of SAR-related emissions of wild-type and non-SAR-signal-producing mutant plants associated SAR with monoterpene emissions. Headspace exposure of Arabidopsis thaliana to a mixture of the bicyclic monoterpenes α-pinene and β-pinene induced defense, accumulation of reactive oxygen species, and expression of SA- and SAR-related genes, including the SAR regulatory AZELAIC ACID INDUCED1 ( AZI1 ) gene and three of its paralogs. Pinene-induced resistance was dependent on SA biosynthesis and signaling and on AZI1 Arabidopsis geranylgeranyl reductase1 mutants with reduced monoterpene biosynthesis were SAR-defective but mounted normal local resistance and methyl salicylate-induced defense responses, suggesting that monoterpenes act in parallel with SA The volatile emissions from SAR signal-emitting plants induced defense in neighboring plants, and this was associated with the presence of α-pinene, β-pinene, and camphene in the emissions of the "sender" plants. Our data suggest that monoterpenes, particularly pinenes, promote SAR, acting through ROS and AZI1 , and likely function as infochemicals in plant-to-plant signaling, thus allowing defense signal propagation between neighboring plants. © 2017 American Society of Plant Biologists. All rights reserved.

  3. Associations among the plasma amino acid profile, obesity, and glucose metabolism in Japanese adults with normal glucose tolerance

    OpenAIRE

    Takashina, Chisa; Tsujino, Ichizo; Watanabe, Taku; Sakaue, Shinji; Ikeda, Daisuke; Yamada, Asuka; Sato, Takahiro; Ohira, Hiroshi; Otsuka, Yoshinori; Oyama-Manabe, Noriko; Ito, Yoichi M.; Nishimura, Masaharu

    2016-01-01

    Background Amino acids (AAs) are emerging as a new class of effective molecules in the etiology of obesity and diabetes mellitus. However, most investigations have focused on subjects with obesity and/or impaired glucose regulation; the possible involvement of AAs in the initial phase of glucose dysregulation remains poorly understood. Furthermore, little attention has been given to possible associations between the pattern/degree of fat deposition and the plasma AA profile. Our objective was...

  4. Intracerebroventricular Kainic Acid-Induced Damage Affects Blood Glucose Level in d-glucose-fed Mouse Model.

    Science.gov (United States)

    Kim, Chea-Ha; Hong, Jae-Seung

    2015-03-01

    We have previously reported that the intracerebroventricular (i.c.v.) administration of kainic acid (KA) results in significant neuronal damage on the hippocampal CA3 region. In this study, we examined possible changes in the blood glucose level after i.c.v. pretreatment with KA. The blood glucose level was elevated at 30 min, began to decrease at 60 min and returned to normal at 120 min after D-glucose-feeding. We found that the blood glucose level in the KA-pretreated group was higher than in the saline-pretreated group. The up-regulation of the blood glucose level in the KA-pretreated group was still present even after 1~4 weeks. The plasma corticosterone and insulin levels were slightly higher in the KA-treated group. Corticosterone levels decreased whereas insulin levels were elevated when mice were fed with D-glucose. The i.c.v. pretreatment with KA for 24 hr caused a significant reversal of D-glucose-induced down-regulation of corticosterone level. However, the insulin level was enhanced in the KA-pretreated group compared to the vehicle-treated group when mice were fed with D-glucose. These results suggest that KA-induced alterations of the blood glucose level are related to cell death in the CA3 region whereas the up-regulation of blood glucose level in the KA-pretreated group appears to be due to a reversal of D-glucose feeding-induced down-regulation of corticosterone level.

  5. A novel glucose biosensor based on phosphonic acid-functionalized silica nanoparticles for sensitive detection of glucose in real samples

    International Nuclear Information System (INIS)

    Zhao, Wenbo; Fang, Yi; Zhu, Qinshu; Wang, Kuai; Liu, Min; Huang, Xiaohua; Shen, Jian

    2013-01-01

    An effective strategy for preparation amperometric biosensor by using the phosphonic acid-functionalized silica nanoparticles (PFSi NPs) as special modified materials is proposed. In such a strategy, glucose oxidase (GOD) was selected as model protein to fabricate glucose biosensor in the presence of phosphonic acid-functionalized silica nanoparticles (PFSi NPs). The PFSi NPs were first modified on the surface of glassy carbon (GC) electrode, then, GOD was adsorbed onto the PFSi NPs film by drop-coating. The PFSi NPs were characterized by transmission electron microscopy (TEM) and nuclear magnetic resonance (NMR) spectra. The interaction of PFSi NPs with GOD was investigated by the circular dicroism spectroscopy (CD). The results showed PFSi NPs could essentially maintain the native conformation of GOD. The direct electron transfer of GOD on (PFSi NPs)/GCE electrode exhibited excellent electrocatalytic activity for the oxidation of glucose. The proposed biosensor modified with PFSi NPs displayed a fast amperometric response (5 s) to glucose, a good linear current–time relation over a wide range of glucose concentrations from 5.00 × 10 −4 to 1.87 × 10 −1 M, and a low detection limit of 2.44 × 10 −5 M (S/N = 3). Moreover, the biosensor can be used for assessment of the concentration of glucose in many real samples (relative error < 3%). The GOD biosensor modified with PFSi NPs will have essential meaning and practical application in future that attributed to the simple method of fabrication and good performance

  6. Complete oxidative conversion of lignocellulose derived non-glucose sugars to sugar acids by Gluconobacter oxydans.

    Science.gov (United States)

    Yao, Ruimiao; Hou, Weiliang; Bao, Jie

    2017-11-01

    Non-glucose sugars derived from lignocellulose cover approximately 40% of the total carbohydrates of lignocellulose biomass. The conversion of the non-glucose sugars to the target products is an important task of lignocellulose biorefining research. Here we report a fast and complete conversion of the total non-glucose sugars from corn stover into the corresponding sugar acids by whole cell catalysis and aerobic fermentation of Gluconobacter oxydans. The conversions include xylose to xylonate, arabinose to arabonate, mannose to mannonate, and galactose to galactonate, as well as with glucose into gluconate. These cellulosic non-glucose sugar acids showed the excellent cement retard setting property. The mixed cellulosic sugar acids could be used as cement retard additives without separation. The conversion of the non-glucose sugars not only makes full use of lignocellulose derived sugars, but also effectively reduces the wastewater treatment burden by removal of residual sugars. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. A kinetic study on the conversion of glucose to levulinic acid

    NARCIS (Netherlands)

    Girisuta, B; Janssen, LPBM; Heeres, HJ

    Levulinic acid has been identified as a promising green. biomass derived platform chemical. A kinetic study oil one of the key steps in the conversion of biomass to levulinic acid, i.e., the acid catalysed decomposition of glucose to levulinic acid has been performed. The experiments were Performed

  8. Green chemicals : A Kinetic Study on the Conversion of Glucose to Levulinic Acid

    NARCIS (Netherlands)

    Girisuta, B.; Janssen, L.P.B.M.; Heeres, H.J.

    2006-01-01

    Levulinic acid has been identified as a promising green, biomass derived platform chemical. A kinetic study on one of the key steps in the conversion of biomass to levulinic acid, i.e., the acid catalysed decomposition of glucose to levulinic acid has been performed. The experiments were performed

  9. Ascorbic acid prevents vascular dysfunction induced by oral glucose load in healthy subjects.

    Science.gov (United States)

    De Marchi, Sergio; Prior, Manlio; Rigoni, Anna; Zecchetto, Sara; Rulfo, Fanny; Arosio, Enrico

    2012-01-01

    To examine the effects of oral glucose load on forearm circulatory regulation before and after ascorbic acid administration in healthy subjects. Microcirculation study with laser Doppler was performed at the hand in basal conditions, after ischemia and after acetylcholine and nitroprusside; strain gauge plethysmography was performed at basal and after ischemia. The tests were repeated in the same sequence 2 hour after oral administration of glucose (75 g). The subjects were randomised for administration of ascorbic acid (1 g bid) or placebo (sodium bicarbonate 1 g bid) for 10 days. After that, the tests were repeated before and after a new oral glucose load. Blood pressure and heart rate were monitored. Macrocirculatory flux, pressure values and heart rate were unvaried throughout the study. The glucose load caused a reduction in the hyperemic peak flow with laser Doppler and plethysmography; it reduced flux recovery time and hyperemic curve area after ischemia; acetylcholine elicited a minor increase in flux with laser Doppler. The response to nitroprusside was unvaried after glucose load as compared to basal conditions. Treatment with ascorbic acid prevented the decrease in hyperemia after glucose, detected with laser Doppler and plethysmography. Ascorbic acid prevented the decreased response to acetylcholine after glucose, the response to nitroprusside was unaffected by ascorbic acid. Results after placebo were unvaried. Oral glucose load impairs endothelium dependent dilation and hyperaemia at microcirculation, probably via oxidative stress; ascorbic acid can prevent it. Copyright © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  10. Isolation and Characterization of Three New Monoterpene Synthases from Artemisia annua

    Science.gov (United States)

    Ruan, Ju-Xin; Li, Jian-Xu; Fang, Xin; Wang, Ling-Jian; Hu, Wen-Li; Chen, Xiao-Ya; Yang, Chang-Qing

    2016-01-01

    Artemisia annua, an annual herb used in traditional Chinese medicine, produces a wealth of monoterpenes and sesquiterpenes, including the well-known sesquiterpene lactone artemisinin, an active ingredient in the treatment for malaria. Here we report three new monoterpene synthases of A. annua. From a glandular trichome cDNA library, monoterpene synthases of AaTPS2, AaTPS5, and AaTPS6, were isolated and characterized. The recombinant proteins of AaTPS5 and AaTPS6 produced multiple products with camphene and 1,8-cineole as major products, respectively, and AaTPS2 produced a single product, β-myrcene. Although both Mg2+ and Mn2+ were able to support their catalytic activities, altered product spectrum was observed in the presence of Mn2+ for AaTPS2 and AaTPS5. Analysis of extracts of aerial tissues and root of A. annua with gas chromatography–mass spectrometry detected more than 20 monoterpenes, of which the three enzymes constituted more than 1/3 of the total. Mechanical wounding induced the expression of all three monoterpene synthase genes, and transcript levels of AaTPS5 and AaTPS6 were also elevated after treatments with phytohormones of methyl jasmonate, salicylic acid, and gibberellin, suggesting a role of these monoterpene synthases in plant–environment interactions. The three new monoterpene synthases reported here further our understanding of molecular basis of monoterpene biosynthesis and regulation in plant. PMID:27242840

  11. Developmental, gustatory, and behavioral responses of leafroller larvae, Choristoneura rosaceana, to tannic acid and glucose.

    Science.gov (United States)

    Panzuto, M; Mauffette, Y; Alber, P J

    2002-01-01

    Soluble sugars are essential nutrients generally perceived as phagostimulants to most insects studied. However, tannins are known as digestibility reducers, hence deleterious to caterpillar development, and as deterrents as well. Previous work demonstrated that larvae of the polyphagous oblique-banded leafroller, Choristoneura rosaceana, performed better when reared on a control + 0.5% tannic acid diet than on the standard control diet and that larvae reared on a control + 5% glucose diet had slower development and reduced survival. This study was designed to elucidate the behavioral and neurophysiological components of the larval responses to tannic acid and glucose. C. rosaceana larvae were reared individually from the first to the sixth instar on one of four different artificial diets: (1) control; (2) control + 5% glucose; (3) control + 0.5% tannic acid; (4) control + 5% glucose + 0.5% tannic acid. After 14 days, larvae reared on the control + 5% glucose diet had not developed past the fourth instar, whereas a considerable proportion of larvae reared on the control + 0.5% tannic acid diet had already attained the pupal stage. Insects reared on the control or the control + 5% glucose + 0.5% tannic acid diet had intermediate development. with most larvae in the fifth instar. In addition, once the mid-sixth instar was reached, the feeding preferences to 25 and 300 mM glucose, 25 mM tannic acid, and 25 mM glucose + 25 mM tannic acid over water were assessed in two-choice tests. Feeding affected preference. Control-reared insects preferred feeding on treatments containing glucose and were not deterred by tannic acid. However, larvae that had been exposed to tannic acid during their development were deterred by tannic acid and their glucose discrimination was impaired. The sensitivity to glucose was also examined from neurophysiological recordings by stimulating the sugar-sensitive cell (cell 1) on the lateral styloconic sensillum of the maxillary galea with

  12. Ferulic acid depletion by cultured soybean seedlings under action of glucose and methionine

    Directory of Open Access Journals (Sweden)

    Herrig Vanessa

    2000-01-01

    Full Text Available Cultured soybean seedlings were used to investigate how glucose or methionine influenced depletion of ferulic acid. Three-day-old seedlings were grown in hydroponic solution containing ferulic acid plus glucose or methionine, and the level of the phenolic acid were monitored in the nutrient culture. The results showed that ferulic acid depletion was more rapid in the presence of those compounds. After 6 h, the increase caused by glucose (0.01 and 0.05 mM was more pronounced than methionine in the same concentrations. On the other hand, methionine (0.1 and 0.2 mM increased depletion more significantly than glucose. Results suggested that both compounds might to increase the allelopathic effects of ferulic acid in the seedlings.

  13. Thermodynamic study of selected monoterpenes

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Červinka, C.; Rocha, M.A.A.; Santos, L.M.N.B.F.; Schröder, B.

    2013-01-01

    Roč. 60, MAY (2013), 117-125 ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : monoterpenes * pinene * vapor pressure * heat capacity * vaporization and sublimation enthalpy * ideal - gas thermodynamic Subject RIV: BJ - Thermodynamics Impact factor: 2.423, year: 2013

  14. The Biosynthetic Origin of Irregular Monoterpenes in Lavandula

    Science.gov (United States)

    Demissie, Zerihun A.; Erland, Lauren A. E.; Rheault, Mark R.; Mahmoud, Soheil S.

    2013-01-01

    Lavender essential oils are constituted predominantly of regular monoterpenes, for example linalool, 1,8-cineole, and camphor. However, they also contain irregular monoterpenes including lavandulol and lavandulyl acetate. Although the majority of genes responsible for the production of regular monoterpenes in lavenders are now known, enzymes (including lavandulyl diphosphate synthase (LPPS)) catalyzing the biosynthesis of irregular monoterpenes in these plants have not been described. Here, we report the isolation and functional characterization of a novel cis-prenyl diphosphate synthase cDNA, termed Lavandula x intermedia lavandulyl diphosphate synthase (LiLPPS), through a homology-based cloning strategy. The LiLPPS ORF, encoding for a 305-amino acid long protein, was expressed in Escherichia coli, and the recombinant protein was purified by nickel-nitrilotriacetic acid affinity chromatography. The approximately 34.5-kDa bacterially produced protein specifically catalyzed the head-to-middle condensation of two dimethylallyl diphosphate units to LPP in vitro with apparent Km and kcat values of 208 ± 12 μm and 0.1 s−1, respectively. LiLPPS is a homodimeric enzyme with a sigmoidal saturation curve and Hill coefficient of 2.7, suggesting a positive co-operative interaction among its catalytic sites. LiLPPS could be used to modulate the production of lavandulol and its derivatives in plants through metabolic engineering. PMID:23306202

  15. Effects of free fatty acids per se on glucose production, gluconeogenesis, and glycogenolysis

    DEFF Research Database (Denmark)

    Staehr, Peter; Hother-Nielsen, Ole; Landau, Bernard R

    2003-01-01

    Insulin-independent effects of a physiological increase in free fatty acid (FFA) levels on fasting glucose production, gluconeogenesis, and glycogenolysis were assessed by administering [6,6-(2)H(2)]-glucose and deuteriated water ((2)H(2)O) in 12 type 1 diabetic patients, during 6-h infusions...

  16. Glucose-lowering effects and mechanisms of the bile acid-sequestering resin sevelamer

    DEFF Research Database (Denmark)

    Brønden, Andreas; Mikkelsen, Kristian; Sonne, David P

    2018-01-01

    AIMS: Sevelamer, a non-absorbable amine-based resin used for treatment of hyperphosphatemia, has been demonstrated to hold a marked bile acid-binding potential alongside beneficial effects on lipid and glucose metabolism. The aim of this study was to investigate the glucose-lowering effect and me...

  17. Influence of Amino Acids in Dairy Products on Glucose Homeostasis: The Clinical Evidence.

    Science.gov (United States)

    Chartrand, Dominic; Da Silva, Marine S; Julien, Pierre; Rudkowska, Iwona

    2017-06-01

    Dairy products have been hypothesized to protect against type 2 diabetes because of their high content of whey proteins, rich in branched-chain amino acids (BCAAs) - leucine, isoleucine and valine - and lysine, which may decrease postprandial glucose responses and stimulate insulin secretion. Paradoxically, epidemiologic studies also show that higher levels of plasma BCAAs have been linked to insulin resistance and type 2 diabetes. Therefore, the objective was to review the recent clinical evidence concerning the intake of amino acids found in dairy proteins so as to determine their impact on glucose homeostasis in healthy persons and in those with prediabetes and type 2 diabetes. Clinical studies have reported that the major dairy amino acids, namely, leucine, isoleucine, glutamine, phenylalanine, proline and lysine, have beneficial effects on glucose homeostasis. Yet the reported doses of amino acids investigated are too elevated to be reached through adequate dairy product intake. The minor dairy amino acids, arginine and glycine, may improve glucose homeostasis by improving other risk factors for type 2 diabetes. Further, the combination of amino acids may also improve glucose-related outcomes, suggesting additive or synergistic effects. Nevertheless, additional long-term studies in individuals with prediabetes and type 2 diabetes are needed to ascertain the benefits for glucose homeostasis of amino acids found in dairy foods. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  18. Evidence connecting old, new and neglected glucose-lowering drugs to bile acid-induced GLP-1 secretion

    DEFF Research Database (Denmark)

    Kårhus, Martin L; Brønden, Andreas; Sonne, David P

    2017-01-01

    Bile acids are amphipathic water-soluble steroid-based molecules best known for their important lipid-solubilizing role in the assimilation of fat. Recently, bile acids have emerged as metabolic integrators with glucose-lowering potential. Among a variety of gluco-metabolic effects, bile acids have...... current evidence connecting established glucose-lowering drugs to bile acid-induced GLP-1 secretion and discusses whether bile acid-induced GLP-1 secretion may constitute a new basis for understanding how metformin, inhibitors of the apical sodium-dependent bile acids transporter, and bile acid...... sequestrants - old, new and neglected glucose-lowering drugs - improve glucose metabolism....

  19. A metabolic switch in brain: glucose and lactate metabolism modulation by ascorbic acid.

    Science.gov (United States)

    Castro, Maite A; Beltrán, Felipe A; Brauchi, Sebastián; Concha, Ilona I

    2009-07-01

    In this review, we discuss a novel function of ascorbic acid in brain energetics. It has been proposed that during glutamatergic synaptic activity neurons preferably consume lactate released from glia. The key to this energetic coupling is the metabolic activation that occurs in astrocytes by glutamate and an increase in extracellular [K(+)]. Neurons are cells well equipped to consume glucose because they express glucose transporters and glycolytic and tricarboxylic acid cycle enzymes. Moreover, neuronal cells express monocarboxylate transporters and lactate dehydrogenase isoenzyme 1, which is inhibited by pyruvate. As glycolysis produces an increase in pyruvate concentration and a decrease in NAD(+)/NADH, lactate and glucose consumption are not viable at the same time. In this context, we discuss ascorbic acid participation as a metabolic switch modulating neuronal metabolism between rest and activation periods. Ascorbic acid is highly concentrated in CNS. Glutamate stimulates ascorbic acid release from astrocytes. Ascorbic acid entry into neurons and within the cell can inhibit glucose consumption and stimulate lactate transport. For this switch to occur, an ascorbic acid flow is necessary between astrocytes and neurons, which is driven by neural activity and is part of vitamin C recycling. Here, we review the role of glucose and lactate as metabolic substrates and the modulation of neuronal metabolism by ascorbic acid.

  20. Glucose and D-Allulose contained medium to support the growth of lactic acid bacteria

    Science.gov (United States)

    Al-Baarri, A. N.; Legowo, A. M.; Pramono, Y. B.; Sari, D. I.; Pangestika, W.

    2018-01-01

    Monosaccharide has been known as support agent for the growth of lactic acid bacteria. However the combination among monosaccharides for supporting the living of bacteria has not been understood well. This research was done for analyzing the combination glucose and D-allulose for the growth of Lactobacillus acidophilus and Streptococcus thermophillus. The NaCl medium containing glucose and D-allulose was used to analyse the growth of bacteria. The study showed that glucose and D-allulose have been detected as supportive agent to L. acidophilus and S. thermophillus specifically. As conclusion, glucose and D-allulose supported the growth of lactic acid bacteria equally. This finding might provide the beneficial information for industry to utilize D-allulose as well as glucose.

  1. Glucose and amino acid metabolism in rat brain during sustained hypoglycemia

    International Nuclear Information System (INIS)

    Wong, K.L.; Tyce, G.M.

    1983-01-01

    The metabolism of glucose in brains during sustained hypoglycemia was studied. [U- 14 C]Glucose (20 microCi) was injected into control rats, and into rats at 2.5 hr after a bolus injection of 2 units of insulin followed by a continuous infusion of 0.2 units/100 g rat/hr. This regimen of insulin injection was found to result in steady-state plasma glucose levels between 2.5 and 3.5 mumol per ml. In the brains of control rats carbon was transferred rapidly from glucose to glutamate, glutamine, gamma-aminobutyric acid and aspartate and this carbon was retained in the amino acids for at least 60 min. In the brains of hypoglycemic rats, the conversion of carbon from glucose to amino acids was increased in the first 15 min after injection. After 15 min, the specific activity of the amino acids decreased in insulin-treated rats but not in the controls. The concentrations of alanine, glutamate, and gamma-amino-butyric acid decreased, and the concentration of aspartate increased, in the brains of the hypoglycemic rats. The concentration of pyridoxal-5'-phosphate, a cofactor in many of the reactions whereby these amino acids are formed from tricarboxylic acid cycle intermediates, was less in the insulin-treated rats than in the controls. These data provide evidence that glutamate, glutamine, aspartate, and GABA can serve as energy sources in brain during insulin-induced hypoglycemia

  2. Maleic acid and aluminum chloride catalyzed conversion of glucose to 5-(hydroxymethyl) furfural and levulinic acid in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ximing [Laboratory of Renewable Resources Engineering and Department of Agricultural and Biological Engineering; Purdue University; West Lafayette; USA; The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Murria, Priya [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Jiang, Yuan [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Xiao, Weihua [Laboratory of Renewable Resources Engineering and Department of Agricultural and Biological Engineering; Purdue University; West Lafayette; USA; College of Engineering; Kenttämaa, Hilkka I. [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Abu-Omar, Mahdi M. [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Mosier, Nathan S. [Laboratory of Renewable Resources Engineering and Department of Agricultural and Biological Engineering; Purdue University; West Lafayette; USA; The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio)

    2016-01-01

    Maleic acid (MA) and AlCl3self-assemble into catalytic complexes (Al–(MA)2–(OH)2(aq)) with improved selectivity for converting glucose to HMF, and levulinic acid.

  3. Conifer-Derived Monoterpenes and Forest Walking

    OpenAIRE

    Sumitomo, Kazuhiro; Akutsu, Hiroaki; Fukuyama, Syusei; Minoshima, Akiho; Kukita, Shin; Yamamura, Yuji; Sato, Yoshiaki; Hayasaka, Taiki; Osanai, Shinobu; Funakoshi, Hiroshi; Hasebe, Naoyuki; Nakamura, Masao

    2015-01-01

    Conifer and broadleaf trees emit volatile organic compounds in the summer. The major components of these emissions are volatile monoterpenes. Using solid phase microextraction fiber as the adsorbant, monoterpenes were successfully detected and identified in forest air samples. Gas chromatography/mass chromatogram of monoterpenes in the atmosphere of a conifer forest and that of serum from subjects who were walking in a forest were found to be similar each other. The amounts of α-pinene in the...

  4. Asiatic acid influences glucose homeostasis in P. berghei murine ...

    African Journals Online (AJOL)

    Background: Glucose homeostasis derangement is a common pathophysiology of malaria whose aetiology is still controversial. The Plasmodium parasite, immunological and inflammatory responses, as well as chemotherapeutics currently used cause hypoglycaemia in malaria. Anti-parasitic and anti-disease drugs are ...

  5. Kinetics of Maleic Acid and Aluminum Chloride Catalyzed Dehydration and Degradation of Glucose

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ximing; Hewetson, Barron B.; Mosier, Nathan S.

    2015-04-16

    We report the positive effect of maleic acid, a dicarboxylic acid, on the selectivity of hexose dehydration to 5-hydroxymethyfurfural (HMF) and subsequent hydrolysis to levulinic and formic acids. We also describe the kinetic analysis of a Lewis acid (AlCl3) alone and in combination with HCl or maleic acid to catalyze the isomerization of glucose to fructose, dehydration of fructose to HMF, hydration of HMF to levulinic and formic acids, and degradation of these compounds to humins. The results show that AlCl3 significantly enhances the rate of glucose conversion to HMF and levulinic acid in the presence of both maleic acid and HCl. In addition, the degradation of HMF to humins, rather than levulinic and formic acids, is reduced by 50% in the presence of maleic acid and AlCl3 compared to HCl combined with AlCl3. The results suggest different reaction mechanisms for the dehydration of glucose and rehydration of HMF between maleic acid and HCl.

  6. Behaviors of glucose decomposition during acid-catalyzed hydrothermal hydrolysis of pretreated Gelidium amansii.

    Science.gov (United States)

    Jeong, Tae Su; Choi, Chang Ho; Lee, Ji Ye; Oh, Kyeong Keun

    2012-07-01

    Acid-catalyzed hydrothermal hydrolysis is one path to cellulosic glucose and subsequently to its dehydration end products such as hydroxymethyl furfural (HMF), formic acid and levulinic acid. The effect of sugar decomposition not only lowers the yield of fermentable sugars but also forms decomposition products that inhibit subsequent fermentation. The present experiments were conducted with four different acid catalysts (H(2)SO(4), HNO(3), HCl, and H(3)PO(4)) at various acid normalities (0.5-2.1N) in batch reactors at 180-210 °C. From the results, H(2)SO(4) was the most suitable catalyst for glucose production, but glucose decomposition occurred during the hydrolysis. The glucose production was maximized at 160.7 °C, 2.0% (w/v) H(2)SO(4), and 40 min, but resulted in a low glucan yield of 33.05% due to the decomposition reactions, which generated formic acid and levulinic acid. The highest concentration of levulinic acid, 7.82 g/L, was obtained at 181.2 °C, 2.0% (w/v) H(2)SO(4), and 40 min. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Optimization of lactic acid production from glucose using geobacillus stearothermophilus strain 15

    Science.gov (United States)

    Kunasundari, Balakrishnan; Naresh, Sandrasekaran; Safie, Mohammad Farhan Mohd

    2017-09-01

    This study investigated the conversion efficiency of glucose to lactic acid by Geobacillus stearothermophilus strain 15. Six parameters (temperature, pH, incubation time, agitation speed, carbon and nitrogen concentrations) were screened to identify the most significant factors in affecting lactic acid production using glucose. Three most significant factors (temperature, pH and incubation time) were further optimized in this experiment to determine the optimal production of lactic acid. Numerical optimization gave the point prediction of lactic acid concentration produced at 9.95 g/L with the desirability of 0.979 at 40°C, pH 8.5, 24 h, 100 rpm with 5% glucose and 3% yeast extract.

  8. Genipin Cross-Linked Glucose Oxidase and Catalase Multi-enzyme for Gluconic Acid Synthesis.

    Science.gov (United States)

    Cui, Caixia; Chen, Haibin; Chen, Biqiang; Tan, Tianwei

    2017-02-01

    In this work, glucose oxidase (GOD) and catalase (CAT) were used simultaneously to produce gluconic acid from glucose. In order to reduce the distance between the two enzymes, and therefore improve efficiency, GOD and CAT were cross-linked together using genipin. Improvements in gluconic acid production were due to quick removal of harmful intermediate hydrogen peroxide by CAT. GOD activity was significantly affected by the proportion of CAT in the system, with GOD activity in the cross-linked multi-enzyme (CLME) being 10 times higher than that in an un-cross-linked GOD/CAT mixture. The glucose conversion rate after 15 h using 15 % glucose was also 10 % higher using the CLME than was measured using a GOD/CAT mixture.

  9. Glucose and protein kinetics in patients undergoing colorectal surgery: perioperative amino acid versus hypocaloric dextrose infusion.

    Science.gov (United States)

    Lugli, Andrea Kopp; Schricker, Thomas; Wykes, Linda; Lattermann, Ralph; Carli, Franco

    2010-11-01

    Surgical injury provokes a stress response that leads to a catabolic state and, when prolonged, interferes with the postoperative recovery process. This study tests the impact of 2 nutrition support regimens on protein and glucose metabolism as part of an integrated approach in the perioperative period incorporating epidural analgesia in 18 nondiabetic patients undergoing colorectal surgery. To test the hypothesis that parenteral amino acid infusion (amino acid group, n = 9) maintains glucose homeostasis while maintaining normoglycemia and reduces proteolysis compared with infusion of dextrose alone (DEX group, n = 9), glucose and protein kinetics were measured before and on the second day after surgery using a stable isotope tracer technique. Postoperatively, the rate of appearance of glucose was higher (P dextrose alone. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Insulin Sensitivity and Glucose Homeostasis Can Be Influenced by Metabolic Acid Load

    Directory of Open Access Journals (Sweden)

    Lucio Della Guardia

    2018-05-01

    Full Text Available Recent epidemiological findings suggest that high levels of dietary acid load can affect insulin sensitivity and glucose metabolism. Consumption of high protein diets results in the over-production of metabolic acids which has been associated with the development of chronic metabolic disturbances. Mild metabolic acidosis has been shown to impair peripheral insulin action and several epidemiological findings suggest that metabolic acid load markers are associated with insulin resistance and impaired glycemic control through an interference intracellular insulin signaling pathways and translocation. In addition, higher incidence of diabetes, insulin resistance, or impaired glucose control have been found in subjects with elevated metabolic acid load markers. Hence, lowering dietary acid load may be relevant for improving glucose homeostasis and prevention of type 2 diabetes development on a long-term basis. However, limitations related to patient acid load estimation, nutritional determinants, and metabolic status considerably flaws available findings, and the lack of solid data on the background physiopathology contributes to the questionability of results. Furthermore, evidence from interventional studies is very limited and the trials carried out report no beneficial results following alkali supplementation. Available literature suggests that poor acid load control may contribute to impaired insulin sensitivity and glucose homeostasis, but it is not sufficiently supportive to fully elucidate the issue and additional well-designed studies are clearly needed.

  11. Flowery odor formation revealed by differential expression of monoterpene biosynthetic genes and monoterpene accumulation in rose (Rosa rugosa Thunb.).

    Science.gov (United States)

    Feng, Liguo; Chen, Chen; Li, Tinglin; Wang, Meng; Tao, Jun; Zhao, Daqiu; Sheng, Lixia

    2014-02-01

    Rosa rugosa is an important ornamental and economical plant. In this paper, four genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), alcohol acyltransferase (AAT) and linalool synthase (LIS) involved in the monoterpene biosynthesis pathways were isolated from R. rugosa 'Tangzi', and the expression patterns of these genes in different flower development stages and different parts of floral organs were determined by real-time quantitative fluorescence PCR. Furthermore, a comprehensive analysis was carried out into the relationship between expression of four monoterpene synthesis genes and accumulation of main volatile monoterpenes and their acetic acid ester derivatives. The results showed that the genes RrDXS, RrDXR and RrLIS showed consistent expressions during the development process for R. rugosa flower from budding to withering stage, the overall expression levels of gene RrDXS and RrLIS were obviously lower as compared with those of gene RrDXR and RrAAT. Although the gene RrDXS, RrDXR, RrAAT and RrLIS were expressed in all parts of R. rugosa floral organs, the expression levels varied significantly. The variations in the constituent and content of volatile monoterpenes including citronellol, geraniol, nerol, linalool, citronellyl acetate, geranyl acetate and neryl acetate at different development stages and parts of floral organs were significantly different. On this basis, we concluded that the gene RrDXR and RrAAT might play a key role in the biosynthesis of volatile monoterpenes in R. rugosa flowers, and the two genes are important candidate genes for the regulation of secondary metabolism for rose aromatic components. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  12. Biocatalytic production of adipic acid from glucose using engineered Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Kaushik Raj

    2018-06-01

    Full Text Available Adipic acid is an important industrial chemical used in the synthesis of nylon-6,6. The commercial synthesis of adipic acid uses petroleum-derived benzene and releases significant quantities of greenhouse gases. Biocatalytic production of adipic acid from renewable feedstocks could potentially reduce the environmental damage and eliminate the need for fossil fuel precursors. Recently, we have demonstrated the first enzymatic hydrogenation of muconic acid to adipic acid using microbial enoate reductases (ERs - complex iron-sulfur and flavin containing enzymes. In this work, we successfully expressed the Bacillus coagulans ER in a Saccharomyces cerevisiae strain producing muconic acid and developed a three-stage fermentation process enabling the synthesis of adipic acid from glucose. The ability to express active ERs and significant acid tolerance of S. cerevisiae highlight the applicability of the developed yeast strain for the biocatalytic production of adipic acid from renewable feedstocks. Keywords: Biosynthesis, Renewable resources, Yeast, Adipic acid, Synthetic biology

  13. Non-enzymatic glucose detection based on phenylboronic acid modified optical fibers

    Science.gov (United States)

    Sun, Xiaolan; Li, Nana; Zhou, Bin; Zhao, Wei; Liu, Liyuan; Huang, Chao; Ma, Longfei; Kost, Alan R.

    2018-06-01

    A non-enzymatic, sensitive glucose sensor was fabricated based on an evanescent wave absorbing optical fiber probe. The optical fiber sensor was functionalized by fixing a poly (phenylboronic acid) (polyPBA) film onto the conical region of the single mode fiber. The reflected light intensity of the polyPBA-functionalized fiber sensor increased proportionally with glucose concentration in the range of 0-60 mM, and the sensor showed good reproducibility and stability. The developed sensor possessed a high sensitivity of 0.1787%/mM and good linearity. The measurement of glucose concentration in human serum was also demonstrated.

  14. Bace1 activity impairs neuronal glucose metabolism: rescue by beta-hydroxybutyrate and lipoic acid

    Directory of Open Access Journals (Sweden)

    John A Findlay

    2015-10-01

    Full Text Available Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer’s disease (AD pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP cleaving enzyme 1 (BACE1, responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.

  15. Catalytic Conversion of Glucose into 5-Hydroxymethylfurfural by Hf(OTf4 Lewis Acid in Water

    Directory of Open Access Journals (Sweden)

    Junjie Li

    2015-12-01

    Full Text Available A series of Lewis acidic metal salts were used for glucose dehydration to 5-hydroymethylfurfural (HMF in water. Effect of valence state, ionic radii of Lewis acidic cation, and the type of anions on the catalytic performance have been studied systematically. The experimental results showed that the valence state played an important role in determining catalytic activity and selectivity. It was found that a higher glucose conversion rate and HMF selectivity could be obtained over high valent Lewis acid salts, where the ionic radii of these Lewis acidic metal salts are usually relatively small. Analysis on the effect of the anions of Lewis acid salts on the catalytic activity and the selectivity suggested that a higher glucose conversion and HMF selectivity could be readily obtained with Cl−. Furthermore, the recyclability of high valence state Lewis acid salt was also studied, however, inferior catalytic performance was observed. The deactivation mechanism was speculated to be the fact that high valence state Lewis acid salt was comparatively easier to undergo hydrolysis to yield complicated metal aqua ions with less catalytic activity. The Lewis acidic activity could be recovered by introducing a stoichiometric amount of hydrochloric acid (HCl to the catalytic before the reaction.

  16. Intracellular ascorbic acid inhibits transport of glucose by neurons, but not by astrocytes.

    Science.gov (United States)

    Castro, Maite A; Pozo, Miguel; Cortés, Christian; García, María de Los Angeles; Concha, Ilona I; Nualart, Francisco

    2007-08-01

    It has been demonstrated that glutamatergic activity induces ascorbic acid (AA) depletion in astrocytes. Additionally, different data indicate that AA may inhibit glucose accumulation in primary cultures of rat hippocampal neurons. Thus, our hypothesis postulates that AA released from the astrocytes during glutamatergic synaptic activity may inhibit glucose uptake by neurons. We observed that cultured neurons express the sodium-vitamin C cotransporter 2 and the facilitative glucose transporters (GLUT) 1 and 3, however, in hippocampal brain slices GLUT3 was the main transporter detected. Functional activity of GLUTs was confirmed by means of kinetic analysis using 2-deoxy-d-glucose. Therefore, we showed that AA, once accumulated inside the cell, inhibits glucose transport in both cortical and hippocampal neurons in culture. Additionally, we showed that astrocytes are not affected by AA. Using hippocampal slices, we observed that upon blockade of monocarboxylate utilization by alpha-cyano-4-hydroxycinnamate and after glucose deprivation, glucose could rescue neuronal response to electrical stimulation only if AA uptake is prevented. Finally, using a transwell system of separated neuronal and astrocytic cultures, we observed that glutamate can reduce glucose transport in neurons only in presence of AA-loaded astrocytes, suggesting the essential role of astrocyte-released AA in this effect.

  17. Proton exchange in systems: Glucose-water and uric acid-water

    International Nuclear Information System (INIS)

    Maarof, S.

    2007-01-01

    It is clear that formation of glucose-water and uric acid-water solutions is related in principle to interaction accepter - donor between hydrogen atom in water and oxygen atom in glucose or uric acid. The proton exchange in hydrogen bond system is an integral process and it goes by tunnel mechanism (transfer of proton within the hydrogen bridge in these structures). Proton exchange process goes very quickly at low concentrations for glucose and uric acid solutions, because these compounds are able to form more than one hydrogen bond, which helps the proton transfer within obtained structure. However, at its high concentrations, the process becomes very slow due to higher viscosity of its solutions, which result in break down of the structures, and more hydrogen bonds. (author)

  18. Anaerobic Degradation of Bicyclic Monoterpenes in Castellaniella defragrans

    Directory of Open Access Journals (Sweden)

    Edinson Puentes-Cala

    2018-02-01

    Full Text Available The microbial degradation pathways of bicyclic monoterpenes contain unknown enzymes for carbon–carbon cleavages. Such enzymes may also be present in the betaproteobacterium Castellaniella defragrans, a model organism to study the anaerobic monoterpene degradation. In this study, a deletion mutant strain missing the first enzyme of the monocyclic monoterpene pathway transformed cometabolically the bicyclics sabinene, 3-carene and α-pinene into several monocyclic monoterpenes and traces of cyclic monoterpene alcohols. Proteomes of cells grown on bicyclic monoterpenes resembled the proteomes of cells grown on monocyclic monoterpenes. Many transposon mutants unable to grow on bicyclic monoterpenes contained inactivated genes of the monocyclic monoterpene pathway. These observations suggest that the monocyclic degradation pathway is used to metabolize bicyclic monoterpenes. The initial step in the degradation is a decyclization (ring-opening reaction yielding monocyclic monoterpenes, which can be considered as a reverse reaction of the olefin cyclization of polyenes.

  19. Interfacial electron transfer of glucose oxidase on poly(glutamic acid)-modified glassy carbon electrode and glucose sensing.

    Science.gov (United States)

    Zhou, Xuechou; Tan, Bingcan; Zheng, Xinyu; Kong, Dexian; Li, Qinglu

    2015-11-15

    The interfacial electron transfer of glucose oxidase (GOx) on a poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) was investigated. The redox peaks measured for GOx and flavin adenine dinucleotide (FAD) are similar, and the anodic peak of GOx does not increase in the presence of glucose in a mediator-free solution. These indicate that the electroactivity of GOx is not the direct electron transfer (DET) between GOx and PGA/GCE and that the observed electroactivity of GOx is ascribed to free FAD that is released from GOx. However, efficient electron transfer occurred if an appropriate mediator was placed in solution, suggesting that GOx is active. The PGA/GCE-based biosensor showed wide linear response in the range of 0.5-5.5 mM with a low detection limit of 0.12 mM and high sensitivity and selectivity for measuring glucose. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Caffeic acid as active principle from the fruit of Xanthium strumarium to lower plasma glucose in diabetic rats.

    Science.gov (United States)

    Hsu, F L; Chen, Y C; Cheng, J T

    2000-04-01

    The antihyperglycemic effect of caffeic acid, one of the phenolic compounds contained in the fruit of Xanthium strumarium, was investigated. After an intravenous injection of caffeic acid into diabetic rats of both streptozotocin-induced and insulin-resistant models, a dose-dependent decrease of plasma glucose was observed. However, a similar effect was not produced in normal rats. An insulin-independent action of caffeic acid can thus be considered. Otherwise, this compound reduced the elevation of plasma glucose level in insulin-resistant rats receiving a glucose challenge test. Also, glucose uptake into the isolated adipocytes was raised by caffeic acid in a concentration-dependent manner. Increase of glucose utilization by caffeic acid seems to be responsible for the lowering of plasma glucose.

  1. Synergism in the effect of prior jasmonic acid application on herbivore-induced volatile emission by Lima bean plants: transcription of a monoterpene synthase gene and volatile emission

    NARCIS (Netherlands)

    Menzel, T.R.; Weldegergis, B.T.; David, A.; Boland, W.; Gols, R.; Loon, van J.J.A.; Dicke, M.

    2014-01-01

    Jasmonic acid (JA) plays a central role in induced plant defence e.g. by regulating the biosynthesis of herbivore-induced plant volatiles that mediate the attraction of natural enemies of herbivores. Moreover, exogenous application of JA can be used to elicit plant defence responses similar to those

  2. Nitrogenous compounds stimulate glucose-derived acid production by oral Streptococcus and Actinomyces.

    Science.gov (United States)

    Norimatsu, Yuka; Kawashima, Junko; Takano-Yamamoto, Teruko; Takahashi, Nobuhiro

    2015-09-01

    Both Streptococcus and Actinomyces can produce acids from dietary sugars and are frequently found in caries lesions. In the oral cavity, nitrogenous compounds, such as peptides and amino acids, are provided continuously by saliva and crevicular gingival fluid. Given that these bacteria can also utilize nitrogen compounds for their growth, it was hypothesized that nitrogenous compounds may influence their acid production; however, no previous studies have examined this topic. Therefore, the present study aimed to assess the effects of nitrogenous compounds (tryptone and glutamate) on glucose-derived acid production by Streptococcus and Actinomyces. Acid production was evaluated using a pH-stat method under anaerobic conditions, whereas the amounts of metabolic end-products were quantified using high performance liquid chromatography. Tryptone enhanced glucose-derived acid production by up to 2.68-fold, whereas glutamate enhanced Streptococcus species only. However, neither tryptone nor glutamate altered the end-product profiles, indicating that the nitrogenous compounds stimulate the whole metabolic pathways involving in acid production from glucose, but are not actively metabolized, nor do they alter metabolic pathways. These results suggest that nitrogenous compounds in the oral cavity promote acid production by Streptococcus and Actinomyces in vivo. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  3. Effect of essential fatty acids on glucose-induced cytotoxicity to retinal vascular endothelial cells

    Directory of Open Access Journals (Sweden)

    Shen Junhui

    2012-07-01

    Full Text Available Abstract Background Diabetic retinopathy is a major complication of dysregulated hyperglycemia. Retinal vascular endothelial cell dysfunction is an early event in the pathogenesis of diabetic retinopathy. Studies showed that hyperglycemia-induced excess proliferation of retinal vascular endothelial cells can be abrogated by docosahexaenoic acid (DHA, 22:6 ω-3 and eicosapentaenoic acid (EPA, 20:5 ω-3. The influence of dietary omega-3 PUFA on brain zinc metabolism has been previously implied. Zn2+ is essential for the activity of Δ6 desaturase as a co-factor that, in turn, converts essential fatty acids to their respective long chain metabolites. Whether essential fatty acids (EFAs α-linolenic acid and linoleic acid have similar beneficial effect remains poorly understood. Methods RF/6A cells were treated with different concentrations of high glucose, α-linolenic acid and linoleic acid and Zn2+. The alterations in mitochondrial succinate dehydrogenase enzyme activity, cell membrane fluidity, reactive oxygen species generation, SOD enzyme and vascular endothelial growth factor (VEGF secretion were evaluated. Results Studies showed that hyperglycemia-induced excess proliferation of retinal vascular endothelial cells can be abrogated by both linoleic acid (LA and α-linolenic acid (ALA, while the saturated fatty acid, palmitic acid was ineffective. A dose–response study with ALA showed that the activity of the mitochondrial succinate dehydrogenase enzyme was suppressed at all concentrations of glucose tested to a significant degree. High glucose enhanced fluorescence polarization and microviscocity reverted to normal by treatment with Zn2+ and ALA. ALA was more potent that Zn2+. Increased level of high glucose caused slightly increased ROS generation that correlated with corresponding decrease in SOD activity. ALA suppressed ROS generation to a significant degree in a dose dependent fashion and raised SOD activity significantly. ALA suppressed

  4. Bile Acid Sequestration Reduces Plasma Glucose Levels in db/db Mice by Increasing Its Metabolic Clearance Rate

    NARCIS (Netherlands)

    Meissner, M.; Herrema, H.J.; Dijk, van Th.; Gerding, A.; Havinga, R.; Boer, T.; Müller, M.R.; Reijngoud, D.J.; Groen, A.K.; Kuipers, F.

    2011-01-01

    Aims/Hypothesis: Bile acid sequestrants (BAS) reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels.

  5. Roles of Chlorogenic Acid on Regulating Glucose and Lipids Metabolism: A Review

    Directory of Open Access Journals (Sweden)

    Shengxi Meng

    2013-01-01

    Full Text Available Intracellular glucose and lipid metabolic homeostasis is vital for maintaining basic life activities of a cell or an organism. Glucose and lipid metabolic disorders are closely related with the occurrence and progression of diabetes, obesity, hepatic steatosis, cardiovascular disease, and cancer. Chlorogenic acid (CGA, one of the most abundant polyphenol compounds in the human diet, is a group of phenolic secondary metabolites produced by certain plant species and is an important component of coffee. Accumulating evidence has demonstrated that CGA exerts many biological properties, including antibacterial, antioxidant, and anticarcinogenic activities. Recently, the roles and applications of CGA, particularly in relation to glucose and lipid metabolism, have been highlighted. This review addresses current studies investigating the roles of CGA in glucose and lipid metabolism.

  6. Isolation and characterization of three new monoterpene synthases from Artemisia annua

    Directory of Open Access Journals (Sweden)

    Ju-Xin eRuan

    2016-05-01

    Full Text Available Artemisia annua, an annual herb used in traditional Chinese medicine, produces a wealth of monoterpenes and sesquiterpenes, including the well-known sesquiterpene lactone artemisinin, an active ingredient in the treatment for malaria. Here we report three new monoterpene synthases of A. annua. From a glandular trichome cDNA library, monoterpene synthases of AaTPS2, AaTPS5 and AaTPS6, were isolated and characterized. The recombinant proteins of AaTPS5 and AaTPS6 produced multiple products with camphene and 1,8-cineole as major products, respectively, and AaTPS2 produced a single product, β-myrcene. Although both Mg2+ and Mn2+ were able to support their catalytic activities, altered product spectrum was observed in the presence of Mn2+ for AaTPS2 and AaTPS5. Analysis of extracts of aerial tissues and root of A. annua with gas chromatography-mass spectrometry (GC-MS detected more than 20 monoterpenes, of which the three enzymes constituted more than 1/3 of the total. Mechanical wounding induced the expression of all three monoterpene synthase genes, and transcript levels of AaTPS5 and AaTPS6 were also elevated after treatments with phytohormones of methyl jasmonate (MeJA, salicylic acid (SA and gibberellin (GA, suggesting a role of these monoterpene synthases in plant-environment interactions. The three new monoterpene synthases reported here further our understanding of molecular basis of monoterpene biosynthesis and regulation in plant.

  7. EXTRACTION-CHROMATOGRAPHIC DETERMINATION OF GLUCOSE AND FRUCTOSE IN THE PRESENCE OF AROMATIC AMINO ACIDS

    Directory of Open Access Journals (Sweden)

    Y. I. Korenman

    2012-01-01

    Full Text Available The extraction of glucose and fructose from aqueous salt solutions containing aromatic amino acids (phenylalanine, tryptophan, tyrosine, hydrophilic solvents (aliphatic alcohols, alkyl acetates, ketones have been studied. The quantitative characteric of the process (the distribution coefficients, the degree of extraction, separation factors are calculeted. The dependence of distribution ratios of monosaccharides from the amino acid content in the solution has been established. A mobile phase for analysis of the concentrate by ascending thin layer chromatography have been developed.

  8. Comparison of palmitic acid kinetics during glucose or ketone body infusions

    Energy Technology Data Exchange (ETDEWEB)

    Birkhahn, R.H.; Block, D.J.; Birkhahn, G.C.; Thomford, N.R.

    1986-03-05

    Ketone body interactions can be observed for extended ketosis by infusion by monoacetoacetin (the monoglyceride of acetoacetic acid). Palmitic acid kinetics were compared on the 5th day of glucose or ketone body-glucose infusions. 20 rats were fed complete diets intravenously at the rate of 50 ml/day. All diets contained vitamins, trace minerals, electrolytes, amino acids and 1 kcal/ml of non-protein energy. Rats were divided by energy source: Group A (n = 10) received energy from glucose and Group B (n = 10) from 72% monoacetoacetin plus 28% glucose. Diets were given at 1/2 and 3/4 rats on days 1 and 2, respectively and at full rate for days 3-5. Urinary nitrogen losses, body weight and dietary intake were measured daily. Palmitate kinetics was measured on day 5 using a continuous infusion of (1-/sup 14/C) palmitate and measuring C-14 in breath and plasma and plasma palmitate by GC. The two groups had similar body weight changes and urinary nitrogen losses over the 3 days of full intake Group A had lower plasma palmitate (88 +/- 7 vs 105 +/- 6 micromol/l) but similar turnover (17.1 +/- 2.4 vs 15.0 +/- 1.9 mmol/hr) and oxidation 2.3 +/- 0.3 vs 2.2 +/- 0.05 mmol/hr) compared to Group B. These data show that feeding monoacetoacetin intravenously does not stimulate fatty acid metabolism in the well nourished rat.

  9. Determination of glucose and uric acid with bienzyme colorimetry on microfluidic paper-based analysis devices.

    Science.gov (United States)

    Chen, Xi; Chen, Jin; Wang, Fubin; Xiang, Xia; Luo, Ming; Ji, Xinghu; He, Zhike

    2012-05-15

    In this work, we first employ a drying method combining with the bienzyme colorimetric detection of glucose and uric acid on microfluidic paper-based analysis devices (μPADs). The channels of 3D μPADs are also designed by us to get better results. The color results are recorded by both Gel Documentation systems and a common camera. By using Gel Documentation systems, the limits of detection (LOD) of glucose and uric acid are 3.81 × 10(-5)M and 4.31 × 10(-5)M, respectively one order of magnitude lower than that of the reported methods on μPADs. By using a common camera, the limits of detection (LOD) of glucose and uric acid are 2.13 × 10(-4)M and 2.87 × 10(-4)M, respectively. Furthermore, the effects of detection conditions have been investigated and discussed comprehensively. Human serum samples are detected with satisfactory results, which are comparable with the clinical testing results. A low-cost, simple and rapid colorimetric method for the simultaneous detection of glucose and uric acid on the μPADs has been developed with enhanced sensitivity. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Biological activity of alligator, avian, and mammalian insulin in juvenile alligators: plasma glucose and amino acids.

    Science.gov (United States)

    Lance, V A; Elsey, R M; Coulson, R A

    1993-02-01

    The biological activity of alligator, turkey, and bovine insulin on plasma glucose and plasma amino acids was tested in fasted juvenile alligators. Preliminary experiments showed that the stress associated with taking the initial blood sample resulted in a hyperglycemic response lasting more than 24 hr. Despite repeated bleedings no additional hyperglycemic events occurred, and blood glucose declined slowly over the next 7 days. Under these conditions the smallest dose of insulin eliciting a hypoglycemic response was 40 micrograms/kg body wt. A dose of 400 micrograms/kg body wt of either alligator or bovine insulin caused a pronounced hypoglycemia by 12 hr postinjection. Maximum decline in plasma glucose occurred at 24 to 36 hr with a slow return to control levels by 120 hr. There were no significant differences in the hypoglycemic responses to any of the three insulins tested. The decline in plasma amino acids was much more rapid than the decline in plasma glucose in response to insulin. Even at the 40 micrograms/kg body wt dose a significant difference from saline-injected control was seen at 2 hr postinjection. Maximum decline in plasma amino acids occurred at 8 to 12 hr with a return to baseline by 36 hr. These results show that the relatively conservative changes in the sequence of alligator insulin (three amino acid substitutions in the B-chain compared with that of chicken) have little effect on biological activity and that alligator insulin receptors do not appear to discriminate among the three insulins.

  11. Comparison of palmitic acid kinetics during glucose or ketone body infusions

    International Nuclear Information System (INIS)

    Birkhahn, R.H.; Block, D.J.; Birkhahn, G.C.; Thomford, N.R.

    1986-01-01

    Ketone body interactions can be observed for extended ketosis by infusion by monoacetoacetin (the monoglyceride of acetoacetic acid). Palmitic acid kinetics were compared on the 5th day of glucose or ketone body-glucose infusions. 20 rats were fed complete diets intravenously at the rate of 50 ml/day. All diets contained vitamins, trace minerals, electrolytes, amino acids and 1 kcal/ml of non-protein energy. Rats were divided by energy source: Group A (n = 10) received energy from glucose and Group B (n = 10) from 72% monoacetoacetin plus 28% glucose. Diets were given at 1/2 and 3/4 rats on days 1 and 2, respectively and at full rate for days 3-5. Urinary nitrogen losses, body weight and dietary intake were measured daily. Palmitate kinetics was measured on day 5 using a continuous infusion of [1- 14 C] palmitate and measuring C-14 in breath and plasma and plasma palmitate by GC. The two groups had similar body weight changes and urinary nitrogen losses over the 3 days of full intake Group A had lower plasma palmitate (88 +/- 7 vs 105 +/- 6 micromol/l) but similar turnover (17.1 +/- 2.4 vs 15.0 +/- 1.9 mmol/hr) and oxidation 2.3 +/- 0.3 vs 2.2 +/- 0.05 mmol/hr) compared to Group B. These data show that feeding monoacetoacetin intravenously does not stimulate fatty acid metabolism in the well nourished rat

  12. Postprandial Differences in the Amino Acid and Biogenic Amines Profiles of Impaired Fasting Glucose Individuals after Intake of Highland Barley

    Directory of Open Access Journals (Sweden)

    Liyan Liu

    2015-07-01

    Full Text Available The aim of this study was to measure the postprandial changes in amino acid and biogenic amine profiles in individuals with impaired fasting glucose (IFG and to investigate the changes of postprandial amino acid and biogenic amine profiles after a meal of highland barley (HB. Firstly, 50 IFG and 50 healthy individuals were recruited for the measurement of 2 h postprandial changes of amino acid and biogenic amine profiles after a glucose load. Secondly, IFG individuals received three different loads: Glucose (GL, white rice (WR and HB. Amino acid and biogenic amine profiles, glucose and insulin were assayed at time zero and 30, 60, 90 and 120 min after the test load. The results showed fasting and postprandial amino acid and biogenic amine profiles were different between the IFG group and the controls. The level of most amino acids and their metabolites decreased after an oral glucose tolerance test, while the postprandial level of γ-aminobutyric acid (GABA increased significantly in IFG individuals. After three different test loads, the area under the curve for glucose, insulin, lysine and GABA after a HB load decreased significantly compared to GL and WR loads. Furthermore, the postprandial changes in the level of GABA between time zero and 120 min during a HB load were associated positively with 2 h glucose and fasting insulin secretion in the IFG individuals. Thus, the HB load produced low postprandial glucose and insulin responses, which induced changes in amino acid and biogenic amine profiles and improved insulin sensitivity.

  13. Assessment of the effects of feed restriction and amino acid supplementation on glucose tolerance in llamas.

    Science.gov (United States)

    Cebra, Christopher K; Tornquist, Susan J; Jester, Rebecca M; Stelletta, Calogero

    2004-07-01

    To assess the effects of prolonged feed deprivation on glucose tolerance, insulin secretion, and lipid homeostasis in llamas. 9 adult female llamas. On each of 2 consecutive days, food was withheld from the llamas for 8 hours. Blood samples were collected before and 5, 15, 30, 45, 60, 120, and 240 minutes after IV injection of dextrose (0.5 g/kg) for determination of plasma insulin and serum glucose, triglyceride, and nonesterified fatty acid concentrations. Between experimental periods, the llamas received supplemental amino acids IV (185 mg/kg in solution). The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 23 days, after which the experimental procedures were repeated. Feed restriction decreased glucose tolerance and had slight effects on insulin secretion in llamas. Basal lipid fractions were higher after feed restriction, but dextrose administration resulted in similar reductions in serum lipid concentrations with and without feed restriction. Insulin secretion was decreased on the second day of each study period, which lessened reduction of serum lipid concentrations but did not affect glucose tolerance. Despite having a comparatively competent pancreatic response, feed-restricted llamas assimilated dextrose via an IV bolus more slowly than did llamas on full rations. However, repeated administration of dextrose reduced insulin secretion and could promote hyperglycemia and fat mobilization. These findings suggested that veterinarians should use alternative methods of supplying energy to camelids with long-term reduced feed intake or consider administering agents to improve the assimilation of glucose.

  14. Associations of fatty acids in cerebrospinal fluid with peripheral glucose concentrations and energy metabolism.

    Directory of Open Access Journals (Sweden)

    Reiner Jumpertz

    Full Text Available Rodent experiments have emphasized a role of central fatty acid (FA species, such as oleic acid, in regulating peripheral glucose and energy metabolism. Thus, we hypothesized that central FAs are related to peripheral glucose regulation and energy expenditure in humans. To test this we measured FA species profiles in cerebrospinal fluid (CSF and plasma of 32 individuals who stayed in our clinical inpatient unit for 6 days. Body composition was measured by dual energy X-ray absorptiometry and glucose regulation by an oral glucose test (OGTT followed by measurements of 24 hour (24EE and sleep energy expenditure (SLEEP as well as respiratory quotient (RQ in a respiratory chamber. CSF was obtained via lumbar punctures; FA concentrations were measured by liquid chromatography/mass spectrometry. As expected, FA concentrations were higher in plasma compared to CSF. Individuals with high concentrations of CSF very-long-chain saturated FAs had lower rates of SLEEP. In the plasma moderate associations of these FAs with higher 24EE were observed. Moreover, CSF monounsaturated long-chain FA (palmitoleic and oleic acid concentrations were associated with lower RQs and lower glucose area under the curve during the OGTT. Thus, FAs in the CSF strongly correlated with peripheral metabolic traits. These physiological parameters were most specific to long-chain monounsaturated (C16:1, C18:1 and very-long-chain saturated (C24:0, C26:0 FAs.Together with previous animal experiments these initial cross-sectional human data indicate that central FA species are linked to peripheral glucose and energy homeostasis.

  15. Monoterpene biosynthesis potential of plant subcellular compartments

    NARCIS (Netherlands)

    Dong, L.; Jongedijk, E.J.; Bouwmeester, H.J.; Krol, van der A.R.

    2016-01-01

    Subcellular monoterpene biosynthesis capacity based on local geranyl diphosphate (GDP) availability or locally boosted GDP production was determined for plastids, cytosol and mitochondria. A geraniol synthase (GES) was targeted to plastids, cytosol, or mitochondria. Transient expression in Nicotiana

  16. Process integration for the conversion of glucose to 2,5-furandicarboxylic acid

    DEFF Research Database (Denmark)

    Boisen, A.; Christensen, T.B.; Fu, Wenjing

    2009-01-01

    The development of biorefineries means that a key feedstock for many new processes will be sugars in various forms, such as glucose or fructose. From these feedstocks a range of chemicals can be synthesized using heterogeneous catalysis, immobilized enzymes, homogeneous catalysts, soluble enzymes...... of the final product value and therefore yield and selectivity in these steps are of crucial importance. In this paper using the conversion of glucose to 2,5-furandicarboxylic acid and associated products as an example, alternative routes will be compared with respect to achievable selectivity, and achievable...

  17. Microbial monoterpene transformations—a review

    OpenAIRE

    Marmulla, Robert; Harder, Jens

    2014-01-01

    Isoprene and monoterpenes constitute a significant fraction of new plant biomass. Emission rates into the atmosphere alone are estimated to be over 500 Tg per year. These natural hydrocarbons are mineralized annually in similar quantities. In the atmosphere, abiotic photochemical processes cause lifetimes of minutes to hours. Microorganisms encounter isoprene, monoterpenes, and other volatiles of plant origin while living in and on plants, in the soil and in aquatic habitats. Below toxic conc...

  18. Microbial monoterpene transformations – A review

    Directory of Open Access Journals (Sweden)

    Robert eMarmulla

    2014-07-01

    Full Text Available Isoprene and monoterpenes constitute a significant fraction of new plant biomass. Emission rates into the atmosphere alone are estimated to be over 500 Tg per year. These natural hydrocarbons are mineralized annually in similar quantities. In the atmosphere, abiotic photochemical processes cause lifetimes of minutes to hours. Microorganisms encounter isoprene, monoterpenes and other volatiles of plant origin while living in and on plants, in the soil and in aquatic habitats. Below toxic concentrations, the compounds can serve as carbon and energy source for aerobic and anaerobic microorganisms. Besides these catabolic reactions, transformations may occur as part of detoxification processes. Initial transformations of monoterpenes involve the introduction of functional groups, oxidation reactions and molecular rearrangements catalyzed by various enzymes. Pseudomonas and Rhodococcus strains and members of the genera Castellaniella and Thauera have become model organisms for the elucidation of biochemical pathways. We review here the enzymes and their genes together with microorganisms known for a monoterpene metabolism, with a strong focus on microorganisms that are taxonomically validly described and currently available from culture collections. Metagenomes of microbiomes with a monoterpene-rich diet confirmed the ecological relevance of monoterpene metabolism and raised concerns on the quality of our insights based on the limited biochemical knowledge.

  19. Kinetics of color development in glucose/Amino Acid model systems at different temperatures

    Directory of Open Access Journals (Sweden)

    Ana Paola Echavarría

    2016-01-01

    Full Text Available This study investigated the influence of temperature on the color development of melanoidins formed from a single combination of glucose with amino acid. The selected amino acid, commonly found in apple juice and highly reactive in the Maillard reaction, were asparagine (Asn, aspartic acid (Asp and glutamic acid (Glu. For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry methods. The effect of temperature on the color intensity, the absorption of melanoidins were also measured at different wavelengths (280, 325, 405. The value of melanoidins formed from all model systems was located on a dominant wavelength of 325 nm, the ultra violet zone of the diagram. A first-order kinetic model was applied to L* and the evolution of color difference ΔE*. In addition, a*, b* values, significantly differences were found in the glucose/aspartic acid model system in the brown-red zone. Therefore, the color development of the melanoidins was influenced by the type of amino acid and temperature, and it is thought that the a* and b* values can be used to explain the differences among the amino acid in the color development of melanoidins.

  20. Fatty Acid Oxidation Compensates for Lipopolysaccharide-Induced Warburg Effect in Glucose-Deprived Monocytes

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    Nora Raulien

    2017-05-01

    Full Text Available Monocytes enter sites of microbial or sterile inflammation as the first line of defense of the immune system and initiate pro-inflammatory effector mechanisms. We show that activation with bacterial lipopolysaccharide (LPS induces them to undergo a metabolic shift toward aerobic glycolysis, similar to the Warburg effect observed in cancer cells. At sites of inflammation, however, glucose concentrations are often drastically decreased, which prompted us to study monocyte function under conditions of glucose deprivation and abrogated Warburg effect. Experiments using the Seahorse Extracellular Flux Analyzer revealed that limited glucose supply shifts monocyte metabolism toward oxidative phosphorylation, fueled largely by fatty acid oxidation at the expense of lipid droplets. While this metabolic state appears to provide sufficient energy to sustain functional properties like cytokine secretion, migration, and phagocytosis, it cannot prevent a rise in the AMP/ATP ratio and a decreased respiratory burst. The molecular trigger mediating the metabolic shift and the functional consequences is activation of AMP-activated protein kinase (AMPK. Taken together, our results indicate that monocytes are sufficiently metabolically flexible to perform pro-inflammatory functions at sites of inflammation despite glucose deprivation and inhibition of the LPS-induced Warburg effect. AMPK seems to play a pivotal role in orchestrating these processes during glucose deprivation in monocytes.

  1. Effect of somatostatin on nonesterified fatty acid levels modifies glucose homeostasis during fasting

    International Nuclear Information System (INIS)

    Hendrick, G.K.; Frizzell, R.T.; Cherrington, A.D.

    1987-01-01

    In the 7-days fasted conscious dog, unlike the postabsorptive conscious dog, somatostatin infusion results in decreased levels of nonesterified fatty acids (NEFA) and increased glucose utilization (R d ) even when insulin and glucagon levels are held constant. The aim of this study was to determine whether NEFA replacement in such animals would prevent the increase in R d . In each of three protocols there was an 80-min tracer equilibration period, a 40-min basal period, and a 3-h test period. During the test period in the first protocol saline was infused, in the second protocol somatostatin was infused along with intraportal replacement amounts of insulin and glucagon (hormone replacement), while in the third protocol somatostatin plus the pancreatic hormones were infused with concurrent heparin plus Intralipid infusion. Glucose turnover was assessed using [3- 3 H]glucose. The peripheral levels of insulin, glucagon, and glucose were similar and constant in all three protocols; however, during somatostatin infusion, exogenous glucose infusion was necessary to maintain euglycemia. The NEFA level was constant during saline infusion and decreased in the hormone replacement protocol. In the hormone replacement plus NEFA protocol, the NEFA level did not change during the first 90-min period and then increased during the second 90-min period. After a prolonged fast in the dog, (1) somatostatin directly or indirectly inhibits adipose tissue NEFA release and causes a decrease in the plasma NEFA level, and (2) this decrease in the NEFA level causes an increase in R d

  2. Perfluorooctanoic acid exposure for 28 days affects glucose homeostasis and induces insulin hypersensitivity in mice

    Science.gov (United States)

    Yan, Shengmin; Zhang, Hongxia; Zheng, Fei; Sheng, Nan; Guo, Xuejiang; Dai, Jiayin

    2015-06-01

    Perfluoroalkyl acids (PFAAs) are widely used in many applications due to their unique physical and chemical characteristics. Because of the increasing prevalence of metabolic syndromes, including obesity, dyslipidemia and insulin resistance, concern has arisen about the roles of environmental pollutants in such diseases. Earlier epidemiologic studies showed a potential association between perfluorooctanoic acid (PFOA) and glucose metabolism, but how PFOA influences glucose homeostasis is still unknown. Here, we report on the modulation of the phosphatidylinositol 3-kinase-serine/threonine protein kinase (PI3K-AKT) signaling pathway in the livers of mice after 28 d of exposure to PFOA. Compared with normal mice, PFOA exposure significantly decreased the expression of the phosphatase and tensin homologue (PTEN) protein and affected the PI3K-AKT signaling pathway in the liver. Tolerance tests further indicated that PFOA exposure induced higher insulin sensitivity and glucose tolerance in mice. Biochemical analysis revealed that PFOA exposure reduced hepatic glycogen synthesis, which might be attributed to gluconeogenesis inhibition. The levels of several circulating proteins were altered after PFOA exposure, including proteins potentially related to diabetes and liver disease. Our results suggest that PFOA affected glucose metabolism and induced insulin hypersensitivity in mice.

  3. Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

    Energy Technology Data Exchange (ETDEWEB)

    Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

    2012-01-01

    The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

  4. Synthesis of 5-hydroxymethylfurfural (HMF) by acid catalyzed dehydration of glucose-fructose mixtures

    DEFF Research Database (Denmark)

    Pedersen, Asbjørn Toftgaard; Ringborg, Rolf Hoffmeyer; Grotkjær, Thomas

    2015-01-01

    allowing the use of the cheapest available source of fructose: high fructose corn syrup. The dehydration was catalyzed by hydrochloric acid and conducted in acetone-water mixtures, which ensured good selectivity towards HMF and eliminated precipitation of polymer by-products (insoluble humins). Through......Synthesis of 5-hydroxymethylfurfural (HMF) from hexoses has been studied extensively in the scientific literature. However, a process has yet to be implemented at industrial scale. In this paper the simultaneous dehydration of glucose and fructose was investigated, in order to develop a process......-products: soluble humins, glucose dimers, anhydroglucose, and formic acid. The reaction conditions in four different reactor configurations were optimized and compared using the kinetic model. It was found that a recirculating reactor setup is preferable, where the equilibrium controlled by-products (anhydroglucose...

  5. Isolation of Monoterpene Dihydrochalcones from Piper montealegreanum Yuncker (Piperaceae).

    Science.gov (United States)

    Alves, Harley da Silva; Rocha, Wilma Raianny Vieira da; Braz-Filho, Raimundo; Chaves, Maria Célia de Oliveira

    2017-06-09

    Four new compounds were isolated from the branches of Piper montealegreanum Yuncker, a shrub found in the Amazon rainforest, including two new dihydrochalcones named claricine ( 1 ) and maisine ( 2 ), a cinnamic acid derivative 3 and a phenylalkanoid 4 , along with a porphyrin identified as the known compound phaeophytin a ( 5 ). The structures were established using spectroscopic experiments, including 1D and 2D NMR and HRESIMS experiments, performed on the two monoterpene dihydrochalcones and their monoacetyl derivatives. The structural diversity of these substances is very important for the Piper genus chemotaxonomy.

  6. Influence of free fatty acids on glucose uptake in prostate cancer cells

    International Nuclear Information System (INIS)

    Andersen, Kim Francis; Divilov, Vadim; Sevak, Kuntalkumar; Koziorowski, Jacek; Lewis, Jason S.; Pillarsetty, NagaVaraKishore

    2014-01-01

    Introduction: The study focuses on the interaction between glucose and free fatty acids (FFA) in malignant human prostate cancer cell lines by an in vitro observation of uptake of fluoro-2-deoxy-D-glucose (FDG) and acetate. Methods: Human prostate cancer cell lines (PC3, CWR22Rv1, LNCaP, and DU145) were incubated for 2 h and 24 h in glucose-containing (5.5 mM) Dulbecco’s Modified Eagle’s Medium (DMEM) with varying concentrations of the free fatty acid palmitate (0–1.0 mM). Then the cells were incubated with [ 18 F]-FDG (1 μCi/mL; 0.037 MBq/mL) in DMEM either in presence or absence of glucose and in presence of varying concentrations of palmitate for 1 h. Standardized procedures regarding cell counting and measuring for 18 F radioactivity were applied. Cell uptake studies with 14 C-1-acetate under the same conditions were performed on PC3 cells. Results: In glucose containing media there was significantly increased FDG uptake after 24 h incubation in all cell lines, except DU145, when upper physiological levels of palmitate were added. A 4-fold increase of FDG uptake in PC3 cells (15.11% vs. 3.94%/10 6 cells) was observed in media with 1.0 mM palmitate compared to media with no palmitate. The same tendency was observed in PC3 and CWR22Rv1 cells after 2 h incubation. In glucose-free media no significant differences in FDG uptake after 24 h incubation were observed. The significant differences after 2 h incubation all pointed in the direction of increased FDG uptake when palmitate was added. Acetate uptake in PC3 cells was significantly lower when palmitate was added in glucose-free DMEM. No clear tendency when comparing FDG or acetate uptake in the same media at different time points of incubation was observed. Conclusions: Our results indicate a FFA dependent metabolic boost/switch of glucose uptake in PCa, with patterns reflecting the true heterogeneity of the disease

  7. The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.

    Directory of Open Access Journals (Sweden)

    Fernando Rodrigues

    Full Text Available Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2, C(3 and C(4. The incorporation of [U-(14C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

  8. Ursolic acid increases glucose uptake through the PI3K signaling pathway in adipocytes.

    Directory of Open Access Journals (Sweden)

    Yonghan He

    Full Text Available BACKGROUND: Ursolic acid (UA, a triterpenoid compound, is reported to have a glucose-lowering effect. However, the mechanisms are not fully understood. Adipose tissue is one of peripheral tissues that collectively control the circulating glucose levels. OBJECTIVE: The objective of the present study was to determine the effect and further the mechanism of action of UA in adipocytes. METHODS AND RESULTS: The 3T3-L1 preadipocytes were induced to differentiate and treated with different concentrations of UA. NBD-fluorescent glucose was used as the tracer to measure glucose uptake and Western blotting used to determine the expression and activity of proteins involved in glucose transport. It was found that 2.5, 5 and 10 µM of UA promoted glucose uptake in a dose-dependent manner (17%, 29% and 35%, respectively. 10 µM UA-induced glucose uptake with insulin stimulation was completely blocked by the phosphatidylinositol (PI 3-kinase (PI3K inhibitor wortmannin (1 µM, but not by SB203580 (10 µM, the inhibitor of mitogen-activated protein kinase (MAPK, or compound C (2.5 µM, the inhibitor of AMP-activated kinase (AMPK inhibitor. Furthermore, the downstream protein activities of the PI3K pathway, phosphoinositide-dependent kinase (PDK and phosphoinositide-dependent serine/threoninekinase (AKT were increased by 10 µM of UA in the presence of insulin. Interestingly, the activity of AS160 and protein kinase C (PKC and the expression of glucose transporter 4 (GLUT4 were stimulated by 10 µM of UA under either the basal or insulin-stimulated status. Moreover, the translocation of GLUT4 from cytoplasm to cell membrane was increased by UA but decreased when the PI3K inhibitor was applied. CONCLUSIONS: Our results suggest that UA stimulates glucose uptake in 3T3-L1 adipocytes through the PI3K pathway, providing important information regarding the mechanism of action of UA for its anti-diabetic effect.

  9. Effect of glucose on poly-γ-glutamic acid metabolism in Bacillus licheniformis.

    Science.gov (United States)

    Yu, Wencheng; Chen, Zhen; Ye, Hong; Liu, Peize; Li, Zhipeng; Wang, Yuanpeng; Li, Qingbiao; Yan, Shan; Zhong, Chuan-Jian; He, Ning

    2017-02-08

    Poly-gamma-glutamic acid (γ-PGA) is a promising macromolecule with potential as a replacement for chemosynthetic polymers. γ-PGA can be produced by many microorganisms, including Bacillus species. Bacillus licheniformis CGMCC2876 secretes γ-PGA when using glycerol and trisodium citrate as its optimal carbon sources and secretes polysaccharides when using glucose as the sole carbon source. To better understand the metabolic mechanism underlying the secretion of polymeric substances, SWATH was applied to investigate the effect of glucose on the production of polysaccharides and γ-PGA at the proteome level. The addition of glucose at 5 or 10 g/L of glucose decreased the γ-PGA concentration by 31.54 or 61.62%, respectively, whereas the polysaccharide concentration increased from 5.2 to 43.47%. Several proteins playing related roles in γ-PGA and polysaccharide synthesis were identified using the SWATH acquisition LC-MS/MS method. CcpA and CcpN co-enhanced glycolysis and suppressed carbon flux into the TCA cycle, consequently slowing glutamic acid synthesis. On the other hand, CcpN cut off the carbon flux from glycerol metabolism and further reduced γ-PGA production. CcpA activated a series of operons (glm and epsA-O) to reallocate the carbon flux to polysaccharide synthesis when glucose was present. The production of γ-PGA was influenced by NrgB, which converted the major nitrogen metabolic flux between NH 4 + and glutamate. The mechanism by which B. licheniformis regulates two macromolecules was proposed for the first time in this paper. This genetic information will facilitate the engineering of bacteria for practicable strategies for the fermentation of γ-PGA and polysaccharides for diverse applications.

  10. Cardiovascular effects of monoterpenes: a review

    Directory of Open Access Journals (Sweden)

    Márcio R. V. Santos

    2011-07-01

    Full Text Available The monoterpenes are secondary metabolites of plants. They have various pharmacological properties including antifungal, antibacterial, antioxidant, anticancer, anti-spasmodic, hypotensive, and vasorelaxant. The purpose of this research was to review the cardiovascular effects of monoterpenes. The data in this resarch were collected using the Internet portals Pubmed, Scopus, and ISI Web of Knowledge between the years 1987 and 2010. In the study 33 monoterpenes were included, which were related to each of the thirteen individual words: artery, cardiovascular, heart, myocyte, vasorelaxant, vessel, hypotension, hypotensive, cardiomyocyte, ventricular, vasodilatory, aorta, and aortic. The research utilized 22 articles published mainly in the journals Phytomedicine, Fundamental Clinical Pharmacology, Planta Medica, Life Science, European Journal of Pharmacology, and Brazilian Journal of Medical and Biological Research. Of the 33 monoterpenes studied surveyed, sixteen of them had already been studied for their effects on the cardiovascular system: carvacrol, citronellol, p-cymene, eucalyptol (1,8-cineole, linalool, menthol, myrtenal, myrtenol, α-pinene, rotundifolone (piperitenone oxide, sobrerol, thymol, α-limonene, α-terpinen-4-ol, α-terpineol, and perillyl alcohol. The main effects observed were vasorelaxation, decreased heart rate and blood pressure. This review showed that the monoterpenes may be considered promising agents for prevention or treatment of diseases of the cardiovascular system.

  11. Cardiovascular effects of monoterpenes: a review

    Directory of Open Access Journals (Sweden)

    Márcio R. V. Santos

    2011-08-01

    Full Text Available The monoterpenes are secondary metabolites of plants. They have various pharmacological properties including antifungal, antibacterial, antioxidant, anticancer, anti-spasmodic, hypotensive, and vasorelaxant. The purpose of this research was to review the cardiovascular effects of monoterpenes. The data in this resarch were collected using the Internet portals Pubmed, Scopus, and ISI Web of Knowledge between the years 1987 and 2010. In the study 33 monoterpenes were included, which were related to each of the thirteen individual words: artery, cardiovascular, heart, myocyte, vasorelaxant, vessel, hypotension, hypotensive, cardiomyocyte, ventricular, vasodilatory, aorta, and aortic. The research utilized 22 articles published mainly in the journals Phytomedicine, Fundamental Clinical Pharmacology, Planta Medica, Life Science, European Journal of Pharmacology, and Brazilian Journal of Medical and Biological Research. Of the 33 monoterpenes studied surveyed, sixteen of them had already been studied for their effects on the cardiovascular system: carvacrol, citronellol, p-cymene, eucalyptol (1,8-cineole, linalool, menthol, myrtenal, myrtenol, α-pinene, rotundifolone (piperitenone oxide, sobrerol, thymol, α-limonene, α-terpinen-4-ol, α-terpineol, and perillyl alcohol. The main effects observed were vasorelaxation, decreased heart rate and blood pressure. This review showed that the monoterpenes may be considered promising agents for prevention or treatment of diseases of the cardiovascular system.

  12. Glycogen storage disease type Ia: linkage of glucose, glycogen, lactic acid, triglyceride, and uric acid metabolism.

    Science.gov (United States)

    Sever, Sakine; Weinstein, David A; Wolfsdorf, Joseph I; Gedik, Reyhan; Schaefer, Ernst J

    2012-01-01

    A female presented in infancy with hypotonia, undetectable serum glucose, lactic acidosis, and triglycerides >5000 mg/dL. The diagnosis of type 1A glycogen storage disease was made via the result of a liver biopsy, which showed increased glycogen and absent glucose-6-phosphatase enzyme activity. The patient was treated with dextrose administered orally, which was replaced by frequent feedings of cornstarch, which resulted in an improvement of her metabolic parameters. At age 18 years of age, she had marked hypertriglyceridemia (3860 mg/dL) and eruptive xanthomas and was treated with fenofibrate, atorvastatin, and fish oil. At age 29 years she was noted to have multiple liver adenomas, severe anemia, and hyperuricemia. Aggressive cornstarch therapy was commenced with a goal of maintaining her blood glucose levels >75 mg/dL and lactate levels triglycerides 179, high-density lipoprotein cholesterol 32, and calculated low-density lipoprotein cholesterol 154. Her weight was stable with a body mass index of 24.8 kg/m(2). Her liver adenomas had decreased in size, and her anemia and hyperuricemia had improved. She was homozygous for the R83C missense mutation in G6PC. Our data indicate that optimized metabolic control to maintain blood glucose levels >75 mg/dL is critical in the management of this disease. Copyright © 2012. Published by Elsevier Inc.

  13. Sex-Dependent Programming of Glucose and Fatty Acid Metabolism in Mouse Offspring by Maternal Protein Restriction

    NARCIS (Netherlands)

    van Straten, Esther M. E.; Bloks, Vincent W.; van Dijk, Theo H.; Baller, Julius F. W.; Huijkman, Nicolette C. A.; Kuipers, Irma; Verkade, Henkjan J.; Plosch, Torsten

    Background: Nutritional conditions during fetal life influence the risk of the development of metabolic syndrome and cardiovascular diseases in adult life (metabolic programming). Impaired glucose tolerance and dysregulated fatty acid metabolism are hallmarks of metabolic syndrome. Objective: We

  14. Activation of Short and Long Chain Fatty Acid Sensing Machinery in the Ileum Lowers Glucose Production in Vivo.

    Science.gov (United States)

    Zadeh-Tahmasebi, Melika; Duca, Frank A; Rasmussen, Brittany A; Bauer, Paige V; Côté, Clémence D; Filippi, Beatrice M; Lam, Tony K T

    2016-04-15

    Evidence continues to emerge detailing the myriad of ways the gut microbiota influences host energy homeostasis. Among the potential mechanisms, short chain fatty acids (SCFAs), the byproducts of microbial fermentation of dietary fibers, exhibit correlative beneficial metabolic effects in humans and rodents, including improvements in glucose homeostasis. The underlying mechanisms, however, remain elusive. We here report that one of the main bacterially produced SCFAs, propionate, activates ileal mucosal free fatty acid receptor 2 to trigger a negative feedback pathway to lower hepatic glucose production in healthy rats in vivo We further demonstrate that an ileal glucagon-like peptide-1 receptor-dependent neuronal network is necessary for ileal propionate and long chain fatty acid sensing to regulate glucose homeostasis. These findings highlight the potential to manipulate fatty acid sensing machinery in the ileum to regulate glucose homeostasis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. A comparison of new measurements of total monoterpene flux with improved measurements of speciated monoterpene flux

    Directory of Open Access Journals (Sweden)

    A. Lee

    2005-01-01

    Full Text Available Many monoterpenes have been identified in forest emissions using gas chromatography (GC. Until now, it has been impossible to determine whether all monoterpenes are appropriately measured using GC techniques. We used a proton transfer reaction mass spectrometer (PTR-MS coupled with the eddy covariance (EC technique to measure mixing ratios and fluxes of total monoterpenes above a ponderosa pine plantation. We compared PTR-MS-EC results with simultaneous measurements of eight speciated monoterpenes, β-pinene, α-pinene, 3-carene, d-limonene, β-phellandrene, α-terpinene, camphene, and terpinolene, made with an automated, in situ gas chromatograph with flame ionization detectors (GC-FID, coupled to a relaxed eddy accumulation system (REA. Monoterpene mixing ratios and fluxes measured by PTR-MS averaged 30±2.3% and 31±9.2% larger than by GC-FID, with larger mixing ratio discrepancies between the two techniques at night than during the day. Two unidentified peaks that correlated with β-pinene were resolved in the chromatograms and completely accounted for the daytime difference and reduced the nighttime mixing ratio difference to 20±2.9%. Measurements of total monoterpenes by PTR-MS-EC indicated that GC-FID-REA measured the common, longer-lived monoterpenes well, but that additional terpenes were emitted from the ecosystem that represented an important contribution to the total mixing ratio above the forest at night.

  16. Myocardial scintigraphy with 16 /sup 123/I hexadecene 9 oique acid: influence of plasma concentrations of fatty acids and glucose

    Energy Technology Data Exchange (ETDEWEB)

    Comet, M.; Pilichowski, P.; Wolf, J.E.; Busquet, G.; Dubois, F.; Mathieu, J.P.; Pernin, C.; Riche, F. (C.H.R.U. de Grenoble (France)); Vidal, M. (U.S.M.G., 38 - Grenoble (France))

    1983-01-01

    After I.V. injection of /sup 123/I hexadecene-9 oic acid to dogs, the decreasing part of the myocardial activity curve is fitted with an exponential which period is calculated. Then the procedure is repeated after I.V. injection of heparin alone (6 dogs), of heparin during an intralipid perfusion (6 dogs) and lastly during a perfusion of a solution of glucose, insulin and potassium (7 dogs). In the two last protocols only, the period of the curve is significantly increased. The increase of the period means perhaps an increase of the intracellular accumulation of fatty acids. Patients must be in the same nutritional state to allow comparison between periods and a measure of the plasma level of NEFA is necessary before each injection of the labelled fatty acid.

  17. Myocardial scintigraphy with 16 123I hexadecene 9 oique acid: influence of plasma concentrations of fatty acids and glucose

    International Nuclear Information System (INIS)

    Comet, M.; Pilichowski, P.; Wolf, J.E.; Busquet, G.; Dubois, F.; Mathieu, J.P.; Pernin, C.; Riche, F.; Vidal, M.

    1983-01-01

    After I.V. injection of 123 I hexadecene-9 oic acid to dogs, the decreasing part of the myocardial activity curve is fitted with an exponential which period is calculated. Then the procedure is repeated after I.V. injection of heparin alone (6 dogs), of heparin during an intralipid perfusion (6 dogs) and lastly during a perfusion of a solution of glucose, insulin and potassium (7 dogs). In the two last protocols only, the period of the curve is significantly increased. The increase of the period means perhaps an increase of the intracellular accumulation of fatty acids. Patients must be in the same nutritional state to allow comparison between periods and a measure of the plasma level of NEFA is necessary before each injection of the labelled fatty acid [fr

  18. Phenylboronic acid functionalized reduced graphene oxide based fluorescence nano sensor for glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Basiruddin, SK; Swain, Sarat K., E-mail: swainsk2@yahoo.co.in

    2016-01-01

    Reduced graphene has emerged as promising tools for detection based application of biomolecules as it has high surface area with strong fluorescence quenching property. We have used the concept of fluorescent quenching property of reduced graphene oxide to the fluorescent probes which are close vicinity of its surface. In present work, we have synthesized fluorescent based nano-sensor consist of phenylboronic acid functionalized reduced graphene oxide (rGO–PBA) and di-ol modified fluorescent probe for detection of biologically important glucose molecules. This fluorescent graphene based nano-probe has been characterized by high resolution transmission electron microscope (HRTEM), Atomic force microscope (AFM), UV–visible, Photo-luminescence (PL) and Fourier transformed infrared (FT-IR) spectroscopy. Finally, using this PBA functionalized reduced GO based nano-sensor, we were able to detect glucose molecule in the range of 2 mg/mL to 75 mg/mL in aqueous solution of pH 7.4. - Highlights: • Easy and simple synthesis of PBA functionalized reduced GO based nano probe. • PBA functionalized reduced GO graphene based nano-probes are characterized. • PBA functionalized reduced GO nano probe is used to detect glucose molecules. • It is very cost-effective and enzyme-free detection of glucose in solution.

  19. Intracerebroventricular administration of okadaic acid induces hippocampal glucose uptake dysfunction and tau phosphorylation.

    Science.gov (United States)

    Broetto, Núbia; Hansen, Fernanda; Brolese, Giovana; Batassini, Cristiane; Lirio, Franciane; Galland, Fabiana; Dos Santos, João Paulo Almeida; Dutra, Márcio Ferreira; Gonçalves, Carlos-Alberto

    2016-06-01

    Intraneuronal aggregates of neurofibrillary tangles (NFTs), together with beta-amyloid plaques and astrogliosis, are histological markers of Alzheimer's disease (AD). The underlying mechanism of sporadic AD remains poorly understood, but abnormal hyperphosphorylation of tau protein is suggested to have a role in NFTs genesis, which leads to neuronal dysfunction and death. Okadaic acid (OKA), a strong inhibitor of protein phosphatase 2A, has been used to induce dementia similar to AD in rats. We herein investigated the effect of intracerebroventricular (ICV) infusion of OKA (100 and 200ng) on hippocampal tau phosphorylation at Ser396, which is considered an important fibrillogenic tau protein site, and on glucose uptake, which is reduced early in AD. ICV infusion of OKA (at 200ng) induced a spatial cognitive deficit, hippocampal astrogliosis (based on GFAP increment) and increase in tau phosphorylation at site 396 in this model. Moreover, we observed a decreased glucose uptake in the hippocampal slices of OKA-treated rats. In vitro exposure of hippocampal slices to OKA altered tau phosphorylation at site 396, without any associated change in glucose uptake activity. Taken together, these findings further our understanding of OKA neurotoxicity, in vivo and vitro, particularly with regard to the role of tau phosphorylation, and reinforce the importance of the OKA dementia model for studying the neurochemical alterations that may occur in AD, such as NFTs and glucose hypometabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. The Role of Circulating Amino Acids in the Hypothalamic Regulation of Liver Glucose Metabolism.

    Science.gov (United States)

    Arrieta-Cruz, Isabel; Gutiérrez-Juárez, Roger

    2016-07-01

    A pandemic of diabetes and obesity has been developing worldwide in close association with excessive nutrient intake and a sedentary lifestyle. Variations in the protein content of the diet have a direct impact on glucose homeostasis because amino acids (AAs) are powerful modulators of insulin action. In this work we review our recent findings on how elevations in the concentration of the circulating AAs leucine and proline activate a metabolic mechanism located in the mediobasal hypothalamus of the brain that sends a signal to the liver via the vagus nerve, which curtails glucose output. This neurogenic signal is strictly dependent on the metabolism of leucine and proline to acetyl-coenzyme A (CoA) and the subsequent production of malonyl-CoA; the signal also requires functional neuronal ATP-sensitive potassium channels. The liver then responds by lowering the rate of gluconeogenesis and glycogenolysis, ultimately leading to a net decrease in glucose production and in concentrations of circulating glucose. Furthermore, we review here how our work with proline suggests a new role of astrocytes in the central regulation of glycemia. Last, we outline how factors such as the consumption of fat-rich diets can interfere with glucoregulatory mechanisms and, in the long term, may contribute to the development of hyperglycemia, a hallmark of type 2 diabetes. © 2016 American Society for Nutrition.

  1. The Role of Circulating Amino Acids in the Hypothalamic Regulation of Liver Glucose Metabolism123

    Science.gov (United States)

    Arrieta-Cruz, Isabel; Gutiérrez-Juárez, Roger

    2016-01-01

    A pandemic of diabetes and obesity has been developing worldwide in close association with excessive nutrient intake and a sedentary lifestyle. Variations in the protein content of the diet have a direct impact on glucose homeostasis because amino acids (AAs) are powerful modulators of insulin action. In this work we review our recent findings on how elevations in the concentration of the circulating AAs leucine and proline activate a metabolic mechanism located in the mediobasal hypothalamus of the brain that sends a signal to the liver via the vagus nerve, which curtails glucose output. This neurogenic signal is strictly dependent on the metabolism of leucine and proline to acetyl-coenzyme A (CoA) and the subsequent production of malonyl-CoA; the signal also requires functional neuronal ATP-sensitive potassium channels. The liver then responds by lowering the rate of gluconeogenesis and glycogenolysis, ultimately leading to a net decrease in glucose production and in concentrations of circulating glucose. Furthermore, we review here how our work with proline suggests a new role of astrocytes in the central regulation of glycemia. Last, we outline how factors such as the consumption of fat-rich diets can interfere with glucoregulatory mechanisms and, in the long term, may contribute to the development of hyperglycemia, a hallmark of type 2 diabetes. PMID:27422516

  2. Analysis of monoterpene hydrocarbons in rural atmospheres

    International Nuclear Information System (INIS)

    Holdren, M.W.; Westberg, H.H.; Zimmerman, P.R.

    1979-01-01

    Gas chromatographic/mass spectrometric analysis of monoterpenes from a rural forested site in the northwestern United States is described. Use of a glass capillary column provided excellent resolution of the hydrocarbons. Increased sensitivity and specificity of the mass spectrometer detector over the flame ionization detector were demonstrated for trace (parts per trillion) atmospheric hydrocarbons. As little as 10 ppt of compound was detectable in 100-cc air samples. Two analytical methods (cryogenic and solid adsorbent--Tenax-GC) were used in the collection of ambient air. Analytical results from the two techniques compared very well. Rural concentrations of the monoterpenes varied considerably depending upon location within the forest canopy. The concentration of individual species never exceeded 1 ppb of compound during a 10-month sampling period. The monoterpene total for all samples fell in the range of 0.5- to 16-ppb compound for C 10 terpene

  3. Associations among circulating branched-chain amino acids and tyrosine with muscle volume and glucose metabolism in individuals without diabetes

    OpenAIRE

    Honda, Tatsuro

    2016-01-01

    Background and Aims: Amino acid metabolites including branched chain amino acids (BCAA) and tyrosine (Tyr) affect glucose metabolism. The effects of BCAA on insulin resistance in patients with diabetes seem to conflict with mechanisms determined in animal models and cultured cells. We investigated the physiological effects of BCAA and Tyr on glucose metabolism among healthy community dwellers to clarify the controversy surrounding the effects of BCAA. Participant and methods: We investigated ...

  4. Identification of four amino acid substitutions in hexokinase II and studies of relationships to NIDDM, glucose effectiveness, and insulin sensitivity

    DEFF Research Database (Denmark)

    Echwald, Søren Morgenthaler; Bjørbaek, C; Hansen, Torben

    1995-01-01

    not predict any change in amino acid composition of the protein. One homozygous and nine heterozygous carriers of the codon 142 mutation were found among the NIDDM patients. The mutations at codons 148, 497, and 844 were each found in one diabetic subject and only on one allele. There were no carriers......Human hexokinase (HK) II, a glucose phosphorylating enzyme in muscle tissue, plays a central role in glucose metabolism. Since reduced insulin-stimulated glucose uptake and reduced glucose-6-phosphate content in muscle have been demonstrated in pre-non-insulin-dependent diabetes mellitus (pre...

  5. Gold electrode modified with a self-assembled glucose oxidase and 2,6-pyridinedicarboxylic acid as novel glucose bioanode for biofuel cells

    NARCIS (Netherlands)

    Ammam, Malika; Fransaer, Jan

    2014-01-01

    In this study, we have constructed a gold electrode modified with (3-aminopropyl)trimethoxysilane/2,6-pyridinedicarboxylic acid/glucose oxidase (abbreviated as, Au/ATS/PDA/GOx) by sequential chemical adsorption. Au/ATS/PDA/GOx electrode was characterized by Fourier Transform Infrared Spectroscopy

  6. Metabolic peculiarities of the citric acid overproduction from glucose in yeasts Yarrowia lipolytica.

    Science.gov (United States)

    Kamzolova, Svetlana V; Morgunov, Igor G

    2017-11-01

    Comparative study of 43 natural yeast strains belonging to 20 species for their capability for overproduction of citric acid (CA) from glucose under nitrogen limitation of cell growth was carried out. As a result, natural strain Yarrowia lipolytica VKM Y-2373 was selected. The effect of growth limitation by biogenic macroelements (nitrogen, phosphorus, or sulfur) on the CA production by the selected strain was studied. It was shown that yeasts Y. lipolytica grown under deficiency of nitrogen, phosphorus, or sulfur were able to excrete CA in industrially sufficient amounts (80-85g/L with the product yield (Y CA ) of 0.70-0.75g/g and the process selectivity of 92.5-95.3%). Based on the obtained data on activities of enzymes involved in the initial stages of glucose oxidation, the cycle of tricarboxylic acids, and the glyoxylate cycle, the conception of the mechanism responsible for the CA overproduction from glucose in Y. lipolytica was formulated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Anaerobic digestion of glucose with separated acid production and methane formation

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R J; Zoetemeyer, R J; Van Deursen, A; Van Andel, J G

    1979-01-01

    In a two-phase anaerobic-digestion system, with separate reactors for the acidification and methane fermentation phases, the glucose of a 1% glucose solution was almost completely converted into biomass and gases. The acid reactor was operated at 30/sup 0/C and a pH of 6.0, with a retention time of 10 h. The main products of the acid-forming phase were hydrogen, carbon dioxide, butyrate and acetate. On a molar base, these products represented over 96% of all products formed. On average, 12% of the COD content of the influent was evolved as hydrogen. The effluent of the first reactor was pumped to the methane reactor after passing through a storage vessel. The methane reactor was operated at 30/sup 0/C, pH 7.8 and a retention time of 100 h. Approximately 98% of the organic substances fed to this reactor were converted to methane, carbon dioxide and biomass. About 11% of the glucose fed to the digesting system was converted to bacterial mass.

  8. Characterization of an inducible UDP-glucose:salicylic acid O-glucosyltransferase from oat roots

    International Nuclear Information System (INIS)

    Yalpani, N.; Schulz, M.; Balke, N.E.

    1990-01-01

    Phytotoxicity of salicylic acid (SA), a phenolic acid that inhibits ion absorption in plant roots, is reduced in oat roots by the action of a UDP-glucose:SA glucosyltransferase (GTase). GTase activity, extracted from oat roots and assayed with [ 14 C]SA, was present at low constitutive levels but increased within 1.5 h of incubation of roots in 0.5 mM SA at pH 6.5. This induction was the result of de novo RNA and protein synthesis. Induction was highly specific towards SA as the inducer. The partially purified, soluble enzyme has a M t of about 50,000 and high specificity towards UDP-glucose as the sugar donor (K m = 0.28 mM) and SA as the glucose acceptor (K m = 0.11 mM). 2-D PAGE of [ 35 S]methionine-labeled proteins extracted from induced and uninduced roots revealed a candidate peptide representing the GTase. This peptide was also present on gels of partially purified GTase

  9. Monoterpene synthases from common sage (Salvia officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, Rodney Bruce (Pullman, WA); Wise, Mitchell Lynn (Pullman, WA); Katahira, Eva Joy (Pullman, WA); Savage, Thomas Jonathan (Christchurch 5, NZ)

    1999-01-01

    cDNAs encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase from common sage (Salvia officinalis) have been isolated and sequenced, and the corresponding amino acid sequences has been determined. Accordingly, isolated DNA sequences (SEQ ID No:1; SEQ ID No:3 and SEQ ID No:5) are provided which code for the expression of (+)-bornyl diphosphate synthase (SEQ ID No:2), 1,8-cineole synthase (SEQ ID No:4) and (+)-sabinene synthase SEQ ID No:6), respectively, from sage (Salvia officinalis). In other aspects, replicable recombinant cloning vehicles are provided which code for (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase, or for a base sequence sufficiently complementary to at least a portion of (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant monoterpene synthases that may be used to facilitate their production, isolation and purification in significant amounts. Recombinant (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase may be used to obtain expression or enhanced expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase in plants in order to enhance the production of monoterpenoids, or may be otherwise employed for the regulation or expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase, or the production of their products.

  10. Low Red Blood Cell Vitamin C Concentrations Induce Red Blood Cell Fragility: A Link to Diabetes Via Glucose, Glucose Transporters, and Dehydroascorbic Acid

    Directory of Open Access Journals (Sweden)

    Hongbin Tu

    2015-11-01

    Full Text Available Strategies to prevent diabetic microvascular angiopathy focus on the vascular endothelium. Because red blood cells (RBCs are less deformable in diabetes, we explored an original concept linking decreased RBC deformability to RBC ascorbate and hyperglycemia. We characterized ascorbate concentrations from human and mouse RBCs and plasma, and showed an inverse relationship between RBC ascorbate concentrations and deformability, measured by osmotic fragility. RBCs from ascorbate deficient mice were osmotically sensitive, appeared as spherocytes, and had decreased β-spectrin. These aberrancies reversed with ascorbate repletion in vivo. Under physiologic conditions, only ascorbate's oxidation product dehydroascorbic acid (DHA, a substrate for facilitated glucose transporters, was transported into mouse and human RBCs, with immediate intracellular reduction to ascorbate. In vitro, glucose inhibited entry of physiologic concentrations of dehydroascorbic acid into mouse and human RBCs. In vivo, plasma glucose concentrations in normal and diabetic mice and humans were inversely related to respective RBC ascorbate concentrations, as was osmotic fragility. Human RBC β-spectrin declined as diabetes worsened. Taken together, hyperglycemia in diabetes produced lower RBC ascorbate with increased RBC rigidity, a candidate to drive microvascular angiopathy. Because glucose transporter expression, DHA transport, and its inhibition by glucose differed for mouse versus human RBCs, human experimentation is indicated.

  11. Development of a glucose-sensitive drug delivery device: Microencapsulated liposomes and poly(2-ethylacrylic acid)

    Science.gov (United States)

    Kanokpanont, Sorada

    The current study is the development a self-regulated, glucose responsive drug delivery system, using dioleoylphosphatidylcholine (DOPC) liposomes, a pH sensitive polymer, poly (2-ethylacrylic acid)(PEAA), and the feed back reaction of glucose with glucose oxidase enzyme (GO). The thesis investigates the use of PEAR and liposomes to work inside a microcapsule in response to the glucose level of the environment, by following the release of fluorescence probes, 8-aminonapthalene-1,3,6-trisulfonic acid, disodium salt/p-xylene-bis-pyridimuim bromide (ANTS/DPX) and a model protein, myoglobin. The continuing studies of PEAR and liposome interaction indicated an evidence of the previous hypothesis of two-mode release at different pHs. Differential scanning calorimetric studies of DOPC and PEAA complexes revealed the possibility of polymer adsorption to the liposomes in the pH range 5.5--7.0 and insertion in the liposome bilayer at pH pH, PEAR concentration, presence of cholesterol in the liposomes, Ca 2+, and the concentration of sodium alginate. We have also shown possibilities of anchoring PEAR on to liposome by covalent conjugation although this led to inactivation of the polymer. It is also possible to entrap small molecular weight PEAA in liposomes. The evidence of the pH-induced protein release by the interaction of PEAA and liposomes was first demonstrated in this thesis. Kinetic parameters of GO were estimated to use as a basis for determination optimal concentration in the capsules. The pH reduction inside the capsule due to GO reaction showed positive results for the use of GO in a non-buffered system. The procedure of liquid-core alginate capsules was modified to facilitate the pH-responsive release of ANTS/DPX and myoglobin. The capsules responded to high blood glucose concentration by releasing myoglobin within 30 minutes. Although more studies are required to improve the response of the system to the normal blood glucose and to control the total protein

  12. Proliferation-dependent changes in amino acid transport and glucose metabolism in glioma cell lines

    International Nuclear Information System (INIS)

    Sasajima, Toshio; Miyagawa, Tadashi; Oku, Takamitsu; Gelovani, Juri G.; Finn, Ronald; Blasberg, Ronald

    2004-01-01

    Amino acid imaging is increasingly being used for assessment of brain tumor malignancy, extent of disease, and prognosis. This study explores the relationship between proliferative activity, amino acid transport, and glucose metabolism in three glioma cell lines (U87, Hs683, C6) at different phases of growth in culture. Growth phase was characterized by direct cell counting, proliferation index determined by flow cytometry, and [ 3 H]thymidine (TdR) accumulation, and was compared with the uptake of two non-metabolized amino acids ([ 14 C]aminocyclopentane carboxylic acid (ACPC) and [ 14 C]aminoisobutyric acid (AIB)), and [ 18 F]fluorodeoxyglucose (FDG). Highly significant relationships between cell number (density), proliferation index, and TdR accumulation rate were observed in all cell lines (r>0.99). Influx (K 1 ) of both ACPC and AIB was directly related to cell density, and inversely related to the proliferation index and TdR accumulation in all cell lines. The volume of distribution (V d ) for ACPC and AIB was lowest during rapid growth and highest during the near-plateau growth phase in all cell lines. FDG accumulation in Hs683 and C6 cells was unaffected by proliferation rate, growth phase, and cell density, whereas FDG accumulation was correlated with TdR accumulation, growth phase, and cell density in U87 cells. This study demonstrates that proliferation rate and glucose metabolism are not necessarily co-related in all glioma cell lines. The values of K 1 and V d for ACPC and AIB under different growth conditions suggest that these tumor cell lines can up-regulate amino acid transporters in their cell membranes when their growth conditions become adverse and less than optimal. (orig.)

  13. Fasting plasma glucose and serum uric acid levels in a general Chinese population with normal glucose tolerance: A U-shaped curve.

    Directory of Open Access Journals (Sweden)

    Yunyang Wang

    Full Text Available Although several epidemiological studies assessed the relationship between fasting plasma glucose (FPG and serum uric acid (SUA levels, the results were inconsistent. A cross-sectional study was conducted to investigate this relationship in Chinese individuals with normal glucose tolerance.A total of 5,726 women and 5,457 men with normal glucose tolerance were enrolled in the study. All subjects underwent a 75-g oral glucose tolerance test. Generalized additive models and two-piecewise linear regression models were applied to assess the relationship.A U-shaped relationship between FPG and SUA was observed. After adjusting for potential confounders, the inflection points of FPG levels in the curves were 4.6 mmol/L in women and 4.7 mmol/L in men respectively. SUA levels decreased with increasing fasting plasma glucose concentrations before the inflection points (regression coefficient [β] = -36.4, P < 0.001 for women; β = -33.5, P < 0.001 for men, then SUA levels increased (β = 17.8, P < 0.001 for women; β = 13.9, P < 0.001 for men. Additionally, serum insulin levels were positively associated with FPG and SUA (P < 0.05.A U-shaped relationship between FPG and SUA levels existed in Chinese individuals with normal glucose tolerance. The association is partly mediated through serum insulin levels.

  14. 40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...

    Science.gov (United States)

    2010-07-01

    ...-deoxy-L-mannose and D-glucose, acetate, calcium magnesium potassium sodium salt. 721.2076 Section 721...-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium potassium sodium... identified as D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...

  15. Model-Based Quantification of the Systemic Interplay between Glucose and Fatty Acids in the Postprandial State.

    Science.gov (United States)

    Sips, Fianne L P; Nyman, Elin; Adiels, Martin; Hilbers, Peter A J; Strålfors, Peter; van Riel, Natal A W; Cedersund, Gunnar

    2015-01-01

    In metabolic diseases such as Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease, the systemic regulation of postprandial metabolite concentrations is disturbed. To understand this dysregulation, a quantitative and temporal understanding of systemic postprandial metabolite handling is needed. Of particular interest is the intertwined regulation of glucose and non-esterified fatty acids (NEFA), due to the association between disturbed NEFA metabolism and insulin resistance. However, postprandial glucose metabolism is characterized by a dynamic interplay of simultaneously responding regulatory mechanisms, which have proven difficult to measure directly. Therefore, we propose a mathematical modelling approach to untangle the systemic interplay between glucose and NEFA in the postprandial period. The developed model integrates data of both the perturbation of glucose metabolism by NEFA as measured under clamp conditions, and postprandial time-series of glucose, insulin, and NEFA. The model can describe independent data not used for fitting, and perturbations of NEFA metabolism result in an increased insulin, but not glucose, response, demonstrating that glucose homeostasis is maintained. Finally, the model is used to show that NEFA may mediate up to 30-45% of the postprandial increase in insulin-dependent glucose uptake at two hours after a glucose meal. In conclusion, the presented model can quantify the systemic interactions of glucose and NEFA in the postprandial state, and may therefore provide a new method to evaluate the disturbance of this interplay in metabolic disease.

  16. Model-Based Quantification of the Systemic Interplay between Glucose and Fatty Acids in the Postprandial State.

    Directory of Open Access Journals (Sweden)

    Fianne L P Sips

    Full Text Available In metabolic diseases such as Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease, the systemic regulation of postprandial metabolite concentrations is disturbed. To understand this dysregulation, a quantitative and temporal understanding of systemic postprandial metabolite handling is needed. Of particular interest is the intertwined regulation of glucose and non-esterified fatty acids (NEFA, due to the association between disturbed NEFA metabolism and insulin resistance. However, postprandial glucose metabolism is characterized by a dynamic interplay of simultaneously responding regulatory mechanisms, which have proven difficult to measure directly. Therefore, we propose a mathematical modelling approach to untangle the systemic interplay between glucose and NEFA in the postprandial period. The developed model integrates data of both the perturbation of glucose metabolism by NEFA as measured under clamp conditions, and postprandial time-series of glucose, insulin, and NEFA. The model can describe independent data not used for fitting, and perturbations of NEFA metabolism result in an increased insulin, but not glucose, response, demonstrating that glucose homeostasis is maintained. Finally, the model is used to show that NEFA may mediate up to 30-45% of the postprandial increase in insulin-dependent glucose uptake at two hours after a glucose meal. In conclusion, the presented model can quantify the systemic interactions of glucose and NEFA in the postprandial state, and may therefore provide a new method to evaluate the disturbance of this interplay in metabolic disease.

  17. Glucose Regulates Hypothalamic Long-chain Fatty Acid Metabolism via AMP-activated Kinase (AMPK) in Neurons and Astrocytes*

    Science.gov (United States)

    Taïb, Bouchra; Bouyakdan, Khalil; Hryhorczuk, Cécile; Rodaros, Demetra; Fulton, Stephanie; Alquier, Thierry

    2013-01-01

    Hypothalamic controls of energy balance rely on the detection of circulating nutrients such as glucose and long-chain fatty acids (LCFA) by the mediobasal hypothalamus (MBH). LCFA metabolism in the MBH plays a key role in the control of food intake and glucose homeostasis, yet it is not known if glucose regulates LCFA oxidation and esterification in the MBH and, if so, which hypothalamic cell type(s) and intracellular signaling mechanisms are involved. The aim of this study was to determine the impact of glucose on LCFA metabolism, assess the role of AMP-activated Kinase (AMPK), and to establish if changes in LCFA metabolism and its regulation by glucose vary as a function of the kind of LCFA, cell type, and brain region. We show that glucose inhibits palmitate oxidation via AMPK in hypothalamic neuronal cell lines, primary hypothalamic astrocyte cultures, and MBH slices ex vivo but not in cortical astrocytes and slice preparations. In contrast, oleate oxidation was not affected by glucose or AMPK inhibition in MBH slices. In addition, our results show that glucose increases palmitate, but not oleate, esterification into neutral lipids in neurons and MBH slices but not in hypothalamic astrocytes. These findings reveal for the first time the metabolic fate of different LCFA in the MBH, demonstrate AMPK-dependent glucose regulation of LCFA oxidation in both astrocytes and neurons, and establish metabolic coupling of glucose and LCFA as a distinguishing feature of hypothalamic nuclei critical for the control of energy balance. PMID:24240094

  18. Glucose regulates hypothalamic long-chain fatty acid metabolism via AMP-activated kinase (AMPK) in neurons and astrocytes.

    Science.gov (United States)

    Taïb, Bouchra; Bouyakdan, Khalil; Hryhorczuk, Cécile; Rodaros, Demetra; Fulton, Stephanie; Alquier, Thierry

    2013-12-27

    Hypothalamic controls of energy balance rely on the detection of circulating nutrients such as glucose and long-chain fatty acids (LCFA) by the mediobasal hypothalamus (MBH). LCFA metabolism in the MBH plays a key role in the control of food intake and glucose homeostasis, yet it is not known if glucose regulates LCFA oxidation and esterification in the MBH and, if so, which hypothalamic cell type(s) and intracellular signaling mechanisms are involved. The aim of this study was to determine the impact of glucose on LCFA metabolism, assess the role of AMP-activated Kinase (AMPK), and to establish if changes in LCFA metabolism and its regulation by glucose vary as a function of the kind of LCFA, cell type, and brain region. We show that glucose inhibits palmitate oxidation via AMPK in hypothalamic neuronal cell lines, primary hypothalamic astrocyte cultures, and MBH slices ex vivo but not in cortical astrocytes and slice preparations. In contrast, oleate oxidation was not affected by glucose or AMPK inhibition in MBH slices. In addition, our results show that glucose increases palmitate, but not oleate, esterification into neutral lipids in neurons and MBH slices but not in hypothalamic astrocytes. These findings reveal for the first time the metabolic fate of different LCFA in the MBH, demonstrate AMPK-dependent glucose regulation of LCFA oxidation in both astrocytes and neurons, and establish metabolic coupling of glucose and LCFA as a distinguishing feature of hypothalamic nuclei critical for the control of energy balance.

  19. Nb-Based Zeolites: Efficient bi-Functional Catalysts for the One-Pot Synthesis of Succinic Acid from Glucose

    Directory of Open Access Journals (Sweden)

    Magdi El Fergani

    2017-12-01

    Full Text Available The one-pot production of succinic acid from glucose was investigated in pure hot water as solvent using Nb (0.02 and 0.05 moles%-Beta zeolites obtained by a post-synthesis methodology. Structurally, they are comprised of residual framework Al-acid sites, extra-framework isolated Nb (V and Nb2O5 pore-encapsulated clusters. The Nb-modified Beta-zeolites acted as bi-functional catalysts in which glucose is dehydrated to levulinic acid (LA which, further, suffers an oxidation process to succinic acid (SA. After the optimization of the reaction conditions, that is, at 180 °C, 18 bar O2, and 12 h reaction time, the oxidation of glucose occurred with a selectivity to succinic acid as high as 84% for a total conversion.

  20. Dietary linolenic acid and fasting glucose and insulin: the National Heart, Lung, and Blood Institute Family Heart Study.

    Science.gov (United States)

    Djoussé, Luc; Hunt, Steven C; Tang, Weihong; Eckfeldt, John H; Province, Michael A; Ellison, R Curtis

    2006-02-01

    To assess whether dietary linolenic acid is associated with fasting insulin and glucose. In a cross-sectional design, we studied 3993 non-diabetic participants of the National Heart, Lung, and Blood Institute Family Heart Study 25 to 93 years of age. Linolenic acid was assessed through a food frequency questionnaire, and laboratory data were obtained after at least a 12-hour fast. We used generalized linear models to calculate adjusted means of insulin and glucose across quartiles of dietary linolenic acid. From the lowest to the highest sex-specific quartile of dietary linolenic acid, means +/- standard error for logarithmic transformed fasting insulin were 4.06 +/- 0.02 (reference), 4.09 +/- 0.02, 4.13 +/- 0.02, and 4.17 +/- 0.02 pM, respectively (trend, p continuous variable, the multivariable adjusted regression coefficient was 0.42 +/- 0.08. There was no association between dietary linolenic acid and fasting glucose (trend p = 0.82). Our data suggest that higher consumption of dietary linolenic acid is associated with higher plasma insulin, but not glucose levels, in non-diabetic subjects. Additional studies are needed to assess whether higher intake of linolenic acid results in an increased insulin secretion and improved glucose use in vivo.

  1. Ursolic acid increases skeletal muscle and brown fat and decreases diet-induced obesity, glucose intolerance and fatty liver disease.

    Directory of Open Access Journals (Sweden)

    Steven D Kunkel

    Full Text Available Skeletal muscle Akt activity stimulates muscle growth and imparts resistance to obesity, glucose intolerance and fatty liver disease. We recently found that ursolic acid increases skeletal muscle Akt activity and stimulates muscle growth in non-obese mice. Here, we tested the hypothesis that ursolic acid might increase skeletal muscle Akt activity in a mouse model of diet-induced obesity. We studied mice that consumed a high fat diet lacking or containing ursolic acid. In skeletal muscle, ursolic acid increased Akt activity, as well as downstream mRNAs that promote glucose utilization (hexokinase-II, blood vessel recruitment (Vegfa and autocrine/paracrine IGF-I signaling (Igf1. As a result, ursolic acid increased skeletal muscle mass, fast and slow muscle fiber size, grip strength and exercise capacity. Interestingly, ursolic acid also increased brown fat, a tissue that shares developmental origins with skeletal muscle. Consistent with increased skeletal muscle and brown fat, ursolic acid increased energy expenditure, leading to reduced obesity, improved glucose tolerance and decreased hepatic steatosis. These data support a model in which ursolic acid reduces obesity, glucose intolerance and fatty liver disease by increasing skeletal muscle and brown fat, and suggest ursolic acid as a potential therapeutic approach for obesity and obesity-related illness.

  2. Generation and Functional Evaluation of Designer Monoterpene Synthases.

    Science.gov (United States)

    Srividya, N; Lange, I; Lange, B M

    2016-01-01

    Monoterpene synthases are highly versatile enzymes that catalyze the first committed step in the pathways toward terpenoids, the structurally most diverse class of plant natural products. Recent advancements in our understanding of the reaction mechanism have enabled engineering approaches to develop mutant monoterpene synthases that produce specific monoterpenes. In this chapter, we are describing protocols to introduce targeted mutations, express mutant enzyme catalysts in heterologous hosts, and assess their catalytic properties. Mutant monoterpene synthases have the potential to contribute significantly to synthetic biology efforts aimed at producing larger amounts of commercially attractive monoterpenes. © 2016 Elsevier Inc. All rights reserved.

  3. Structural relationships and vasorelaxant activity of monoterpenes

    Directory of Open Access Journals (Sweden)

    Cardoso Lima Tamires

    2012-09-01

    Full Text Available Abstract Background and purpose of the study The hypotensive activity of the essential oil of Mentha x villosa and its main constituent, the monoterpene rotundifolone, have been reported. Therefore, our objective was to evaluate the vasorelaxant effect of monoterpenes found in medicinal plants and establish the structure-activity relationship of rotundifolone and its structural analogues on the rat superior mesenteric artery. Methods Contractions of the vessels were induced with 10 μM of phenylephine (Phe in rings with endothelium. During the tonic phase of the contraction, the monoterpenes (10-8 - 10-3, cumulatively were added to the organ bath. The extent of relaxation was expressed as the percentage of Phe-induced contraction. Results The results from the present study showed that both oxygenated terpenes (rotundifolone, (+-limonene epoxide, pulegone epoxide, carvone epoxide, and (+-pulegone and non-oxygenated terpene ((+-limonene exhibit relaxation activity. The absence of an oxygenated molecular structure was not a critical requirement for the molecule to be bioactive. Also it was found that the position of ketone and epoxide groups in the monoterpene structures influence the vasorelaxant potency and efficacy. Major conclusion The results suggest that the presence of functional groups in the chemical structure of rotundifolone is not essential for its vasorelaxant activity.

  4. Thermodynamic study of selected monoterpenes II

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Červinka, C.

    2014-01-01

    Roč. 79, Dec (2014), 272-279 ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : monoterpenes * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization and sublimation enthalpy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.679, year: 2014

  5. Thermodynamic study of selected monoterpenes III

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Červinka, C.

    2014-01-01

    Roč. 79, Dec (2014), 280-289 ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : monoterpenes * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization and sublimation enthalpy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.679, year: 2014

  6. Metabolic engineering of monoterpene biosynthesis in plants

    NARCIS (Netherlands)

    Lücker, J.

    2002-01-01

    Monoterpenes are a large group of compounds that belong to the terpenoid family of natural compounds in plants. They are small, volatile, lipophilic substances of which around one thousand different structures have been

  7. Mechanism of monoterpene volatilization in Salvia mellifera

    Energy Technology Data Exchange (ETDEWEB)

    Dement, W A; Tyson, B J; Mooney, H A

    1975-01-01

    Monoterpene volatilization in Salvia mellifera is primarily dependent on the vapor pressures of the terpenes as they are influenced by temperature, the humidity of the air surrounding the leaf and the surface area of oil present on the leaf. 12 references, 1 figure, 2 tables.

  8. Highly reactive light-dependent monoterpenes in the Amazon

    Science.gov (United States)

    Jardine, A. B.; Jardine, K. J.; Fuentes, J. D.; Martin, S. T.; Martins, G.; Durgante, F.; Carneiro, V.; Higuchi, N.; Manzi, A. O.; Chambers, J. Q.

    2015-03-01

    Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis.

  9. A glucose-responsive pH-switchable bioelectrocatalytic sensor based on phenylboronic acid-diol specificity

    International Nuclear Information System (INIS)

    Gao, Peiyi; Wang, Zhihua; Yang, Lele; Ma, Tengfei; Yang, Ling; Guo, Qianqiong; Huang, Shasheng

    2015-01-01

    Graphical abstract: A pH-switchable bioelectrocatayltic sensor was developed, which exhibited an obvious anodic current in acidic conditions as “ON” state, yet a prohibited signal in alkaline conditions as “OFF” state. With the change of pH and/or the presence of glucose, our proposed biosensor produced the corresponding amplified signal, providing a better sensitivity. - Abstract: Aminophenylboronic acid moieties were covalently grafted onto mercaptobenzoic acid moieties, and glucose oxidase was then immobilized through boronic acid-diol specific recognition to form a pH-sensitive electrosensor switching between pH 5.8 and pH 8.0 base solution. Using potassium ferricyanide as electroactive probe, the response was intensified in acidic condition while hindered in alkaline condition. The sharp and stable contrast in current was performed alternately upon the change of pH like a “pH switch”. In the presence of glucose, the response to glucose was further amplified catalytically by glucose oxidase on “ON” state, while electron transfer was inhibited on “OFF” state. Furthermore, when our sensor was on “ON” state, it showed a good linearity ranging from 0 to 30 μmol L −1 of glucose, with a detection limit of 348 nmol L −1 (S/B = 3) and a dynamic range extending to 50 μmol L −1 . Glucose-responsive, pH-switchable and catalytically-amplified, our biosensor provided a new method for the detection of glucose in the form of pH switch in human serum sample, and was promising to more complicated environment

  10. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes

    Science.gov (United States)

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C.

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, Pprediabetic state. PMID:26999667

  11. An amperometric enzyme electrode and its biofuel cell based on a glucose oxidase-poly(3-anilineboronic acid)-Pd nanoparticles bionanocomposite for glucose biosensing.

    Science.gov (United States)

    Sun, Lingen; Ma, Yixuan; Zhang, Pei; Chao, Long; Huang, Ting; Xie, Qingji; Chen, Chao; Yao, Shouzhuo

    2015-06-01

    A new amperometric enzyme electrode and its biofuel cell were fabricated based on a glucose oxidase (GOx)-poly(3-anilineboronic acid) (PABA)-Pd nanoparticles (PdNPs) bionanocomposite for biosensing of glucose. Briefly, Pd was electroplated on a multiwalled carbon nanotubes (MWCNTs)-modified Au electrode, and the GOx-PABA-PdNPs bionanocomposite was prepared on the Pd(plate)/MWCNTs/Au electrode through the chemical oxidation of a GOx-3-anilineboronic acid adduct by Na2PdCl4, followed by electrode-modification with an outer-layer chitosan (CS) film. The thus-prepared CS/GOx-PABA-PdNPs/Pd(plate)/MWCNTs/Au electrode exhibited a linear amperometric response to glucose concentration from 2.0 μM to 4.5 mM with a sensitivity of 160 μA/mM/cm(2), sub-μM detection limit, and excellent operation/storage stability in the first-generation biosensing mode, as well as excellent analytical performance in the second-generation biosensing mode. The good recoveries of glucose obtained from spiked urine samples revealed the application potential of our amperometric enzyme electrode. In addition, a glucose/O2 biofuel cell was constructed using this enzyme electrode as the anode and a Pt/MWCNTs/Au electrode as the cathode, and this biofuel cell as a self-powered biosensing device showed a linear voltage response to glucose concentration from 100 μM to 13.5 mM with a sensitivity of 43.5 mV/mM/cm(2) and excellent operation/storage stability. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Design, synthesis and structure of new potential electrochemically active boronic acid-based glucose sensors

    DEFF Research Database (Denmark)

    Norrild, Jens Chr.; Søtofte, Inger

    2002-01-01

    In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report the synthe......In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report...... the synthesis of the compounds and our investigations on glucose complexation as studied by C-13 NMR spectroscopy. The crystal structure of 2,4,6-tris[2-(N-ferrocenylmethyl-N-methylaminomethyl) phenyl] boroxin (13) (boroxin of boronic acid 3) (boroxin = cyclotriboroxane) was obtained and compared...... with structures obtained of 2,4,6-tris[2-(N,N-dimethylaminomethyl)phenyl]boroxin (14) and 2,2-dimethyl-1,3-diyl[2-(N,N-dimethylaminomethyl)phenyl]boronate (15). The structure of 13 shows the existence of intramolecular B-N bonds in the solid phase....

  13. Antinociceptive and anticonvulsant effects of the monoterpene linalool oxide.

    Science.gov (United States)

    Souto-Maior, Flávia Negromonte; Fonsêca, Diogo Vilar da; Salgado, Paula Regina Rodrigues; Monte, Lucas de Oliveira; de Sousa, Damião Pergentino; de Almeida, Reinaldo Nóbrega

    2017-12-01

    Linalool oxide (OXL) (a monoterpene) is found in the essential oils of certain aromatic plants, or it is derived from linalool. The motivation for this work is the lack of psychopharmacological studies on this substance. To evaluate OXL's acute toxicity, along with its anticonvulsant and antinociceptive activities in male Swiss mice. OXL (50, 100 and 150 mg/kg, i.p.) was investigated for acute toxicity and in the Rota-rod test. Antinociceptive activity was evaluated by the acetic acid-induced writhing test, and by formalin testing. Anticonvulsant effects were demonstrated by testing for pentylenetetrazol (PTZ)-induced seizures and by Maximum Electroshock headset (MES) test. OXL was administered to the animals intraperitoneally 30 min before for pharmacological tests. OXL showed an LD 50 of ∼721 (681-765) mg/kg. In the Rota-rod test, it was observed that OXL caused no damage to the animal's motor coordination. OXL significantly reduced (p monoterpene may lead to the development of a new molecule with even higher potency and selectivity.

  14. Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate.

    Directory of Open Access Journals (Sweden)

    Maxi Meissner

    Full Text Available AIMS/HYPOTHESIS: Bile acid sequestrants (BAS reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology. METHODS: Lean and diabetic db/db mice were treated with 2% (wt/wt in diet Colesevelam HCl (BAS for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-(13C]-glucose, [2-(13C]-glycerol, [1-(2H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns. RESULTS: Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001, a ∼300% increased glucokinase flux (p = 0.001 and a ∼200% increased total hepatic glucose production rate (p = 0.0002. BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317 but not in liver (p = 0.189. Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030 and 3-fold in db/db mice (p = 0.002. CONCLUSIONS/INTERPRETATION: BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.

  15. Association of Branched and Aromatic Amino Acids Levels with Metabolic Syndrome and Impaired Fasting Glucose in Hypertensive Patients

    OpenAIRE

    Weng, Liming; Quinlivan, Eoin; Gong, Yan; Beitelshees, Amber L.; Shahin, Mohamed H.; Turner, Stephen T.; Chapman, Arlene B.; Gums, John G.; Johnson, Julie A.; Frye, Reginald F.; Garrett, Timothy J.; Cooper-DeHoff, Rhonda M.

    2015-01-01

    Background: The three branched amino acids (valine, leucine, and isoleucine) and two aromatic amino acids (tyrosine and phenylalanine) have been associated with many adverse metabolic pathways, including diabetes. However, these associations have been identified primarily in otherwise healthy Caucasian populations. We aimed to investigate the association of this five-amino-acid signature with metabolic syndrome and impaired fasting glucose (IFG) in a hypertensive cohort of Caucasian and Afric...

  16. Inhibitors of Fatty Acid Synthesis Induce PPAR α -Regulated Fatty Acid β -Oxidative Genes: Synergistic Roles of L-FABP and Glucose.

    Science.gov (United States)

    Huang, Huan; McIntosh, Avery L; Martin, Gregory G; Petrescu, Anca D; Landrock, Kerstin K; Landrock, Danilo; Kier, Ann B; Schroeder, Friedhelm

    2013-01-01

    While TOFA (acetyl CoA carboxylase inhibitor) and C75 (fatty acid synthase inhibitor) prevent lipid accumulation by inhibiting fatty acid synthesis, the mechanism of action is not simply accounted for by inhibition of the enzymes alone. Liver fatty acid binding protein (L-FABP), a mediator of long chain fatty acid signaling to peroxisome proliferator-activated receptor- α (PPAR α ) in the nucleus, was found to bind TOFA and its activated CoA thioester, TOFyl-CoA, with high affinity while binding C75 and C75-CoA with lower affinity. Binding of TOFA and C75-CoA significantly altered L-FABP secondary structure. High (20 mM) but not physiological (6 mM) glucose conferred on both TOFA and C75 the ability to induce PPAR α transcription of the fatty acid β -oxidative enzymes CPT1A, CPT2, and ACOX1 in cultured primary hepatocytes from wild-type (WT) mice. However, L-FABP gene ablation abolished the effects of TOFA and C75 in the context of high glucose. These effects were not associated with an increased cellular level of unesterified fatty acids but rather by increased intracellular glucose. These findings suggested that L-FABP may function as an intracellular fatty acid synthesis inhibitor binding protein facilitating TOFA and C75-mediated induction of PPAR α in the context of high glucose at levels similar to those in uncontrolled diabetes.

  17. Strecker Aldehyde Formation in Wine: New Insights into the Role of Gallic Acid, Glucose, and Metals in Phenylacetaldehyde Formation.

    Science.gov (United States)

    Monforte, Ana Rita; Martins, Sara I F S; Silva Ferreira, Antonio C

    2018-03-14

    Strecker degradation (SD) leading to the formation of phenylacetaldehyde (PA) was studied in wine systems. New insights were gained by using two full factorial designs focusing on the effects of (1) pH and (2) temperature. In each design of experiments (DoE) three factors, glucose, gallic acid, and metals at two levels (present or absence), were varied while phenylalanine was kept constant. The obtained results gave a clear indication, with statistical significance, that in wine conditions, the SD occurs in the presence of metals preferentially via the phenolic oxidation independent of the temperature (40 or 80 °C). The reaction of the amino acid with the o-quinone formed by the oxidation of the gallic acid seems to be favored when compared with the SD promoted by the reaction with α-dicarbonyls formed by MR between glucose and phenylalanine. In fact, kinetics results showed that the presence of glucose had an inhibitory effect on PA rate of formation. PA formation was 4 times higher in the control wine when compared to the same wine with 10 g/L glucose added. By gallic acid quinone quantitation it is shown that glucose affects directly the concentration of the quinone. decreasing the rate of quinone formation. This highlights the role of sugar in o-quinone concentration and consequently in the impact on Strecker aldehyde formation, a promising new perspective regarding wine shelf-life understanding.

  18. Involvement of atypical protein kinase C in the regulation of cardiac glucose and long-chain fatty acid uptake

    Directory of Open Access Journals (Sweden)

    Daphna D.J. Habets

    2012-09-01

    Full Text Available Aim: The signaling pathways involved in the regulation of cardiac GLUT4 translocation/glucose uptake and CD36 translocation/ long-chain fatty acid uptake are not fully understood. We compared in heart/muscle-specific PKC-λ knockout mice the roles of atypical PKCs (PKC-ζ and PKC-λ in regulating cardiac glucose and fatty acid uptake. Results: Neither insulin-stimulated nor AMPK-mediated glucose and fatty acid uptake were inhibited upon genetic PKC-λ ablation in cardiomyocytes. In contrast, myristoylated PKC-ζ pseudosubstrate inhibited both insulin-stimulated and AMPK-mediated glucose and fatty acid uptake by >80% in both wild-type and PKC-λ-knockout cardiomyocytes. In PKC-λ knockout cardiomyocytes, PKC-ζ is the sole remaining atypical PKC isoform, and its expression level is not different from wild-type cardiomyocytes, in which it contributes to 29% and 17% of total atypical PKC expression and phosphorylation, respectively. Conclusion: Taken together, atypical PKCs are necessary for insulin-stimulated and AMPK-mediated glucose uptake into the heart, as well as for insulin-stimulated and AMPK-mediated fatty acid uptake. However, the residual PKC-ζ activity in PKC-λ-knockout cardiomyocytes is sufficient to allow optimal stimulation of glucose and fatty acid uptake, indicating that atypical PKCs are necessary but not rate-limiting in the regulation of cardiac substrate uptake and that PKC-λ and PKC-ζ have interchangeable functions in these processes.

  19. Response of plasma glucose, insulin, and nonesterified fatty acids to intravenous glucose tolerance tests in dairy cows during a 670-day lactation.

    Science.gov (United States)

    Marett, L C; Auldist, M J; Moate, P J; Wales, W J; Macmillan, K L; Dunshea, F R; Leury, B J

    2015-01-01

    This experiment investigated the metabolic response of dairy cows undergoing an extended lactation to a frequently sampled intravenous glucose tolerance test. The experiment used 12 multiparous Holstein cows that calved in late winter in a seasonally calving pasture-based system and were managed for a 670-d lactation by delaying rebreeding. In each of four 5-wk experimental periods commencing at approximately 73, 217, 422, and 520 (±9.1) days in milk (DIM), cows were offered a diet of perennial ryegrass (73 and 422 DIM) or pasture hay and silage (217 and 520 DIM) supplemented with 1kg of DM grain (control; CON) or 6kg of DM grain (GRN) as a ration. Daily energy intake was approximately 160 and 215 MJ of metabolizable energy/cow for the CON and GRN treatments, respectively. At all other times, cows were managed as a single herd and grazed pasture supplemented with grain to an estimated minimum daily total intake of 180 MJ of metabolizable energy/cow. Cows were fitted with an indwelling jugular catheter during the final week of each experimental period. The standard intravenous glucose tolerance test using 0.3g of glucose per kilogram of body weight was performed on each cow at approximately 100, 250, 460, and 560 DIM. Plasma concentrations of glucose, insulin, and nonesterified fatty acids (NEFA) responses were measured. Milk yield, milk solids yield, body weight, and basal plasma glucose were greater in the GRN compared with the CON treatment. The area under the plasma response curve relative to baseline (AUC) for glucose, insulin, and NEFA and their apparent fractional clearance rates indicated varied whole body responsiveness to insulin in terms of glucose metabolism throughout the 670-d lactation. The glucose AUC 0 to 20 min postinfusion was increased at 560 DIM, indicating reduced utilization of glucose by the mammary gland at this stage of lactation. The NEFA clearance rate, 6 to 30 min postinfusion, was greater at 460 and 560 DIM. These data indicated an

  20. Uric Acid or 1-Methyl Uric Acid in the Urinary Bladder Increases Serum Glucose, Insulin, True Triglyceride, and Total Cholesterol Levels in Wistar Rats

    Directory of Open Access Journals (Sweden)

    T. Balasubramanian

    2003-01-01

    Full Text Available In animals deprived of food for a long period, a drop in the fat mass below 5% of the total body mass results in an increase in blood glucocorticoids and uric acid levels, followed by foraging activity. Since the glucocorticoids increase the uric acid excretion, an increase in the level of uric acid in the bladder urine could be the signal for this feeding behaviour and subsequent fat storage. Accumulation of fat is associated with hyperglycaemia, hyperinsulinaemia, hyperlipidaemia, and hypercholesterolaemia as seen in the metabolic syndrome or hibernation. It is hypothesized that uric acid or its structurally related compound, 1-methyl uric acid (one of the metabolites of the methyl xanthines namely caffeine, theophylline, and theobromine present in coffee, tea, cocoa, and some drugs, can act on the urinary bladder mucosa and increases the blood glucose, insulin, triglyceride, and cholesterol levels. In rats, perfusion of the urinary bladder with saturated aqueous solution of uric acid or 1-methyl uric acid results in a significant increase in the serum levels of glucose, insulin, true triglyceride, and total cholesterol in comparison with perfusion of the bladder with distilled water at 20, 40, and 80 min. The uric acid or the 1-methyl uric acid acts on the urinary bladder mucosa and increases the serum glucose, insulin, true triglyceride, and total cholesterol levels.

  1. Kinetics of amino acid and glucose absorption following pancreatic diversion in the pig

    Science.gov (United States)

    Rerat, A.; Calmes, R.; Corring, T.; Vaissade, P.

    1996-01-01

    An experiment was conducted in the pig to determine the consequences of deprivation of exocrine pancreatic secretion on the composition and quantity of nutrients absorbed after intake of a balanced diet. Five growing pigs (53.8 kg body weight) were fitted with permanent catheters in the portal vein and the carotid artery and with an electromagnetic flow probe around the portal vein to measure the exchanges between the blood and the intestinal lumen. They were also fitted with a permanent catheter in the duct of Wirsung to educe the exocrine pancreatic secretion and another one in the duodenum in order to reintroduce it. In each animal, glucose, amino-N and amino acid absorption as well as insulin and glucagon production were measured over a period of 10 h after the meal (semi-purified diet based on purified starch and containing 180 g fish meal/kg, DM content of the meal 731 g), either in the presence of pancreatic juice (group C: immediate reintroduction), or in the absence of pancreatic juice (group D: deprivation). The deprivation of pancreatic juice provoked a marked depression in the absorption of glucose (D 67.9 (SEM 27.9) g/10 h, C 437.7 (SEM 39.5) g/10 h, P juice. Insulin production was much lower (by 64%, P juice whereas that of glucagon was not affected.

  2. Aminocarnitine and acylaminocarnitines: Carnitine acyltransferase inhibitors affecting long-chain fatty acid and glucose metabolism

    International Nuclear Information System (INIS)

    Clark, D.J.

    1989-01-01

    DL-Aminocarnitine (DL-3-amino-4-trimethylaminobutyrate) and the acylaminocarnitines acetyl-, decanoyl- and palmitoyl-DL-aminocarnitine have been synthesized and tested as inhibitors of carnitine palmitoyl-transferase and carnitine acetyltransferase in vitro and in vivo. Acetyl-DL-aaminocarnitine is the most potent reversible inhibitor of carnitine acetyltransferase reported to date, and is competitive with respect to acetyl-L-carnitine. Mice given acetyl-DL-aminocarnitine metabolize [U- 14 C]acetyl-L-carnitine at about 60% of the rate of control mice. Palmitoyl-DL-aminocarnitine is the most potent reversible inhibitor of carnitine palmitoyltransferase reported to date. Decanoyl-DL-aminocarnitine and DL-aminocarnitine are also very potent inhibitors; all compounds inhibit the catabolism of [ 14 C]palmitate to 14 CO 2 in intact mice by at least 50%. Carnitine palmitoyltransferase controls the entry of long-chain fatty acids into the mitochondrial matrix for β-oxidation. The inhibition of carnitine palmitoyltransferase by aminocarnitine or acylaminocarnitines in vivo prevents or reverses ketogenesis in fasted mice, and causes the reversible accumulation of triglycerides in liver, kidney and plasma. Administration of DL-aminocarnitine to streptozotocindiabetic mice lowers plasma glucose levels and improves the glucose tolerance test

  3. Protein Carbamylation in Peritoneal Dialysis and the Effect of Low Glucose Plus Amino Acid Solutions.

    Science.gov (United States)

    Trottier, Caitlin; Perl, Jeffrey; Freeman, Megan; Thadhani, Ravi; Berg, Anders; Kalim, Sahir

    2018-01-01

    Protein carbamylation is a post-translational urea-driven protein modification associated with mortality. Free amino acids (AAs) competitively inhibit protein carbamylation and parenteral AA therapy reduces carbamylation in hemodialysis (HD) patients. Peritoneal dialysis (PD) yields differences in urea clearance and AA balance compared with HD, but the influence of PD and intraperitoneal AA solutions on carbamylation is unclear. Thus, we first measured carbamylated albumin (C-Alb; a marker of carbamylation load) in 100 diabetic HD patients frequency-matched by age, sex, and race to 98 diabetic PD subjects from the IMPENDIA trial, which originally compared the metabolic effects of low-glucose PD solutions (incorporating icodextrin and AAs) to a control group (dextrose-only solutions). We then determined the effects of the AA-enriched PD solutions by measuring the 6-month change in C-Alb within the IMPENDIA cohort by treatment allocation (48 treated vs 50 controls). Peritoneal dialysis patients, when compared with HD patients, had higher baseline urea and higher C-Alb. Among IMPENDIA participants, there was no difference in C-Alb change in either arm, but treated subjects showed a trend towards increased carbamylation. Treated subjects also demonstrated an increase in urea, possibly explaining the carbamylation trend. In summary, carbamylation levels in PD patients appeared higher than in matched HD patients. A regimen of AA and low-glucose PD solutions did not reduce C-Alb in IMPENDIA subjects. Copyright © 2018 International Society for Peritoneal Dialysis.

  4. Responses of Blood Glucose, Insulin, Glucagon, and Fatty Acids to Intraruminal Infusion of Propionate in Hanwoo

    Directory of Open Access Journals (Sweden)

    Y. K. Oh

    2015-02-01

    Full Text Available This study was carried out to investigate the effects of intraruminal infusion of propionate on ruminal fermentation characteristics and blood hormones and metabolites in Hanwoo (Korean cattle steers. Four Hanwoo steers (average body wt. 270 kg, 13 month of age equipped with rumen cannula were infused into rumens with 0.0 M (Water, C, 0.5 M (37 g/L, T1, 1.0 M (74 g/L, T2 and 1.5 M (111 g/L, T3 of propionate for 1 hour per day and allotted by 4×4 Latin square design. On the 5th day of infusion, samples of rumen and blood were collected at 0, 60, 120, 180, and 300 min after intraruminal infusion of propionate. The concentrations of serum glucose and plasma glucagon were not affected (p>0.05 by intraruminal infusion of propionate. The serum insulin concentration at 60 min after infusion was significantly (p<0.05 higher in T3 than in C, while the concentration of non-esterified fatty acid (NEFA at 60 and 180 min after infusion was significantly (p<0.05 lower in the propionate treatments than in C. Hence, intraruminal infusion of propionate stimulates the secretion of insulin, and decreases serum NEFA concentration rather than the change of serum glucose concentration.

  5. Effect of glucose and insulin infusion on the myocardial extraction of a radioiodinated methyl-substituted fatty acid

    International Nuclear Information System (INIS)

    Bianco, J.A.; Elmaleh, D.R.; Leppo, J.A.; King, M.A.; Moring, A.; Livni, E.; Espinoza, E.; Alpert, J.S.; Strauss, H.W.; Massachusetts General Hospital, Boston

    1986-01-01

    We investigated the one-way. An extraction of 14-iodophenyl-tetradecanoic acid (BMTDA) in the canine heart under fasting conditions and during infusion of glucose plus insulin in eight an esthetized greyhound dogs. Myocardial extraction measurements were made with dual tracer approach, using Tc-99m albumin as reference tracer. Prior to, and during, infusion of 10% glucose and 25 units of regular insulin, heart rate, blood pressure, plasma glucose, insulin and free fatty acid levels were measured. Myocardial blood flow was determined using Sn-113 and Ru-103 radioactive microspheres. The mean extraction fraction of BMTDA was 0.38+-SEM 0.06 at baseline and increased to 0.44+-0.06 during hyperglycemia plus insulin (P<0.025). Plasma glucose and insulin were higher during the infusion (P<0.01) while plasma free fatty acids significantly declined (P<0.01). There were no changes in hemodynamics or myocardial blood flow during the infusion. We conclude that glucose and insulin infusion result in increased first-pass extraction fraction of radioiodinated BMTDA unaccompanied by changes in coronary flow or hemodynamics, implying an insulin-mediated augmented transport of BMTDA. (orig.)

  6. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  7. Long-term dynamics of monoterpene synthase activities, monoterpene storage pools and emissions in boreal Scots pine

    OpenAIRE

    Vanhatalo, Anni; Ghirardo, Andrea; Juurola, Eija; Schnitzler, Jörg-Peter; Zimmer, Ina; Hellén, Heidi; Hakola, Hannele; Bäck, Jaana

    2018-01-01

    Seasonal variations in monoterpene emissions from Scots pine (Pinus sylvestris) are well documented, and emissions are often shown to follow the incident temperatures due to effects on compound volatility. Recent studies have indicated a link between monoterpene emissions and physiological drivers such as photosynthetic capacity during needle development. The complex interplay between the dynamic changes in the biosynthetic capacity to produce monoterpenes and the temperature-dependent evapor...

  8. Retrobiosynthetic NMR studies with 13C-labeled glucose. Formation of gallic acid in plants and fungi

    International Nuclear Information System (INIS)

    Werner, I.; Bacher, A.; Eisenreich, W.

    1997-01-01

    The biosynthesis of gallic acid was studied in cultures of the fungus Phycomyces blakesleeanus and in leaves of the tree Rhus typhina. Fungal cultures were grown with [1-13C]glucose or with a mixture of unlabeled glucose and [U-13C6]glucose. Young leaves of R. typhina were kept in an incubation chamber and were supplied with a solution containing a mixture of unlabeled glucose and [U-13C6]glucose via the leaf stem. Isotope distributions in isolated gallic acid and aromatic amino acids were analyzed by one-dimensional 1H and 13C NMR spectroscopy. A quantitative analysis of the complex isotopomer composition of metabolites was obtained by deconvolution of the 13C13C coupling multiplets using numerical simulation methods. This approach required the accurate analysis of heavy isotope chemical shift effects in a variety of different isotopomers and the analysis of long range 13C13C coupling constants. The resulting isotopomer patterns were interpreted using a retrobiosynthetic approach based on a comparison between the isotopomer patterns of gallic acid and tyrosine. The data show that both in the fungus and in the plant all carbon atoms of gallic acid are biosynthetically equivalent to carbon atoms of shikimate. Notably, the carboxylic group of gallic acid is derived from the carboxylic group of an early intermediate of the shikimate pathway and not from the side chain of phenylalanine or tyrosine. It follows that the committed precursor of gallic acid is an intermediate of the shikimate pathway prior to prephenate or arogenate, most probably 5-dehydroshikimate. A formation of gallic acid via phenylalanine, the lignin precursor, caffeic acid, or 3,4, 5-trihydroxycinnamic acid can be ruled out as major pathways in the fungus and in young leaves of R. typhina. The incorporation of uniformly 13C-labeled glucose followed by quantitative NMR analysis of isotopomer patterns is suggested as a general method for biosynthetic studies. As shown by the plant experiment, this

  9. Insulin response of the glucose and fatty acid metabolism in dry dairy cows across a range of body condition scores.

    Science.gov (United States)

    De Koster, J; Hostens, M; Van Eetvelde, M; Hermans, K; Moerman, S; Bogaert, H; Depreester, E; Van den Broeck, W; Opsomer, G

    2015-07-01

    The objective of the present research was to determine the insulin response of the glucose and fatty acid metabolism in dry dairy cows with a variable body condition score (BCS). Ten pregnant Holstein Friesian dairy cows (upcoming parity 2 to 5) were selected based on BCS at the beginning of the study (2mo before expected parturition date). During the study, animals were monitored weekly for BCS and backfat thickness and in the last 2wk, blood samples were taken for determination of serum nonesterified fatty acid (NEFA) concentration. Animals underwent a hyperinsulinemic euglycemic clamp test in the third week before the expected parturition date. The hyperinsulinemic euglycemic clamp test consisted of 4 consecutive insulin infusions with increasing insulin doses: 0.1, 0.5, 2, and 5mIU/kg per minute. For each insulin infusion period, a steady state was defined as a period of 30min where no or minor changes of the glucose infusion were necessary to keep the blood glucose concentration constant and near basal levels. During the steady state, the glucose infusion rate [steady state glucose infusion rate (SSGIR) in µmol/kg per minute] and NEFA concentration [steady state NEFA concentration (SSNEFA) in mmol/L] were determined and reflect the insulin response of the glucose and fatty acid metabolism. Dose response curves were created based on the insulin concentrations during the steady state and the SSGIR or SSNEFA. The shape of the dose response curves is determined by the concentration of insulin needed to elicit the half maximal effect (EC50) and the maximal SSGIR or the minimal SSNEFA for the glucose or fatty acid metabolism, respectively. The maximal SSGIR was negatively associated with variables reflecting adiposity of the cows (BCS, backfat thickness, NEFA concentration during the dry period, and absolute weight of the different adipose depots determined after euthanasia and dissection of the different depots), whereas the EC50 of the glucose metabolism was

  10. Sensitive colorimetric assay for uric acid and glucose detection based on multilayer-modified paper with smartphone as signal readout.

    Science.gov (United States)

    Wang, Xu; Li, Fang; Cai, Ziqi; Liu, Kaifan; Li, Jing; Zhang, Boyang; He, Jianbo

    2018-04-01

    In this work, a multilayer-modified paper-based colorimetric sensing platform with improved color uniformity and intensity was developed for the sensitive and selective determination of uric acid and glucose with smartphone as signal readout. In detail, chitosan, different kinds of chromogenic reagents, and horseradish peroxidase (HRP) combined with a specific oxidase, e.g., uricase or glucose oxidase (GOD), were immoblized onto the paper substrate to form a multilayer-modified test paper. Hydrogen peroxide produced by the oxidases (uricase or GOD) reacts with the substrates (uric acid or glucose), and could oxidize the co-immoblized chromogenic reagents to form colored products with HRP as catalyst. A simple strategy by placing the test paper on top of a light-emitting diode lamp was adopted to efficiently prevent influence from the external light. The color images were recorded by the smartphone camera, and then the gray values of the color images were calculated for quantitative analysis. The developed method provided a wide linear response from 0.01 to 1.0 mM for uric acid detection and from 0.02 to 4.0 mM for glucose detection, with a limit of detection (LOD) as low as 0.003 and 0.014 mM, respectively, which was much lower than for previously reported paper-based colorimetric assays. The proposed assays were successfully applied to uric acid and glucose detection in real serum samples. Furthermore, the enhanced analytical performance of the proposed method allowed the non-invasive detection of glucose levels in tear samples, which holds great potential for point-of-care analysis. Graphical abstract ᅟ.

  11. Low-protein, high-carbohydrate diet increases glucose uptake and fatty acid synthesis in brown adipose tissue of rats.

    Science.gov (United States)

    Aparecida de França, Suélem; Pavani Dos Santos, Maísa; Nunes Queiroz da Costa, Roger Vinícius; Froelich, Mendalli; Buzelle, Samyra Lopes; Chaves, Valéria Ernestânia; Giordani, Morenna Alana; Pereira, Mayara Peron; Colodel, Edson Moleta; Marlise Balbinotti Andrade, Cláudia; Kawashita, Nair Honda

    2014-04-01

    The aim of this study was to evaluate glucose uptake and the contribution of glucose to fatty acid (FA) synthesis and the glycerol-3-phosphate (G3P) of triacylglycerol synthesis by interscapular brown adipose tissue (IBAT) of low-protein, high-carbohydrate (LPHC) diet-fed rats. LPHC (6% protein; 74% carbohydrate) or control (17% protein; 63% carbohydrate) diets were administered to rats (∼ 100 g) for 15 d. Total FA and G3P synthesis and the synthesis of FA and G3P from glucose were evaluated in vivo by (3)H2O and (14)C-glucose. Sympathetic neural contribution for FA synthesis was evaluated by comparing the synthesis in denervated (7 d before) IBAT with that of the contralateral innervated side. The insulin signaling and β3 adrenergic receptor (β3-AR) contents, as well as others, were determined by Western blot (Student's t test or analysis of variance; P ≤ 0.05). Total FA synthesis in IBAT was 133% higher in the LPHC group and was reduced 85% and 70% by denervation for the LPHC and control groups, respectively. Glucose uptake was 3.5-fold higher in the IBAT of LPHC rats than in that of the control rats, and the contribution of glucose to the total FA synthesis increased by 12% in control rats compared with 18% in LPHC rats. The LPHC diet increased the G3P generation from glucose by 270% and the insulin receptor content and the p-AKT insulin stimulation in IBAT by 120% and reduced the β3-AR content by 50%. The LPHC diet stimulated glucose uptake, both the total rates and the rates derived from glucose-dependent FA and G3P synthesis, by increasing the insulin sensitivity and the sympathetic flux, despite a reduction in the β3-AR content. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Attenuated Effects of Bile Acids on Glucose Metabolism and Insulin Sensitivity in a Male Mouse Model of Prenatal Undernutrition

    NARCIS (Netherlands)

    Ma, Huijuan; Sales, Vicencia M.; Wolf, Ashley R.; Subramanian, Sathish; Matthews, Tucker J.; Chen, Michael; Sharma, Aparna; Gall, Walt; Kulik, Wim; Cohen, David E.; Adachi, Yusuke; Griffin, Nicholas W.; Gordon, Jeffrey I.; Patti, Mary-Elizabeth; Isganaitis, Elvira

    2017-01-01

    Prenatal undernutrition and low birth weight are associated with risk of type 2 diabetes and obesity. Prenatal caloric restriction results in low birth weight, glucose intolerance, obesity, and reduced plasma bile acids (BAs) in offspring mice. Because BAs can regulate systemic metabolism and

  13. Acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance

    NARCIS (Netherlands)

    van Dijk, A.E.; Olthof, M.R.; Meeuse, J.C.; Seebus, E.; Heine, R.J.; van Dam, R.M.

    2009-01-01

    OBJECTIVE - Coffee consumption has been associated with lower risk of type 2 diabetes. We evaluated the acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance. RESEARCH DESIGN AND METHODS - We conducted a randomized crossover

  14. Involvement of atypical protein kinase C in the regulation of cardiac glucose and long-chain fatty acid uptake

    DEFF Research Database (Denmark)

    Habets, Daphna D J; Luiken, Joost J F P; Ouwens, Margriet

    2012-01-01

    Aim: The signaling pathways involved in the regulation of cardiac GLUT4 translocation/glucose uptake and CD36 translocation/long-chain fatty acid uptake are not fully understood. We compared in heart/muscle-specific PKC-¿ knockout mice the roles of atypical PKCs (PKC-¿ and PKC-¿) in regulating...

  15. A comparative study of serum uric acid, glucose, calcium and magnesium in pre-eclampsia and normal pregnancy

    Directory of Open Access Journals (Sweden)

    Arun Dhungana

    2017-09-01

    Full Text Available Background: Preeclampsia is associated with liver function abnormalities and renal function impairment. The objective of this study is to compare serum uric acid, glucose, calcium and magnesium in pre-eclampsia with normal pregnancy. Materials and Methods: Normal pregnant women and pre eclamptic women of age group 20-40 years were included. Serum magnesium, calcium, glucose, uric acid were analyzed.Results: Mean serum magnesium level in preeclampsia (1.83 ± 0.21mg/dl was lesser in comparison to normal pregnant women (2.03 ± 0.16 mg/dl. Serum calcium level was lower (8.10 ±0.56mg/dl than control (9.59 ±0.62 mg/dl with p<0.001. Uric acid, glucose and lactate dehydrogenase in preeclamptic women was significantly higher than that in normal pregnant women (6.14 ± 0.85 vs.4.01 ± 0.62, p=<0.001, (94.17± 18.65 vs.86.34 ± 10.19, p=0.033 and ( 466.80 ± 97.29 vs. 194.22 ± 39.76, p=<0.001 respectively.Conclusion: There were significant changes in serum magnesium, uric acid, calcium, glucose, lactate dehydrogenase and total protein in pregnant women.

  16. Dietary fatty acid composition during pregnancy and lactation in the rat programs growth and glucose metabolism in the offspring.

    NARCIS (Netherlands)

    Siemelink, M.; Verhoef, A.; Dormans, J.A.M.A.; Span, P.N.; Piersma, A.H.

    2002-01-01

    AIMS/HYPOTHESIS. We investigated of the effects of fatty acid composition of the maternal diet on fetal and postnatal growth, morphology of the pancreas and glucose metabolism and muscle hexosamine concentrations in the adult offspring of rats. METHODS. High-fat diets enriched with either saturated

  17. Production of 3-hydroxypropionic acid from glucose and xylose by metabolically engineered Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Kanchana R. Kildegaard

    2015-12-01

    Full Text Available Biomass, the most abundant carbon source on the planet, may in the future become the primary feedstock for production of fuels and chemicals, replacing fossil feedstocks. This will, however, require development of cell factories that can convert both C6 and C5 sugars present in lignocellulosic biomass into the products of interest. We engineered Saccharomyces cerevisiae for production of 3-hydroxypropionic acid (3HP, a potential building block for acrylates, from glucose and xylose. We introduced the 3HP biosynthetic pathways via malonyl-CoA or β-alanine intermediates into a xylose-consuming yeast. Using controlled fed-batch cultivation, we obtained 7.37±0.17 g 3HP L−1 in 120 hours with an overall yield of 29±1% Cmol 3HP Cmol−1 xylose. This study is the first demonstration of the potential of using S. cerevisiae for production of 3HP from the biomass sugar xylose. Keywords: Metabolic engineering, Biorefineries, 3-hydroxypropionic acid, Saccharomyces cerevisiae, Xylose utilization

  18. [Analysis of variation of monoterpene glycosides and polyhydroxy compounds in paeoniae radix alba during preliminary processing].

    Science.gov (United States)

    Xu, Yuan; Liu, Pei; Yan, Hui; Qian, Da-Wei; Duan, Jin-Ao

    2014-05-01

    To investigate variation of monoterpene glycosides and polyhydroxy compounds in Paeoniae Radix Alba dried by different processing methods. The crude drugs were processed sequentially as washed, removed the head, tail, fine roots and dried. The samples were divided into eight groups by whether peeled and decocted or not. Each group was dried by 35, 45, 60, 80,100, 120 degrees C, sun-dried and shade-dried. HPLC-PDA method was adopted to determine the content of monoterpene glycosides compounds (paeoniflorin alibiflorin, oxypaeoniflorin and benzoylpaeoniflorin), polyhydroxy compounds (catechin and gallic acid) and benzoic acid. Chromatographic conditions: Phecad C18 column (250 mm x 4.6 mm, 5 microm). A principal component analysis (PCA) method was used subsequently to get data processed. The retained content of seven constituents decreased in those peeled crude drug, and after cooked, monoterpene glycosides and polyhydroxy compounds increased while the benzoic acid decreased. It was believed that rele- vant enzymes were inactivated while being cooked so that drying temperature showed little influence on the biotransformation. Contents of effective ingredients in Paeoniae Radix Alba are influenced by drying processing. The preferable method shows to be that crude drug should be cooked before being peeled and dried. As a matter of processing convtence, it is suggested to be peeled and sliced before being dried.

  19. A randomized controlled trial: branched-chain amino acid levels and glucose metabolism in patients with obesity and sleep apnea.

    Science.gov (United States)

    Barceló, Antonia; Morell-Garcia, Daniel; Salord, Neus; Esquinas, Cristina; Pérez, Gerardo; Pérez, Antonio; Monasterio, Carmen; Gasa, Merce; Fortuna, Ana Maria; Montserrat, Josep Maria; Mayos, Mercedes

    2017-12-01

    There is evidence that changes in branched-chain amino acid (BCAA) levels may correlate with the efficacy of therapeutic interventions for affecting improvement in metabolic control. The objective of this study was to evaluate whether serum concentrations of BCAAs (leucine, isoleucine, valine) could mediate in insulin sensitivity and glucose tolerance after continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnea (OSA). A prospective randomized controlled trial of OSA patients with morbid obesity was conducted. Eighty patients were randomized into two groups: 38 received conservative treatment and 42 received CPAP treatment for 12 weeks. Plasma levels of BCAA, glucose tolerance and insulin resistance were evaluated at baseline and after treatment. After treatment, significant decreases of leucine levels were observed in both groups when compared with baseline levels (P fasting plasma glucose and glycosylated haemoglobin values only in the conservative group (P < 0.05). In summary, we found that the treatment with CPAP for 12 weeks caused similar changes in circulating BCAAs concentrations to conservative treatment and a differential metabolic response of CPAP and conservative treatment was observed between the relationship of BCAAs and glucose homeostasis. Additional studies are needed to determine the interplay between branched-chain amino acids and glucose metabolism in patients with sleep apnea. © 2017 European Sleep Research Society.

  20. Catalpic acid decreases abdominal fat deposition, improves glucose homeostasis and upregulates PPAR alpha expression in adipose tissue.

    Science.gov (United States)

    Hontecillas, Raquel; Diguardo, Maggie; Duran, Elisa; Orpi, Marcel; Bassaganya-Riera, Josep

    2008-10-01

    Catalpic acid (CAT) is a conjugated linolenic acid (CLN) isomer containing trans-9, trans-11, cis-13 double bonds in an 18-carbon chain and it is found primarily in the seed oil of ornamental and medicinal trees and shrubs of the family Bignoniaceae. The objective of this study was to investigate whether CAT decreases obesity and ameliorates insulin sensitivity and glucose tolerance in mice fed high-fat diets. To test the efficacy of CAT in decreasing obesity and diabetes we used both a model of diet-induced obesity (DIO) and a genetic model of obesity (i.e., mice lacking the leptin receptor). Blood was collected on days 0, 7, 14, 21 and 28 for determining fasting glucose and insulin concentrations in plasma. In addition, a glucose tolerance test was administered on day 28. We found that dietary CAT (1g/100g) decreased fasting plasma glucose and insulin concentrations, ameliorated the glucose normalizing ability following glucose challenge and decreased abdominal white adipose tissue accumulation. In white adipose tissue (WAT), CAT upregulated peroxisome proliferator-activated receptor (PPAR) alpha and its responsive genes [i.e., stearoyl-coenzyme A desaturase (SCD1) and enoyl-coenzyme A hydratase (ECH)], increased concentrations of high-density lipoprotein (HDL) cholesterol and decreased plasma triglyceride (TG) levels. CAT decreased abdominal fat deposition, increased HDL cholesterol, decreased TG concentrations, decreased glucose and insulin homeostasis and modulated WAT gene expression in a manner reminiscent of the actions of the PPAR alpha-activating fibrate class of lipid-lowering drugs.

  1. Loss of Hepatic Mitochondrial Long-Chain Fatty Acid Oxidation Confers Resistance to Diet-Induced Obesity and Glucose Intolerance.

    Science.gov (United States)

    Lee, Jieun; Choi, Joseph; Selen Alpergin, Ebru S; Zhao, Liang; Hartung, Thomas; Scafidi, Susanna; Riddle, Ryan C; Wolfgang, Michael J

    2017-07-18

    The liver has a large capacity for mitochondrial fatty acid β-oxidation, which is critical for systemic metabolic adaptations such as gluconeogenesis and ketogenesis. To understand the role of hepatic fatty acid oxidation in response to a chronic high-fat diet (HFD), we generated mice with a liver-specific deficiency of mitochondrial long-chain fatty acid β-oxidation (Cpt2 L-/- mice). Paradoxically, Cpt2 L-/- mice were resistant to HFD-induced obesity and glucose intolerance with an absence of liver damage, although they exhibited serum dyslipidemia, hepatic oxidative stress, and systemic carnitine deficiency. Feeding an HFD induced hepatokines in mice, with a loss of hepatic fatty acid oxidation that enhanced systemic energy expenditure and suppressed adiposity. Additionally, the suppression in hepatic gluconeogenesis was sufficient to improve HFD-induced glucose intolerance. These data show that inhibiting hepatic fatty acid oxidation results in a systemic hormetic response that protects mice from HFD-induced obesity and glucose intolerance. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Fluorescence properties of 3-amino phenylboronic acid and its interaction with glucose and ZnS:Cu quantum dots.

    Science.gov (United States)

    Kur-Kowalska, Karolina; Przybyt, Małgorzata; Ziółczyk, Paulina; Sowiński, Przemysław; Miller, Ewa

    2014-08-14

    Preliminary results of a study of the interaction between 3-amino phenylboronic acid and glucose or ZnS:Cu quantum dots are presented in this paper. ZnS:Cu quantum dots with mercaptopropionic acid as a capping agent were obtained and characterized. Quenching of 3-amino phenylboronic acid fluorescence was studied by steady-state and timeresolved measurements. For fluorescence quenching with glucose the results of steady-state measurements fulfill Stern-Volmer equation. The quenching constants are increasing with growing pH. The decay of fluorescence is monoexponential with lifetime about 8.4 ns, which does not depend on pH and glucose concentration indicating static quenching. The quenching constant can be interpreted as apparent equilibrium constant of estrification of boronic group with diol. Quantum dots are also quenching 3-amino phenylboronic acid fluorescence. Fluorescence lifetime, in this case, is slightly decreasing with increasing concentration of quantum dots. The quenching constants are increasing slightly with pH's growth. Quenching mechanism of 3-amino phenylboronic acid fluorescence by quantum dots needs further experiments to be fully explained. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Loss of Hepatic Mitochondrial Long-Chain Fatty Acid Oxidation Confers Resistance to Diet-Induced Obesity and Glucose Intolerance

    Directory of Open Access Journals (Sweden)

    Jieun Lee

    2017-07-01

    Full Text Available The liver has a large capacity for mitochondrial fatty acid β-oxidation, which is critical for systemic metabolic adaptations such as gluconeogenesis and ketogenesis. To understand the role of hepatic fatty acid oxidation in response to a chronic high-fat diet (HFD, we generated mice with a liver-specific deficiency of mitochondrial long-chain fatty acid β-oxidation (Cpt2L−/− mice. Paradoxically, Cpt2L−/− mice were resistant to HFD-induced obesity and glucose intolerance with an absence of liver damage, although they exhibited serum dyslipidemia, hepatic oxidative stress, and systemic carnitine deficiency. Feeding an HFD induced hepatokines in mice, with a loss of hepatic fatty acid oxidation that enhanced systemic energy expenditure and suppressed adiposity. Additionally, the suppression in hepatic gluconeogenesis was sufficient to improve HFD-induced glucose intolerance. These data show that inhibiting hepatic fatty acid oxidation results in a systemic hormetic response that protects mice from HFD-induced obesity and glucose intolerance.

  4. Glucose-stimulated insulin response in pregnant sheep following acute suppression of plasma non-esterified fatty acid concentrations

    Directory of Open Access Journals (Sweden)

    Sriskandarajah Nadarajah

    2004-09-01

    Full Text Available Abstract Background Elevated non-esterified fatty acids (NEFA concentrations in non-pregnant animals have been reported to decrease pancreatic responsiveness. As ovine gestation advances, maternal insulin concentrations fall and NEFA concentrations increase. Experiments were designed to examine if the pregnancy-associated rise in NEFA concentration is associated with a reduced pancreatic sensitivity to glucose in vivo. We investigated the possible relationship of NEFA concentrations in regulating maternal insulin concentrations during ovine pregnancy at three physiological states, non-pregnant, non-lactating (NPNL, 105 and 135 days gestational age (dGA, term 147+/- 3 days. Methods The plasma concentrations of insulin, growth hormone (GH and ovine placental lactogen (oPL were determined by double antibody radioimmunoassay. Insulin responsiveness to glucose was measured using bolus injection and hyperglycaemic clamp techniques in 15 non-pregnant, non-lactating ewes and in nine pregnant ewes at 105 dGA and near term at 135 dGA. Plasma samples were also collected for hormone determination. In addition to bolus injection glucose and insulin Area Under Curve calculations, the Mean Plasma Glucose Increment, Glucose Infusion Rate and Mean Plasma Insulin Increment and Area Under Curve were determined for the hyperglycaemic clamp procedures. Statistical analysis of data was conducted with Students t-tests, repeated measures ANOVA and 2-way ANOVA. Results Maternal growth hormone, placental lactogen and NEFA concentrations increased, while basal glucose and insulin concentrations declined with advancing gestation. At 135 dGA following bolus glucose injections, peak insulin concentrations and insulin area under curve (AUC profiles were significantly reduced in pregnant ewes compared with NPNL control ewes (p Conclusions Results suggest that despite an acute suppression of circulating NEFA concentrations during pregnancy, the associated steroids and hormones

  5. Effects of furfural and acetic acid on growth and lipid production from glucose and xylose by Rhodotorula glutinis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guochang; French, William Todd; Hernandez, Rafael; Alley, Earl; Paraschivescu, Maria [Dave C. Swalm School of Chemical Engineering, Mississippi State University, P.O. Box 9595, Mississippi State, MS 39762 (United States)

    2011-01-15

    Microbial conversion of lignocellulosic sugars to triacylglycerols (a biodiesel or renewable diesel feedstock) was investigated using the oleaginous yeast Rhodotorula glutinis (ATCC 15125). In the shake flask experiments, R. glutinis was first grown in a nitrogen-rich medium utilizing an artificial acid hydrolysate of lignocellulosic biomass switchgrass as the sole carbon and energy source. Once the culture had reached the stationary phase, the cells were harvested and transferred to a fresh nitrogen-free media containing artificial acid hydrolysate sugars for lipid accumulation. Analysis of the data collected showed that the yeast were able to grow in the medium containing artificial acid hydrolysate sugars as the carbon and energy source. The net specific Growth rate(s) indicated that the presence of acetic acid and furfural in the artificial acid hydrolysate inhibited the growth of R. glutinis on glucose, but not the growth on xylose. The lipid accumulated in the cells, determined by gravimetrical method, increased from initial 4.3%-39.0% of dry cell mass weight. The major fatty acids of the accumulated lipids were palmitic acid, stearic acid, oleic acid, linoleic acid and {gamma}-linoleic acid. These results indicate that it is feasible to convert the sugars in acid hydrolysate of lignocellulosic biomass to triacylglycerols using R. glutinis. (author)

  6. Effects of dietary substitution of mixed amino acids for glucose on the splanchnic metabolism of plasma triglycerides, cholesterol, carbohydrates, and amino acids in conscious fed baboons.

    Science.gov (United States)

    Wolfe, B M; Redinger, R N; Marliss, E B; Grace, D M

    1983-04-01

    Splanchnic metabolism was studied in the fed state during prolonged constant intravenous administration of tracer amounts of [9,10]-3H palmitic acid and the calculated isocaloric intraduodenal administration (13 mg/min X kg body wt0.75) of either (1) glucose, (2) 15% mixed amino acids and 85% glucose or (3) 45% mixed amino acids and 55% glucose to conscious, restrained female baboons that had been maintained on a similar diet (supplemented in essential nutrients) for the previous 9 days. Secretion of plasma triglycerides from the splanchnic region was quantified from splanchnic flow and radiochemical measurements of transsplanchnic gradients of 3H-labeled free fatty acids and triglycerides. Mean splanchnic secretion of plasma triglycerides increased significantly as the proportion of dietary calories derived from amino acids was varied from 0 to 15 to 45% (mean values 1.1 +/- 0.1, 2.6 +/- 0.2 and 4.2 +/- 0.3 mumol/min kg body wt0.75, respectively, p less than 0.05). Increased triglyceride secretion was attributable to both significantly higher rates of esterification of free fatty acids taken up in the splanchnic region to triglycerides released into hepatic venous blood plasma (mean values 10 +/- 1, 16 +/- 2 and 34 +/- 5%, respectively) and to significantly higher rates of secretion of triglycerides derived from precursors other than free fatty acids. Higher intake of amino acids was also associated with both higher plasma concentrations of cholesterol and higher values for hepatic oxidation of cholesterol to bile acids.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Effects of medium-chain fatty acids and oleic acid on blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities

    DEFF Research Database (Denmark)

    Tholstrup, T.; Ehnholm, C.; Jauhiainen, M.

    2004-01-01

    Background: Dietary medium-chain fatty acids (MCFAs) are of nutritional interest because they are more easily absorbed from dietary medium-chain triacylglycerols (MCTs) than are long-chain fatty acids from, for example, vegetable oils. It has generally been claimed that MCFAs do not increase plasma...... cholesterol, although this claim is poorly documented. Objective: We compared the effects of a diet rich in either MCFAs or oleic acid on fasting blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities in healthy men. Design: In a study with a double-blind, randomized, crossover...... plasma total triacylglycerol (P = 0.0361), and higher plasma glucose (P = 0.033). Plasma HDL-cholesterol and insulin concentrations and activities of cholesterol ester transfer protein and phospholipid transfer protein did not differ significantly between the diets. Conclusions: Compared with fat high...

  8. Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter

    DEFF Research Database (Denmark)

    Ståhlberg, Tim; Rodriguez, Sergio; Fristrup, Peter

    2011-01-01

    The dehydration of glucose and other hexose carbohydrates to 5‐(hydroxymethyl)furfural (HMF) was investigated in imidazolium‐based ionic liquids with boric acid as a promoter. A yield of up to 42 % from glucose and as much as 66 % from sucrose was obtained. The yield of HMF decreased as the conce......The dehydration of glucose and other hexose carbohydrates to 5‐(hydroxymethyl)furfural (HMF) was investigated in imidazolium‐based ionic liquids with boric acid as a promoter. A yield of up to 42 % from glucose and as much as 66 % from sucrose was obtained. The yield of HMF decreased...

  9. Gallic Acid Ameliorated Impaired Glucose and Lipid Homeostasis in High Fat Diet-Induced NAFLD Mice

    Science.gov (United States)

    Chao, Jung; Huo, Teh-Ia; Cheng, Hao-Yuan; Tsai, Jen-Chieh; Liao, Jiunn-Wang; Lee, Meng-Shiou; Qin, Xue-Mei; Hsieh, Ming-Tsuen; Pao, Li-Heng; Peng, Wen-Huang

    2014-01-01

    Gallic acid (GA), a naturally abundant plant phenolic compound in vegetables and fruits, has been shown to have potent anti-oxidative and anti-obesity activity. However, the effects of GA on nonalcoholic fatty liver disease (NAFLD) are poorly understood. In this study, we investigated the beneficial effects of GA administration on nutritional hepatosteatosis model by a more “holistic view” approach, namely 1H NMR-based metabolomics, in order to prove efficacy and to obtain information that might lead to a better understanding of the mode of action of GA. Male C57BL/6 mice were placed for 16 weeks on either a normal chow diet, a high fat diet (HFD, 60%), or a high fat diet supplemented with GA (50 and 100 mg/kg/day, orally). Liver histopathology and serum biochemical examinations indicated that the daily administration of GA protects against hepatic steatosis, obesity, hypercholesterolemia, and insulin resistance among the HFD-induced NAFLD mice. In addition, partial least squares discriminant analysis scores plots demonstrated that the cluster of HFD fed mice is clearly separated from the normal group mice plots, indicating that the metabolic characteristics of these two groups are distinctively different. Specifically, the GA-treated mice are located closer to the normal group of mice, indicating that the HFD-induced disturbances to the metabolic profile were partially reversed by GA treatment. Our results show that the hepatoprotective effect of GA occurs in part through a reversing of the HFD caused disturbances to a range of metabolic pathways, including lipid metabolism, glucose metabolism (glycolysis and gluconeogenesis), amino acids metabolism, choline metabolism and gut-microbiota-associated metabolism. Taken together, this study suggested that a 1H NMR-based metabolomics approach is a useful platform for natural product functional evaluation. The selected metabolites are potentially useful as preventive action biomarkers and could also be used to help

  10. Effects of carbon dioxide on cell growth and propionic acid production from glycerol and glucose by Propionibacterium acidipropionici.

    Science.gov (United States)

    Zhang, An; Sun, Jianxin; Wang, Zhongqiang; Yang, Shang-Tian; Zhou, Haiying

    2015-01-01

    The effects of CO2 on propionic acid production and cell growth in glycerol or glucose fermentation were investigated in this study. In glycerol fermentation, the volumetric productivity of propionic acid with CO2 supplementation reached 2.94g/L/day, compared to 1.56g/L/day without CO2. The cell growth using glycerol was also significantly enhanced with CO2. In addition, the yield and productivity of succinate, the main intermediate in Wood-Werkman cycle, increased 81% and 280%, respectively; consistent with the increased activities of pyruvate carboxylase and propionyl CoA transferase, two key enzymes in the Wood-Werkman cycle. However, in glucose fermentation CO2 had minimal effect on propionic acid production and cell growth. The carbon flux distributions using glycerol or glucose were also analyzed using a stoichiometric metabolic model. The calculated maintenance coefficient (mATP) increased 100%, which may explain the increase in the productivity of propionic acid in glycerol fermentation with CO2 supplement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Gut microbiota metabolites, amino acid metabolites and improvements in insulin sensitivity and glucose metabolism: the POUNDS Lost trial.

    Science.gov (United States)

    Heianza, Yoriko; Sun, Dianjianyi; Li, Xiang; DiDonato, Joseph A; Bray, George A; Sacks, Frank M; Qi, Lu

    2018-06-02

    Alterations in gut microbiota have been linked to host insulin resistance, diabetes and impaired amino acid metabolism. We investigated whether changes in gut microbiota-dependent metabolite of trimethylamine N-oxide (TMAO) and its nutrient precursors (choline and L-carnitine) were associated with improvements in glucose metabolism and diabetes-related amino acids in a weight-loss diet intervention. We included 504 overweight and obese adults who were randomly assigned to one of four energy-reduced diets varying in macronutrient intake. The 6-month changes (Δ) in TMAO, choline and L-carnitine levels after the intervention were calculated. Greater decreases in choline and L-carnitine were significantly (p<0.05) associated with greater improvements in fasting insulin concentrations and homeostasis model assessment of insulin resistance (HOMA-IR) at 6 months. The reduction of choline was significantly related to 2-year improvements in glucose and insulin resistance. We found significant linkages between dietary fat intake and ΔTMAO for changes in fasting glucose, insulin and HOMA-IR (p interaction <0.05); a greater increase in TMAO was related to lesser improvements in the outcomes among participants who consumed a high-fat diet. In addition, ΔL-carnitine and Δcholine were significantly related to changes in amino acids (including branched-chain and aromatic amino acids). Interestingly, the associations of ΔTMAO, Δcholine and ΔL-carnitine with diabetes-related traits were independent of the changes in amino acids. Our findings underscore the importance of changes in TMAO, choline and L-carnitine in improving insulin sensitivity during a weight-loss intervention for obese patients. Dietary fat intake may modify the associations of TMAO with insulin sensitivity and glucose metabolism. NCT00072995. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless

  12. Synthesis and characterization of microparticles based on poly-methacrylic acid with glucose oxidase for biosensor applications.

    Science.gov (United States)

    Hervás Pérez, J P; López-Ruiz, B; López-Cabarcos, E

    2016-01-01

    In the line of the applicability of biocompatible monomers pH and temperature dependent, we assayed poly-methacrylic acid (p-MAA) microparticles as immobilization system in the design of enzymatic biosensors. Glucose oxidase was used as enzyme model for the study of microparticles as immobilization matrices and as biological material in the performance of glucose biosensors. The enzyme immobilization method was optimized by investigating the influence of monomer concentration and cross-linker content (N',N'-methylenebisacrylamide), used in the preparation of the microparticles in the response of the biosensors. The kinetics of the polymerization and the effects of the temperature were studied, also the conversion of the polymerization was determinates by a weight method. The structure of the obtained p-MAA microparticles were studied through scanning electron microscopy (SEM) and differential scanning microscopy (DSC). The particle size measurements were performed with a Galai-Cis 1 particle analyzer system. Furthermore, the influence of the swelling behavior of hydrogel matrix as a function of pH and temperature were studied. Analytical properties such as sensitivity, linear range, response time and detection limit were studied for the glucose biosensors. The sensitivity for glucose detection obtained with poly-methacrylic acid (p-MAA) microparticles was 11.98mAM(-1)cm(-2) and 10μM of detection limit. A Nafion® layer was used to eliminate common interferents of the human serum such as uric and ascorbic acids. The biosensors were used to determine glucose in human serum samples with satisfactory results. When stored in a frozen phosphate buffer solution (pH 6.0) at -4°C, the useful lifetime of all biosensors was at least 550 days. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Optimization of renewable levulinic acid production from glucose conversion catalyzed by Fe/HY zeolite catalyst in aqueous medium

    International Nuclear Information System (INIS)

    Ramli, Nur Aainaa Syahirah; Amin, Nor Aishah Saidina

    2015-01-01

    Highlights: • Dehydration of glucose as model compound to LA over Fe/HY zeolite catalyst. • RSM coupled with BBD for optimization of LA yield from glucose. • Optimization involving evaluation of four parameters gave 61.8% of optimum LA yield. • Direct conversion of OPF over Fe/HY zeolite yielded 17.6% LA with 54.8% efficiency. • Reusability of Fe/HY zeolite catalyst was tested for five successive cycles. - Abstract: Levulinic acid (LA) is a versatile chemical with numerous applications. In this study, the conversions of glucose and oil palm fronds (OPF) to LA have been conducted over 10% Fe/HY zeolite catalyst. The optimization of LA yield from glucose conversion using Box–Behnken design and response surface methodology reported 61.8% yield, which can be achieved at temperature 173.4 °C, reaction time 3.3 h, 0.93 g of glucose and 0.89 g 10% Fe/HY zeolite. The LA yield from OPF conversion conducted at the optimum conditions was 17.6% with 54.8% process efficiency. It was also observed that Fe leaching from 10% Fe/HY zeolite was insignificant and recycled 10% Fe/HY zeolite gave sufficient performance for five successive cycles. This study emphasizes the potential of Fe/HY zeolite catalyst for catalytic conversion of lignocellulosic biomass to LA

  14. High Glucose-Induced Cardiomyocyte Death May Be Linked to Unbalanced Branched-Chain Amino Acids and Energy Metabolism

    Directory of Open Access Journals (Sweden)

    Xi Zhang

    2018-04-01

    Full Text Available High glucose-induced cardiomyocyte death is a common symptom in advanced-stage diabetic patients, while its metabolic mechanism is still poorly understood. The aim of this study was to explore metabolic changes in high glucose-induced cardiomyocytes and the heart of streptozotocin-induced diabetic rats by 1H-NMR-based metabolomics. We found that high glucose can promote cardiomyocyte death both in vitro and in vivo studies. Metabolomic results show that several metabolites exhibited inconsistent variations in vitro and in vivo. However, we also identified a series of common metabolic changes, including increases in branched-chain amino acids (BCAAs: leucine, isoleucine and valine as well as decreases in aspartate and creatine under high glucose condition. Moreover, a reduced energy metabolism could also be a common metabolic characteristic, as indicated by decreases in ATP in vitro as well as AMP, fumarate and succinate in vivo. Therefore, this study reveals that a decrease in energy metabolism and an increase in BCAAs metabolism could be implicated in high glucose-induced cardiomyocyte death.

  15. Cofactor balance by nicotinamide nucleotide transhydrogenase (NNT) coordinates reductive carboxylation and glucose catabolism in the tricarboxylic acid (TCA) cycle.

    Science.gov (United States)

    Gameiro, Paulo A; Laviolette, Laura A; Kelleher, Joanne K; Iliopoulos, Othon; Stephanopoulos, Gregory

    2013-05-03

    Cancer and proliferating cells exhibit an increased demand for glutamine-derived carbons to support anabolic processes. In addition, reductive carboxylation of α-ketoglutarate by isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) was recently shown to be a major source of citrate synthesis from glutamine. The role of NAD(P)H/NAD(P)(+) cofactors in coordinating glucose and glutamine utilization in the tricarboxylic acid (TCA) cycle is not well understood, with the source(s) of NADPH for the reductive carboxylation reaction remaining unexplored. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial enzyme that transfers reducing equivalents from NADH to NADPH. Here, we show that knockdown of NNT inhibits the contribution of glutamine to the TCA cycle and activates glucose catabolism in SkMel5 melanoma cells. The increase in glucose oxidation partially occurred through pyruvate carboxylase and rendered NNT knockdown cells more sensitive to glucose deprivation. Importantly, knocking down NNT inhibits reductive carboxylation in SkMel5 and 786-O renal carcinoma cells. Overexpression of NNT is sufficient to stimulate glutamine oxidation and reductive carboxylation, whereas it inhibits glucose catabolism in the TCA cycle. These observations are supported by an impairment of the NAD(P)H/NAD(P)(+) ratios. Our findings underscore the role of NNT in regulating central carbon metabolism via redox balance, calling for other mechanisms that coordinate substrate preference to maintain a functional TCA cycle.

  16. Influence of gibberellin and daminozide on the expression of terpene synthases and on monoterpenes in common sage (Salvia officinalis).

    Science.gov (United States)

    Schmiderer, Corinna; Grausgruber-Gröger, Sabine; Grassi, Paolo; Steinborn, Ralf; Novak, Johannes

    2010-07-01

    Common sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants, with antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, composed mainly of the monoterpenes 1,8-cineole, alpha-thujone, beta-thujone and camphor, is responsible for some of these effects. Gibberellins regulate diverse physiological processes in plants, such as seed germination, shoot elongation and cell division. In this study, we analyzed the effect of exogenously applied plant growth regulators, namely gibberellic acid (GA(3)) and daminozide, on leaf morphology and essential oil formation of two leaf stages during the period of leaf expansion. Essential oil content increased with increasing levels of gibberellins and decreased when gibberellin biosynthesis was blocked with daminozide. With increasing levels of gibberellins, 1,8-cineole and camphor contents increased. Daminozide blocked the accumulation of alpha- and beta-thujone. GA(3) at the highest level applied also led to a significant decrease of alpha- and beta-thujone. Monoterpene synthases are a class of enzymes responsible for the first step in monoterpene biosynthesis, competing for the same substrate geranylpyrophosphate. The levels of gene expression of the three most important monoterpene synthases in sage were investigated, 1,8-cineole synthase leading directly to 1,8-cineole, (+)-sabinene synthase responsible for the first step in the formation of alpha- and beta-thujone, and (+)-bornyl diphosphate synthase, the first step in camphor biosynthesis. The foliar application of GA(3) increased, while daminozide significantly decreased gene expression of the monoterpene synthases. The amounts of two of the end products, 1,8-cineole and camphor, were directly correlated with the levels of gene expression of the respective monoterpene synthases, indicating transcriptional control, while the formation of alpha- and beta

  17. Chemical analysis of particulate and gaseous products from the monoterpene oxidation in the SAPHIR chamber during the EUCAARI campaign 2008

    Science.gov (United States)

    Kahnt, A.; Iinuma, Y.; Herrmann, H.; Mentel, T. F.; Fisseha, R.; Kiendler-Scharr, A.

    2009-04-01

    The atmospheric oxidation of monoterpenes leads to multifunctional products with lower vapour pressure. These products condense and coagulate to existing particles leading to particle formation and growth. In order to obtain better insights into the mechanisms and the importance of sources to organic aerosol, a mixture of monoterpenes was oxidised in the SAPHIR outdoor chamber during the EUCAARI campaign in 2008. The mixture was made of α-pinene, β-pinene, limonene, 3-carene and ocimene, representing a typical monoterpene emission from a boreal forest. In addition, two sesquiterpenes (α-farnesene and caryophyllene) were reacted together with the monoterpene mixture in some experiments. The VOC (volatile organic compound) mixture was reacted under tropospheric oxidation and light conditions in a prolonged time scale over two days. In the present study, a special emphasis is put on the detection of carbonyl compounds from the off-line analysis of collected filter and denuder samples from the campaign in 2008. The oxidation products which contain carbonyl groups are important first stable intermediates during the monoterpene and sesquiterpene oxidation. They react further with atmospheric oxidants to form lower volatile acidic compounds, contributing to secondary organic aerosol (SOA). Commonly used methods for the analysis of carbonyl compounds involve derivatisation steps prior to separation and subsequent UV or MS detection. In the present study, 2,4-dinitrophenylhydrazine (DNPH) was used to derivatise the extracted filter and denuder samples. The DNPH converts aldehyde- and keto-groups to stable hydrazones, which can be purified afterwards using a solid phase extraction (SPE) cartridge. The derivatised samples were analysed with HPLC/ESI-TOFMS which allowed us to determine the exact chemical formula of unknown products. In addition to known carbonyl compounds from monoterpene oxidation such as pinonaldehyde and nopinon, previously unreported molecular masses

  18. 3-Nitropropionic acid neurotoxicity in organotypic striatal and corticostriatal slice cultures is dependent on glucose and glutamate

    DEFF Research Database (Denmark)

    Storgaard, J; Kornblit, B T; Zimmer, J

    2000-01-01

    of lactate dehydrogenase in the medium and glutamic acid decarboxylase in tissue homogenates. 3-NPA toxicity (25-100 microM in 5 mM glucose, 24-48 h) appeared to be highly dependent on culture medium glucose levels. 3-NPA treatment caused also a dose-dependent lactate increase, reaching a maximum......Mitochondrial inhibition by 3-nitropropionic acid (3-NPA) causes striatal degeneration reminiscent of Huntington's disease. We studied 3-NPA neurotoxicity and possible indirect excitotoxicity in organotypic striatal and corticostriatal slice cultures. Neurotoxicity was quantified by assay...... of threefold increase above control at 100 microM. Both a high dose of glutamate (5 mM) and glutamate uptake blockade by dl-threo-beta-hydroxyaspartate potentiated 3-NPA neurotoxicity in corticostriatal slice cultures. Furthermore, striatum from corticostriatal cocultures was more sensitive to 3-NPA than...

  19. Efficient production of L-lactic acid by newly isolated thermophilic Bacillus coagulans WCP10-4 with high glucose tolerance.

    Science.gov (United States)

    Zhou, Xingding; Ye, Lidan; Wu, Jin Chuan

    2013-05-01

    A thermophilic Bacillus coagulans WCP10-4 with tolerance to high concentration of glucose was isolated from soil and used to produce optically pure L-lactic acid from glucose and starch. In batch fermentation at pH 6.0, 240 g/L of glucose was completely consumed giving 210 g/L of L-lactic acid with a yield of 95 % and a productivity of 3.5 g/L/h. In simultaneous saccharification and fermentation at 50 °C without sterilizing the medium, 200 g/L of corn starch was completely consumed producing 202.0 g/L of L-lactic acid. To the best of our knowledge, this strain shows the highest osmotic tolerance to glucose among the strains ever reported for lactic acid production. This is the first report of simultaneous saccharification and fermentation of starch for lactic acid production under a non-sterilized condition.

  20. Ca²⁺ signal contributing to the synthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia'.

    Science.gov (United States)

    Hu, Zenghui; Li, Tianjiao; Zheng, Jian; Yang, Kai; He, Xiangfeng; Leng, Pingsheng

    2015-06-01

    The floral scent is an important part of plant volatile compounds, and is influenced by environmental factors. The emission of monoterpenes of Lilium 'siberia' is regulated by light intensity, but the mechanism is large unknown. In this study, the expression of Li-mTPS, a monoterpene synthase gene in the tepals of Lilium 'siberia', and net Ca(2+) flux were investigated after exposure to different levels of light intensity (0, 100, 300, 600, 1000, and 1500 μmol m(-2) s(-1)). Moreover the effect of LaCl3 and ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) on the Li-mTPS expression, monoterpene emission, and net Ca(2+) flux were examined at 600 μmol m(-2) s(-1). The results showed that along with the enhancement of light intensity, the expression level of Li-mTPS increased gradually, and the net Ca(2+) influx was also enhanced showing a similar pattern. It was found that LaCl3 and EGTA effectively inhibited the increase in expression of Li-mTPS and the net Ca(2+) influx induced by light treatment. Moreover, the release amounts of monoterpenes decreased significantly after treatment with LaCl3 and EGTA. So it can be concluded that Ca(2+) signal contributed to the biosynthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia' tepals. The increased light intensity firstly triggered the Ca(2+) influx to cytoplasm, and then the gene expression of monoterpene synthases downstream was activated to regulate the biosynthesis and emission of monoterpenes. But in the signaling pathway other mechanisms were thought to be involved in the emission of monoterpenes regulated by light intensity, which need to be investigated in future research. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. Measurement and COrrelation on Viscosity and Apparent Molar Volume of Ternary System for L—ascorbic Acid in Aqueous D—Glucose and Sucrose Solutions

    Institute of Scientific and Technical Information of China (English)

    赵长伟; 马沛生

    2003-01-01

    Visosities and densities at ,several temperatures from 293.15 K to 313.15K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations.The parameters of density,Viscosity coefficient B and partial molar volume are calculated by regression.The experimental results show that densities and viscositis decrease as temperature increases at the same solute and solvent (glucose and sucrose aueous solution)concentrations,and increase with concentration of glucose and sucrose at the same solute concentration and temperature,B increases with concentration of glucose and sucrose and temaperature,L-ascorbic acid is sturcture-breaker or structure-making for the glucose and sucrose aqueous solutions ,Furthermore,the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

  2. Phytanic acid stimulates glucose uptake in a model of skeletal muscles, the primary porcine myotubes

    DEFF Research Database (Denmark)

    Che, Brita Ngum; Oksbjerg, Niels; Hellgren, Lars

    2013-01-01

    and tritiated 2-deoxyglucose (2-DOG) was used to measure glucose uptake, in relation to PA and 2-DOG exposure times and also in relation to PA and insulin concentrations. The MIXED procedure model of SAS was used for statistical analysis of data. RESULTS: PA increased glucose uptake by approximately 35...

  3. Effects of intravenous glucose infusion and nutritional balance on serum concentrations of nonesterified fatty acids, glucose, insulin, and progesterone in nonlactating dairy cows.

    Science.gov (United States)

    Vieira, F V R; Lopes, C N; Cappellozza, B I; Scarpa, A B; Cooke, R F; Vasconcelos, J L M

    2010-07-01

    The objective of this study was to evaluate serum concentrations of nonesterified fatty acids, glucose, insulin, and progesterone in nonlactating dairy cows according to nutritional balance and glucose infusion. Ten nonlactating, ovariectomized Gir x Holstein cows were stratified by body weight (BW) and body condition score (BCS) on d -28 of the study, and randomly assigned to 1) negative nutrient balance (NB) or 2) positive nutrient balance (PB). From d -28 to d 0, cows were allocated according to nutritional treatment (5 cows/treatment) into 2 low-quality pastures with reduced forage availability. However, PB cows individually received, on average, 3 kg/cow per day (as-fed) of a concentrate during the study. All cows had an intravaginal progesterone releasing device inserted on d -14, which remained in cows until the end of the study. Cow BW and BCS were assessed again on d 0. On d 0, cows within nutritional treatment were randomly assigned to receive, in a crossover design containing 2 periods of 24h each, 1) intravenous glucose infusion (GLU; 0.5 g of glucose/kg of BW, as a 5% glucose solution administered, on average, at 32 mL/min over a 3-h period), or 2) intravenous saline infusion (SAL; 0.9% solution infused on average at 32 mL/min over a 3-h period). Prior to the beginning of each period, all cows were fasted for 12h. Blood samples were collected, relative to the beginning of the infusion, at -12 and -11.5h (beginning of fasting), and at -0.5, 0, 0.5, 1, 2, 3, 4, 5, and 6h. Following the last blood collection of period 1, cows received (PB) or not (NB) concentrate and were returned to their respective pastures. Changes in BCS and BW were greater in NB cows compared with PB cows (-0.60 and -0.25+/-0.090 for BCS, respectively; -22.4 and 1.2+/-6.58 kg for BW, respectively). Cows receiving GLUC had greater glucose concentrations from 0.5 to 3h relative to infusion compared with SAL cows. Insulin concentrations were greater in PB cows assigned to GLUC compared

  4. A novel screen-printed microfluidic paper-based electrochemical device for detection of glucose and uric acid in urine.

    Science.gov (United States)

    Yao, Yong; Zhang, Chunsun

    2016-10-01

    A novel screen-printed microfluidic paper-based analytical device with all-carbon electrode-enabled electrochemical assay (SP-ACE-EC-μPAD) has been developed. The fabrication of these devices involved wax screen-printing, which was simple, low-cost and energy-efficient. The working, counter and reference electrodes were screen-printed using carbon ink on the patterned paper devices. Different wax screen-printing processes were examined and optimized, which led to an improved method with a shorter heating time (~5 s) and a lower heating temperature (75 °C). Different printing screens were examined, with a 300-mesh polyester screen yielding the highest quality wax screen-prints. The carbon electrodes were screen-printed on the μPADs and then examined using cyclic voltammetry. The analytical performance of the SP-ACE-EC-μPADs for the detection of glucose and uric acid in standard solutions was investigated. The results were reproducible, with a linear relationship [R(2) = 0.9987 (glucose) or 0.9997 (uric acid)] within the concentration range of interest, and with detection limits as low as 0.35 mM (glucose) and 0.08 mM (uric acid). To determine the clinical utility of the μPADs, chronoamperometry was used to analyze glucose and uric acid in real urine samples using the standard addition method. Our devices were able to detect the analytes of interest in complex real-world biological samples, and have the potential for use in a wide variety of applications.

  5. PLANT VOLATILES. Biosynthesis of monoterpene scent compounds in roses.

    Science.gov (United States)

    Magnard, Jean-Louis; Roccia, Aymeric; Caissard, Jean-Claude; Vergne, Philippe; Sun, Pulu; Hecquet, Romain; Dubois, Annick; Hibrand-Saint Oyant, Laurence; Jullien, Frédéric; Nicolè, Florence; Raymond, Olivier; Huguet, Stéphanie; Baltenweck, Raymonde; Meyer, Sophie; Claudel, Patricia; Jeauffre, Julien; Rohmer, Michel; Foucher, Fabrice; Hugueney, Philippe; Bendahmane, Mohammed; Baudino, Sylvie

    2015-07-03

    The scent of roses (Rosa x hybrida) is composed of hundreds of volatile molecules. Monoterpenes represent up to 70% percent of the scent content in some cultivars, such as the Papa Meilland rose. Monoterpene biosynthesis in plants relies on plastid-localized terpene synthases. Combining transcriptomic and genetic approaches, we show that the Nudix hydrolase RhNUDX1, localized in the cytoplasm, is part of a pathway for the biosynthesis of free monoterpene alcohols that contribute to fragrance in roses. The RhNUDX1 protein shows geranyl diphosphate diphosphohydrolase activity in vitro and supports geraniol biosynthesis in planta. Copyright © 2015, American Association for the Advancement of Science.

  6. An antimutagenic monoterpene from Malachra fasciata (Malvaveae)

    International Nuclear Information System (INIS)

    Ragasa, Consolacion Y.; Agbayani, Virgilio; Hernandez, Reynan B.; Rideout, John A.

    1997-01-01

    A monoterpene was isolated from the leaves of Malachra fasciata by gravity column chromatography. Its structure was elucidated by extensive1D and 2D NMR spectroscopy. It was identified as loliolide by comparison of its 1 H and 1 3 C NMR spectral data with those found in the literature. The compound was tested for its antimutagenicity potential by the use of the micronucleus test. Results of the study indicated a 64.4% reduction in micronucleated polychromatic erythrocytes induced by mitomycin C, when loliolide at a dosage of 14.8 mg/kg was administered to mice of the Swiss strain. Another isolate from the leaves of the plant was stigmasterol which structure was determined by comparison of its 1 H NMR spectal data with those found in the literature. (Author)

  7. Thermodynamic study of selected monoterpenes III

    International Nuclear Information System (INIS)

    Štejfa, Vojtěch; Fulem, Michal; Růžička, Květoslav; Červinka, Ctirad

    2014-01-01

    Highlights: • (−)-trans-Pinane, (+)-Δ-carene, eucalyptol, and limonene were studied. • New thermodynamic data were measured and calculated. • Many of thermodynamic data are reported for the first time. - Abstract: A thermodynamic study of selected monoterpenes, (−)-trans-pinane, (+)-Δ-carene, eucalyptol, (+)-limonene, and (−)-limonene, is presented in this work. The vapor pressure measurements were performed using the static method over the environmentally important temperature range (238 to 308) K. Liquid heat capacities were measured by Tian–Calvet calorimetry in the temperature interval (258 to 355) K. The phase behavior was investigated by differential scanning calorimetry (DSC) from T = 183 K. The thermodynamic properties in the ideal-gas state were calculated by combining statistical thermodynamic and density functional theory (DFT) calculations. Calculated ideal-gas heat capacities and experimental data for vapor pressures and condensed phase heat capacities were treated simultaneously to obtain a consistent thermodynamic description

  8. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    International Nuclear Information System (INIS)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-01-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO_2 and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO_2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  9. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

    2016-11-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  10. Contrasting effects of exercise and NOS inhibition on tissue-specific fatty acid and glucose uptake in mice.

    Science.gov (United States)

    Rottman, Jeffrey N; Bracy, Deanna; Malabanan, Carlo; Yue, Zou; Clanton, Jeff; Wasserman, David H

    2002-07-01

    Isotopic techniques were used to test the hypothesis that exercise and nitric oxide synthase (NOS) inhibition have distinct effects on tissue-specific fatty acid and glucose uptakes in a conscious, chronically catheterized mouse model. Uptakes were measured using the radioactive tracers (125)I-labeled beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) and deoxy-[2-(3)H]glucose (DG) during treadmill exercise with and without inhibition of NOS. [(125)I]BMIPP uptake at rest differed substantially among tissues with the highest levels in heart. With exercise, [(125)I]BMIPP uptake increased in both heart and skeletal muscles. In sedentary mice, NOS inhibition induced by nitro-L-arginine methyl ester (L-NAME) feeding increased heart and soleus [(125)I]BMIPP uptake. In contrast, exercise, but not L-NAME feeding, resulted in increased heart and skeletal muscle [2-(3)H]DG uptake. Significant interactions were not observed in the effects of combined exercise and L-NAME feeding on [(125)I]BMIPP and [2-(3)H]DG uptakes. In the conscious mouse, exercise and NOS inhibition produce distinct patterns of tissue-specific fatty acid and glucose uptake; NOS is not required for important components of exercise-associated metabolic signaling, or other mechanisms compensate for the absence of this regulatory mechanism.

  11. Dermal exposure to monoterpenes during wood work.

    Science.gov (United States)

    Eriksson, Kare; Wiklund, Leif

    2004-06-01

    The dermal exposure to the suspected allergenic monoterpenes [small alpha]-pinene, [small beta]-pinene and [capital Delta](3)-carene was assessed with a patch sampling technique. The patch used was made of activated charcoal sandwiched between two layers of cotton cloth. Patches were fastened at 12 different spots on a sampling overall and at the front of a cap to estimate the potential exposure of the body. Fastening two patches on a cotton glove, one patch representing the dorsal side and one patch representing the palm of the hand respectively, assessed the exposure on the hands. Sampling was carried out during collecting of pine and spruce boards in sawmills and during sawing of pine wood pieces in joinery shops respectively. The potential dermal exposure of the total body was 29.0-1 890 mg h(-1) with a geometric mean (GM) of 238 mg h(-1) during sawing. During collecting the GM was estimated to 100 mg h(-1) with a range of 12.2-959 mg h(-1). The hands had a mean exposure of 9.24 mg h(-1) during sawing and 3.25 mg h(-1) during collecting respectively. The good correlation between the mass of contamination on the individual body parts and the potential body exposure indicates that sampling can be performed on one body part to give a good estimation of the potential body exposure. Monoterpenes were detected at patches fastened underneath the protective clothing indicating a contamination of the skin of the worker. The patch used may overestimate the dermal exposure.

  12. Hepatocyte MyD88 affects bile acids, gut microbiota and metabolome contributing to regulate glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Duparc, Thibaut; Plovier, Hubert; Marrachelli, Vannina G

    2017-01-01

    performed microarrays and quantitative PCRs in the liver. In addition, we investigated the gut microbiota composition, bile acid profile and both liver and plasma metabolome. We analysed the expression pattern of genes in the liver of obese humans developing non-alcoholic steatohepatitis (NASH). RESULTS...... proliferator activator receptor-α, farnesoid X receptor (FXR), liver X receptors and STAT3) and bile acid profiles involved in glucose, lipid metabolism and inflammation. In addition to these alterations, the genetic deletion of MyD88 in hepatocytes changes the gut microbiota composition and their metabolomes...

  13. DL-2-amino-3-phosphonopropionic acid protects primary neurons from oxygen-glucose deprivation induced injury

    Directory of Open Access Journals (Sweden)

    Di Cui

    2017-02-01

    Full Text Available Cerebral infarction is a type of ischemic stroke and is one of the main causes of irreversible brain damage. Although multiple neuroprotective agents have been investigated recently, the potential of DL-2-amino-3-phosphonopropionic acid (DL-AP3 in treating oxygen-glucose deprivation (OGD-induced neuronal injury, has not been clarified yet. This study was aimed to explore the role of DL-AP3 in primary neuronal cell cultures. Primary neurons were divided into four groups: (1 a control group that was not treated; (2 DL-AP3 group treated with 10 μM of DL-AP3; (3 OGD group, in which neurons were cultured under OGD conditions; and (4 OGD + DL-AP3 group, in which OGD model was first established and then the cells were treated with 10 μM of DL-AP3. Neuronal viability and apoptosis were measured using Cell Counting Kit-8 and flow cytometry. Expressions of phospho-Akt1 (p-Akt1 and cytochrome c were detected using Western blot. The results showed that DL-AP3 did not affect neuronal viability and apoptosis in DL-AP3 group, nor it changed p-Akt1 and cytochrome c expression (p > 0.05. In OGD + DL-AP3 group, DL-AP3 significantly attenuated the inhibitory effects of OGD on neuronal viability (p < 0.001, and reduced OGD induced apoptosis (p < 0.01. Additionally, the down-regulation of p-Akt1 and up-regulation of cytochrome c, induced by OGD, were recovered to some extent after DL-AP3 treatment (p < 0.05 or p < 0.001. Overall, DL-AP3 could protect primary neurons from OGD-induced injury by affecting the viability and apoptosis of neurons, and by regulating the expressions of p-Akt1 and cytochrome c.

  14. DL-2-amino-3-phosphonopropionic acid protects primary neurons from oxygen-glucose deprivation induced injury.

    Science.gov (United States)

    Cui, Di; Xu, Jun; Xu, Quanyi; Zuo, Guokun

    2017-02-21

    Cerebral infarction is a type of ischemic stroke and is one of the main causes of irreversible brain damage. Although multiple neuroprotective agents have been investigated recently, the potential of DL-2-amino-3-phosphonopropionic acid (DL-AP3) in treating oxygen-glucose deprivation (OGD)-induced neuronal injury, has not been clarified yet. This study was aimed to explore the role of DL-AP3 in primary neuronal cell cultures. Primary neurons were divided into four groups: (1) a control group that was not treated; (2) DL-AP3 group treated with 10 μM of DL-AP3; (3) OGD group, in which neurons were cultured under OGD conditions; and (4) OGD + DL-AP3 group, in which OGD model was first established and then the cells were treated with 10 μM of DL-AP3. Neuronal viability and apoptosis were measured using Cell Counting Kit-8 and flow cytometry. Expressions of phospho-Akt1 (p-Akt1) and cytochrome c were detected using Western blot. The results showed that DL-AP3 did not affect neuronal viability and apoptosis in DL-AP3 group, nor it changed p-Akt1 and cytochrome c expression (p > 0.05). In OGD + DL-AP3 group, DL-AP3 significantly attenuated the inhibitory effects of OGD on neuronal viability (p neurons from OGD-induced injury by affecting the viability and apoptosis of neurons, and by regulating the expressions of p-Akt1 and cytochrome c.

  15. Serum bile acids are higher in humans with prior gastric bypass: potential contribution to improved glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Patti, Mary-Elizabeth; Houten, Sander M; Bianco, Antonio C

    2009-01-01

    , glycochenodeoxycholic, and glycodeoxycholic acids were all significantly higher in GB compared to Ov (P glucose (r = -0.59, P triglycerides (r = -0.40, P = 0.05), and positively correlated with adiponectin (r = -0.48, P ... performed cross-sectional analysis of fasting serum bile acid composition and both fasting and post-meal metabolic variables, in three subject groups: (i) post-GB surgery (n = 9), (ii) without GB matched to preoperative BMI of the index cohort (n = 5), and (iii) without GB matched to current BMI...... of the index cohort (n = 10). Total serum bile acid concentrations were higher in GB (8.90 +/- 4.84 micromol/l) than in both overweight (3.59 +/- 1.95, P = 0.005, Ov) and severely obese (3.86 +/- 1.51, P = 0.045, MOb). Bile acid subfractions taurochenodeoxycholic, taurodeoxycholic, glycocholic...

  16. Hyperlipidaemia is associated with increased insulin-mediated glucose metabolism, reduced fatty acid metabolism and normal blood pressure in transgenic mice overexpressing human apolipoprotein C1

    NARCIS (Netherlands)

    Koopmans, S.J.; Jong, M.C.; Que, I.; Dahlmans, V.E.H.; Pijl, H.; Radder, J.K.; Frölich, M.; Havekes, L.M.

    2001-01-01

    Aims/hypothesis. Insulin resistance for glucose metabolism is associated with hyperlipidaemia and high blood pressure. In this study we investigated the effect of primary hyperlipidaemia on basal and insulin-mediated glucose and on non-esterified fatty acid (NEFA) metabolism and mean arterial

  17. Myeloperoxidase amplified high glucose-induced endothelial dysfunction in vasculature: Role of NADPH oxidase and hypochlorous acid.

    Science.gov (United States)

    Tian, Rong; Ding, Yun; Peng, Yi-Yuan; Lu, Naihao

    2017-03-11

    Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H 2 O 2 ), have emerged as important molecules in the pathogenesis of diabetic endothelial dysfunction. Additionally, neutrophils-derived myeloperoxidase (MPO) and MPO-catalyzed hypochlorous acid (HOCl) play important roles in the vascular injury. However, it is unknown whether MPO can use vascular-derived ROS to induce diabetic endothelial dysfunction. In the present study, we demonstrated that NADPH oxidase was the main source of ROS formation in high glucose-cultured human umbilical vein endothelial cells (HUVECs), and played a critical role in high glucose-induced endothelial dysfunction such as cell apoptosis, loss of cell viability and reduction of nitric oxide (NO). However, the addition of MPO could amplify the high glucose-induced endothelial dysfunction which was inhibited by the presence of apocynin (NADPH oxidase inhibitor), catalase (H 2 O 2 scavenger), or methionine (HOCl scavenger), demonstrating the contribution of NADPH oxidase-H 2 O 2 -MPO-HOCl pathway in the MPO/high glucose-induced vascular injury. In high glucose-incubated rat aortas, MPO also exacerbated the NADPH oxidase-induced impairment of endothelium-dependent relaxation. Consistent with these in vitro data, in diabetic rat aortas, both MPO expresion and NADPH oxidase activity were increased while the endothelial function was simultaneously impaired. The results suggested that vascular-bound MPO could amplify high glucose-induced vascular injury in diabetes. MPO-NADPH oxidase-HOCl may represent an important pathogenic pathway in diabetic vascular diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Weight-related differences in glucose metabolism and free fatty acid production in two South African population groups.

    Science.gov (United States)

    Punyadeera, C; van der Merwe, M T; Crowther, N J; Toman, M; Immelman, A R; Schlaphoff, G P; Gray, I P

    2001-08-01

    The effects of free fatty acids (FFA), leptin, tumour necrosis factor (TNF) alpha and body fat distribution on in vivo oxidation of a glucose load were studied in two South African ethnic groups. Anthropometric and various metabolic indices were measured at fasting and during a 7 h oral glucose tolerance test (OGTT). Body composition was measured using bioelectrical impedance analysis and subcutaneous and visceral fat mass was assessed using a five- and two-level CT-scan respectively. Glucose oxidation was evaluated by measuring the ratio of (13)CO(2) to (12)CO(2) in breath following ingestion of 1-(13)C-labelled glucose. Ten lean black women (LBW), ten obese black women (OBW), nine lean white women (LWW) and nine obese white women (OWW) were investigated after an overnight fast. Visceral fat levels were significantly higher (Pdifferences in glucose oxidation however; in the lean subjects of both ethnic groups the area under the curve (AUC) was higher than in obese subjects (Pgroups. Percentage suppression of FFAs at 30 min of the OGTT was 24+/-12% in OWW and -38+/-23% (Pgroup. AUC for FFAs during the late postprandial period (120--420 min) was significantly higher in OWW than OBW (Pgroups compared to the lean women. Glucose oxidation is reduced in obese subjects of both ethnic groups; inter- and intra-ethnic differences were observed in visceral fat mass and FFA production and it is possible that such differences may play a role in the differing prevalences of obesity-related disorders that have been reported in these two populations.

  19. Improving monoterpene geraniol production through geranyl diphosphate synthesis regulation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Zhao, Jianzhi; Bao, Xiaoming; Li, Chen; Shen, Yu; Hou, Jin

    2016-05-01

    Monoterpenes have wide applications in the food, cosmetics, and medicine industries and have recently received increased attention as advanced biofuels. However, compared with sesquiterpenes, monoterpene production is still lagging in Saccharomyces cerevisiae. In this study, geraniol, a valuable acyclic monoterpene alcohol, was synthesized in S. cerevisiae. We evaluated three geraniol synthases in S. cerevisiae, and the geraniol synthase Valeriana officinalis (tVoGES), which lacked a plastid-targeting peptide, yielded the highest geraniol production. To improve geraniol production, synthesis of the precursor geranyl diphosphate (GPP) was regulated by comparing three specific GPP synthase genes derived from different plants and the endogenous farnesyl diphosphate synthase gene variants ERG20 (G) (ERG20 (K197G) ) and ERG20 (WW) (ERG20 (F96W-N127W) ), and controlling endogenous ERG20 expression, coupled with increasing the expression of the mevalonate pathway by co-overexpressing IDI1, tHMG1, and UPC2-1. The results showed that overexpressing ERG20 (WW) and strengthening the mevalonate pathway significantly improved geraniol production, while expressing heterologous GPP synthase genes or down-regulating endogenous ERG20 expression did not show positive effect. In addition, we constructed an Erg20p(F96W-N127W)-tVoGES fusion protein, and geraniol production reached 66.2 mg/L after optimizing the amino acid linker and the order of the proteins. The best strain yielded 293 mg/L geraniol in a fed-batch cultivation, a sevenfold improvement over the highest titer previously reported in an engineered S. cerevisiae strain. Finally, we showed that the toxicity of geraniol limited its production. The platform developed here can be readily used to synthesize other monoterpenes.

  20. Susceptibility to Verticillium longisporum is linked to monoterpene production by TPS23/27 in Arabidopsis.

    Science.gov (United States)

    Roos, Jonas; Bejai, Sarosh; Mozūraitis, Raimondas; Dixelius, Christina

    2015-02-01

    The fungus Verticillium longisporum is a soil-borne plant pathogen of increasing economic importance, and information on plant responses to it is limited. To identify the genes and components involved in the early stages of infection, transcripts in roots of V. longisporum-challenged Arabidopsis Col-0 and the susceptible NON-RACE SPECIFIC DISEASE RESISTANCE 1 (ndr1-1) mutant were compared using ATH1 gene chips. The analysis revealed altered transcript levels of several terpene biosynthesis genes, including the monoterpene synthase TPS23/27. When transgenic 35S:TPS23/27 and TPS23/27-amiRNA plants were monitored the over-expresser line showed enhanced fungal colonization whereas the silenced genotype was indistinguishable from Col-0. Transcript analysis of terpene biosynthesis genes suggested that only the TPS23/27 pathway is affected in the two transgenic genotypes. To confirm changes in monoterpene production, emitted volatiles were determined using solid-phase microextraction and gas chromatography-mass spectrometry. Levels of all identified TPS23/27 monoterpene products were significantly altered in the transgenic plants. A stimulatory effect on conidial germination and hyphal growth of V. longisporum was also seen in co-cultivation with 35S:TPS23/27 plants and upon exposure to 1,8-cineole, the main product of TPS23/27. Methyl jasmonate treatments of myc2-1 and myc2-2 mutants and analysis of TPS23/27:uidA in the myc2-2 background suggested a dependence on jasmonic acid mediated by the transcription factor MYC2. Taken together, our results show that TPS23/27-produced monoterpenes stimulate germination and subsequent invasion of V. longisporum in Arabidopsis roots. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  1. Yields of 2-deoxy-D-gluconic, D-gluconic and other sugar acids in gamma-irradiated aqueous solutions of D-glucose. [Gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Esterbauer, H; Schubert, J; Sanders, E B; Sweeley, C C [Pittsburgh Univ., Pa. (USA); Michigan State Univ., East Lansing (USA). Dept. of Biochemistry)

    1977-03-01

    The yields of 2-deoxy-D-gluconic, D-gluconic and other sugar acids from /sup 60/Co-gamma irradiated (dose-rate = 4 Krads/min) D-glucose solutions are reported. The acids produced upon radiolysis were separated from glucose and neutral products by anion exchange, assayed by gas chromatography of the trimethylsilyl derivatives, and definitive identification made by mass spectrometry. In He degassed, irradiated 0.055 M glucose G(2-deoxy-D-gluconic acid) = 0.62 and G(D-gluconic acid) = 0.20. The approximate G values for the other identified acids are: glyceric acid 0.03, 2-deoxy-tetronic acid 0.04, tetronic acid 0.03, 4-deoxypentonic acid 0.02, deoxyketogluconic acid 0.17. In N/sub 2/O saturated glucose solutions D-gluconic acid yields increased by a factor of approximately 1.9 while that of 2-deoxy-D-gluconic acid increased by a factor of only approximately 1.1.

  2. Common variants related to serum uric acid concentrations are associated with glucose metabolism and insulin secretion in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Xue Sun

    Full Text Available Elevated serum uric acid concentration is an independent risk factor and predictor of type 2 diabetes (T2D. Whether the uric acid-associated genes have an impact on T2D remains unclear. We aimed to investigate the effects of the uric acid-associated genes on the risk of T2D as well as glucose metabolism and insulin secretion.We recruited 2,199 normal glucose tolerance subjects from the Shanghai Diabetes Study I and II and 2,999 T2D patients from the inpatient database of Shanghai Diabetes Institute. Fifteen single nucleotide polymorphisms (SNPs mapped in or near 11 loci (PDZK1, GCKR, LRP2, SLC2A9, ABCG2, LRRC16A, SLC17A1, SLC17A3, SLC22A11, SLC22A12 and SF1 were genotyped and serum biochemical parameters related to uric acid and T2D were determined.SF1 rs606458 showed strong association to T2D in both males and females (p = 0.034 and 0.0008. In the males, LRRC16A was associated with 2-h insulin and insulin secretion (p = 0.009 and 0.009. SLC22A11 was correlated with HOMA-B and insulin secretion (p = 0.048 and 0.029. SLC2A9 rs3775948 was associated with 2-h glucose (p = 0.043. In the females, LRP2 rs2544390 and rs1333049 showed correlations with fasting insulin, HOMA-IR and insulin secretion (p = 0.028, 0.033 and 0.052 and p = 0.034, 0.047 and 0.038, respectively. SLC2A9 rs11722228 was correlated with 2-h glucose, 2-h insulin and insulin secretion (p = 0.024, 0.049 and 0.049, respectively.Our results indicated that the uric acid-associated genes have an impact on the risk of T2D, glucose metabolism and insulin secretion in a Chinese population.

  3. Deletion of the Saccharomyces cerevisiae ARO8 gene, encoding an aromatic amino acid transaminase, enhances phenylethanol production from glucose.

    Science.gov (United States)

    Romagnoli, Gabriele; Knijnenburg, Theo A; Liti, Gianni; Louis, Edward J; Pronk, Jack T; Daran, Jean-Marc

    2015-01-01

    Phenylethanol has a characteristic rose-like aroma that makes it a popular ingredient in foods, beverages and cosmetics. Microbial production of phenylethanol currently relies on whole-cell bioconversion of phenylalanine with yeasts that harbour an Ehrlich pathway for phenylalanine catabolism. Complete biosynthesis of phenylethanol from a cheap carbon source, such as glucose, provides an economically attractive alternative for phenylalanine bioconversion. In this study, synthetic genetic array (SGA) screening was applied to identify genes involved in regulation of phenylethanol synthesis in Saccharomyces cerevisiae. The screen focused on transcriptional regulation of ARO10, which encodes the major decarboxylase involved in conversion of phenylpyruvate to phenylethanol. A deletion in ARO8, which encodes an aromatic amino acid transaminase, was found to underlie the transcriptional upregulation of ARO10 during growth, with ammonium sulphate as the sole nitrogen source. Physiological characterization revealed that the aro8Δ mutation led to substantial changes in the absolute and relative intracellular concentrations of amino acids. Moreover, deletion of ARO8 led to de novo production of phenylethanol during growth on a glucose synthetic medium with ammonium as the sole nitrogen source. The aro8Δ mutation also stimulated phenylethanol production when combined with other, previously documented, mutations that deregulate aromatic amino acid biosynthesis in S. cerevisiae. The resulting engineered S. cerevisiae strain produced >3 mm phenylethanol from glucose during growth on a simple synthetic medium. The strong impact of a transaminase deletion on intracellular amino acid concentrations opens new possibilities for yeast-based production of amino acid-derived products. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Electro chemiluminescence Biosensor Based on Thioglycolic Acid-Capped Cd Se QDs for Sensing Glucose

    International Nuclear Information System (INIS)

    Jung, E. Y.; Ye, J. H.; Choi, S. H.; Jung, S. H.

    2016-01-01

    In order to detect low level glucose concentration, an electro chemiluminescence (ECL) biosensor based on TGA-capped Cd Se quantum dots (QDs) was fabricated by the immobilization of Cd Se QDs after modifying the surface of a glassy carbon electrode (GCE) with 4-amino thiophenol diazonium salts by the electrochemical method. For the detection of glucose concentration, glucose oxidase (GOD) was immobilized onto the fabricated Cd Se QDs-modified electrode. The fabricated ECL biosensor based on TGA-capped Cd Se QDs was characterized using a scanning electron microscope (SEM), UV-vis spectrophotometry, transmission electron microscopy (TEM), a fluorescence spectrometer (PL), and cyclic voltammetry (CV). The fabricated ECL biosensor based on TGA-capped Cd Se QDs is suitable for the detection of glucose concentrations in real human blood samples.

  5. Electrochemiluminescence Biosensor Based on Thioglycolic Acid-Capped CdSe QDs for Sensing Glucose

    Directory of Open Access Journals (Sweden)

    Eun-Young Jung

    2016-01-01

    Full Text Available In order to detect low level glucose concentration, an electrochemiluminescence (ECL biosensor based on TGA-capped CdSe quantum dots (QDs was fabricated by the immobilization of CdSe QDs after modifying the surface of a glassy carbon electrode (GCE with 4-aminothiophenol diazonium salts by the electrochemical method. For the detection of glucose concentration, glucose oxidase (GOD was immobilized onto the fabricated CdSe QDs-modified electrode. The fabricated ECL biosensor based on TGA-capped CdSe QDs was characterized using a scanning electron microscope (SEM, UV-vis spectrophotometry, transmission electron microscopy (TEM, a fluorescence spectrometer (PL, and cyclic voltammetry (CV. The fabricated ECL biosensor based on TGA-capped CdSe QDs is suitable for the detection of glucose concentrations in real human blood samples.

  6. Effects of glucogenic and ketogenic feeding strategies on splanchnic glucose and amino acid metabolism in postpartum transition Holstein cows.

    Science.gov (United States)

    Larsen, M; Kristensen, N B

    2012-10-01

    Nine periparturient Holstein cows catheterized in major splanchnic vessels were used in a complete randomized design with repeated measurements to investigate effects of glucogenic and ketogenic feeding strategies on splanchnic metabolism of glucose and amino acids. At parturition, cows were assigned to 1 of 3 feeding strategies: a glucogenic diet (GLCG) based on sodium hydroxide treated wheat grain (56.5% of diet dry matter); a ketogenic diet (KETO) based on fodder beets (40.5% of diet dry matter); or an alfalfa-glucogenic strategy (ALF-GLCG) supplying 100% alfalfa (Medicago sativa L.) haylage at the day of parturition, followed by a 6-d linear shift to the GLCG diet. Samples were obtained 14 d before expected parturition as well as at 4, 15, and 29 d in milk (DIM). The net portal release of glucose was greatest with GLCG, reflecting the higher intake of ruminal escape starch with GLCG, as compared with a lower starch intake with KETO. Postpartum, the portal recovery of feed starch was greater (28 ± 3%, mean ± SEM) with KETO as compared with GLCG (15 ± 4%). At 4 DIM, the net hepatic release of glucose was greatest with KETO and least with ALF-GLCG, whereafter it increased as lactation progressed with ALF-GLCG and GLCG, but not with KETO. The high alfalfa haylage allowance at 4 DIM with the ALF-GLCG treatment induced the lowest net release of nutrients from the splanchnic tissues at 4 DIM. The hepatic removal of lactate as percent of total influx (mean ± SEM) increased from 27 ± 3% prepartum to 56 ± 3% at 4 DIM. The hepatic removal of lactate as percent of net portal release increased from 144 ± 10% prepartum to 329 ± 17% at 4 DIM with ALF-GLCG and KETO as compared with 242 ± 20% in GLCG. No clear evidence for an amino acid sparing effect in splanchnic tissues from increasing small intestinal glucose absorption was observed. In conclusion, the glucogenic feeding strategy induced the highest glucogenic status among the tested feeding strategies due to

  7. Antitumor Activity of Monoterpenes Found in Essential Oils

    Directory of Open Access Journals (Sweden)

    Marianna Vieira Sobral

    2014-01-01

    Full Text Available Cancer is a complex genetic disease that is a major public health problem worldwide, accounting for about 7 million deaths each year. Many anticancer drugs currently used clinically have been isolated from plant species or are based on such substances. Accumulating data has revealed anticancer activity in plant-derived monoterpenes. In this review the antitumor activity of 37 monoterpenes found in essential oils is discussed. Chemical structures, experimental models, and mechanisms of action for bioactive substances are presented.

  8. Monoterpene emissions from an understory species, Pteridium aquilinum

    Science.gov (United States)

    Madronich, Monica B.; Greenberg, James P.; Wessman, Carol A.; Guenther, Alex B.

    2012-07-01

    Monoterpene emissions from the dominant understory species Pteridium aquilinum (Bracken fern) in a mixed temperate forest were measured in the field during the summers of 2006, 2007 and 2008. The results showed that Bracken fern emitted monoterpenes at different rates depending if the plants were located in the understory or in open areas. Understory plants emitted monoterpene levels ranging from 0.002 to 13 μgC gdw-1 h-1. Open area plants emitted monoterpene levels ranging from 0.005 to 2.21 μgC gdw-1 h-1. During the summer of 2008 greenhouse studies were performed to complement the field studies. Only 3% of the greenhouse Bracken fern plants emitted substantial amounts of monoterpenes. The average emission, 0.15 μgC gdw-1 h-1 ± 0.9 μgC gdw-1 h-1, was much lower than that observed in the field. The factors controlling monoterpene emissions are not clear, but this study provides evidence of the potential importance of understory vegetation to ecosystem total hydrocarbon emissions and emphasizes the need for longer-term field studies.

  9. ZIF-67 derived porous Co3O4 hollow nanopolyhedron functionalized solution-gated graphene transistors for simultaneous detection of glucose and uric acid in tears.

    Science.gov (United States)

    Xiong, Can; Zhang, Tengfei; Kong, Weiyu; Zhang, Zhixiang; Qu, Hao; Chen, Wei; Wang, Yanbo; Luo, Linbao; Zheng, Lei

    2018-03-15

    Biomarkers in tears have attracted much attention in daily healthcare sensing and monitoring. Here, highly sensitive sensors for simultaneous detection of glucose and uric acid are successfully constructed based on solution-gated graphene transistors (SGGTs) with two separate Au gate electrodes, modified with GOx-CHIT and BSA-CHIT respectively. The sensitivity of the SGGT is dramatically improved by co-modifying the Au gate with ZIF-67 derived porous Co 3 O 4 hollow nanopolyhedrons. The sensing mechanism for glucose sensor is attributed to the reaction of H 2 O 2 generated by the oxidation of glucose near the gate, while the sensing mechanism for uric acid is due to the direct electro-oxidation of uric acid molecules on the gate. The optimized glucose and uric acid sensors show the detection limits both down to 100nM, far beyond the sensitivity required for non-invasive detection of glucose and uric acid in tears. The glucose and uric acid in real tear samples was quantitatively detected at 323.2 ± 16.1μM and 98.5 ± 16.3μM by using the functionalized SGGT device. Due to the low-cost, high-biocompatibility and easy-fabrication features of the ZIF-67 derived porous Co 3 O 4 hollow nanopolyhedron, they provide excellent electrocatalytic nanomaterials for enhancing sensitivity of SGGTs for a broad range of disease-related biomarkers. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Antifungal Monoterpene Derivatives from the Plant Endophytic Fungus Pestalotiopsis foedan.

    Science.gov (United States)

    Xu, Dan; Zhang, Bing-Yang; Yang, Xiao-Long

    2016-10-01

    A new monoterpene lactone, (1R,4R,5R,8S)-8-hydroxy-4,8-dimethyl-2-oxabicyclo[3.3.1]nonan-3-one (1), along with one related known compound, (2R)-2-[(1R)-4-methylcyclohex-3-en-1-yl]propanoic acid (2), were isolated from the liquid culture of the plant endophytic fungus Pestalotiopsis foedan obtained from the branch of Bruguiera sexangula. The structure and absolute configuration of 1 were determined on the basis of extensive analysis of NMR spectra combined with computational methods via calculation of the optical rotation (OR) and 13 C-NMR. Both compounds exhibited strong antifungal activities against Botrytis cinerea and Phytophthora nicotianae with MIC values of 3.1 and 6.3 μg/ml, respectively, which are comparable to those of the known antifungal drug ketoconazole. Compound 2 also showed modest antifungal activity against Candida albicans with a MIC value of 50 μg/ml. © 2016 Wiley-VHCA AG, Zürich.

  11. Red blood transfusion in preterm infants: changes in glucose, electrolytes and acid base balance

    Directory of Open Access Journals (Sweden)

    Shereen Abdelghaffar

    2012-01-01

    Full Text Available Background: Preterm neonates comprise the most heavily transfused group of patients, and about 85% of extremely low birth weight newborns receive a transfusion by the end of their hospital stay. The aim of this study was to assess the possible metabolic effects of RBC transfusion on preterm infants, especially during the first 2 weeks of life, and its relation to blood volume. Materials and Methods: This study was conducted on 40 preterm neonates with gestational age of less than or equal to 34 weeks. They received RBCs transfusion during first 2 weeks of life. Venous blood samples of infants were collected 2 to 4 hours before and 1 hour after the end of transfusion to evaluate hemoglobin (Hb level, hematocrit, acid-base, electrolytes, and glucose status. Then, infants were classified into two main groups: those who received RBCs volume less than or 20 ml/kg and those who received RBCs volume more than 20 ml/kg. Results: Infants received a mean volume of 20.38 ± 3.2 ml/kg RBCs (range, 10.9 - 26.6 ml/kg at a median age of 9.8 ± 3.6 days. After transfusion, a significant increase of mean Hb (P<0.001, mean Hct (P<0.001, pH (P<0.001, pO 2 (P<0.05, and a significant decrease of the pCO2 (41.46 ± 8.8torr vs 35.4 ± 9.34 torr; P<0.001 were observed. In addition, there was a significant increase of serum K + (P<0.001, and a significant decrease of Ca +2 (P<0.001. A positive correlation was found between the K + intake and the changes of kalemia (r = 0.99; P = 0.00. Furthermore, we observed an inverse correlation between the patients′ calcium intake and the changes of calcemia (r = -0.35; P = 0.02. On comparing the changes in clinical and biochemical variables between two groups after transfusion, we observed a significant increase in mean Hb and Hct associated with a significant decrease in mean serum Ca +2 (P<0.001 in the group receiving the larger blood volume. Conclusion: RBC transfusion was effective in improving anemia, oxygenation, increasing

  12. Effects of glucogenic and ketogenic feeding strategies on splanchnic glucose and amino acid metabolism in postpartum transition Holstein cows

    DEFF Research Database (Denmark)

    Larsen, Mogens; Kristensen, Niels Bastian

    2012-01-01

    assigned to 1 of 3 feeding strategies: a glucogenic diet (GLCG) based on sodium hydroxide treated wheat grain (56.5% of diet dry matter); a ketogenic diet (KETO) based on fodder beets (40.5% of diet dry matter); or an alfalfa-glucogenic strategy (ALF-GLCG) supplying 100% alfalfa (Medicago sativa L......Nine periparturient Holstein cows catheterized in major splanchnic vessels were used in a complete randomized design with repeated measurements to investigate effects of glucogenic and ketogenic feeding strategies on splanchnic metabolism of glucose and amino acids. At parturition, cows were.......) haylage at the day of parturition, followed by a 6-d linear shift to the GLCG diet. Samples were obtained 14 d before expected parturition as well as at 4, 15, and 29 d in milk (DIM). The net portal release of glucose was greatest with GLCG, reflecting the higher intake of ruminal escape starch with GLCG...

  13. Maintenance of plasma branched-chain amino acid concentrations during glucose infusion directs essential amino acids to extra-mammary tissues in lactating dairy cows.

    Science.gov (United States)

    Curtis, Richelle V; Kim, Julie J M; Doelman, John; Cant, John P

    2018-05-01

    The objectives of this study were to investigate the effects of branched-chain AA (BCAA) supplementation when glucose is infused postruminally into lactating dairy cows consuming a diet low in crude protein (CP) and to test the hypothesis that low BCAA concentrations are responsible for the poor stimulation of milk protein yield by glucose. Twelve early-lactation Holstein cows were randomly assigned to 15% and 12% CP diets in a switchback design of 6-wk periods. Cows consuming the 12% CP diet received 96-h continuous jugular infusions of saline and 1 kg/d of glucose with 0, 75, or 150 g/d of BCAA in a Latin square sequence of treatments. Compared with saline, glucose infusion did not affect dry matter intake but increased milk yield by 2.2 kg/d and milk protein and lactose yields by 63 and 151 g/d, respectively. Mammary plasma flow increased 36% during glucose infusion compared with saline infusion, possibly because of a 31% decrease in total acetate plus β-hydroxybutyrate concentrations. Circulating concentrations of total essential AA and BCAA decreased 19 and 31%, respectively, during infusion of glucose, yet net mammary uptakes of AA remained unchanged compared with saline infusion. The addition of 75 and 150 g/d of BCAA to glucose infusions increased arterial concentrations of BCAA to 106 and 149%, respectively, of the concentrations in saline-infused cows, but caused a decrease in concentrations of non-branched-chain essential AA in plasma, as well as their mammary uptakes and milk protein yields. Plasma urea concentration was not affected by BCAA infusion, indicating no change in catabolism of AA. The lack of mammary and catabolic effects leads us to suggest that BCAA exerted their effects on plasma concentrations of the other essential AA by stimulating utilization in skeletal muscle for protein accretion. Results indicate that the glucose effect on milk protein yield was not limited by low BCAA concentrations, and that a stimulation of extra-mammary use

  14. Effect of oleic acid on the production of ethanol and fructose from glucose/fructose mixtures in an immobilized cell reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guenette, M E [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering; [IOGEN Corp., Ottawa, ON (Canada); Duvnjak, Z [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering; [IOGEN Corp., Ottawa, ON (Canada)

    1996-12-31

    Saccharomyces cerevisiae ATCC 39859 was immobilized onto small cubes of wood to produce ethanol and very enriched fructose syrup from glucose/fructose mixtures through the selective fermentation of glucose. A maximum ethanol productivity of 21.9 g/l.h was attained from a feed containing 9.7% (w/v) glucose and 9.9% (w/v) fructose. An ethanol concentration, glucose conversion and fructose yield of 29.6 g/l, 62% and 99% were obtained, respectively. This resulted in a final fructose/glucose ratio of 2.7. At lower ethanol productivity levels the fructose/glucose ratio increases, as does the ethanol concentration in the effluent. The addition of 30 mg/l oleic acid to the medium increased the ethanol productivity and its concentration by 13% at a dilution rate of 0.74 h{sup -1}. (orig.)

  15. Emission and Accumulation of Monoterpene and the Key Terpene Synthase (TPS) Associated with Monoterpene Biosynthesis in Osmanthus fragrans Lour

    OpenAIRE

    Zeng, Xiangling; Liu, Cai; Zheng, Riru; Cai, Xuan; Luo, Jing; Zou, Jingjing; Wang, Caiyun

    2016-01-01

    Osmanthus fragrans is an ornamental and economically important plant known for its magnificent aroma, and the most important aroma-active compounds in flowers are monoterpenes, mainly β-ocimene, linalool and linalool derivatives. To understand the molecular mechanism of monoterpene production, we analyzed the emission and accumulation patterns of these compounds and the transcript levels of the genes involved in their biosynthesis in two O. fragrans cultivars during flowering stages. The resu...

  16. Phosphomolybdic acid functionalized graphene loading copper nanoparticles modified electrodes for non-enzymatic electrochemical sensing of glucose

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jiaoyan; Cao, Xiyue [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Xia, Jianfei, E-mail: xiajianfei@126.com [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Gong, Shida [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Wang, Zonghua, E-mail: wangzonghua@qdu.edu.cn [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Lu, Lin [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Zibo Normal College, Zibo, Shandong 255100 (China)

    2016-08-31

    A sensitive non-enzymatic glucose electrochemical biosensor (Cu/PMo{sub 12}-GR/GCE) was developed based on the combination of copper nanoparticles (CuNPs) and phosphomolybdic acid functionalized graphene (PMo{sub 12}-GR). PMo{sub 12}-GR films were modified on the surface of glassy carbon electrode (GCE) through electrostatic self-assembly with the aid of poly diallyl dimethyl ammonium chloride (PDDA). Then CuNPs were successfully decorated onto the PMo{sub 12}-GR modified GCE through electrodeposition. The morphology of Cu/PMo{sub 12}-GR/GCE was characterized by scanning electron microscope (SEM). Cyclic voltammetry (CV) and chronoamperometry were used to investigate the electrochemical performances of the biosensor. The results indicated that the modified electrode displayed a synergistic effect of PMo{sub 12}-GR sheets and CuNPs towards the electro-oxidation of glucose in the alkaline solution. At the optimal detection potential of 0.50 V, the response towards glucose presented a linear response ranging from 0.10 μM to 1.0 mM with a detection limit of 3.0 × 10{sup −2} μM (S/N = 3). In addition, Cu/PMo{sub 12}-GR/GCE possessed a high selectivity, good reproducibility, excellent stability and acceptable recovery, which indicating the potential application in clinical field. - Highlights: • Cu/PMo{sub 12}-GR/GCE as a non-enzymatic glucose electrochemical sensor. • PMo{sub 12} is efficient for the uniform growth of Cu-NPs and electron transport. • The sensor exhibits good sensitivity and specificity towards glucose.

  17. Molecular cloning and expression levels of the monoterpene synthase gene (ZMM1 in Cassumunar ginger (Zingiber montanum (Koenig Link ex Dietr.

    Directory of Open Access Journals (Sweden)

    Bua-In Saowaluck

    2014-01-01

    Full Text Available Cassumunar ginger (Zingiber montanum (Koenig Link ex Dietr. is a native Thai herb with a high content and large variety of terpenoids in its essential oil. Improving the essential oil content and quality of cassumunar ginger is difficult for a breeder due to its clonally propagated nature. In this research, we describe the isolation and expression level of the monoterpene synthase gene that controls the key step of essential oil synthesis in this plant and evaluate the mechanical wounding that may influence the transcription level of the monoterpene synthase gene. To isolate the gene, the selected clones from DNA derived from young leaves were sequenced and analyzed and the monoterpene synthase gene from cassumunar ginger (ZMM1 was identified. The ZMM1 CDS containing 1 773 bp (KF500399 is predicted to encode a protein of 590 amino acids. The deduced amino acid sequence is 40-74% identical with known sequences of other angiosperm monoterpene synthases belonging to the isoprenoid biosynthesis C1 superfamily. A transcript of ZMM1 was detected almost exclusively in the leaves and was related to leaf wounding. The results of this research offer insight into the control of monoterpene synthesis in this plant. This finding can be applied to breeding programs or crop management of cassumunar ginger for better yield and quality of essential oil.

  18. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation.

    Science.gov (United States)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian; Wagtberg Sen, Jette; Rasmussen, Søren Kofoed; Kontoravdi, Cleo; Weilguny, Dietmar; Andersen, Mikael Rørdam

    2015-03-01

    Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylation-related product quality. In this work, different fed-batch processes with two chemically defined proprietary media and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards energy and recombinant product, respectively. Accumulation of by-products such as NH4(+) and lactate as a consequence of unbalanced nutrient supply to cell activities inhibits cell growth. The levels of Leu and Arg in the culture, which relate to cell growth and IgG productivity, need to be well controlled. Amino acids with the highest consumption rates correlate with the most abundant amino acids present in the produced IgG, and thus require sufficient availability during culture. Case-by-case analysis is necessary for understanding the effect of media and process optimization on glycosylation. We found that in certain cases the presence of Man5 glycan can be linked to limitation of UDP-GlcNAc biosynthesis as a result of insufficient extracellular Gln. However, under different culture conditions, high Man5 levels can also result from low α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase (GnTI) and UDP-GlcNAc transporter activities, which may be attributed to high level of NH4+ in the cell culture. Furthermore, galactosylation of the mAb Fc glycans

  19. Application of FIGAERO (Filter Inlet for Gases and AEROsol) coupled to a high resolution time of flight chemical ionization mass spectrometer to field and chamber organic aerosol: Implications for carboxylic acid formation and gas-particle partitioning from monoterpene oxidation

    Science.gov (United States)

    Lopez-Hilfiker, F.; Mohr, C.; Ehn, M.; Rubach, F.; Mentel, T. F.; Kleist, E.; Wildt, J.; Thornton, J. A.

    2013-12-01

    We present measurements of a large suite of gas and particle phase carboxylic acid containing compounds made with a Filter Inlet for Gas and AEROsol (FIGAERO) coupled to a high resolution time of flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington. A prototype operated with acetate negative ion proton transfer chemistry was deployed on the Julich Plant Atmosphere Chamber to study a-pinene oxidation, and a modified version was deployed at the SMEAR II forest station in Hyytiälä, Finland and SOAS, in Brent Alabama. We focus here on results from JPAC and Hyytiälä, where we utilized the same ionization method most selective towards carboxylic acids. In all locations, 100's of organic acid compounds were observed in the gas and particles and many of the same composition acids detected in the gas-phase were detected in the particles upon temperature programmed thermal desorption. Particulate organics detected by FIGAERO are highly correlated with organic aerosol mass measured by an AMS, providing additional volatility and molecular level information about collected aerosol. The fraction of a given compound measured in the particle phase follows expected trends with elemental composition, but many compounds would not be well described by an absorptive partitioning model assuming unity activity coefficients. Moreover the detailed structure in the thermal desorption signals reveals a contribution from thermal decomposition of large molecular weight organics and or oligomers with implications for partitioning measurements and model validation

  20. Oleic acid and glucose regulate glucagon-like peptide 1 receptor expression in a rat pancreatic ductal cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Leshuai W.; McMahon Tobin, Grainne A.; Rouse, Rodney L., E-mail: rodney.rouse@fda.hhs.gov

    2012-10-15

    The glucagon-like peptide 1 receptor (GLP1R) plays a critical role in glucose metabolism and has become an important target for a growing class of drugs designed to treat type 2 diabetes. In vitro studies were designed to investigate the effect of the GLP1R agonist, exenatide (Ex4), in “on-target” RIN-5mF (islet) cells as well as in “off-target” AR42J (acinar) and DSL-6A/C1 (ductal) cells in a diabetic environment. Ex4 increased islet cell proliferation but did not affect acinar cells or ductal cells at relevant concentrations. A high caloric, high fat diet is a risk factor for impaired glucose tolerance and type-2 diabetes. An in vitro Oleic acid (OA) model was used to investigate the effect of Ex4 in a high calorie, high fat environment. At 0.1 and 0.4 mM, OA mildly decreased the proliferation of all pancreatic cell types. Ex4 did not potentiate the inhibitory effect of OA on cell proliferation. Akt phosphorylation in response to Ex4 was diminished in OA-treated ductal cells. GLP1R protein detected by western blot was time and concentration dependently decreased after glucose stimulation in OA-treated ductal cells. In ductal cells, OA treatment altered the intracellular localization of GLP1R and its co-localization with early endosome and recycling endosomes. Chloroquine (lysosomal inhibitor), N-acetyl-L-cysteine (reactive oxygen species scavenger) and wortmannin (a phosphatidylinositol-3-kinase inhibitor), fully or partially, rescued GLP1R protein in OA-pretreated, glucose-stimulated ductal cells. The impact of altered regulation on phenotype/function is presently unknown. However, these data suggest that GLP1R regulation in ductal cells can be altered by a high fat, high calorie environment. -- Highlights: ► Exenatide did not inhibit islet, acinar or ductal cell proliferation. ► GLP1R protein decreased after glucose stimulation in oleic acid-treated ductal cells. ► Oleic acid treatment altered localization of GLP1R with early and recycling

  1. Oleic acid and glucose regulate glucagon-like peptide 1 receptor expression in a rat pancreatic ductal cell line

    International Nuclear Information System (INIS)

    Zhang, Leshuai W.; McMahon Tobin, Grainne A.; Rouse, Rodney L.

    2012-01-01

    The glucagon-like peptide 1 receptor (GLP1R) plays a critical role in glucose metabolism and has become an important target for a growing class of drugs designed to treat type 2 diabetes. In vitro studies were designed to investigate the effect of the GLP1R agonist, exenatide (Ex4), in “on-target” RIN-5mF (islet) cells as well as in “off-target” AR42J (acinar) and DSL-6A/C1 (ductal) cells in a diabetic environment. Ex4 increased islet cell proliferation but did not affect acinar cells or ductal cells at relevant concentrations. A high caloric, high fat diet is a risk factor for impaired glucose tolerance and type-2 diabetes. An in vitro Oleic acid (OA) model was used to investigate the effect of Ex4 in a high calorie, high fat environment. At 0.1 and 0.4 mM, OA mildly decreased the proliferation of all pancreatic cell types. Ex4 did not potentiate the inhibitory effect of OA on cell proliferation. Akt phosphorylation in response to Ex4 was diminished in OA-treated ductal cells. GLP1R protein detected by western blot was time and concentration dependently decreased after glucose stimulation in OA-treated ductal cells. In ductal cells, OA treatment altered the intracellular localization of GLP1R and its co-localization with early endosome and recycling endosomes. Chloroquine (lysosomal inhibitor), N-acetyl-L-cysteine (reactive oxygen species scavenger) and wortmannin (a phosphatidylinositol-3-kinase inhibitor), fully or partially, rescued GLP1R protein in OA-pretreated, glucose-stimulated ductal cells. The impact of altered regulation on phenotype/function is presently unknown. However, these data suggest that GLP1R regulation in ductal cells can be altered by a high fat, high calorie environment. -- Highlights: ► Exenatide did not inhibit islet, acinar or ductal cell proliferation. ► GLP1R protein decreased after glucose stimulation in oleic acid-treated ductal cells. ► Oleic acid treatment altered localization of GLP1R with early and recycling

  2. Thermodynamic study of selected monoterpenes II

    International Nuclear Information System (INIS)

    Štejfa, Vojtěch; Fulem, Michal; Růžička, Květoslav; Červinka, Ctirad

    2014-01-01

    Highlights: • (−)-Borneol, (−)-camphor, (±)-camphene, and (+)-fenchone were studied. • New thermodynamic data were measured and calculated. • Most of thermodynamic data are reported for the first time. - Abstract: A thermodynamic study of selected monoterpenes, (−)-borneol, (−)-camphor, (±)-camphene, and (+)-fenchone is presented in this work. The vapor pressure measurements were performed using the static method over the environmentally important temperature range from (238 to 308) K. Heat capacities of condensed phases were measured by Tian–Calvet calorimetry in the temperature interval from (258 to 355) K. The phase behavior was investigated by differential scanning calorimetry (DSC) from subambient temperatures up to the fusion temperatures. The thermodynamic properties in the ideal-gas state were calculated by combining statistical thermodynamic and density functional theory (DFT) calculations. Calculated ideal-gas heat capacities and experimental data for vapor pressures and condensed phase heat capacities were treated simultaneously to obtain a consistent thermodynamic description

  3. Monoterpene biosynthesis potential of plant subcellular compartments.

    Science.gov (United States)

    Dong, Lemeng; Jongedijk, Esmer; Bouwmeester, Harro; Van Der Krol, Alexander

    2016-01-01

    Subcellular monoterpene biosynthesis capacity based on local geranyl diphosphate (GDP) availability or locally boosted GDP production was determined for plastids, cytosol and mitochondria. A geraniol synthase (GES) was targeted to plastids, cytosol, or mitochondria. Transient expression in Nicotiana benthamiana indicated local GDP availability for each compartment but resulted in different product levels. A GDP synthase from Picea abies (PaGDPS1) was shown to boost GDP production. PaGDPS1 was also targeted to plastids, cytosol or mitochondria and PaGDPS1 and GES were coexpressed in all possible combinations. Geraniol and geraniol-derived products were analyzed by GC-MS and LC-MS, respectively. GES product levels were highest for plastid-targeted GES, followed by mitochondrial- and then cytosolic-targeted GES. For each compartment local boosting of GDP biosynthesis increased GES product levels. GDP exchange between compartments is not equal: while no GDP is exchanged from the cytosol to the plastids, 100% of GDP in mitochondria can be exchanged to plastids, while only 7% of GDP from plastids is available for mitochondria. This suggests a direct exchange mechanism for GDP between plastids and mitochondria. Cytosolic PaGDPS1 competes with plastidial GES activity, suggesting an effective drain of isopentenyl diphosphate from the plastids to the cytosol. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Gallic Acid Decreases Inflammatory Cytokine Secretion Through Histone Acetyltransferase/Histone Deacetylase Regulation in High Glucose-Induced Human Monocytes.

    Science.gov (United States)

    Lee, Wooje; Lee, Sang Yeol; Son, Young-Jin; Yun, Jung-Mi

    2015-07-01

    Hyperglycemia contributes to diabetes and several diabetes-related complications. Gallic acid is a polyhydroxy phenolic compound found in various natural products. In this study, we investigated the effects and mechanism of gallic acid on proinflammatory cytokine secretion in high glucose-induced human monocytes (THP-1 cells). THP-1 cells were cultured under normoglycemic or hyperglycemic conditions, in the absence or presence of gallic acid. Hyperglycemic conditions significantly induced histone acetylation, nuclear factor-κB (NF-κB) activation, and proinflammatory cytokine release from THP-1 cells, whereas gallic acid suppressed NF-κB activity and cytokine release. It also significantly reduced CREB-binding protein/p300 (CBP/p300, a NF-κB coactivator) gene expression, acetylation levels, and CBP/p300 histone acetyltransferase (HAT) activity. In addition, histone deacetylase 2 (HDAC2) expression was significantly induced. These results suggest that gallic acid inhibits hyperglycemic-induced cytokine production in monocytes through epigenetic changes involving NF-κB. Therefore, gallic acid may have potential for the treatment and prevention of diabetes and its complications.

  5. Human adipose tissue blood flow during prolonged exercise, III. Effect of beta-adrenergic blockade, nicotinic acid and glucose infusion

    DEFF Research Database (Denmark)

    Bülow, J

    1981-01-01

    Subcutaneous adipose tissue blood flow (ATBF) was measured in six male subjects by the 133Xe-washout technique during 3-4 h of exercise at a work load corresponding to an oxygen uptake of about 1.71/min. The measurements were done during control conditions, during blockade of lipolysis by nicotinic...... of work. No increase in lipolysis and no increase in ATBF were found when lipolysis was blocked by nicotinic acid (0.3 g/h). Propranolol treatment (0.15 mg/kg) reduced lipolysis and nearly abolished the increase in ATBF during exercise. Intravenous administration of glucose (about 0.25 g/min) did...

  6. Effect of petroleum vapors inhalation on intestinal absorption of glucose and some amino acids in the rat

    International Nuclear Information System (INIS)

    Szablicka, E.; Oledzka, R.

    1989-01-01

    The proper intestinal absorption of nutrients, particularly sugars and amino acids, is necessary to keep the organism healthy. It is well known that various toxic compounds present in the environment can have an unfavorable influence. On the other hand it is also known that crude oil which pollutes the aqueous environment affects birds' gastrointestinal tract. Little is known about the influence of petroleum vapors on the gastrointestinal tract of animals and humans. The present study was undertaken to determine the effect of petroleum vapors inhalation on intestinal absorption of some nutrients (glucose, leucine, methionine) in rats

  7. Serum Bile Acids Are Higher in Humans With Prior Gastric Bypass: Potential Contribution to Improved Glucose and Lipid Metabolism

    Science.gov (United States)

    Patti, Mary-Elizabeth; Houten, Sander M.; Bianco, Antonio C.; Bernier, Raquel; Larsen, P. Reed; Holst, Jens J.; Badman, Michael K.; Maratos-Flier, Eleftheria; Mun, Edward C.; Pihlajamaki, Jussi; Auwerx, Johan; Goldfine, Allison B.

    2015-01-01

    The multifactorial mechanisms promoting weight loss and improved metabolism following Roux-en-Y gastric bypass (GB) surgery remain incompletely understood. Recent rodent studies suggest that bile acids can mediate energy homeostasis by activating the G-protein coupled receptor TGR5 and the type 2 thyroid hormone deiodinase. Altered gastrointestinal anatomy following GB could affect enterohepatic recirculation of bile acids. We assessed whether circulating bile acid concentrations differ in patients who previously underwent GB, which might then contribute to improved metabolic homeostasis. We performed cross-sectional analysis of fasting serum bile acid composition and both fasting and post-meal metabolic variables, in three subject groups: (i) post-GB surgery (n = 9), (ii) without GB matched to preoperative BMI of the index cohort (n = 5), and (iii) without GB matched to current BMI of the index cohort (n = 10). Total serum bile acid concentrations were higher in GB (8.90 ± 4.84 µmol/l) than in both overweight (3.59 ± 1.95, P = 0.005, Ov) and severely obese (3.86 ± 1.51, P = 0.045, MOb). Bile acid subfractions taurochenodeoxycholic, taurodeoxycholic, glycocholic, glycochenodeoxycholic, and glycodeoxycholic acids were all significantly higher in GB compared to Ov (P fasting triglycerides (r = −0.40, P = 0.05), and positively correlated with adiponectin (r = −0.48, P < 0.02) and peak glucagon-like peptide-1 (GLP-1) (r = 0.58, P < 0.003). Total bile acids strongly correlated inversely with thyrotropic hormone (TSH) (r = −0.57, P = 0.004). Together, our data suggest that altered bile acid levels and composition may contribute to improved glucose and lipid metabolism in patients who have had GB. PMID:19360006

  8. Monoterpene and sesquiterpene synthases and the origin of terpene skeletal diversity in plants.

    Science.gov (United States)

    Degenhardt, Jörg; Köllner, Tobias G; Gershenzon, Jonathan

    2009-01-01

    The multitude of terpene carbon skeletons in plants is formed by enzymes known as terpene synthases. This review covers the monoterpene and sesquiterpene synthases presenting an up-to-date list of enzymes reported and evidence for their ability to form multiple products. The reaction mechanisms of these enzyme classes are described, and information on how terpene synthase proteins mediate catalysis is summarized. Correlations between specific amino acid motifs and terpene synthase function are described, including an analysis of the relationships between active site sequence and cyclization type and a discussion of whether specific protein features might facilitate multiple product formation.

  9. Glycolic acid synthesis during dark glucose U14C metabolism, in French Bean and Maize leaves

    International Nuclear Information System (INIS)

    Cailliau-Commanay, Lucienne; Calmes, Jean; Latche, J.-C.; Cavalie, Gerard

    1977-01-01

    Serine, glycerate and glycolate are among the first radioactive compounds when French Bean and Maize leaves are fed with glucose U 14 C. Failing to detect radioactive glycine suggests that glycolate so synthesized is unavailable for the photorespiration glycolate pool [fr

  10. Effect of abomasal glucose infusion on splanchnic amino acid metabolism in periparturient dairy cows

    DEFF Research Database (Denmark)

    Larsen, Mogens; Kristensen, Niels Bastian

    2009-01-01

    Six Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the portal vein, hepatic vein, mesenteric vein, and an artery were used to study the effects of abomasal glucose infusion on splanchnic AA metabolism. The experimental design was a split plot, with cow as the whole...

  11. The existence of an insulin-stimulated glucose and non-essential but not essential amino acid substrate interaction in diabetic pigs

    NARCIS (Netherlands)

    Koopmans, S.J.; Meulen, van der J.; Wijdenes, J.W.; Corbijn, H.; Dekker, R.A.

    2011-01-01

    Background The generation of energy from glucose is impaired in diabetes and can be compensated by other substrates like fatty acids (Randle cycle). Little information is available on amino acids (AA) as alternative energy-source in diabetes. To study the interaction between insulin-stimulated

  12. Branched chain enriched amino acid versus glucose treatment of hepatic encephalopathy. A double-blind study of 65 patients with cirrhosis

    DEFF Research Database (Denmark)

    Vilstrup, Hendrik; Gluud, C; Hardt, F

    1990-01-01

    We studied the effects of infusion of a branched chain enriched amino acid mixture versus glucose on acute hepatic encephalopathy in patients with cirrhosis. Sixty-five patients were randomly treated with 1 g/kg per day of an amino acid mixture with 40% branched chain contents (32 patients...

  13. Effect of Phenolic Compounds from Elderflowers on Glucose- and Fatty Acid Uptake in Human Myotubes and HepG2-Cells

    Directory of Open Access Journals (Sweden)

    Giang Thanh Thi Ho

    2017-01-01

    Full Text Available Type 2 diabetes (T2D is manifested by progressive metabolic impairments in tissues such as skeletal muscle and liver, and these tissues become less responsive to insulin, leading to hyperglycemia. In the present study, stimulation of glucose and oleic acid uptake by elderflower extracts, constituents and metabolites were tested in vitro using the HepG2 hepatocellular liver carcinoma cell line and human skeletal muscle cells. Among the crude extracts, the 96% EtOH extract showed the highest increase in glucose and oleic acid uptake in human skeletal muscle cells and HepG2-cells. The flavonoids and phenolic acids contained therein were potent stimulators of glucose and fatty acid uptake in a dose-dependent manner. Most of the phenolic constituents and several of the metabolites showed high antioxidant activity and showed considerably higher α-amylase and α-glucosidase inhibition than acarbose. Elderflower might therefore be valuable as a functional food against diabetes.

  14. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Science.gov (United States)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-11-01

    Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  15. Intravenous supplementation of acetate, glucose or essential amino acids to an energy and protein deficient diet in lactating dairy goats

    DEFF Research Database (Denmark)

    Safayi, S.; Nielsen, M. O.

    2013-01-01

    amino acid supply is suboptimal. Goats were fed a basal diet deficient in energy (90% of requirements) and protein (80% of requirements), and were randomly allocated to 4 treatments in a balanced 4 x 4 Latin square design. The treatments consisted of 4-d continuous intravenous infusions of isoosmotic...... and close to significantly by ACE, but not by GLU treatment. GLU reduced milk protein percentage compared to all other treatments. High milk protein yields on EM and ACE treatments were associated with higher arterial AVD for acetate and oxygen (not significant for ACE), and higher AVD also for beta......In the present experiment we aimed to study, if milk synthesis is more sensitive toward deficiency in supply of amino acids in early (EL) versus late lactation (LL), and if energy yielding substrates in the form of acetate (but not glucose) can contribute to sustain milk (protein) synthesis, when...

  16. A role for AMPK in the inhibition of glucose-6-phosphate dehydrogenase by polyunsaturated fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Kohan, Alison B.; Talukdar, Indrani; Walsh, Callee M. [Department of Biochemistry, West Virginia University, Morgantown, WV (United States); Salati, Lisa M., E-mail: lsalati@hsc.wvu.edu [Department of Biochemistry, West Virginia University, Morgantown, WV (United States)

    2009-10-09

    Both polyunsaturated fatty acids and AMPK promote energy partitioning away from energy consuming processes, such as fatty acid synthesis, towards energy generating processes, such as {beta}-oxidation. In this report, we demonstrate that arachidonic acid activates AMPK in primary rat hepatocytes, and that this effect is p38 MAPK-dependent. Activation of AMPK mimics the inhibition by arachidonic acid of the insulin-mediated induction of G6PD. Similar to intracellular signaling by arachidonic acid, AMPK decreases insulin signal transduction, increasing Ser{sup 307} phosphorylation of IRS-1 and a subsequent decrease in AKT phosphorylation. Overexpression of dominant-negative AMPK abolishes the effect of arachidonic acid on G6PD expression. These data suggest a role for AMPK in the inhibition of G6PD by polyunsaturated fatty acids.

  17. Intensification of conversion of glucose to lactic acid : equilibria and kinetics for back extraction of lactic acid using trimethylamine

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, A. Bert M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

  18. Intensification of conversion of glucose to lactic acid: equilibria and kinetics for back extraction of lactic acid using trimethylamine

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

  19. Associations among circulating branched-chain amino acids and tyrosine with muscle volume and glucose metabolism in individuals without diabetes.

    Science.gov (United States)

    Honda, Tatsuro; Kobayashi, Yoshinao; Togashi, Kenji; Hasegawa, Hiroshi; Iwasa, Motoh; Taguchi, Osamu; Takei, Yoshiyuki; Sumida, Yasuhiro

    2016-05-01

    Amino acid metabolites, including branched-chain amino acids (BCAA) and tyrosine (Tyr), affect glucose metabolism. The effects of BCAA on insulin resistance in patients with diabetes seem to conflict with mechanisms determined in animal models and cultured cells. The aim of this study was to clarify the controversy surrounding the effects of BCAA by investigating the physiological effects of BCAA and Tyr on glucose metabolism in healthy community dwellers. We investigated associations among BCAA and Tyr and metabolic parameters in 78 residents (median age, 52 y) of Mie, Japan, who did not have prediabetes, diabetes, or a body mass index >30 kg/m(2). Muscle volume, serum BCAA, and Tyr levels were higher in men than in women (n = 32 and 46, respectively; all P BCAA positively with muscle volume (regression coefficient/t/p/95% confidence interval, 281.8/3.7/0.0004/129.7-433.8), fasting blood glucose (FBG; 12699.4/3.22/0.0020/4830.9-20567.8), fasting immunoreactive insulin (IRI; 8505.1/2.75/0.0078/2322.5-14687.6), and homeostasis model assessment of β-cell function (HOMA-β; 893.6/2.58/0.0122/201.8-1585.5), and negatively with the HOMA-insulin resistance (HOMA-IR; -9294.1/-2.89/0.0052/-15711.0 to -2877.1). Tyr positively correlated with fasting IRI (26/2.77/0.0072/7.3-44.7). Insulin sensitivity and muscle volume are positively associated with BCAA in individuals without diabetes. In turn, BCAA correlate with increased FBG and fasting IRI levels. Tyr correlated with fasting IRI, but not with insulin sensitivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Human adipose tissue blood flow during prolonged exercise, III. Effect of beta-adrenergic blockade, nicotinic acid and glucose infusion

    DEFF Research Database (Denmark)

    Bülow, J

    1981-01-01

    acid, during acute i.v. beta-adrenergic blockade by propranolol, and during continuous i.v. infusion of glucose. The most pronounced lipid mobilization and utilization during work was seen in the control experiments where ATBF rose 3-fold on average from the initial rest period to the third hour...... of work. No increase in lipolysis and no increase in ATBF were found when lipolysis was blocked by nicotinic acid (0.3 g/h). Propranolol treatment (0.15 mg/kg) reduced lipolysis and nearly abolished the increase in ATBF during exercise. Intravenous administration of glucose (about 0.25 g/min) did......Subcutaneous adipose tissue blood flow (ATBF) was measured in six male subjects by the 133Xe-washout technique during 3-4 h of exercise at a work load corresponding to an oxygen uptake of about 1.71/min. The measurements were done during control conditions, during blockade of lipolysis by nicotinic...

  1. Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, α-D-Glucose and Tannic acid)

    International Nuclear Information System (INIS)

    Ostovari, A.; Hoseinieh, S.M.; Peikari, M.; Shadizadeh, S.R.; Hashemi, S.J.

    2009-01-01

    The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, α-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > α-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

  2. Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, {alpha}-D-Glucose and Tannic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Ostovari, A. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)], E-mail: A.Ostovari@gmail.com; Hoseinieh, S.M.; Peikari, M. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Shadizadeh, S.R. [Petroleum Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Hashemi, S.J. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)

    2009-09-15

    The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, {alpha}-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > {alpha}-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

  3. Synthesis of 'cineole cassette' monoterpenes in Nicotiana section Alatae: gene isolation, expression, functional characterization and phylogenetic analysis.

    Science.gov (United States)

    Fähnrich, Anke; Brosemann, Anne; Teske, Laura; Neumann, Madeleine; Piechulla, Birgit

    2012-08-01

    The scent bouquets of flowers of Nicotiana species, particularly those of section Alatae, are rich in monoterpenes, including 1,8-cineole, limonene, β-myrcene, α- and β-pinene, sabinene, and α-terpineol. New terpene synthase genes were isolated from flowers of Nicotiana bonariensis, N. forgetiana, N. longiflora, and N. mutabilis. The recombinant enzymes synthesize simultaneously the characteristic 'cineole cassette' monoterpenes with 1,8-cineole as the dominant volatile product. Interestingly, amino acid sequence comparison and phylogenetic tree construction clustered the newly isolated cineole synthases (CIN) of section Alatae together with the catalytically similar CIN of N. suaveolens of section Suaveolentes, thus suggesting a common ancestor. These CIN genes of N. bonariensis, N. forgetiana, N. longiflora, and N. mutabilis are distinct from the terpineol synthases (TERs) of the taxonomically related N. alata and N. langsdorfii (both Alatae), thus indicating gene diversification of monoterpene synthases in section Alatae. Furthermore, the presence of CINs in species of the American section Alatae supports the hypothesis that one parent of the Australian section Suaveolentes was a member of the present section Alatae. Amino acid sequences of the Nicotiana CINs and TERs were compared to identify relevant amino acids of the cyclization reaction from α-terpineol to 1,8-cineole.

  4. Glucose transformation to 5-hydroxymethylfurfural in acidic ionic liquid: A quantum mechanical study.

    Science.gov (United States)

    Arifin; Puripat, Maneeporn; Yokogawa, Daisuke; Parasuk, Vudhichai; Irle, Stephan

    2016-01-30

    Isomerization and transformation of glucose and fructose to 5-hydroxymethylfurfural (HMF) in both ionic liquids (ILs) and water has been studied by the reference interaction site model self-consistent field spatial electron density distribution (RISM-SCF-SEDD) method coupled with ab initio electronic structure theory, namely coupled cluster single, double, and perturbative triple excitation (CCSD(T)). Glucose isomerization to fructose has been investigated via cyclic and open chain mechanisms. In water, the calculations support the cyclic mechanism of glucose isomerization; with the predicted activation free energy is 23.8 kcal mol(-1) at experimental condition. Conversely, open ring mechanism is more favorable in ILs with the energy barrier is 32.4 kcal mol(-1) . Moreover, the transformation of fructose into HMF via cyclic mechanism is reasonable; the calculated activation barriers are 16.0 and 21.5 kcal mol(-1) in aqueous and ILs solutions, respectively. The solvent effects of ILs could be explained by the decomposition of free energies and radial distribution functions of solute-solvent that are produced by RISM-SCF-SEDD. © 2015 Wiley Periodicals, Inc.

  5. Emission and Accumulation of Monoterpene and the Key Terpene Synthase (TPS) Associated with Monoterpene Biosynthesis in Osmanthus fragrans Lour

    Science.gov (United States)

    Zeng, Xiangling; Liu, Cai; Zheng, Riru; Cai, Xuan; Luo, Jing; Zou, Jingjing; Wang, Caiyun

    2016-01-01

    Osmanthus fragrans is an ornamental and economically important plant known for its magnificent aroma, and the most important aroma-active compounds in flowers are monoterpenes, mainly β-ocimene, linalool and linalool derivatives. To understand the molecular mechanism of monoterpene production, we analyzed the emission and accumulation patterns of these compounds and the transcript levels of the genes involved in their biosynthesis in two O. fragrans cultivars during flowering stages. The results showed that both emission and accumulation of monoterpenes varied with flower development and glycosylation had an important impact on floral linalool emission during this process. Gene expression demonstrated that the transcript levels of terpene synthase (TPS) genes probably played a key role in monoterpene production, compared to the genes in the MEP pathway. Phylogenetic analysis showed that OfTPS1 and OfTPS2 belonged to a TPS-g subfamily, and OfTPS3 and OfTPS4 clustered into a TPS-b subfamily. Their transient and stable expression in tobacco leaves suggested that OfTPS1 and OfTPS2 exclusively produced β-linalool, and trans-β-ocimene was the sole product from OfTPS3, while OfTPS4, a predictive sesquiterpene synthase, produced α-farnesene. These results indicate that OfTPS1, OfTPS2, and OfTPS3 could account for the major floral monoterpenes, linalool and trans-β-ocimene, produced in O. fragrans flowers. PMID:26793212

  6. Emission and accumulation of monoterpene and the key terpene synthase (TPS associated with monoterpene biosynthesis in Osmanthus fragrans Lour.

    Directory of Open Access Journals (Sweden)

    Xaingling eZeng

    2016-01-01

    Full Text Available Osmanthus fragrans is an ornamental and economically important plant known for its magnificent aroma, and the most important aroma-active compounds in flowers are monoterpenes, mainly β-ocimene, linalool and linalool derivatives. To understand the molecular mechanism of monoterpene production, we analyzed the emission and accumulation patterns of these compounds and the transcript levels of the genes involved in their biosynthesis in two O. fragrans cultivars during flowering stages. The results showed that both emission and accumulation of monoterpenes varied with flower development and glycosylation had an important impact on floral linalool emission during this process. Gene expression demonstrated that the transcript levels of terpene synthase (TPS genes probably played a key role in monoterpene production, compared to the genes in the MEP pathway. Phylogenetic analysis showed that OfTPS1 and OfTPS2 belonged to a TPS-g subfamily, and OfTPS3 and OfTPS4 clustered into a TPS-b subfamily. Their transient and stable expression in tobacco leaves suggested that OfTPS1 and OfTPS2 exclusively produced β-linalool, and trans-β-ocimene was the sole product from OfTPS3, while OfTPS4, a predictive sesquiterpene synthase, produced α-farnesene. These results indicate that OfTPS1, OfTPS2 and OfTPS3 could account for the major floral monoterpenes, linalool and trans-β-ocimene, produced in O. fragrans flowers.

  7. Synthesis of monoterpene piperidines from the iridoid glucoside antirrhinoside

    DEFF Research Database (Denmark)

    Franzyk, Henrik; Frederiksen, Signe Maria; Jensen, Søren Rosendal

    1997-01-01

    Synthesis of five novel piperidine monoterpene alkaloids using the iridoid glucoside antirrhinoside as a synthon is described. Two strategies for their preparation were investigated: the first possible pathway involved an intermediate diol from which the piperidine ring was expected to be constru......Synthesis of five novel piperidine monoterpene alkaloids using the iridoid glucoside antirrhinoside as a synthon is described. Two strategies for their preparation were investigated: the first possible pathway involved an intermediate diol from which the piperidine ring was expected...... to be constructed via reaction of its ditosylate with an amine; the second strategy involved a double reductive amination as the key step to the piperidine ring, which proved successful. The stereochemistry of C-5 and C-9 in the obtained piperidine monoterpenes was the same as that reported for alfa...

  8. New zwitterionic monoterpene indole alkaloids from Uncaria rhynchophylla.

    Science.gov (United States)

    Guo, Qiang; Yang, Hongshuai; Liu, Xinyu; Si, Xiali; Liang, Hong; Tu, Pengfei; Zhang, Qingying

    2018-01-31

    Four new zwitterionic monoterpene indole alkaloids, rhynchophyllioniums A-D (1-4), together with eight known alkaloids (5-12), were isolated from the hook-bearing stems of Uncaria rhynchophylla. Their structures were elucidated by extensive spectroscopic data analysis of MS, 1D and 2D NMR, and ECD, and the zwitterionic forms and absolute configurations of 1 and 2 were unambiguously confirmed by single crystal X-ray diffraction analysis. All the isolates, including the monoterpene indole alkaloids with free C-22 carboxyl group and those with C-22 carboxyl methyl ester, were proved to be naturally coexisting in the herb by LC-MS analysis. This is the first report of monoterpene indole alkaloids that exist in the form of zwitterion. Additionally, the cytotoxic activities of all isolates against A549, HepG2, and MCF-7 cell lines are reported. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Design, synthesis and structure of new potential electrochemically active boronic acid-based glucose sensors

    DEFF Research Database (Denmark)

    Norrild, Jens Chr.; Søtofte, Inger

    2002-01-01

    In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report the synthe......In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report...

  10. Gibberellic Acid-Stimulated Arabidopsis6 Serves as an Integrator of Gibberellin, Abscisic Acid, and Glucose Signaling during Seed Germination in Arabidopsis.

    Science.gov (United States)

    Zhong, Chunmei; Xu, Hao; Ye, Siting; Wang, Shiyi; Li, Lingfei; Zhang, Shengchun; Wang, Xiaojing

    2015-11-01

    The DELLA protein REPRESSOR OF ga1-3-LIKE2 (RGL2) plays an important role in seed germination under different conditions through a number of transcription factors. However, the functions of the structural genes associated with RGL2-regulated germination are less defined. Here, we report the role of an Arabidopsis (Arabidopsis thaliana) cell wall-localized protein, Gibberellic Acid-Stimulated Arabidopsis6 (AtGASA6), in functionally linking RGL2 and a cell wall loosening expansin protein (Arabidopsis expansin A1 [AtEXPA1]), resulting in the control of embryonic axis elongation and seed germination. AtGASA6-overexpressing seeds showed precocious germination, whereas transfer DNA and RNA interference mutant seeds displayed delayed seed germination under abscisic acid, paclobutrazol, and glucose (Glc) stress conditions. The differences in germination rates resulted from corresponding variation in cell elongation in the hypocotyl-radicle transition region of the embryonic axis. AtGASA6 was down-regulated by RGL2, GLUCOSE INSENSITIVE2, and ABSCISIC ACID-INSENSITIVE5 genes, and loss of AtGASA6 expression in the gasa6 mutant reversed the insensitivity shown by the rgl2 mutant to paclobutrazol and the gin2 mutant to Glc-induced stress, suggesting that it is involved in regulating both the gibberellin and Glc signaling pathways. Furthermore, it was found that the promotion of seed germination and length of embryonic axis by AtGASA6 resulted from a promotion of cell elongation at the embryonic axis mediated by AtEXPA1. Taken together, the data indicate that AtGASA6 links RGL2 and AtEXPA1 functions and plays a role as an integrator of gibberellin, abscisic acid, and Glc signaling, resulting in the regulation of seed germination through a promotion of cell elongation. © 2015 American Society of Plant Biologists. All Rights Reserved.

  11. Potential contribution of exposed resin to ecosystem emissions of monoterpenes

    Science.gov (United States)

    Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

    2013-10-01

    Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

  12. PROPERTIES OF NEW SALTS OF 2-(5-(ADAMANTANE-1-YL-4-R-1,2,4-TRIAZOLE-3-YLTIOACETIC ACIDS IN THE GLUCOSE TOLERANCE TEST

    Directory of Open Access Journals (Sweden)

    V. M. Odyntsova

    2015-04-01

    Full Text Available The concentration of glucose in the blood is one of the integral indicators of the internal environment that reflects the metabolism of carbohydrates, proteins and fats in the body. Glucose is a key component of human metabolism. The level of blood sugar is one of the most important controlled constants of body that defines homeostasis and displays the status of carbohydrate metabolism. Low blood sugar (hypoglycemia is a dangerous condition when blood glucose is critically low. The aim of research. The aim of our study was pharmacological screening of the effects of the newly synthesized salts of 2-(5-adamantane-1-yl-4-R-1,2,4-tirazol-3-yltioacetic acids on glucose blood level in experimental animals. Materials and methods. The compounds have been synthesized at the Department of Inorganic Chemistry and Toxicology of Zaporozhye State Medical University (the Head of the chair, Professor Panasenko O.I.. Blood glucose levels of saults of2-(5-adamantane-1-yl-4-R-1,2,4-tirazol-3-yltioacetic acids in rats have been evaluated by intraperitoneal glucose tolerance test (IGTT. IGTT was reproduced by glucose load on animals in a dose of 2 g / kg of rat’s body weight. White nonlinear rats weighing 160-230 g were involved in experiments. Animals were divided into 13 groups of 7 animals in each group: the 1st is intact one; the 2nd is control one with glycemia (untreated, the 3rd group of the animals received glibenclamide in the dose of 1 mg / kg; the groups 3-13 received 1,2,4-triazole derivatives. The compounds were dissolved in purified water at the rate of 1 ml per 100 g of animals’ weight and were injected intraperitoneally. Glucose content in blood has been measured by glucosidase method using glucometer «Accu Chek Active» in 30 minutes from the load moment. The research results have been processed by modern statistical methods of analysis on a personal computer using a standard software package Microsoft Office 2010 (Microsoft Excel and

  13. An efficient protocol for incorporation of an unnatural amino acid in perdeuterated recombinant proteins using glucose-based media

    Energy Technology Data Exchange (ETDEWEB)

    Venditti, Vincenzo; Fawzi, Nicolas L.; Clore, G. Marius, E-mail: mariusc@mail.nih.gov [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    2012-03-15

    The in vivo incorporation of unnatural amino acids into proteins is a well-established technique requiring an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is incorporated at a position encoded by a TAG amber codon. Although this technology provides unique opportunities to engineer protein structures, poor protein yields are usually obtained in deuterated media, hampering its application in the protein NMR field. Here, we describe a novel protocol for incorporating unnatural amino acids into fully deuterated proteins using glucose-based media (which are relevant to the production, for example, of amino acid-specific methyl-labeled proteins used in the study of large molecular weight systems). The method consists of pre-induction of the pEVOL plasmid encoding the tRNA/aminoacyl-tRNA synthetase pair in a rich, H{sub 2}O-based medium prior to exchanging the culture into a D{sub 2}O-based medium. Our protocol results in high level of isotopic incorporation ({approx}95%) and retains the high expression level of the target protein observed in Luria-Bertani medium.

  14. Effects of short-term metformin treatment on insulin sensitivity of blood glucose and free fatty acids.

    Science.gov (United States)

    Iannello, S; Camuto, M; Cavaleri, A; Milazzo, P; Pisano, M G; Bellomia, D; Belfiore, F

    2004-01-01

    Based on the known effect of metformin (MET) in improving insulin sensitivity in type 2 diabetes, with the scope to focus the effects on glycaemic and free fatty acids (FFA) levels, we studied the effects of a short-term treatment with this drug in obese subjects and obese patients with diabetes or family history of diabetes (FHD). We used a method to allow us to evaluate the possible difference of insulin sensibility with regard to the insulin action on glycaemia and blood FFA, both in the basal state and during oral glucose tolerance test (OGTT). Insulin sensitivity was investigated before and after MET treatment (850 mg bid for 10 days) in seven obese subjects with normal glucose tolerance and without FHD and 13 obese patients with diabetes (n=7) or FHD (n=6). By using specifically designed formulae, we calculated four insulin-sensitivity indices (ISI) from basal level (b) and area values (a) (during OGTT) of insulinaemia, glycaemia (gly) or FFA (ffa), namely: ISI (gly)-b, ISI (gly)-a, ISI (ffa)-b and ISI (ffa)-a. In patients with diabetes or FHD, MET improved ISI (gly)-b (0.79 +/- 0.06 vs. 0.59 +/- 0.07, p<0.001) and ISI (gly)-a (0.69 +/- 0.09 vs. 0.51 +/- 0.07, p<0.05), whereas only minor changes occurred for ISI (ffa)-b and ISI (ffa)-a. In contrast, in simple obese subjects, MET induced further deterioration of both ISI (gly)-a (0.47 +/- 0.07 vs. 0.64 +/- 0.10, p<0.01) and ISI (ffa)-a (0.43 +/- 0.07 vs. 0.55 +/- 0.08, p<0.05). Fasting level and total area of lactate were high in the obese patients and were not affected by MET. A statistically significant increase (p<0.01), however, was observed for the 'decremental' area of lactate in obese subjects with diabetes or FHD, which might probably contribute to the reduction of insulin resistance induced by the drug in these patients. Although the low number of subjects studied precludes absolute conclusions, data would suggest that MET improved ISI towards glucose but not towards FFA, in the diabetic and

  15. The influence of monoterpene synthase transformation on the odour of tabacco.

    NARCIS (Netherlands)

    Tamer, el M.K.; Smeets, M.A.M.; Holthuysen, N.T.E.; Lucker, J.; Tang, A.; Roozen, J.P.; Bouwmeester, H.J.; Voragen, A.G.J.

    2003-01-01

    Monoterpenes are an important class of terpenoids that are commonly present in plant essential oils. These can be extracted from plants and are used in the flavouring and perfumery industry. Monoterpene synthases are the key enzymes in monoterpene biosynthesis, as they catalyse the cyclisation of

  16. Effects of cytochalasin B on the uptake of ascorbic acid and glucose by 3T3 fibroblasts: Mechanism of impaired ascorbate transport in diabetes

    International Nuclear Information System (INIS)

    Fay, M.J.; Bush, M.J.; Verlangieri, A.J.

    1990-01-01

    Hyperglycemia and/or hypoinsulinemia have been found to inhibit L-ascorbic acid cellular transport. The resultant decrease in intracellular ascorbic acid may de-inhibit aryl sulfatase B and increase degradation of sulfated glycosaminoglycans (sGAG). This could lead to a degeneration of the extracellular matrix and result in increased intimal permeability, the initiating event in atherosclerosis. The present studies show that the glucose transport inhibitor cytochalasin B blocked the uptake of 3 H-2-deoxy-D-glucose by mouse 3T3 fibroblasts. Cytochalasin B also blocked the uptake of 14 C-L-ascorbic acid. The results of these studies further support the hypothesis that glucose and ascorbate share a common transport system. This may have important implications concerning the vascular pathology associated with diabetes mellitus

  17. [13C] GC-C-IRMS analysis of methylboronic acid derivatives of glucose from liver glycogen after the ingestion of [13C] labeled tracers in rats.

    Science.gov (United States)

    Luengo, Catherine; Azzout-Marniche, Dalila; Fromentin, Claire; Piedcoq, Julien; Lemosquet, Sophie; Tomé, Daniel; Gaudichon, Claire

    2009-11-01

    We developed a complete method to measure low [(13)C] enrichments in glycogen. Fourteen rats were fed a control diet. Six of them also ingested either [U-(13)C] glucose (n=2) or a mixture of 20 [U-(13)C] amino acids (n=4). Hepatic glycogen was extracted, digested to glucose and purified on anion-cation exchange resins. After the optimization of methylboronic acid derivatization using GC-MS, [(13)C] enrichment of extracted glucose was measured by GC-C-IRMS. The accuracy was addressed by measuring the enrichment excess of a calibration curve, which observed values were in good agreement with the expected values (R=0.9979). Corrected delta values were -15.6+/-1.6 delta(13)C (per thousand) for control rats (n=8) and increased to -5 to 8 delta(13)C (per thousand) per thousand and 12-14 delta(13)C (per thousand) per thousand after the ingestion of [U-(13)C] amino acids or [U-(13)C] glucose as oral tracers, respectively. The method enabled the determination of dietary substrate transfer into glycogen. The sequestration of dietary glucose in liver glycogen 4 h after the meal was 35% of the ingested dose whereas the transfer of carbon skeletons from amino acids was only 0.25 to 1%.

  18. Effect of prolonged intravenous glucose and essential amino acid infusion on nitrogen balance, muscle protein degradation and ubiquitin-conjugating enzyme gene expression in calves

    Directory of Open Access Journals (Sweden)

    Scaife Jes R

    2008-02-01

    Full Text Available Abstract Background Intravenous infusions of glucose and amino acids increase both nitrogen balance and muscle accretion. We hypothesised that co-infusion of glucose (to stimulate insulin and essential amino acids (EAA would act additively to improve nitrogen balance by decreasing muscle protein degradation in association with alterations in muscle expression of components of the ubiquitin-proteasome proteolytic pathway. Methods We examined the effect of a 5 day intravenous infusions of saline, glucose, EAA and glucose + EAA, on urinary nitrogen excretion and muscle protein degradation. We carried out the study in 6 restrained calves since ruminants offer the advantage that muscle protein degradation can be assessed by excretion of 3 methyl-histidine and multiple muscle biopsies can be taken from the same animal. On the final day of infusion blood samples were taken for hormone and metabolite measurement and muscle biopsies for expression of ubiquitin, the 14-kDa E2 ubiquitin conjugating enzyme, and proteasome sub-units C2 and C8. Results On day 5 of glucose infusion, plasma glucose, insulin and IGF-1 concentrations were increased while urea nitrogen excretion and myofibrillar protein degradation was decreased. Co-infusion of glucose + EAA prevented the loss of urinary nitrogen observed with EAA infusions alone and enhanced the increase in plasma IGF-1 concentration but there was no synergistic effect of glucose + EAA on the decrease in myofibrillar protein degradation. Muscle mRNA expression of the ubiquitin conjugating enzyme, 14-kDa E2 and proteasome sub-unit C2 were significantly decreased, after glucose but not amino acid infusions, and there was no further response to the combined infusions of glucose + EAA. Conclusion Prolonged glucose infusion decreases myofibrillar protein degradation, prevents the excretion of infused EAA, and acts additively with EAA to increase plasma IGF-1 and improve net nitrogen balance. There was no evidence of

  19. Free fatty acid-induced hepatic insulin resistance is attenuated following lifestyle intervention in obese individuals with impaired glucose tolerance.

    Science.gov (United States)

    Haus, Jacob M; Solomon, Thomas P J; Marchetti, Christine M; Edmison, John M; González, Frank; Kirwan, John P

    2010-01-01

    The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans. Obese men and women (n = 23) with impaired glucose tolerance were randomly assigned to either exercise training with a eucaloric (EU; approximately 1800 kcal; n = 11) or hypocaloric (HYPO; approximately 1300 kcal; n = 12) diet for 12 wk. Hepatic glucose production (HGP; milligrams per kilogram fat-free mass(-1) per minute(-1)) and hepatic insulin resistance were determined using a two-stage sequential hyperinsulinemic (40 mU/m(2) . min(-1)) euglycemic (5.0 mm) clamp with [3-(3)H]glucose. Measures were obtained at basal, during insulin infusion (INS; 120 min), and insulin plus intralipid/heparin infusion (INS/FFA; 300 min). At baseline, basal HGP was similar between groups; hyperinsulinemia alone did not completely suppress HGP, whereas INS/FFA exhibited less suppression than INS (EU, 4.6 +/- 0.8, 2.0 +/- 0.5, and 2.6 +/- 0.4; HYPO, 3.8 +/- 0.5, 1.2 +/- 0.3, and 2.3 +/- 0.4, respectively). After the intervention the HYPO group lost more body weight (P HYPO: -50 +/- 20%, before vs. after, P = 0.02). In contrast, the ability of insulin to overcome FFA-induced hepatic insulin resistance and HGP was improved only in the HYPO group (EU: -15 +/- 24% vs. HYPO: -58 +/- 19%, P = 0.02). Both lifestyle interventions are effective in reducing hepatic insulin resistance under basal and hyperinsulinemic conditions. However, the reversal of FFA-induced hepatic insulin resistance is best achieved with a combined exercise/caloric-restriction intervention.

  20. Wheat bran with enriched gamma-aminobutyric acid attenuates glucose intolerance and hyperinsulinemia induced by a high-fat diet.

    Science.gov (United States)

    Shang, Wenting; Si, Xu; Zhou, Zhongkai; Strappe, Padraig; Blanchard, Chris

    2018-05-23

    In this study, the level of gamma-aminobutyric acid (GABA) in wheat bran was increased to be six times higher through the action of endogenous glutamate decarboxylase compared with untreated bran. The process of GABA formation in wheat bran also led to an increased level of phenolic compounds with enhanced antioxidant capacity 2 times higher than the untreated status. The interventional effect of a diet containing GABA-enriched bran on hyperinsulinemia induced by a high-fat diet (HFD) was investigated in a rat model. The results showed that, when compared with animals fed with HFD-containing untreated bran (NB group), the consumption of HFD-containing GABA-enriched bran (GB group) demonstrated a greater improvement of insulin resistance/sensitivity as revealed by the changes in the homeostatic model assessment for insulin resistance index (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). The expression of hepatic genes, cytochrome P450 family 7 subfamily A member 1 (Cyp7a1) and ubiquitin C (Ubc), which are involved in the adipogenesis-associated PPAR signalling pathway, was found to be significantly down-regulated in the GB group compared with the HFD group (P = 0.0055). Meanwhile, changes in the expression of a number of genes associated with lipid metabolism and gluconeogenesis were also noted in the GB group versus the HFD group, but not in the NB group, indicating different regulatory patterns between the two brans in a high-fat diet. More importantly, the analysis of key genes related to glucose metabolism further revealed that the expression of insulin-induced gene 1/2 (Insig-1/2) was increased following GB intervention with a corresponding reduction in phosphoenolpyruvate carboxykinase 1 (Pepck) and glucose-6-phosphatase, catalytic subunit (G6pc) expression, suggesting that glucose homeostasis is greatly improved through the intervention of GABA-enriched bran in the context of a high-fat diet.

  1. Responsive Boronic Acid-Decorated (Co)polymers: From Glucose Sensors to Autonomous Drug Delivery.

    Science.gov (United States)

    Vancoillie, Gertjan; Hoogenboom, Richard

    2016-10-19

    Boronic acid-containing (co)polymers have fascinated researchers for decades, garnering attention for their unique responsiveness toward 1,2- and 1,3-diols, including saccharides and nucleotides. The applications of materials that exert this property are manifold including sensing, but also self-regulated drug delivery systems through responsive membranes or micelles. In this review, some of the main applications of boronic acid containing (co)polymers are discussed focusing on the role of the boronic acid group in the response mechanism. We hope that this summary, which highlights the importance and potential of boronic acid-decorated polymeric materials, will inspire further research within this interesting field of responsive polymers and polymeric materials.

  2. Responsive Boronic Acid-Decorated (Copolymers: From Glucose Sensors to Autonomous Drug Delivery

    Directory of Open Access Journals (Sweden)

    Gertjan Vancoillie

    2016-10-01

    Full Text Available Boronic acid-containing (copolymers have fascinated researchers for decades, garnering attention for their unique responsiveness toward 1,2- and 1,3-diols, including saccharides and nucleotides. The applications of materials that exert this property are manifold including sensing, but also self-regulated drug delivery systems through responsive membranes or micelles. In this review, some of the main applications of boronic acid containing (copolymers are discussed focusing on the role of the boronic acid group in the response mechanism. We hope that this summary, which highlights the importance and potential of boronic acid-decorated polymeric materials, will inspire further research within this interesting field of responsive polymers and polymeric materials.

  3. Effects of ethanol on pancreatic beta-cell death: interaction with glucose and fatty acids.

    Science.gov (United States)

    Dembele, Korami; Nguyen, K Hoa; Hernandez, Tiffany A; Nyomba, B L Grégoire

    2009-04-01

    Western lifestyle plays an important role in the prevalence of type 2 diabetes by causing insulin resistance and pancreatic beta-cell dysfunction, a prerequisite for the development of diabetes. High fat diet and alcohol are major components of the western diet. The aim of the present study was to investigate the effects of ethanol and fatty acids on beta-cell survival and metabolism. We treated the rat beta-cell line RINm5F with ethanol, a mixture of palmitic and oleic acids, or both. Reactive oxygen species (ROS) were determined by (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) (CM-H2DCFDA) fluorescence assay, and mitochondrial activity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by determining ATP production. Cell viability was assessed with a cell counter and trypan blue exclusion, and the mode of cell death by Hoechst33342 and propidium iodide staining. With both ethanol and fatty acid treatments, MTT reduction and ATP production decreased, whereas ROS production increased. Ethanol treatment had no effect on cell number, whereas fatty acid treatment reduced the cell number. Cell incubation with ethanol, fatty acids, or both increased the number of Hoechst 33342-positive nuclei. However, the majority of nuclei from fatty acid-treated cells were stained with propidium iodide, indicating a loss of plasma membrane integrity. We conclude that both ethanol and fatty acids generate cellular oxidative stress, and affect mitochondrial function in RINm5F beta-cells. However, ethanol causes beta-cell death by apoptosis, whereas fatty acids cause cell death predominantly by necrosis. It is not known whether these results are applicable to human beta-cells.

  4. Associations between Dietary Acid-Base Load and Cardiometabolic Risk Factors in Adults: The Tehran Lipid and Glucose Study

    Directory of Open Access Journals (Sweden)

    Zahra Bahadoran

    2015-06-01

    Full Text Available BackgroundIn this study we investigated the associations of dietary acid-base load, identified by potential renal acid load (PRAL and protein to potassium (Pro:K ratio, with cardiometabolic risk factors in Tehranian adults.MethodsA cross-sectional study was conducted within the framework of the fourth phase of the Tehran Lipid and Glucose Study (2009 to 2011 on 5,620 men and women aged 19 to 70 years. Dietary data were collected by a trained dietitian using a validated, 147-food item, semi-quantitative food frequency questionnaire, and dietary PRAL and Pro:K ratio were calculated. Multiple linear regression models with adjustment for potential confounding variables were used to evaluate the associations of dietary acid-base load with anthropometric measures, blood pressure, serum triglycerides, high density lipoprotein cholesterol (HDL-C, serum creatinine, and fasting blood glucose.ResultsThe mean±SD age of the participants was 39.8±12.8 years and 54% of participants were women. Mean±SD PRAL was -22.0±29.1; mean PRAL was -15.6 in men and -26.8 in women. Dietary PRAL was associated with weight (β=0.098, P<0.001, waist circumference (β=0.062, P<0.01, serum triglycerides (β=0.143, P<0.01, HDL-C (β=-0.11, P<0.01, diastolic blood pressure (β=0.062, P<0.01, and serum creatinine (β=0.142, P<0.001. Pro:K ratio was associated with weight (β=0.055, P<0.001, waist circumference (β=0.04, P<0.01, serum HDL-C (β=-0.06, P<0.01, serum triglycerides (β=0.03, P<0.05, diastolic blood pressure (β=0.026, P<0.05, and serum creatinine (β=0.07, P<0.01.ConclusionA more acidic dietary acid-base load may be a risk factor for the development of metabolic disorders.

  5. Regulation of blood glucose level by kainic acid in mice: involvement of glucocorticoid system and non-NMDA receptors.

    Science.gov (United States)

    Kim, Chea-Ha; Park, Soo-Hyun; Sim, Yun-Beom; Kim, Sung-Su; Jung, Jun-Sub; Sharma, Naveen; Suh, Hong-Won

    2017-02-28

    Kainic acid (KA) is a well-known excitatory neurotoxic substance. In the present study, effects of KA-injected intraperitoneally (i.p.), intracerebroventricularly (i.c.v.) or intrathecally (i.t.) on the blood glucose level were investigated in ICR mice. We found that KA administered intraperitoneally (i.p.), intracerebroventricularly (i.c.v.) or intrathecally (i.t.) increased the blood glucose and corticosterone levels, suggesting that KA-induced hyperglycemia appeared to be due to increased blood corticosterone level. In support of this finding, adrenalectomy causes a reduction of KA-induced hyperglycemia and neuronal cell death in CA3 regions of the hippocampus. In addition, pretreatment with i.c.v. or i.t. injection of CNQX (6-cyano-7-nitroquinoxaline-2, 3-dione; a non-NMDA receptor blocker) attenuated the i.p. and i.c.v. administered KA-induced hyperglycemia. KA administered i.c.v. caused an elevation of the blood corticosterone level whereas the plasma insulin level was reduced. Moreover, i.c.v. pretreatment with CNQX inhibited the decrease of plasma insulin level induced by KA i.c.v. injection, whereas the KA-induced plasma corticosterone level was further enhanced by CNQX pretreatment. Our results suggest that KA administered systemically or centrally produces hyperglycemia. A glucocorticoid system appears to be involved in KA-induced hyperglycemia. Furthermore, central non-N-methyl-D-aspartate receptors may be responsible for KA-induced hyperglycemia.

  6. Electrocatalytic glucose sensor

    Energy Technology Data Exchange (ETDEWEB)

    Gebhardt, U; Luft, G; Mund, K; Preidel, W; Richter, G J

    1983-01-01

    An artificial pancreas consists of an insulin depot, a dosage unit and a glucose sensor. The measurement of the actual glucose concentration in blood is still an unsolved problem. Two methods are described for an electrocatalytic glucose sensor. Under the interfering action of amino acids and urea in-vitro measurements show an error of between 10% and 20%.

  7. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian

    2015-01-01

    optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylationrelated product quality. In this work, different fed-batch processes with two chemically defined proprietary media......Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process...... and glutamine concentrations and uptake rates were positively correlated with intracellular UDP-Gal availability. All these findings are important for optimization of fed-batch culture for improving IgG production and directing glycosylation quality....

  8. Geographic variation in shortleaf pine (Pinus echinata Mill.) - cortical monoterpenes

    Science.gov (United States)

    R.C. Schmidtling; J.H. Myszewski; C.E. McDaniel

    2005-01-01

    Cortical monoterpenes were assayed in bud tissue from 16 Southwide Southern Pine Seed Source Study (SSPSS) sources and from 6 seed orchard sources fiom across the natural range of the species, to examine geogaphic variation in shortleaf pine. Spruce pine and pond pine were also sampled. The results show geographic differences in all of the major terpenes. There was no...

  9. Variations in the monoterpene composition of ponderosa pine wood oleoresin

    Science.gov (United States)

    Richard H. Smith

    1964-01-01

    A wide range in quantitative composition of the wood oleoresin monoterpenes was found among 64 ponderosa pines in the central Sierra Nevada by gas chromatographic analysis. An inverse relationship was found in the amount of β-pinene and Δ3-carene. Practically no difference in composition could be associated with (a) type of...

  10. Low temperature fluidized wood chip drying with monoterpene analysis

    Science.gov (United States)

    Bridget N. Bero; Alarick Reiboldt; Ward Davis; Natalie Bedard; Evan Russell

    2011-01-01

    This paper describes the drying of ponderosa pine wood chips at low (20°C and 50°C) temperatures using a bench-scale batch pulsed fluidizer to evaluate both volatile pine oils (monoterpenes) and moisture losses during drying.

  11. Capturing of the monoterpene olefin limonene produced in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Jongedijk, E.J.; Cankar, K.; Ranzijn, J.; Krol, van der A.R.; Bouwmeester, H.J.; Beekwilder, M.J.

    2015-01-01

    Monoterpene olefins such as limonene are plant compounds with applications as flavouring and fragrance agents, as solvents and potentially also in polymer and fuel chemistry. We engineered baker's yeast Saccharomyces cerevisiae to express a (-)-limonene synthase from Perilla frutescens and a

  12. Effects of ascorbic acid and glucose oxidase levels on the viability of probiotic bacteria and the physical and sensory characteristics in symbiotic ice-cream

    Directory of Open Access Journals (Sweden)

    M. B. Akın

    2015-05-01

    Full Text Available In this study, the effects of addition of different amounts of ascorbic acid and glucose oxidase on the properties of symbiotic ice cream were investigated. Ice-cream containing inulin (2 % (w/w was produced by mixing fortified milk fermented with probiotic strains with the ice-cream mixes containing different ascorbic acid and glucose oxidase concentrations (0.025, 0.05, 0.1 (w/w. The cultures were grown (37 °C, 12 h in UHT skimmed milk. The fermented milk was added to the ice-cream mix up to a level of 10 % w/w. Increasing the concentration of ascorbic acid stimulated the growth of Lactobacillus acidophilus LA-5 (L. acidophilus and Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12. On contrary, increasing the concentration of glucose oxidase negatively affected the growth of L. acidophilus and Bifidobacterium BB-12. However, both, ascorbic acid and glucose oxidase concentration had no effect on physical and sensory properties of ice cream. The results suggested that the addition of ascorbic acid stimulated the growth of L. acidophilus and Bifidobacterium BB-12 and could be recommended for ice cream production.

  13. Chronic dietary exposure to branched chain amino acids impairs glucose disposal in vegans but not in omnivores.

    Science.gov (United States)

    Gojda, J; Rossmeislová, L; Straková, R; Tůmová, J; Elkalaf, M; Jaček, M; Tůma, P; Potočková, J; Krauzová, E; Waldauf, P; Trnka, J; Štich, V; Anděl, M

    2017-05-01

    Branched chain amino acids (BCAA) are among nutrients strongly linked with insulin sensitivity (IS) measures. We investigated the effects of a chronic increase of BCAA intake on IS in two groups of healthy subjects differing in their basal consumption of BCAA, that is, vegans and omnivores. Eight vegans and eight matched omnivores (five men and three women in each group) received 15 g (women) or 20 g (men) of BCAA daily for 3 months. Anthropometry, blood analyses, glucose clamp, arginine test, subcutaneous abdominal adipose tissue (AT) and skeletal muscle (SM) biopsies (mRNA levels of selected metabolic markers, respiratory chain (RC) activity) were performed at baseline, after the intervention and after a 6 month wash-out period. Compared with omnivores, vegans had higher IS at baseline (GIR, glucose infusion rate: 9.6±2.4 vs 7.1±2.4 mg/kg/min, 95% CI for difference: 0.55 to 5.82) that declined after the intervention and returned to baseline values after the wash-out period (changes in GIR with 95% CI, 3-0 months: -1.64 [-2.5; -0.75] and 9-3 months: 1.65 [0.75; 2.54] mg/kg/min). No such change was observed in omnivores. In omnivores the intervention led to an increased expression of lipogenic genes (DGAT2, FASN, PPARγ, SCD1) in AT. SM RC activity increased in both groups. Negative impact of increased BCAA intake on IS was only detected in vegans, that is, subjects with low basal amino acids/BCAA intake, which appear to be unable to induce sufficient compensatory changes within AT and SM on a BCAA challenge.

  14. Predictors of monoterpene exposure in the Danish furniture industry.

    Science.gov (United States)

    Hagström, Katja; Jacobsen, Gitte; Sigsgaard, Torben; Schaumburg, Inger; Erlandsen, Mogens; Schlunssen, Vivi

    2012-04-01

    Individuals who work with pine in the furniture industry may be exposed to monoterpenes, the most abundant of which are α-pinene, β-pinene, and Δ(3)-carene. Monoterpenes are suspected to cause dermatitis and to harm the respiratory system. An understanding of the predictors of monoterpene exposure is therefore important in preventing these adverse effects. These predictors may include general characteristics of the work environment and specific work operations. We sought to assess the extent to which workers are exposed to monoterpenes and to identify possible predictors of monoterpene exposure in the pine furniture industry in Denmark. Passive measurements of the levels of selected monoterpenes (α-pinene, β-pinene, and Δ(3)-carene) were performed on 161 subjects from 17 pine furniture factories in Viborg County, Denmark; one sample was acquired from each worker. Additionally, wood dust samples were collected from 145 workers. Data on potential predictors of exposure were acquired over the course of the day on which the exposure measurements were recorded and could be assigned to one of four hierarchic ordered levels: worker, machine, department, and factory. In addition to univariate analyses, a mixed model was used to account for imbalances within the data and random variation with each of the hierarchically ordered levels. The geometric mean (GM) monoterpene content observed over the 161 measurements was 7.8 mg m(-3) [geometric standard deviation (GSD): 2.4]; the GM wood dust level over 145 measurements was 0.58 mg m(-3) (GSD: 1.49). None of the measured samples exceeded the occupational exposure limit for terpenes in Denmark (25 ppm, 150 mg m(-3)). In the univariate analyses, half of the predictors tested were found to be significant; the multivariate model indicated that only three of the potential predictors were significant. These were the recirculation of air in rooms used for the processing of wood (a factory level predictor), the presence of a

  15. Effects of 5 Thio-D-Glucose on cellular adenosine triphosphate levels and deoxyribonucleic acid rejoining in hypoxic and aerobic Chinese hamster cells

    International Nuclear Information System (INIS)

    Nagle, W.A.; Moss, A.J. Jr.; Roberts, H.G. Jr.; Baker, M.L.

    1980-01-01

    Intracellular adenosine triphosphate (ATP) levels were measured in both hypoxic and aerobic cultures of V79 Chinese hamster cells treated with 5-thio-D-glucose (5-SH-D-Glc). This glucose analog, a known inhibitor of D-glucose transport and metabolism, reduced ATP in cell cultures allowed to become hypoxic by cell metabolism, but not in aerobic cultures treated similarly. Cells depleted of ATP were unable to rejoin x-ray induced deoxyribonucleic acid (DNA) strand breaks as measured by the alkaline sucrose gradient sedimentation technique. The inference for radiation therapy is that inhibition of glucose metabolism selectively depletes energy reserves in hypoxic cells, rendering these cells more radiosensitive and leading to a more effective tumor treatment

  16. The effect of n-3 fatty acids on glucose homeostasis and insulin sensitivity

    Czech Academy of Sciences Publication Activity Database

    Flachs, Pavel; Rossmeisl, Martin; Kopecký, Jan

    2014-01-01

    Roč. 63, Suppl.1 (2014), S93-S118 ISSN 0862-8408 R&D Projects: GA MZd(CZ) NT13763 Institutional support: RVO:67985823 Keywords : diabetes * obesity * inflammation * metabolic syndrome * omega-3 fatty acids Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.293, year: 2014

  17. Serum bile acids and leptin interact with glucose metabolism in patients with liver cirrhosis

    NARCIS (Netherlands)

    Valentini, Luzia; Glaeser, Silja; Schuetz, Tatjana; Omar, Ajmal; Kasim, Esmatollah; Kroencke, Thomas; Tietge, Uwe J. F.; Lochs, Herbert; Schulzke, Joerg-Dieter; Brabant, Georg; Ockenga, Johann

    Background & aims: We investigated possible involvements of bile acids (BA) and leptin in hepatogenous insulin resistance being present in up to 90% of cirrhotic patients. Methods: Blood was analysed in 10 cirrhotic patients (8m/2f, 48 +/- 10.4 yrs) and 10 controls (8m/2f, 43 +/- 9.3 yrs) after oral

  18. Glucagon-like peptide-1 reduces contractile function and fails to boost glucose utilization in normal hearts in the presence of fatty acids.

    Science.gov (United States)

    Nguyen, T Dung; Shingu, Yasushige; Amorim, Paulo A; Schwarzer, Michael; Doenst, Torsten

    2013-10-09

    GLP-1 and exendin-4, which are used as insulin sensitizers or weight reducing drugs, were shown to improve glucose uptake in the heart. However, the direct effects of GLP-1 or exendin-4 on normal hearts in the presence of fatty acids, the main cardiac substrates, have never been investigated. We therefore assessed the effects of GLP-1 or exendin-4 on myocardial glucose uptake (GU), glucose oxidation (GO) and cardiac performance (CP) under conditions of fatty acid utilization. Rat hearts were perfused with only glucose (5 mM) or glucose (5 mM) plus oleate (0.4 mM) as substrates for 60 min. After 30 min, GLP-1 or exendin-4 (0.5 nM or 5 nM) was added. In the absence of oleate, GLP-1 increased both GU and GO. Exendin-4 increased GO but showed no effect on GU. Neither GLP-1 nor exendin-4 affected CP. However, when oleate was present, GLP-1 failed to stimulate glucose utilization and exendin-4 even decreased GU. Furthermore, now GLP-1 reduced CP. In contrast to prior reports, this negative inotropic effect could not be blocked by the protein kinase A inhibitor H-89. We then measured myocardial GO and CP in rats receiving a 4-week GLP-1 infusion. Interestingly, this chronic treatment resulted in a significant reduction in both GO and CP. Under the influence of oleate, GLP-1 reduces contractile function and fails to stimulate glucose utilization in normal hearts. Exendin-4 may acutely reduce cardiac glucose uptake but not contractility. We suggest advanced investigation of heart function and metabolism in patients treating with these peptides. © 2013.

  19. The existence of an insulin-stimulated glucose and non-essential but not essential amino acid substrate interaction in diabetic pigs

    Directory of Open Access Journals (Sweden)

    Wijdenes Jan

    2011-05-01

    Full Text Available Abstract Background The generation of energy from glucose is impaired in diabetes and can be compensated by other substrates like fatty acids (Randle cycle. Little information is available on amino acids (AA as alternative energy-source in diabetes. To study the interaction between insulin-stimulated glucose and AA utilization in normal and diabetic subjects, intraportal hyperinsulinaemic euglycaemic euaminoacidaemic clamp studies were performed in normal (n = 8 and streptozotocin (120 mg/kg induced diabetic (n = 7 pigs of ~40-45 kg. Results Diabetic vs normal pigs showed basal hyperglycaemia (19.0 ± 2.0 vs 4.7 ± 0.1 mmol/L, P P P P P P P . Essential AA clearance was largely unchanged (72.9 ± 8.5 vs 63.3 ± 8.5 mL/kg· min, however clearances of threonine (P P Conclusions The ratio of insulin-stimulated glucose versus AA clearance was decreased 5.4-fold in diabetic pigs, which was caused by a 3.6-fold decrease in glucose clearance and a 2.0-fold increase in non-essential AA clearance. In parallel with the Randle concept (glucose - fatty acid cycle, the present data suggest the existence of a glucose and non-essential AA substrate interaction in diabetic pigs whereby reduced insulin-stimulated glucose clearance seems to be partly compensated by an increase in non-essential AA clearance whereas essential AA are preferentially spared from an increase in clearance.

  20. Monoterpene biosynthesis in lemon (Citrus limon) cDNA isolation and functional analysis of four monoterpene synthases

    NARCIS (Netherlands)

    Lücker, J.; Tamer, El M.K.; Schwab, W.; Verstappen, F.W.A.; Plas, van der L.H.W.; Bouwmeester, H.J.; Verhoeven, H.A.

    2002-01-01

    Citrus limon possesses a high content and large variety of monoterpenoids, especially in the glands of the fruit flavedo. The genes responsible for the production of these monoterpenes have never been isolated. By applying a random sequencing approach to a cDNA library from mRNA isolated from the

  1. The biosynthetic origin of irregular monoterpenes in Lavandula: isolation and biochemical characterization of a novel cis-prenyl diphosphate synthase gene, lavandulyl diphosphate synthase.

    Science.gov (United States)

    Demissie, Zerihun A; Erland, Lauren A E; Rheault, Mark R; Mahmoud, Soheil S

    2013-03-01

    Lavender essential oils are constituted predominantly of regular monoterpenes, for example linalool, 1,8-cineole, and camphor. However, they also contain irregular monoterpenes including lavandulol and lavandulyl acetate. Although the majority of genes responsible for the production of regular monoterpenes in lavenders are now known, enzymes (including lavandulyl diphosphate synthase (LPPS)) catalyzing the biosynthesis of irregular monoterpenes in these plants have not been described. Here, we report the isolation and functional characterization of a novel cis-prenyl diphosphate synthase cDNA, termed Lavandula x intermedia lavandulyl diphosphate synthase (LiLPPS), through a homology-based cloning strategy. The LiLPPS ORF, encoding for a 305-amino acid long protein, was expressed in Escherichia coli, and the recombinant protein was purified by nickel-nitrilotriacetic acid affinity chromatography. The approximately 34.5-kDa bacterially produced protein specifically catalyzed the head-to-middle condensation of two dimethylallyl diphosphate units to LPP in vitro with apparent Km and kcat values of 208 ± 12 μm and 0.1 s(-1), respectively. LiLPPS is a homodimeric enzyme with a sigmoidal saturation curve and Hill coefficient of 2.7, suggesting a positive co-operative interaction among its catalytic sites. LiLPPS could be used to modulate the production of lavandulol and its derivatives in plants through metabolic engineering.

  2. Synergistic effect of Aspergillus tubingensis CTM 507 glucose oxidase in presence of ascorbic acid and alpha amylase on dough properties, baking quality and shelf life of bread

    OpenAIRE

    Kriaa, Mouna; Ouhibi, Rabeb; Graba, Héla; Besbes, Souhail; Jardak, Mohamed; Kammoun, Radhouane

    2015-01-01

    The impact of Aspergillus tubingensis glucose oxidase (GOD) in combination with α-amylase and ascorbic acid on dough properties, qualities and shelf life of bread was investigated. Regression models of alveograph and texture parameters of dough and bread were adjusted. Indeed, the mixture of GOD (44 %) and ascorbic acid (56 %) on flour containing basal improver showed its potential as a corrective action to get better functional and rheological properties of dough and bread texture. Furthermo...

  3. Structures of bilirubin conjugates synthesized in vitro from bilirubin and uridine diphosphate glucuronic acid, uridine diphosphate glucose or uridine diphosphate xylose by preparations from rat liver

    NARCIS (Netherlands)

    Fevery, J.; Leroy, P.; van de Vijver, M.; Heirwegh, K. P.

    1972-01-01

    1. In incubation mixtures containing digitonin-activated or untreated preparations from rat liver, albumin-solubilized bilirubin as the acceptor substrate and (a) UDP-glucuronic acid, (b) UDP-glucose or (c) UDP-xylose as the sugar donor, formation of the following ester glycosides was demonstrated:

  4. FGF19 regulates cell proliferation, glucose and bile acid metabolism via FGFR4-dependent and independent pathways.

    Directory of Open Access Journals (Sweden)

    Ai-Luen Wu

    Full Text Available Fibroblast growth factor 19 (FGF19 is a hormone-like protein that regulates carbohydrate, lipid and bile acid metabolism. At supra-physiological doses, FGF19 also increases hepatocyte proliferation and induces hepatocellular carcinogenesis in mice. Much of FGF19 activity is attributed to the activation of the liver enriched FGF Receptor 4 (FGFR4, although FGF19 can activate other FGFRs in vitro in the presence of the coreceptor βKlotho (KLB. In this report, we investigate the role of FGFR4 in mediating FGF19 activity by using Fgfr4 deficient mice as well as a variant of FGF19 protein (FGF19v which is specifically impaired in activating FGFR4. Our results demonstrate that FGFR4 activation mediates the induction of hepatocyte proliferation and the suppression of bile acid biosynthesis by FGF19, but is not essential for FGF19 to improve glucose and lipid metabolism in high fat diet fed mice as well as in leptin-deficient ob/ob mice. Thus, FGF19 acts through multiple receptor pathways to elicit pleiotropic effects in regulating nutrient metabolism and cell proliferation.

  5. Cover Picture: Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter (Chem. Eur. J. 5/2011)

    DEFF Research Database (Denmark)

    Ståhlberg, Tim Johannes Bjarki; Rodriguez, Sergio; Fristrup, Peter

    2011-01-01

    Boric acid promotes the dehydration of glucose to 5-(hydroxy)methylfurfural in ionic liquids. Computational analyses by DFT calculations show a significant decrease in energy for the isomerization of glucose to fructose when the sugars are bound to boric acid and isotopic labeling NMR studies con...

  6. Genetic and nongenetic determinants of skeletal muscle glucose transporter 4 messenger ribonucleic acid levels and insulin action in twins

    DEFF Research Database (Denmark)

    Storgaard, Heidi; Poulsen, Pernille; Ling, Charlotte

    2006-01-01

    -stimulated expressions of GLUT4 were independently and significantly related to whole-body in vivo insulin action, nonoxidative glucose metabolism, and glucose oxidation. CONCLUSION: We show that skeletal muscle GLUT4 gene expression in twins is significantly and independently related to glucose metabolism...

  7. Role of FAT/CD36 in fatty acid sensing, energy, and glucose homeostasis regulation in DIO and DR rats.

    Science.gov (United States)

    Le Foll, Christelle; Dunn-Meynell, Ambrose A; Levin, Barry E

    2015-02-01

    Hypothalamic fatty acid (FA) sensing neurons alter their activity utilizing the FA translocator/receptor, FAT/CD36. Depletion of ventromedial hypothalamus (VMH) CD36 with adeno-associated viral vector expressing CD36 shRNA (AAV CD36 shRNA) leads to redistribution of adipose stores and insulin resistance in outbred rats. This study assessed the requirement of VMH CD36-mediated FA sensing for the regulation of energy and glucose homeostasis in postnatal day 5 (P5) and P21 selectively bred diet-induced obese (DIO) and diet-resistant (DR) rats using VMH AAV CD36 shRNA injections. P5 CD36 depletion altered VMH neuronal FA sensing predominantly in DIO rats. After 10 wk on a 45% fat diet, DIO rats injected with VMH AAV CD36 shRNA at P21 ate more and gained more weight than DIO AAV controls, while DR AAV CD36 shRNA-injected rats gained less weight than DR AAV controls. VMH CD36 depletion increased inguinal fat pad weights and leptin levels in DIO and DR rats. Although DR AAV CD36 shRNA-injected rats became as obese as DIO AAV controls, only DIO control and CD36 depleted rats became insulin-resistant on a 45% fat diet. VMH CD36 depletion stunted linear growth in DIO and DR rats. DIO rats injected with AAV CD36 shRNA at P5 had increased fat mass, mostly due to a 45% increase in subcutaneous fat. They were also insulin-resistant with an associated 71% increase of liver triglycerides. These results demonstrate that VMH CD36-mediated FA sensing is a critical factor in the regulation of energy and glucose homeostasis and fat deposition in DIO and DR rats.

  8. Circulating Docosahexaenoic Acid Associates with Insulin-Dependent Skeletal Muscle and Whole Body Glucose Uptake in Older Women Born from Normal Weight Mothers

    Directory of Open Access Journals (Sweden)

    Robert M. Badeau

    2017-02-01

    Full Text Available Background: Obesity among pregnant women is common, and their offspring are predisposed to obesity, insulin resistance, and diabetes. The circulating metabolites that are related to insulin resistance and are associated with this decreased tissue-specific uptake are unknown. Here, we assessed metabolite profiles in elderly women who were either female offspring from obese mothers (OOM or offspring of lean mothers (OLM. Metabolic changes were tested for associations with metrics for insulin resistance. Methods: Thirty-seven elderly women were separated into elderly offspring from obese mothers (OOM; n = 17 and elderly offspring from lean/normal weight mothers (OLM; n = 20 groups. We measured plasma metabolites using proton nuclear magnetic resonance (1H-NMR and insulin-dependent tissue-specific glucose uptake in skeletal muscle was assessed. Associations were made between metabolites and glucose uptake. Results: Compared to the OLM group, we found that the docosahexaenoic acid percentage of the total long-chain n-3 fatty acids (DHA/FA was significantly lower in OOM (p = 0.015. DHA/FA associated significantly with skeletal muscle glucose uptake (GU (p = 0.031 and the metabolizable glucose value derived from hyperinsulinemic-euglycemic clamp technique (M-value in the OLM group only (p = 0.050. Conclusions: DHA/FA is associated with insulin-dependent skeletal muscle glucose uptake and this association is significantly weakened in the offspring of obese mothers.

  9. Protective Effects of Ferulic Acid on High Glucose-Induced Protein Glycation, Lipid Peroxidation, and Membrane Ion Pump Activity in Human Erythrocytes.

    Directory of Open Access Journals (Sweden)

    Weerachat Sompong

    Full Text Available Ferulic acid (FA is the ubiquitous phytochemical phenolic derivative of cinnamic acid. Experimental studies in diabetic models demonstrate that FA possesses multiple mechanisms of action associated with anti-hyperglycemic activity. The mechanism by which FA prevents diabetes-associated vascular damages remains unknown. The aim of study was to investigate the protective effects of FA on protein glycation, lipid peroxidation, membrane ion pump activity, and phosphatidylserine exposure in high glucose-exposed human erythrocytes. Our results demonstrated that FA (10-100 μM significantly reduced the levels of glycated hemoglobin (HbA1c whereas 0.1-100 μM concentrations inhibited lipid peroxidation in erythrocytes exposed to 45 mM glucose. This was associated with increased glucose consumption. High glucose treatment also caused a significant reduction in Na+/K+-ATPase activity in the erythrocyte plasma membrane which could be reversed by FA. Furthermore, we found that FA (0.1-100 μM prevented high glucose-induced phosphatidylserine exposure. These findings provide insights into a novel mechanism of FA for the prevention of vascular dysfunction associated with diabetes.

  10. Photoelectrocatalytic oxidation of glucose at a ruthenium complex modified titanium dioxide electrode promoted by uric acid and ascorbic acid for photoelectrochemical fuel cells

    Science.gov (United States)

    Lu, Shuo-Jian; Ji, Shi-Bo; Liu, Jun-Chen; Li, Hong; Li, Wei-Shan

    2015-01-01

    The simultaneous presence of uric acid (UA) and ascorbic acid (AA) is first found to largely promote the photoelectrocatalytic oxidation of glucose (GLU) at an indium-tin oxide (ITO) or TiO2 nanoparticles/ITO electrode modified with [Ru(tatp)3]2+ (tatp = 1,4,8,9-tetra-aza-triphenylene) possessing good redox activity and nanoparticle size distribution. A well-defined electrocatalytic peak for GLU oxidation is shown at 0.265 V (vs. SCE) under approximate physiological conditions upon incorporation of UA and AA. The [Ru(tatp)3]2+/ITO electrode exhibits attractive amperometric oxidation responses towards GLU, UA and AA, while controlled potentiostatically at 0.3 V, 0.7 V and 1.0 V, respectively, indicating high sensitivity and excellent reproducibility. On basis of the photoelectrocatalysis of [Ru(tatp)3]2+/TiO2/ITO anode, a GLU concentration-dependent photoelectrochemical fuel cell vs. SCE is elaborately assembled. The proposed free-enzyme photoelectrochemical fuel cell employing 0.1 M GLU associated with 0.01 M UA and 0.01 M AA as fuel shows open-circuit photovoltage of 0.608 V, short-circuit photocurrent density of 124.5 μA cm-2 and maximum power density of 21.75 μW cm-2 at 0.455 V, fill factor of 0.32 and photoenergy conversion efficiency of 36.65%, respectively.

  11. First-pass uptake and oxidation of glucose by the splanchnic tissue in young goats fed soy protein-based milk diets with or without amino acid supplementation: glucose metabolism in goat kids after soy feeding.

    Science.gov (United States)

    Schönhusen, U; Junghans, P; Flöter, A; Steinhoff-Wagner, J; Görs, S; Schneider, F; Metges, C C; Hammon, H M

    2013-04-01

    The study was designed to examine whether feeding soy protein isolate as partial replacement of casein (CN) affects glucose metabolism in young goats and whether effects may be ameliorated by supplementation of those AA known to be lower concentrated in soy than in CN. Goat kids (d 20 of age) were fed comparable milk protein diets, in which 50% of the crude protein was either CN (control, CON), soy protein isolate (SPI), or soy protein isolate supplemented with AA (SPIA) for 43 d (n=8 per group). On d 62 of age, a single bolus dose of d-[(13)C6]glucose (10mg/kg of BW) was given with the morning diet, and simultaneously, a single bolus dose of d-[6,6-(2)H2]glucose (5mg/kg of BW) was injected into a jugular vein. Blood samples were collected between -30 and +420 min relative to the tracer administration to measure the (13)C and (2)H enrichments of plasma glucose and the (13)C enrichment of blood CO2. Glucose first-pass uptake by the splanchnic tissues was calculated from the rate of appearance of differentially labeled glucose tracer in plasma. Glucose oxidation was calculated from (13)C enrichment in blood CO2. In addition, plasma concentrations of triglycerides, nonesterified fatty acids, glucose, insulin, and glucagon were measured. On d 63 of age, kids were killed and jejunal mucosa and liver samples were collected to measure lactase mRNA levels and lactase and maltase activities in the jejunum and activities of pyruvate carboxylase and phosphoenolpyruvate carboxykinase (PEPCK) in the liver. Basal plasma glucose concentration tended to be higher in the CON than the SPIA group, whereas basal insulin was higher in the CON group than the SPI and SPIA groups, and glucagon was higher in the CON than the SPIA group. Plasma glucose and insulin concentrations increased during the first hour after feeding, whereas plasma glucagon increased immediately after feeding and after 1h of feeding. First-pass uptake and glucose oxidation were not affected by diet. Maltase

  12. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Science.gov (United States)

    Everman, Sarah; Mandarino, Lawrence J; Carroll, Chad C; Katsanos, Christos S

    2015-01-01

    Plasma branched-chain amino acids (BCAA) are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity. To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans. Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U) during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5) to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5). In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U) in association with the above BCAA infusion (N = 4) or under the same conditions without BCAA infusion (N = 3). Plasma glucose turnover was measured prior to and during insulin infusion. Insulin infusion completely suppressed the endogenous glucose production (EGP) across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05). Insulin infusion stimulated whole-body glucose disposal rate (GDR) across all groups. However, the increase (%) in GDR was not different [median (1st quartile - 3rd quartile)] between Control and BCAA in either the 40U ([199 (167-278) vs. 186 (94-308)] or 80 U ([491 (414-548) vs. 478 (409-857)] experiments (P > 0.05). Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P BCAA in either of the experiments (P > 0.05). Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  13. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Directory of Open Access Journals (Sweden)

    Sarah Everman

    Full Text Available Plasma branched-chain amino acids (BCAA are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity.To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans.Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5 to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5. In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U in association with the above BCAA infusion (N = 4 or under the same conditions without BCAA infusion (N = 3. Plasma glucose turnover was measured prior to and during insulin infusion.Insulin infusion completely suppressed the endogenous glucose production (EGP across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05. Insulin infusion stimulated whole-body glucose disposal rate (GDR across all groups. However, the increase (% in GDR was not different [median (1st quartile - 3rd quartile] between Control and BCAA in either the 40U ([199 (167-278 vs. 186 (94-308] or 80 U ([491 (414-548 vs. 478 (409-857] experiments (P > 0.05. Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P 0.05.Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  14. Serum uric acid and disorders of glucose metabolism: the role of glycosuria

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, J.A.M. [Divisão de Nefrologia, Departamento de Medicina Clínica, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, RJ (Brazil); Kang, H.C. [Departamento de Patologia, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, RJ (Brazil); Greffin, S. [Divisão de Nefrologia, Departamento de Medicina Clínica, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, RJ (Brazil); Garcia Rosa, M.L. [Departamento de Epidemiologia e Bioestatística, Universidade Federal Fluminense, Niterói, RJ (Brazil); Lugon, J.R. [Divisão de Nefrologia, Departamento de Medicina Clínica, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, RJ (Brazil)

    2014-08-22

    Hyperuricemia has been associated with hypertension, diabetes mellitus, and metabolic syndrome. We studied the association between hyperuricemia and glycemic status in a nonrandomized sample of primary care patients. This was a cross-sectional study of adults ≥20 years old who were members of a community-based health care program. Hyperuricemia was defined as a value >7.0 mg/dL for men and >6.0 mg/dL for women. The sample comprised 720 participants including controls (n=257) and patients who were hypertensive and euglycemic (n=118), prediabetic (n=222), or diabetic (n=123). The mean age was 42.4±12.5 years, 45% were male, and 30% were white. The prevalence of hyperuricemia increased from controls (3.9%) to euglycemic hypertension (7.6%) and prediabetic state (14.0%), with values in prediabetic patients being statistically different from controls. Overall, diabetic patients had an 11.4% prevalence of hyperuricemia, which was also statistically different from controls. Of note, diabetic subjects with glycosuria, who represented 24% of the diabetic participants, had a null prevalence of hyperuricemia, and statistically higher values for fractional excretion of uric acid, Na excretion index, and prevalence of microalbuminuria than those without glycosuria. Participants who were prediabetic or diabetic but without glycosuria had a similarly elevated prevalence of hyperuricemia. In contrast, diabetic patients with glycosuria had a null prevalence of hyperuricemia and excreted more uric acid and Na than diabetic subjects without glycosuria. The findings can be explained by enhanced proximal tubule reabsorption early in the course of dysglycemia that decreases with the ensuing glycosuria at the late stage of the disorder.

  15. Serum uric acid and disorders of glucose metabolism: the role of glycosuria

    International Nuclear Information System (INIS)

    Andrade, J.A.M.; Kang, H.C.; Greffin, S.; Garcia Rosa, M.L.; Lugon, J.R.

    2014-01-01

    Hyperuricemia has been associated with hypertension, diabetes mellitus, and metabolic syndrome. We studied the association between hyperuricemia and glycemic status in a nonrandomized sample of primary care patients. This was a cross-sectional study of adults ≥20 years old who were members of a community-based health care program. Hyperuricemia was defined as a value >7.0 mg/dL for men and >6.0 mg/dL for women. The sample comprised 720 participants including controls (n=257) and patients who were hypertensive and euglycemic (n=118), prediabetic (n=222), or diabetic (n=123). The mean age was 42.4±12.5 years, 45% were male, and 30% were white. The prevalence of hyperuricemia increased from controls (3.9%) to euglycemic hypertension (7.6%) and prediabetic state (14.0%), with values in prediabetic patients being statistically different from controls. Overall, diabetic patients had an 11.4% prevalence of hyperuricemia, which was also statistically different from controls. Of note, diabetic subjects with glycosuria, who represented 24% of the diabetic participants, had a null prevalence of hyperuricemia, and statistically higher values for fractional excretion of uric acid, Na excretion index, and prevalence of microalbuminuria than those without glycosuria. Participants who were prediabetic or diabetic but without glycosuria had a similarly elevated prevalence of hyperuricemia. In contrast, diabetic patients with glycosuria had a null prevalence of hyperuricemia and excreted more uric acid and Na than diabetic subjects without glycosuria. The findings can be explained by enhanced proximal tubule reabsorption early in the course of dysglycemia that decreases with the ensuing glycosuria at the late stage of the disorder

  16. In vitro analysis of radioprotective effect of monoterpenes

    International Nuclear Information System (INIS)

    Ken-ichi Kudo; Tadashi Hanafusa; Toshiro Ono

    2017-01-01

    Monoterpenes are naturally occurring hydrocarbons composed of two units of isoprenes. They exhibit antioxidant activity to scavenge reactive oxygen species, such as hydroxyl radicals. We investigated the potential of monoterpenes such as thymol, linalool, and menthol to act as radioprotectants. The proliferation of EL4 cells, a mouse lymphoma cell line, treated with linalool at a concentration of 500 μM or more was not affected by X-ray irradiation. Plasmid-nicking assay performed using formamidopyrimidine-DNA glycosylase showed that linalool prevented single strand breaks and oxidized purines on pUC19 plasmid DNA. These findings indicate that linalool has the ability to scavenge reactive oxygen species and is a potential radioprotector. (author)

  17. Monoterpene emissions from a Ponderosa Pine forest. Does age matter?

    Science.gov (United States)

    Madronich, M. B.; Guenther, A. B.; Wessman, C. A.

    2011-12-01

    Determining the emissions rate of biogenic volatile organic carbon (BVOC) from plants is a challenge. Biological variability makes it difficult to assess accurately those emissions rates. It is known that photosynthetic active radiation (PAR), temperature, nutrients as well as the biology of the plant affect emissions. However, less is known about the variability of the emissions with respect to the life cycle of the plants. This study is focusing on the difference of monoterpene emission rates from mature Ponderosa Pine trees and saplings in the field. Preliminary calculations show that there is a significant difference between total monoterpene emissions in mature trees (0.24±0.04 μgC/gdwh) and saplings (0.37±0.02 μgC/gdwh).

  18. Sesquiterpene lactones and monoterpene glucosides from plant species Picris echoides

    Directory of Open Access Journals (Sweden)

    MILUTIN STEFANOVIC

    2000-11-01

    Full Text Available Investigation of the constituents of the aerial parts of domestic plant species Picris echoides afforded the sesquiterpene lactones, i.e., guaianolides jacquilenin (1, 11-epi-jacquilenin (2, achillin (3 and eudesmanolide telekin (4. The chemical indentification of the two monoterpene glucosides (–-cis-chrysanthenol-b-D-glucopyranoside (5 and its 6’-acetate 6 is also repoted. The guaianolide achillin (3 and the two monoterpene glucosides 5 and 6 were isolated for the first time from this plant species. Isolation was achieved by column chromatography and the structures were established mainly by the interpretation of their physical and spectral data, which were in agreement with those in the literature.

  19. Xylem monoterpenes of pines: distribution, variation, genetics, function

    Science.gov (United States)

    Richard Smith

    2000-01-01

    The monoterpenes of about 16,000 xylem resin samples of pine (Pinus) speciesand hybrids—largely from the western United States—were analyzed in this long-term study of the resistance of pines to attack by bark beetles (Coleoptera:Scolytidae), with special emphasis on resistance to the western pine beetle(Dendroctonus brevicomis). The samples were analyzed by gas liquid...

  20. Cyclic monoterpene mediated modulations of Arabidopsis thaliana phenotype

    Science.gov (United States)

    Kriegs, Bettina; Jansen, Marcus; Hahn, Katrin; Peisker, Helga; Šamajová, Olga; Beck, Martina; Braun, Silvia; Ulbrich, Andreas; Baluška, František

    2010-01-01

    Monoterpenes at high atmospheric concentrations are strong growth inhibitors in allelopathic interactions. Effects depend on dose, molecular structure of the monoterpene and on the species of the receiver plant. Stomata are among the first targets affected by camphor and menthol. Previously, it could be demonstrated that the compounds induce swelling of the protoplasts, prevent stomatal closure and enhance transpiration. In this study, we show that the block of stomatal closure is accompanied by changes to the cytoskeleton, which has a direct role in stomatal movements. Although MPK3 (MAP3 kinase) and ABF4 gene expressions are induced within six hours, stomatal closure is prevented. In contrast to ABF4, ABF2 (both transcription factors) is not induced. MPK3 and ABF4 both encode for proteins involved in the process of stomatal closure. The expression of PEPCase, an enzyme important for stomatal opening, is downregulated. The leaves develop stress symptoms, mirrored by transient changes in the expression profile of additional genes: lipoxygenase 2 (LOX2), CER5, CER6 (both important for wax production) and RD29B (an ABA inducible stress protein). Non-invasive methods showed a fast response of the plant to camphor fumigations both in a rapid decrease of the quantum yield and in the relative growth rate. Repeated exposures to the monoterpenes resulted finally in growth reduction and a stress related change in the phenotype. It is proposed that high concentrations or repeated exposure to monoterpenes led to irreversible damages, whereas low concentrations or short-term fumigations may have the potential to strengthen the plant fitness. PMID:20484979

  1. Production of aromas and fragrances through microbial oxidation of monoterpenes

    Directory of Open Access Journals (Sweden)

    H. F. Rozenbaum

    2006-09-01

    Full Text Available Aromas and fragrances can be obtained through the microbial oxidation of monoterpenes. Many microorganisms can be used to carry out extremely specific conversions using substrates of low commercial value. However, for many species, these substrates are highly toxic, consequently inhibiting their metabolism. In this work, the conversion ability of Aspergillus niger IOC-3913 for terpenic compounds was examined. This species was preselected because of its high resistance to toxic monoterpenic substrates. Though it has been grown in media containing R-limonene (one of the cheapest monoterpenic hydrocarbons, which is widely available on the market, the species has not shown the ability to metabolize it, since biotransformation products were not detected in high resolution gas chromatography analyses. For this reason, other monoterpenes (alpha-pinene, beta-pinene and camphor were used as substrates. These compounds were shown to be metabolized by the selected strain, producing oxidized compounds. Four reaction systems were used: a biotransformation in a liquid medium with cells in growth b with pre-grown cultures c with cells immobilized in a synthetic polymer network and d in a solid medium to which the substrate was added via the gas phase. The main biotransformation products were found in all the reaction systems, although the adoption of previously cultivated cells seemed to favor biotransformation. Cell immobilization seemed to be a feasible strategy for alleviating the toxic effect of the substrate. Through mass spectrometry it was possible to identify verbenone and alpha-terpineol as the biotransformation products of alpha-pinene and beta-pinene, respectively. The structures of the other oxidation products are described.

  2. Interaction between Marine-Derived n-3 Long Chain Polyunsaturated Fatty Acids and Uric Acid on Glucose Metabolism and Risk of Type 2 Diabetes Mellitus: A Case-Control Study.

    Science.gov (United States)

    Li, Kelei; Wu, Kejian; Zhao, Yimin; Huang, Tao; Lou, Dajun; Yu, Xiaomei; Li, Duo

    2015-08-26

    The present case-control study explored the interaction between marine-derived n-3 long chain polyunsaturated fatty acids (n-3 LC PUFAs) and uric acid (UA) on glucose metabolism and risk of type 2 diabetes mellitus (T2DM). Two hundred and eleven healthy subjects in control group and 268 T2DM subjects in case group were included. Plasma phospholipid (PL) fatty acids and biochemical parameters were detected by standard methods. Plasma PL C22:6n-3 was significantly lower in case group than in control group, and was negatively correlated with fasting glucose (r = -0.177, p < 0.001). Higher plasma PL C22:6n-3 was associated with lower risk of T2DM, and the OR was 0.32 (95% confidence interval (CI), 0.12 to 0.80; p = 0.016) for per unit increase of C22:6n-3. UA was significantly lower in case group than in control group. UA was positively correlated with fasting glucose in healthy subjects, but this correlation became negative in T2DM subjects. A significant interaction was observed between C22:6n-3 and UA on fasting glucose (p for interaction = 0.005): the lowering effect of C22:6n-3 was only significant in subjects with a lower level of UA. In conclusion, C22:6n-3 interacts with UA to modulate glucose metabolism.

  3. Laboratory studies of monoterpene secondary organic aerosol formation and evolution

    Science.gov (United States)

    Thornton, J. A.; D'Ambro, E.; Zhao, Y.; Lee, B. H.; Pye, H. O. T.; Schobesberger, S.; Shilling, J.; Liu, J.

    2017-12-01

    We have conducted a series of chamber experiments to study the molecular composition and properties of secondary organic aerosol (SOA) formed from monoterpenes under a range of photochemical and dark conditions. We connect variations in the SOA mass yield to molecular composition and volatility, and use a detailed Master Chemical Mechanism (MCM) based chemical box model with dynamic gas-particle partitioning to examine the importance of various peroxy radical reaction mechanisms in setting the SOA yield and properties. We compare the volatility distribution predicted by the model to that inferred from isothermal room-temperature evaporation experiments using the FIGAERO-CIMS where SOA particles collected on a filter are allowed to evaporate under humidified pure nitrogen flow stream for up to 24 hours. We show that the combination of results requires prompt formation of low volatility SOA from predominantly gas-phase mechanisms, with important differences between monoterpenes (alpha-Pinene and delta-3-Carene) followed by slower non-radical particle phase chemistry that modulates both the chemical and physical properties of the SOA. Implications for the regional evolution of atmospheric monoterpene SOA are also discussed.

  4. Dynamics of Monoterpene Formation in Spike Lavender Plants

    Directory of Open Access Journals (Sweden)

    Isabel Mendoza-Poudereux

    2017-12-01

    Full Text Available The metabolic cross-talk between the mevalonate (MVA and the methylerythritol phosphate (MEP pathways was analyzed in spike lavender (Lavandula latifolia Med on the basis of 13CO2-labelling experiments using wildtype and transgenic plants overexpressing the 3-hydroxy-3-methylglutaryl CoA reductase (HMGR, the first and key enzyme of the MVA pathway. The plants were labelled in the presence of 13CO2 in a gas chamber for controlled pulse and chase periods of time. GC/MS and NMR analysis of 1,8-cineole and camphor, the major monoterpenes present in their essential oil, indicated that the C5-precursors, isopentenyl diphosphate (IPP and dimethylallyl diphosphate (DMAPP of both monoterpenes are predominantly biosynthesized via the MEP pathway. Surprisingly, overexpression of HMGR did not have significant impact upon the crosstalk between the MVA and MEP pathways indicating that the MEP route is the preferred pathway for the synthesis of C5 monoterpene precursors in spike lavender.

  5. The Antigerminative Activity of Twenty-Seven Monoterpenes

    Directory of Open Access Journals (Sweden)

    Laura De Martino

    2010-09-01

    Full Text Available Monoterpenes, the main constituents of essential oils, are known for their many biological activities. The present work studied the potential biological activity of twenty-seven monoterpenes, including monoterpene hydrocarbons and oxygenated ones, against seed germination and subsequent primary radicle growth of Raphanus sativus L. (radish and Lepidium sativum L. (garden cress, under laboratory conditions. The compounds, belonging to different chemical classes, showed different potency in affecting both parameters evaluated. The assayed compounds demonstrated a good inhibitory activity in a dose-dependent way. In general, radish seed is more sensitive than garden cress and its germination appeares more inhibited by alcohols; at the highest concentration tested, the more active substances were geraniol, borneol, (±-β-citronellol and α-terpineol. Geraniol and carvone inhibited, in a significant way, the germination of garden cress, at the highest concentration tested. Radicle elongation of two test species was inhibited mainly by alcohols and ketones. Carvone inhibited the radicle elongation of both seeds, at almost all concentrations assayed, while 1,8-cineole inhibited their radicle elongation at the lowest concentrations (10−5 M, 10−6 M.

  6. Acidic Pretreatment of Wheat Straw in Decanol for the Production of Surfactant, Lignin and Glucose

    Directory of Open Access Journals (Sweden)

    Boris Estrine

    2011-12-01

    Full Text Available Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF. The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals.

  7. Poly(brilliant green) and poly(thionine) modified carbon nanotube coated carbon film electrodes for glucose and uric acid biosensors.

    Science.gov (United States)

    Ghica, M Emilia; Brett, Christopher M A

    2014-12-01

    Poly(brilliant green) (PBG) and poly(thionine) (PTH) films have been formed on carbon film electrodes (CFEs) modified with carbon nanotubes (CNT) by electropolymerisation using potential cycling. Voltammetric and electrochemical impedance characterisation were performed. Glucose oxidase and uricase, as model enzymes, were immobilised on top of PBG/CNT/CFE and PTH/CNT/CFE for glucose and uric acid (UA) biosensing. Amperometric determination of glucose and UA was carried out in phosphate buffer pH 7.0 at -0.20 and +0.30 V vs. SCE, respectively, and the results were compared with other similarly modified electrodes existing in the literature. An interference study and recovery measurements in natural samples were successfully performed, indicating these architectures to be good and promising biosensor platforms. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Cloning and Characterizing Genes Involved in Monoterpene Induced Mammary Tumor Regression.

    Science.gov (United States)

    1996-10-01

    AD GRANT NUMBER DAMDI7-94-J-4041 TITLE: Cloning and Characterizing Genes Involved in Monoterpene Induced Mammary Tumor Regression PRINCIPAL...October 1996 Annual (1 Sep 95 - 31 Aug 96) 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Cloning and Characterizing Genes Involved in Monoterpene Induced... Monoterpene -induced/repressed genes were identified in regressing rat mammary carcinomas treated with dietary limonene using a newly developed method

  9. Do monoterpenes released from feverfew (Tanacetum parthenium) plants cause airborne Compositae dermatitis?

    DEFF Research Database (Denmark)

    Paulsen, E.; Christensen, Lars Porskjær; Andersen, K.E.

    2002-01-01

    The Compositae plant feverfew (Tanacetum parthenium) is an important sensitizer in Europe and has been suspected of causing airborne Compositae dermatitis. A previous investigation of substances emitted from feverfew plants detected no sesquiterpene lactones, however, but mainly monoterpenes...... airborne dermatitis, mimicking photosensitivity, and the disappearance of symptoms upon removal of feverfew plants suggest monoterpenes as a possible contributing factor. Similar associations between doubtful positive monoterpene reactions and clinical patterns, fragrance/colophonium allergy and relevance...

  10. Maternal High Folic Acid Supplement Promotes Glucose Intolerance and Insulin Resistance in Male Mouse Offspring Fed a High-Fat Diet

    Directory of Open Access Journals (Sweden)

    Yifan Huang

    2014-04-01

    Full Text Available Maternal nutrition may influence metabolic profiles in offspring. We aimed to investigate the effect of maternal folic acid supplement on glucose metabolism in mouse offspring fed a high-fat diet (HFD. Sixty C57BL/6 female mice were randomly assigned into three dietary groups and fed the AIN-93G diet containing 2 (control, 5 (recommended folic acid supplement, RFolS or 40 (high folic acid supplement, HFolS mg folic acid/kg of diet. All male offspring were fed HFD for eight weeks. Physiological, biochemical and genetic variables were measured. Before HFD feeding, developmental variables and metabolic profiles were comparable among each offspring group. However, after eight weeks of HFD feeding, the offspring of HFolS dams (Off-HFolS were more vulnerable to suffer from obesity (p = 0.009, glucose intolerance (p < 0.001 and insulin resistance (p < 0.001, compared with the controls. Off-HFolS had reduced serum adiponectin concentration, accompanied with decreased adiponectin mRNA level but increased global DNA methylation level in white adipose tissue. In conclusion, our results suggest maternal HFolS exacerbates the detrimental effect of HFD on glucose intolerance and insulin resistance in male offspring, implying that HFolS during pregnancy should be adopted cautiously in the general population of pregnant women to avoid potential deleterious effect on the metabolic diseases in their offspring.

  11. One-pot synthesis of biocompatible boronic acid-functionalized poly(methyl methacrylate) nanoparticles at sub-100 nm scale for glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sakalak, Huseyin [Selcuk University, Metallurgy and Materials Engineering (Turkey); Ulasan, Mehmet; Yavuz, Emine [Selcuk University, Advanced Technology Research and Application Center (Turkey); Camli, Sevket Tolga, E-mail: tolgacamli@gmail.com [Biyotez Machinery Chemistry R& D Co. Ltd. (Turkey); Yavuz, Mustafa Selman, E-mail: selmanyavuz@selcuk.edu.tr [Selcuk University, Metallurgy and Materials Engineering (Turkey)

    2014-12-15

    Poly(methyl methacrylate) nanoparticles containing 4-vinylphenyl boronic acid were synthesized in one pot by surfactant-free emulsion polymerization. The nanoparticles were characterized by scanning electron microscopy and dynamic light scattering. Boron content in the nanoparticles was confirmed by electron-dispersive X-ray spectroscopy. In polymerization process, several co-monomer ratios were studied in order to obtain optimum nanoparticle size. Average hydrodynamic diameter and polydispersity index of nanoparticles versus variation of acetone percentage in the solvent mixture and total monomer concentration were investigated. The effect of boronic acid concentration in the monomer mixture on nanoparticle size and size distribution was also reported. Without further functionalization to the nanoparticles, the catechol dye, alizarin red S, was bound to boronic acid-containing nanoparticles. These nanoparticles behave as a nanosensor by which glucose or fructose can be easily detected. Dye-containing nanoparticles were undertaken displacement reaction by glucose or fructose. The glucose or fructose content was also monitored by UV–Visible spectrophotometer. Furthermore, cytotoxicity studies of boronic acid-carrying poly(methyl methacrylate) nanoparticles were carried out in 3T3 cells, which showed no toxicity effect on the cells.

  12. One-pot synthesis of biocompatible boronic acid-functionalized poly(methyl methacrylate) nanoparticles at sub-100 nm scale for glucose sensing

    International Nuclear Information System (INIS)

    Sakalak, Huseyin; Ulasan, Mehmet; Yavuz, Emine; Camli, Sevket Tolga; Yavuz, Mustafa Selman

    2014-01-01

    Poly(methyl methacrylate) nanoparticles containing 4-vinylphenyl boronic acid were synthesized in one pot by surfactant-free emulsion polymerization. The nanoparticles were characterized by scanning electron microscopy and dynamic light scattering. Boron content in the nanoparticles was confirmed by electron-dispersive X-ray spectroscopy. In polymerization process, several co-monomer ratios were studied in order to obtain optimum nanoparticle size. Average hydrodynamic diameter and polydispersity index of nanoparticles versus variation of acetone percentage in the solvent mixture and total monomer concentration were investigated. The effect of boronic acid concentration in the monomer mixture on nanoparticle size and size distribution was also reported. Without further functionalization to the nanoparticles, the catechol dye, alizarin red S, was bound to boronic acid-containing nanoparticles. These nanoparticles behave as a nanosensor by which glucose or fructose can be easily detected. Dye-containing nanoparticles were undertaken displacement reaction by glucose or fructose. The glucose or fructose content was also monitored by UV–Visible spectrophotometer. Furthermore, cytotoxicity studies of boronic acid-carrying poly(methyl methacrylate) nanoparticles were carried out in 3T3 cells, which showed no toxicity effect on the cells

  13. Stearic acid-rich interesterified fat and trans-rich fat raise the LDL/HDL ratio and plasma glucose relative to palm olein in humans

    Directory of Open Access Journals (Sweden)

    Karupaiah Tilakavati

    2007-01-01

    Full Text Available Abstract Background Dietary trans-rich and interesterified fats were compared to an unmodified saturated fat for their relative impact on blood lipids and plasma glucose. Each fat had melting characteristics, plasticity and solids fat content suitable for use as hardstock in margarine and other solid fat formulations. Methods Thirty human volunteers were fed complete, whole food diets during 4 wk periods, where total fat (~31% daily energy, >70% from the test fats and fatty acid composition were tightly controlled. A crossover design was used with 3 randomly-assigned diet rotations and repeated-measures analysis. One test fat rotation was based on palm olein (POL and provided 12.0 percent of energy (%en as palmitic acid (16:0; a second contained trans-rich partially hydrogenated soybean oil (PHSO and provided 3.2 %en as trans fatty acids plus 6.5 %en as 16:0, while the third used an interesterified fat (IE and provided 12.5 %en as stearic acid (18:0. After 4 wk the plasma lipoproteins, fatty acid profile, as well as fasting glucose and insulin were assessed. In addition, after 2 wk into each period an 8 h postprandial challenge was initiated in a subset of 19 subjects who consumed a meal containing 53 g of test fat. Results After 4 wk, both PHSO and IE fats significantly elevated both the LDL/HDL ratio and fasting blood glucose, the latter almost 20% in the IE group relative to POL. Fasting 4 wk insulin was 10% lower after PHSO (p > 0.05 and 22% lower after IE (p Conclusion Both PHSO and IE fats altered the metabolism of lipoproteins and glucose relative to an unmodified saturated fat when fed to humans under identical circumstances.

  14. On the interaction of uranium with the bioligands citric acid and glucose

    International Nuclear Information System (INIS)

    Steudtner, Robin

    2011-01-01

    fluorescence lifetimes determined at 153 K were 79 ± 15 μs (1:0:1) and 10 ± 3 μs (2:0:2). In this work not only the model complexation of the hexavalent uranium but also the complex behaviour of the tetravalent uranium in presence of citric acid were studied. In all samples the uranium citrate complexes were detected as dissolved species. In addition to the spectroscopy detection of the new forming uranium citrate species the complex formation could be analyzed the complex formation constant and the single component spectrum for all complexes. Complex formation constant for the citrate species of the hexavalent uranium of log β 203 = 22.67 ± 0.34 ([(UO 2 ) 2 (Cit) 3 ] 5- ) and of log β 103 = 12.35 ± 0.22 ([UO 2 (Cit) 3 ] 7- ) and for the complexes of the tetravalent uranium of log β 1-21 = -9.74 ± 0.23 ([U(OH) 2 Cit] - ) und log β 1-31 = -20.36 ± 0.22 ([U(OH) 3 Cit] 2- ) were calculated for the first time. Also to the complex behaviour and the redox behaviour of uranium in presence of citric acid were investigated. The photochemical reduction of uranium(VI) by citric acid at aerobic and anaerobic conditions was detected by UV-Vis spectroscopy. The reaction at aerobic conditions showed which unknown influence organic ligands can have on the chemical behaviour of uranium. The highest reduction rate could be determinate between pH 3.5 and 4 with 52 % at aerobic conditions and 66 % at anaerobic conditions. With increase of the pH the amount of reduced uranium(VI) decreases. In the oxygen system a reduction above pH 7 wasn't detectable. These results are in a very good correspondence with model calculation of the uranium(VI) speciation in urine.

  15. Post-prandial glucose levels and consumption of omega 3 fatty acids and saturated fats among two rural populations in Kenya.

    Science.gov (United States)

    Wanjihia, V W; Kiplamai, F K; Waudo, J N; Boit, M K

    2009-06-01

    Amount and quality of dietary fat modifies glucose tolerance. Omega 3 Fatty Acids (n-3F A) are polyunsaturated fats, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found primarily in fish and they have a positive effect on glucose tolerance. To compare risk of type 2 diabetes mellitus (T2DM), as demonstrated thourough impaired glucose tolerance (IGT), and n-3FA intake among two rural populations. A descriptive, cross-sectional comparative study. Bondo District (Luo Community) and Kericho District (Kipsigis Community) of the Lake Victoria basin of Kenya. Sample of 150 individuals, aged above 18 years was randomly selected from each of the two communities. Impaired glucose tolerance (IGT) was measured according to World Health Organisation diagnostic criteria. The intake of n-3FA was determined using a 24 hour dietary recall and food frequency schedule. Data was analysed using SPSS and Pearson Correlation Coefficient was used to test correlation between n-3FA consumption and IGT. The inter-group comparisons were done using the t-test and analysis of variance. The prevalence of IGT was 11.8% among the Kipsigis and 4.8% among the Luo (Pfats (r=-0.002, p=0.973). The levels of IGT were significantly lower (Pfats intake and IGT. The saturated fat ingested did not affect the level of post-prandial glucose. The Luo who consumed higher n-3FA amounts, recorded lower levels of IGT than the Kipsigis who had significantly lower consumption. Effective screening methods should be used at the existing health units to determine risk factors of type 2 diabetes mellitus like IGT among patients. This could help in advising them accordingly on lifestyle changes, especially concerning diet and beneficial fats.

  16. Cofactor Balance by Nicotinamide Nucleotide Transhydrogenase (NNT) Coordinates Reductive Carboxylation and Glucose Catabolism in the Tricarboxylic Acid (TCA) Cycle*♦

    Science.gov (United States)

    Gameiro, Paulo A.; Laviolette, Laura A.; Kelleher, Joanne K.; Iliopoulos, Othon; Stephanopoulos, Gregory

    2013-01-01

    Cancer and proliferating cells exhibit an increased demand for glutamine-derived carbons to support anabolic processes. In addition, reductive carboxylation of α-ketoglutarate by isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) was recently shown to be a major source of citrate synthesis from glutamine. The role of NAD(P)H/NAD(P)+ cofactors in coordinating glucose and glutamine utilization in the tricarboxylic acid (TCA) cycle is not well understood, with the source(s) of NADPH for the reductive carboxylation reaction remaining unexplored. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial enzyme that transfers reducing equivalents from NADH to NADPH. Here, we show that knockdown of NNT inhibits the contribution of glutamine to the TCA cycle and activates glucose catabolism in SkMel5 melanoma cells. The increase in glucose oxidation partially occurred through pyruvate carboxylase and rendered NNT knockdown cells more sensitive to glucose deprivation. Importantly, knocking down NNT inhibits reductive carboxylation in SkMel5 and 786-O renal carcinoma cells. Overexpression of NNT is sufficient to stimulate glutamine oxidation and reductive carboxylation, whereas it inhibits glucose catabolism in the TCA cycle. These observations are supported by an impairment of the NAD(P)H/NAD(P)+ ratios. Our findings underscore the role of NNT in regulating central carbon metabolism via redox balance, calling for other mechanisms that coordinate substrate preference to maintain a functional TCA cycle. PMID:23504317

  17. Production of tannase by Aspergillus niger Aa-20 in submerged and solid-state fermentation: influence of glucose and tannic acid.

    Science.gov (United States)

    Aguilar, C N; Augur, C; Favela-Torres, E; Viniegra-González, G

    2001-05-01

    Tannase production by Aspergillus niger Aa-20 was studied in submerged (SmF) and solid-state (SSF) fermentation systems with different tannic acid and glucose concentrations. Tannase activity and productivity were at least 2.5 times higher in SSF than in SmF. Addition of high tannic acid concentrations increased total tannase activity in SSF, while in SmF it was decreased. In SmF, total tannase activity increased from 0.57 to 1.03 IU/mL, when the initial glucose concentration increased from 6.25 to 25 g/L, but a strong catabolite repression of tannase synthesis was observed in SmF when an initial glucose concentration of 50 g/L was used. In SSF, maximal values of total tannase activity decreased from 7.79 to 2.51 IU when the initial glucose concentration was increased from 6.25 to 200 g/L. Kinetic results on tannase production indicate that low tannase activity titers in SmF could be associated to an enzyme degradation process which is not present in SSF. Tannase titers produced by A. niger Aa-20 are fermentation system-dependent, favoring SSF over SmF.

  18. Improvements in glucose metabolism early after gastric bypass surgery are not explained by increases in total bile acids and fibroblast growth factor 19 concentrations

    DEFF Research Database (Denmark)

    Jørgensen, Nils B; Dirksen, Carsten; Bojsen-Møller, Kirstine N

    2015-01-01

    Context: Bile acids and fibroblast growth factor 19 (FGF19) have been suggested as key mediators of the improvements in glucose metabolism after Roux-en-Y gastric bypass (RYGB). Objective: To describe fasting and postprandial state total bile acid (TBA) and FGF19 concentrations before and after...... (T2D) patients and 12 normal glucose tolerant (NGT) subjects participated in the study. Intervention: A 4-hour liquid meal test was performed before and 1 week, 3 months, and 1 year after RYGB. Main Outcome Measures: We measured fasting and postprandial TBA and FGF19 concentrations. Results: Fasting...... TBA concentrations decreased in NGT subjects (P TBA was decreased in NGT subjects 1 week after RYGB (before surgery, 567...

  19. Effect of Ramadan fasting on glucose level, lipid profile, HbA1c and uric acid among medical students in Karachi, Pakistan.

    Science.gov (United States)

    Khan, Nazeer; Rasheed, Abdur; Ahmed, Hassaan; Aslam, Faiza; Kanwal, Fatima

    2017-06-14

    To assess the effect of Ramadan fasting on blood pressure, fasting glucose, lipid profile, uric acid, HbA1c, body mass index, body adiposity index and visceral adiposity index among fasting medical students, 35 students were recorded before, during and after Ramadan (August) 2011, for their blood pressure, anthropometric measurements, questionnaire response and blood sample. A blood sample was taken at each visit for glucose, lipid profile and HbA1c. Total physical activity, weight-to-height ratio, body adiposity index and visceral adiposity index were calculated for insulin sensitivity. Changes in anthropometric measurements were not statistically significant. However, physical activities increased significantly after Ramadan. Changes in blood pressure, fasting blood sugar, total cholesterol, HbA1c, uric acid and triglyceride were not statistically significant. Mean high density lipoprotein decreased significantly in Ramadan, while low density lipoprotein increased significantly.

  20. Evaluation of efficient glucose release using sodium hydroxide and phosphoric acid as pretreating agents from the biomass of Sesbania grandiflora (L.) Pers.: A fast growing tree legume.

    Science.gov (United States)

    Mund, Nitesh K; Dash, Debabrata; Barik, Chitta R; Goud, Vaibhav V; Sahoo, Lingaraj; Mishra, Prasannajit; Nayak, Nihar R

    2017-07-01

    Sesbania grandiflora (L.) Pers. is one of the fast growing tree legumes having the efficiency to produce around 50tha -1 above ground dry matters in a year. In this study, biomass of 2years old S. grandiflora was selected for the chemical composition, pretreatments and enzymatic hydrolysis studies. The stem biomass with a wood density of 3.89±0.01gmcm -3 contains about 38% cellulose, 12% hemicellulose and 28% lignin. Enzymatic hydrolysis of pretreated biomass revealed that phosphoric acid (H 3 PO 4 ) pretreated samples even at lower cellulase loadings [1 Filter Paper Units (FPU)], could efficiently convert about 86% glucose, while, even at higher cellulase loadings (60FPU) alkali pretreated biomass could convert only about 58% glucose. The effectiveness of phosphoric acid pretreatment was also supported by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effects of diterpene acids on components of a conifer bark beetle-fungal interaction : tolerance by Ips pini and sensitivity by its associate Ophiostoma ips

    Science.gov (United States)

    Brian J. Kopper; Barbara L. Illman; Philip J. Kersten; Kier D. Klepzig; Kenneth F. Raffa

    2005-01-01

    Conifer resin and phloem tissue contain several phytochemical groups, composed primarily of monoterpenes, diterpene acids, and stilbene phenolics. The effects of monoterpenes and phenolics on stem-colonizing bark beetles and their associated microorganisms have been studied to some extent, but the roles of diterpene acids are largely unknown. Diterpene acids are known...

  2. Effects of diterpene acids on components of a conifer bark beetle–fungal interaction: tolerance by Ips pini and sensitivity by its associate Ophiostoma ips

    Science.gov (United States)

    Brian J. Kopper; Barbara L. Illman; Philip J. Kersten; Kier D. Klepzig; Kenneth F. Raffa

    2005-01-01

    Conifer resin and phloem tissue contain several phytochemical groups,composed primarily of monoterpenes,diterpene acids, and stilbene phenolics. The effects of monoterpenes and phenolics on stem-colonizing bark beetles and their associated microorganisms have been studied to some extent, but the roles of diterpene acids are largely unknown. Diterpene acids are known to...

  3. Glucose and lipid metabolism in rats supplemented with glycyrrhizic acid exposed to short- or long- term stress and fed on a high-calorie diet

    OpenAIRE

    Yaw, Hui Ping

    2017-01-01

    Stress and consumption of high-calorie diet are well-recognized as the primary contributor to various metabolic diseases such as the metabolic syndrome. Glycyrrhizic acid (GA), an active compound in the root extract of the licorice plant, Glycyrrhiza glabra has been shown to improve hyperglycaemia and dyslipidaemia in rats fed on a high- calorie diet. However, the effect of GA on glucose and lipid metabolism in rats under stress in combination with high- calorie diet has yet to be expl...

  4. The Effect of Buffering High Acid Load Meal with Sodium Bicarbonate on Postprandial Glucose Metabolism in Humans-A Randomized Placebo-Controlled Study.

    Science.gov (United States)

    Kozan, Pinar; Blythe, Jackson C; Greenfield, Jerry R; Samocha-Bonet, Dorit

    2017-08-11

    Background: High dietary acid load relates to increased risk of type 2 diabetes in epidemiological studies. We aimed to investigate whether buffering a high acid load meal with an alkalizing treatment changes glucose metabolism post meal. Methods: Non-diabetic participants ( n = 32) were randomized to receive either 1680 mg NaHCO₃ or placebo, followed by a high acid load meal in a double-blind placebo-controlled crossover (1-4 weeks apart) study. Thirty (20 men) participants completed the study. Venous blood pH, serum bicarbonate, blood glucose, serum insulin, C -peptide, non-esterified fatty acid (NEFA), and plasma glucagon-like peptide-1 (GLP-1) concentrations were measured at baseline (fasting) and at 15-30 min intervals for 3 h post meal. Results: The treatment was well tolerated. Venous blood pH declined in the first 15 min post meal with the placebo ( p = 0.001), but not with NaHCO₃ ( p = 0.86) and remained decreased with the placebo for 3 h ( p interaction = 0.04). On average over the 3 h blood pH iAUC was greater with NaHCO₃ compared with placebo ( p = 0.02). However, postprandial glucose, insulin, C -peptide, NEFA and GLP-1 were not different between treatments ( p interaction ≥ 0.07). Conclusions: An alkalizing medication administered pre-meal has no acute effect on glycaemia and insulin response in healthy individuals. Long-term interventions in at-risk populations are necessary to investigate the effect of sustained alkalization on glucose metabolism.

  5. Discriminative Ability of Plasma Branched-Chain Amino Acid Levels for Glucose Intolerance in Families At Risk for Type 2 Diabetes.

    Science.gov (United States)

    Jainandunsing, Sjaam; Wattimena, J L Darcos; Verhoeven, Adrie J M; Langendonk, Janneke G; Rietveld, Trinet; Isaacs, Aaron J; Sijbrands, Eric J G; de Rooij, Felix W M

    2016-04-01

    Insulin resistance and glucose intolerance have been associated with increased plasma levels of branched-chain amino acids (BCAA). BCAA levels do not predict T2DM in the population. We determined the discriminative ability of fasting BCAA levels for glucose intolerance in nondiabetic relatives of patients with T2DM of two different ethnicities. Based on oral glucose tolerance test (OGTT), first-degree relatives of patients with T2DM were categorized as normal glucose tolerance, prediabetes, or T2DM. Included were 34, 12, and 18 Caucasian and 22, 12, and 23 Asian Indian participants, respectively. BCAA levels were measured in fasting plasma together with alanine, phenylalanine, and tyrosine. Insulin sensitivity and beta-cell function were assessed by indices derived from an extended OGTT and their relationship with plasma BCAA levels was assessed in multivariate regression analysis. The value of the amino acids for discriminating prediabetes among nondiabetic family members was determined with the area under the curve of receiver-operated characteristics (c-index). BCAA levels were higher in diabetic than in normoglycemic family members in the Caucasians (P = 0.001) but not in the Asian Indians. In both groups, BCAA levels were associated with waist-hip ratio (β = 0.31; P = 0.03 and β = 0.42; P = 0.001, respectively) but not with indices of insulin sensitivity or beta-cell function. The c-index of BCAA for discriminating prediabetes among nondiabetic participants was 0.83 and 0.74 in Caucasians and Asian Indians, respectively, which increased to 0.84 and 0.79 by also including the other amino acids. The c-index of fasting glucose for discriminating prediabetes increased from 0.91 to 0.92 in Caucasians and 0.85 to 0.97 (P = 0.04) in Asian Indians by inclusion of BCAA+alanine, phenylalanine, and tyrosine. Adding fasting plasma BCAA levels, combined with phenylalanine, tyrosine and alanine to fasting glucose improved discriminative ability for the prediabetic state

  6. Transcription factor Nrf1 is topologically repartitioned across membranes to enable target gene transactivation through its acidic glucose-responsive domains.

    Science.gov (United States)

    Zhang, Yiguo; Ren, Yonggang; Li, Shaojun; Hayes, John D

    2014-01-01

    The membrane-bound Nrf1 transcription factor regulates critical homeostatic and developmental genes. The conserved N-terminal homology box 1 (NHB1) sequence in Nrf1 targets the cap'n'collar (CNC) basic basic-region leucine zipper (bZIP) factor to the endoplasmic reticulum (ER), but it is unknown how its activity is controlled topologically within membranes. Herein, we report a hitherto unknown mechanism by which the transactivation activity of Nrf1 is controlled through its membrane-topology. Thus after Nrf1 is anchored within ER membranes, its acidic transactivation domains (TADs), including the Asn/Ser/Thr-rich (NST) glycodomain situated between acidic domain 1 (AD1) and AD2, are transiently translocated into the lumen of the ER, where NST is glycosylated in the presence of glucose to yield an inactive 120-kDa Nrf1 glycoprotein. Subsequently, portions of the TADs partially repartition across membranes into the cyto/nucleoplasmic compartments, whereupon an active 95-kDa form of Nrf1 accumulates, a process that is more obvious in glucose-deprived cells and may involve deglycosylation. The repartitioning of Nrf1 out of membranes is monitored within this protein by its acidic-hydrophobic amphipathic glucose-responsive domains, particularly the Neh5L subdomain within AD1. Therefore, the membrane-topological organization of Nrf1 dictates its post-translational modifications (i.e. glycosylation, the putative deglycosylation and selective proteolysis), which together control its ability to transactivate target genes.

  7. Quantification of centimeter-scale spatial variation in PAH, glucose and benzoic acid mineralization and soil organic matter in road-side soil

    Energy Technology Data Exchange (ETDEWEB)

    Hybholt, Trine K.; Aamand, Jens [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Johnsen, Anders R., E-mail: arj@geus.dk [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)

    2011-05-15

    The aim of the study was to determine centimeter-scale spatial variation in mineralization potential in diffusely polluted soil. To this end we employed a 96-well microplate method to measure the mineralization of {sup 14}C-labeled organic compounds in deep-well microplates and thereby compile mineralization curves for 348 soil samples of 0.2-cm{sup 3}. Centimeter-scale spatial variation in organic matter and the mineralization of glucose, benzoic acid, and PAHs (phenanthrene and pyrene) was determined for urban road-side soil sampled as arrays (7 x 11 cm) of 96 subsamples. The spatial variation in mineralization was visualized by means of 2-D contour maps and quantified by means of semivariograms. The geostatistical analysis showed that the easily degradable compounds (glucose and benzoic acid) exhibited little spatial variation in mineralization potential, whereas the mineralization was highly heterogeneous for the PAH compounds that require specialized degraders. The spatial heterogeneity should be taken into account when estimating natural attenuation rates. - Highlights: > Geostatistics were applied at the centimeter scale. > Glucose and benzoic acid mineralization showed little spatial variation. > PAH mineralization was highly variable at the sub-centimeter scale. > High spatial heterogeneity may be caused by low functional redundancy. - This study supports the hypothesis that specialized xenobiotic degraders may show high spatial heterogeneity in soil due to low functional redundancy.

  8. Properties of L-ascorbic acid in water and binary aqueous mixtures of D-glucose and D-fructose at different temperatures

    Science.gov (United States)

    Sharma, Ravi; Thakur, R. C.; Sani, Balwinder; Kumar, Harsh

    2017-12-01

    Using density and sound velocity partial molar volumes, partial molar adiabatic compressibilities, partial molar expansibilities and structure of L-ascorbic acid have been determined in water and aqueous mixtures of D-glucose and D-fructose at different concentrations and temperatures. Masson's equation was used to analyze the measured data. The obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. It is found that the L-ascorbic acid acts as structure breaker in water as well in binary studied mixtures.

  9. (13)C/(12)C isotope ratios of organic acids, glucose and fructose determined by HPLC-co-IRMS for lemon juices authenticity.

    Science.gov (United States)

    Guyon, Francois; Auberger, Pauline; Gaillard, Laetita; Loublanches, Caroline; Viateau, Maryse; Sabathié, Nathalie; Salagoïty, Marie-Hélène; Médina, Bernard

    2014-03-01

    High performance liquid chromatography linked to isotope ratio mass spectrometry via an interface allowing the chemical oxidation of organic matter (HPLC-co-IRMS) was used to simultaneously determine carbon 13 isotope ratio (δ(13)C) of organic acids, glucose and fructose in lime and lemon juices. Because of the significant difference between organic acids and sugars concentrations, the experimental protocol was optimised by applying a "current jump" to the IRMS device. The filament current is increased of 300μA during elution in order to enhance IRMS sensitivity. Then, analysis were performed on 35 lemon and lime fruits from various geographical origins and squeezed in the laboratory. An overall average δ(13)C values of -25.40±1.62‰, -23.83±1.82‰ and -25.67±1.72‰ is found for organic acids mixture mainly made up of citric acid, glucose and fructose, respectively. These authentic samples allowed the definition of a confidence domain to which have been confronted 30 commercial juices (24 "pure juices" and 6 coming from concentrate). Among these 30 samples, 10 present δ(13)C values outside the defined range revealing an added "C4" type organic acids or sugars, addition not specified on the label that is not in agreement with EU regulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Urinary loss of glucose, phosphate, and protein by diffusion into proximal straight tubules injured by D-serine and maleic acid

    International Nuclear Information System (INIS)

    Carone, F.A.; Nakamura, S.; Goldman, B.

    1985-01-01

    In several models of acute renal failure leakage of glomerular filtrate out of the tubule is an important pathogenetic mechanism; however, bidirectional diffusion of solute to account for certain pathophysiologic features of acute renal failure has received meager attention. Using micropuncture and clearance methods, the authors assessed sequentially leakage of solutes and inulin across proximal straight tubules (PST) injured by two nephrotoxins. In d-serine-treated rats with extensive necrosis of PST, the basis for glucosuria and tubular leakage of inulin was studied. Glucose absorption by the proximal convoluted tubule and glucose delivery to the PST were normal, but glucose delivery to the distal tubule was increased nearly 8-fold, indicating diffusion of glucose from interstitial to tubular luminal fluid across the necrotic PST. Total kidney inulin clearance was greatly reduced, but single nephron glomerular filtration rate, based on proximal convoluted tubule samples, was normal, indicating tubular loss of inulin. Urinary recovery of [ 14 C]inulin infused into tubular lumina revealed that proximal convoluted tubule and distal tubule were impermeable to inulin and that inulin diffused out of the necrotic PST. The progressive return over 6 days of tubular impermeability for inulin correlated with relining of PST with new cells. In maleic acid-treated rats the site and extent of tubular necrosis and the nature of urinary loss of solutes were studied. Microdissection revealed that maleic acid caused limited necrosis of PST which averaged 7.4% of total proximal tubular length. Increased urinary excretion of protein, phosphate, and glucose and increased tubular permeability to microinfused [ 14 C]inulin occurred with the onset of PST necrosis, and return of these abnormalities to normal correlated with the degree of cellular repair of the PST

  11. Effects of Ghrelin on Triglyceride Accumulation and Glucose Uptake in Primary Cultured Rat Myoblasts under Palmitic Acid-Induced High Fat Conditions

    Directory of Open Access Journals (Sweden)

    Lingling Han

    2015-01-01

    Full Text Available This study aimed to study the effects of acylated ghrelin on glucose and triglyceride metabolism in rat myoblasts under palmitic acid- (PA- induced high fat conditions. Rat myoblasts were treated with 0, 10−11, 10−9, or 10−7 M acylated ghrelin and 0.3 mM PA for 12 h. Triglyceride accumulation was determined by Oil-Red-O staining and the glycerol phosphate dehydrogenase-peroxidase enzymatic method, and glucose uptake was determined by isotope tracer. The glucose transporter 4 (GLUT4, AMP-activated protein kinase (AMPK, acetyl-CoA carboxylase (ACC, and uncoupling protein 3 (UCP3 were assessed by RT-PCR and western blot. Compared to 0.3 mM PA, ghrelin at 10−9 and 10−7 M reduced triglyceride content (5.855 ± 0.352 versus 5.030 ± 0.129 and 4.158 ± 0.254 mM, P<0.05 and prevented PA-induced reduction of glucose uptake (1.717 ± 0.264 versus 2.233 ± 0.333 and 2.333 ± 0.273 10−2 pmol/g/min, P<0.05. The relative protein expression of p-AMPKα/AMPKα, UCP3, and p-ACC under 0.3 mM PA was significantly reduced compared to controls (all P<0.05, but those in the 10−9 and 10−7 M ghrelin groups were significantly protected from 0.3 mM PA (all P<0.05. In conclusion, acylated ghrelin reduced PA-induced triglyceride accumulation and prevented the PA-induced decrease in glucose uptake in rat myoblasts. These effects may involve fatty acid oxidation.

  12. Oral treatment with γ-aminobutyric acid improves glucose tolerance and insulin sensitivity by inhibiting inflammation in high fat diet-fed mice.

    Directory of Open Access Journals (Sweden)

    Jide Tian

    Full Text Available Adipocyte and β-cell dysfunction and macrophage-related chronic inflammation are critical for the development of obesity-related insulin resistance and type 2 diabetes mellitus (T2DM, which can be negatively regulated by Tregs. Our previous studies and those of others have shown that activation of γ-aminobutyric acid (GABA receptors inhibits inflammation in mice. However, whether GABA could modulate high fat diet (HFD-induced obesity, glucose intolerance and insulin resistance has not been explored. Here, we show that although oral treatment with GABA does not affect water and food consumption it inhibits the HFD-induced gain in body weights in C57BL/6 mice. Furthermore, oral treatment with GABA significantly reduced the concentrations of fasting blood glucose, and improved glucose tolerance and insulin sensitivity in the HFD-fed mice. More importantly, after the onset of obesity and T2DM, oral treatment with GABA inhibited the continual HFD-induced gain in body weights, reduced the concentrations of fasting blood glucose and improved glucose tolerance and insulin sensitivity in mice. In addition, oral treatment with GABA reduced the epididymal fat mass, adipocyte size, and the frequency of macrophage infiltrates in the adipose tissues of HFD-fed mice. Notably, oral treatment with GABA significantly increased the frequency of CD4(+Foxp3(+ Tregs in mice. Collectively, our data indicated that activation of peripheral GABA receptors inhibited the HFD-induced glucose intolerance, insulin resistance, and obesity by inhibiting obesity-related inflammation and up-regulating Treg responses in vivo. Given that GABA is safe for human consumption, activators of GABA receptors may be valuable for the prevention of obesity and intervention of T2DM in the clinic.

  13. Agmatine protects Müller cells from high-concentration glucose-induced cell damage via N-methyl-D-aspartic acid receptor inhibition.

    Science.gov (United States)

    Han, Ning; Yu, Li; Song, Zhidu; Luo, Lifu; Wu, Yazhen

    2015-07-01

    Neural injury is associated with the development of diabetic retinopathy. Müller cells provide structural and metabolic support for retinal neurons. High glucose concentrations are known to induce Müller cell activity. Agmatine is an endogenous polyamine, which is enzymatically formed in the mammalian brain and has exhibited neuroprotective effects in a number of experimental models. The aims of the present study were to investigate whether agmatine protects Müller cells from glucose-induced damage and to explore the mechanisms underlying this process. Lactate dehydrogenase activity and tumor necrosis factor-α mRNA expression were significantly reduced in Müller cells exposed to a high glucose concentration, following agmatine treatment, compared with cells not treated with agmatine. In addition, agmatine treatment inhibited glucose-induced Müller cell apoptosis, which was associated with the regulation of Bax and Bcl-2 expression. Agmatine treatment suppressed glucose-induced phosphorylation of mitogen-activated protein kinase (MAPK) protein in Müller cells. The present study demonstrated that the protective effects of agmatine on Müller cells were inhibited by N-methyl-D-aspartic acid (NMDA). The results of the present study suggested that agmatine treatment protects Müller cells from high-concentration glucose-induced cell damage. The underlying mechanisms may relate to the anti-inflammatory and antiapoptotic effects of agmatine, as well as to the inhibition of the MAPK pathway, via NMDA receptor suppression. Agmatine may be of use in the development of novel therapeutic approaches for patients with diabetic retinopathy.

  14. Glucose and Fructose to Platform Chemicals: Understanding the Thermodynamic Landscapes of Acid-Catalysed Reactions Using High-Level ab Initio Methods

    Energy Technology Data Exchange (ETDEWEB)

    Assary, Rajeev S.; Kim, Taijin; Low, John; Greeley, Jeffrey P.; Curtiss, Larry A.

    2012-12-28

    Molecular level understanding of acid-catalysed conversion of sugar molecules to platform chemicals such as hydroxy-methyl furfural (HMF), furfuryl alcohol (FAL), and levulinic acid (LA) is essential for efficient biomass conversion. In this paper, the high-level G4MP2 method along with the SMD solvation model is employed to understand detailed reaction energetics of the acid-catalysed decomposition of glucose and fructose to HMF. Based on protonation free energies of various hydroxyl groups of the sugar molecule, the relative reactivity of gluco-pyranose, fructo-pyranose and fructo-furanose are predicted. Calculations suggest that, in addition to the protonated intermediates, a solvent assisted dehydration of one of the fructo-furanosyl intermediates is a competing mechanism, indicating the possibility of multiple reaction pathways for fructose to HMF conversion in aqueous acidic medium. Two reaction pathways were explored to understand the thermodynamics of glucose to HMF; the first one is initiated by the protonation of a C2–OH group and the second one through an enolate intermediate involving acyclic intermediates. Additionally, a pathway is proposed for the formation of furfuryl alcohol from glucose initiated by the protonation of a C2–OH position, which includes a C–C bond cleavage, and the formation of formic acid. The detailed free energy landscapes predicted in this study can be used as benchmarks for further exploring the sugar decomposition reactions, prediction of possible intermediates, and finally designing improved catalysts for biomass conversion chemistry in the future.

  15. The beneficial effects of n-3 polyunsaturated fatty acids on diet induced obesity and impaired glucose control do not require Gpr120.

    Directory of Open Access Journals (Sweden)

    Mikael Bjursell

    Full Text Available GPR120 (Ffar4 has been postulated to represent an important receptor mediating the improved metabolic profile seen upon ingestion of a diet enriched in polyunsaturated fatty acids (PUFAs. GPR120 is highly expressed in the digestive system, adipose tissue, lung and macrophages and also present in the endocrine pancreas. A new Gpr120 deficient mouse model on pure C57bl/6N background was developed to investigate the importance of the receptor for long-term feeding with a diet enriched with fish oil. Male Gpr120 deficient mice were fed two different high fat diets (HFDs for 18 weeks. The diets contained lipids that were mainly saturated (SAT or mainly n-3 polyunsaturated fatty acids (PUFA. Body composition, as well as glucose, lipid and energy metabolism, was studied. As expected, wild type mice fed the PUFA HFD gained less body weight and had lower body fat mass, hepatic lipid levels, plasma cholesterol and insulin levels and better glucose tolerance as compared to those fed the SAT HFD. Gpr120 deficient mice showed a similar improvement on the PUFA HFD as was observed for wild type mice. If anything, the Gpr120 deficient mice responded better to the PUFA HFD as compared to wild type mice with respect to liver fat content, plasma glucose levels and islet morphology. Gpr120 deficient animals were found to have similar energy, glucose and lipid metabolism when fed HFD PUFA compared to wild type mice. Therefore, GPR120 appears to be dispensable for the improved metabolic profile associated with intake of a diet enriched in n-3 PUFA fatty acids.

  16. Local and regional variation in the monoterpenes of ponderosa pine wood oleoresin

    Science.gov (United States)

    R.H. Smith; R.L. Peloquin; P.C. Passof

    1969-01-01

    A gas chromatographic analysis of the mono-terpenes of 927 ponderosa pines, representing to some degree a major portion of the species' range, showed considerable local and regional diversity in composition. Five major monoterpenes— α-pinene, β-pinene, 3-carene, myrcene, and limonene—were analyzed. There is some evidence to support the...

  17. Host-tree monoterpenes and biosynthesis of aggregation pheromones in the bark beetle ips paraconfusus

    Science.gov (United States)

    In the 1970-80s, vapors of the common conifer tree monoterpenes, myrcene and a-pinene, were shown to serve as precursors of ipsenol, ipsdienol and cis-verbenol, aggregation pheromone components of Ips paraconfusus. A paradigm developed that Ips bark beetles utilize pre-formed monoterpene precursors ...

  18. Cytosolic monoterpene biosynthesis is supported by plastid-generated geranyl diphosphate substrate in transgenic tomato fruits.

    Science.gov (United States)

    Gutensohn, Michael; Orlova, Irina; Nguyen, Thuong T H; Davidovich-Rikanati, Rachel; Ferruzzi, Mario G; Sitrit, Yaron; Lewinsohn, Efraim; Pichersky, Eran; Dudareva, Natalia

    2013-08-01

    Geranyl diphosphate (GPP), the precursor of most monoterpenes, is synthesized in plastids from dimethylallyl diphosphate and isopentenyl diphosphate by GPP synthases (GPPSs). In heterodimeric GPPSs, a non-catalytic small subunit (GPPS-SSU) interacts with a catalytic large subunit, such as geranylgeranyl diphosphate synthase, and determines its product specificity. Here, snapdragon (Antirrhinum majus) GPPS-SSU was over-expressed in tomato fruits under the control of the fruit ripening-specific polygalacturonase promoter to divert the metabolic flux from carotenoid formation towards GPP and monoterpene biosynthesis. Transgenic tomato fruits produced monoterpenes, including geraniol, geranial, neral, citronellol and citronellal, while exhibiting reduced carotenoid content. Co-expression of the Ocimum basilicum geraniol synthase (GES) gene with snapdragon GPPS-SSU led to a more than threefold increase in monoterpene formation in tomato fruits relative to the parental GES line, indicating that the produced GPP can be used by plastidic monoterpene synthases. Co-expression of snapdragon GPPS-SSU with the O. basilicum α-zingiberene synthase (ZIS) gene encoding a cytosolic terpene synthase that has been shown to possess both sesqui- and monoterpene synthase activities resulted in increased levels of ZIS-derived monoterpene products compared to fruits expressing ZIS alone. These results suggest that re-direction of the metabolic flux towards GPP in plastids also increases the cytosolic pool of GPP available for monoterpene synthesis in this compartment via GPP export from plastids. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  19. Process-based modelling of biogenic monoterpene emissions combining production and release from storage

    NARCIS (Netherlands)

    Schurgers, G.; Arneth, A.; Holzinger, R.|info:eu-repo/dai/nl/337989338; Goldstein, A.H.

    2009-01-01

    Monoterpenes, primarily emitted by terrestrial vegetation, can influence atmospheric ozone chemistry, and can form precursors for secondary organic aerosol. The short-term emissions of monoterpenes have been well studied and understood, but their long-term variability, which is particularly

  20. HAA1 and PRS3 overexpression boosts yeast tolerance towards acetic acid improving xylose or glucose consumption: unravelling the underlying mechanisms.

    Science.gov (United States)

    Cunha, Joana T; Costa, Carlos E; Ferraz, Luís; Romaní, Aloia; Johansson, Björn; Sá-Correia, Isabel; Domingues, Lucília

    2018-04-02

    Acetic acid tolerance and xylose consumption are desirable traits for yeast strains used in industrial biotechnological processes. In this work, overexpression of a weak acid stress transcriptional activator encoded by the gene HAA1 and a phosphoribosyl pyrophosphate synthetase encoded by PRS3 in a recombinant industrial Saccharomyces cerevisiae strain containing a xylose metabolic pathway was evaluated in the presence of acetic acid in xylose- or glucose-containing media. HAA1 or PRS3 overexpression resulted in superior yeast growth and higher sugar consumption capacities in the presence of 4 g/L acetic acid, and a positive synergistic effect resulted from the simultaneous overexpression of both genes. Overexpressing these genes also improved yeast adaptation to a non-detoxified hardwood hydrolysate with a high acetic acid content. Furthermore, the overexpression of HAA1 and/or PRS3 was found to increase the robustness of yeast cell wall when challenged with acetic acid stress, suggesting the involvement of the modulation of the cell wall integrity pathway. This study clearly shows HAA1 and/or, for the first time, PRS3 overexpression to play an important role in the improvement of industrial yeast tolerance towards acetic acid. The results expand the molecular toolbox and add to the current understanding of the mechanisms involved in higher acetic acid tolerance, paving the way for the further development of more efficient industrial processes.

  1. Dietary abscisic acid ameliorates glucose tolerance and obesity-related inflammation in db/db mice fed high-fat diets.

    Science.gov (United States)

    Guri, Amir J; Hontecillas, Raquel; Si, Hongwei; Liu, Dongmin; Bassaganya-Riera, Josep

    2007-02-01

    Despite their efficacy in improving insulin sensitivity, thiazolidinediones (TZDs) are associated with a number of side effects (i.e. weight gain, hepatotoxicity, congestive heart failure) that have limited their use by millions of diabetic patients. We have investigated whether abscisic acid (ABA), a naturally occurring phytochemical with structural similarities to TZDs, could be used as an alternative to TZDs to improve glucose homeostasis. We first examined whether ABA, similar to TZDs, activates PPARgamma in vitro. We next determined the lowest effective dose of dietary ABA (100 mg/kg) and assessed its effect on glucose tolerance, obesity-related inflammation, and mRNA expression of PPARgamma and its responsive genes in white adipose tissue (WAT) of db/db mice fed high-fat diets. We found that ABA induced transactivation of PPARgamma in 3T3-L1 pre-adipocytes in vitro. Dietary ABA-supplementation for 36 days decreased fasting blood glucose concentrations, ameliorated glucose tolerance, and increased mRNA expression of PPARgamma and its responsive genes (i.e., adiponectin, aP2, and CD36) in WAT. We also found that adipocyte hypertrophy, tumor necrosis factor-alpha (TNF-alpha) expression, and macrophage infiltration in WAT were significantly attenuated in ABA-fed mice. These findings suggest that ABA could be used as a nutritional intervention against type II diabetes and obesity-related inflammation.

  2. Enhanced hyluronic acid production in Streptococcus zooepidemicus by over expressing HasA and molecular weight control with Niscin and glucose

    Directory of Open Access Journals (Sweden)

    Alireza Zakeri

    2017-12-01

    Full Text Available Hyaluronic acid (HA is a high molecular weight linear polysaccharide, endowed with unique physiological and biological properties. Given its unique properties, HA have unprecedented applications in the fields of medicine and cosmetics. The ever growing demand for HA production is the driving force behind the need for finding and developing novel and amenable sources of the HA producers. Microbial fermentation of Streptococcus zooepidemicus deemed as one the most expeditious and pervasive methods of HA production. Herein, a wild type Streptococcus zooepidemicus, intrinsically expressing high levels of HA, was selected and optimized for HA production. HasA gene was amplified and introduced into the wild type Streptococcus zooepidemicus, under the control of Nisin promoter. The HasA over-expression increased the HA production, while the molecular weight was decreased. In order to compensate for molecular weight loss, the glucose concentration was increased to an optimum amount of 90 g/L. It is hypostatizes that excess glucose would rectify the distribution of the monomers and each HasA molecule would be provided with sufficient amount of substrates to lengthen the HA molecules. Arriving at an improved strain and optimized cultivating condition would pave the way for industrial grade HA production with high quality and quantity. Keywords: Streptococcus zooepidemicus, Hyaluronic acid, HasA, Glucose, Molecular weight

  3. Momordica charantia ameliorates insulin resistance and dyslipidemia with altered hepatic glucose production and fatty acid synthesis and AMPK phosphorylation in high-fat-fed mice.

    Science.gov (United States)

    Shih, Chun-Ching; Shlau, Min-Tzong; Lin, Cheng-Hsiu; Wu, Jin-Bin

    2014-03-01

    Momordica charantia Linn. (Cucurbitaceae) fruit is commonly known as bitter melon. C57BL/6J mice were firstly divided randomly into two groups: the control (CON) group was fed with a low-fat diet, whereas the experimental group was fed a 45% high-fat (HF) diet for 8 weeks. Afterwards, the CON group was treated with vehicle, whereas the HF group was subdivided into five groups and still on HF diet and was given orally M. charantia extract (MCE) or rosiglitazone (Rosi) or not for 4 weeks. M. charantia decreased the weights of visceral fat and caused glucose lowering. AMP-activated protein kinase (AMPK) is a major cellular regulator of lipid and glucose metabolism. MCE significantly increases the hepatic protein contents of AMPK phosphorylation by 126.2-297.3% and reduces expression of phosphenolpyruvate carboxykinase (PEPCK) and glucose production. Most importantly, MCE decreased expression of hepatic 11beta hydroxysteroid dehydroxygenase (11beta-HSD1) gene, which contributed in attenuating diabetic state. Furthermore, MCE lowered serum triglycerides (TGs) by inhibition of hepatic fatty acid synthesis by dampening sterol response element binding protein 1c and fatty acid synthase mRNA leading to reduction in TGs synthesis. This study demonstrates M. charantia ameliorates diabetic and hyperlipidemic state in HF-fed mice occurred by regulation of hepatic PEPCK, 11beta-HSD1 and AMPK phosphorylation. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Hyperthermal surface ionization mass spectrometry of organic molecules: monoterpenes

    International Nuclear Information System (INIS)

    Kishi, Hiroshi; Fujii, Toshihiro.

    1997-01-01

    This paper describes an experimental study on the influence of kinetic energy of fast monoterpene molecules on the surface ionization efficiency and on the mass spectral patterns, using rhenium oxide (ReO 2 ) surface. Molecular kinetic energy, given to the molecules through the acceleration in the seeded supersonic molecular beam, ranged from 1 to 10 eV. Hyperthermal surface ionization mass spectra (HSIMS) were taken for various incident kinetic energies and surface temperatures. The observed mass spectra were interpreted in a purely empirical way, by means of evidence from the previous investigations, and they were compared with conventional EI techniques and with the thermal energy surface ionization technique (SIOMS; Surface Ionization Organic Mass Spectrometry). Ionization efficiency (β) was also studied. Under hyperthermal surface ionization (HSI) conditions, many kinds of fragment ions, including quite abundant odd electron ions (OE +· ) are observed. HSIMS patterns of monoterpenes are different among 6-isomers, contrary to those of SIOMS and EIMS, where very similar patterns for isomers are observed. HSIMS patterns are strongly dependent on the molecular kinetic energies. The surface temperature does not affect much the spectral patterns, but it controls the total amount of ion formation. We conclude from these mass spectral findings, HSI-mechanism contains an impulsive process of ion formation, followed by the fragmentation process as a results of the internal energies acquired through the collision processes. (author)

  5. Do multiple herbivores maintain chemical diversity of Scots pine monoterpenes?

    Science.gov (United States)

    Iason, Glenn R.; O'Reilly-Wapstra, Julianne M.; Brewer, Mark J.; Summers, Ron W.; Moore, Ben D.

    2011-01-01

    A central issue in our understanding of the evolution of the diversity of plant secondary metabolites (PSMs) is whether or not compounds are functional, conferring an advantage to the plant, or non-functional. We examine the hypothesis that the diversity of monoterpene PSMs within a plant species (Scots pine Pinus sylvestris) may be explained by different compounds acting as defences against high-impact herbivores operating at different life stages. We also hypothesize that pairwise coevolution, with uncorrelated interactions, is more likely to result in greater PSM diversity, than diffuse coevolution. We tested whether up to 13 different monoterpenes in Scots pine were inhibitory to herbivory by slugs (Arion ater), bank voles (Clethrionomys glareolus), red deer (Cervus elaphus) and capercaillie (Tetrao urogallus), each of which attack trees at a different life stage. Plants containing more α-pinene were avoided by both slugs and capercaillie, which may act as reinforcing selective agents for this dominant defensive compound. Herbivory by red deer and capercaillie were, respectively, weakly negatively associated with δ3-carene, and strongly negatively correlated with the minor compound β-ocimene. Three of the four herbivores are probably contributory selective agents on some of the terpenes, and thus maintain some, but by no means all, of the phytochemical diversity in the species. The correlated defensive function of α-pinene against slugs and capercaillie is consistent with diffuse coevolutionary processes. PMID:21444308

  6. Inhibition of intestinal bile acid transporter Slc10a2 improves triglyceride metabolism and normalizes elevated plasma glucose levels in mice.

    Directory of Open Access Journals (Sweden)

    Thomas Lundåsen

    Full Text Available Interruption of the enterohepatic circulation of bile acids increases cholesterol catabolism, thereby stimulating hepatic cholesterol synthesis from acetate. We hypothesized that such treatment should lower the hepatic acetate pool which may alter triglyceride and glucose metabolism. We explored this using mice deficient of the ileal sodium-dependent BA transporter (Slc10a2 and ob/ob mice treated with a specific inhibitor of Slc10a2. Plasma TG levels were reduced in Slc10a2-deficient mice, and when challenged with a sucrose-rich diet, they displayed a reduced response in hepatic TG production as observed from the mRNA levels of several key enzymes in fatty acid synthesis. This effect was paralleled by a diminished induction of mature sterol regulatory element-binding protein 1c (Srebp1c. Unexpectedly, the SR-diet induced intestinal fibroblast growth factor (FGF 15 mRNA and normalized bile acid synthesis in Slc10a2-/- mice. Pharmacologic inhibition of Slc10a2 in diabetic ob/ob mice reduced serum glucose, insulin and TGs, as well as hepatic mRNA levels of Srebp1c and its target genes. These responses are contrary to those reported following treatment of mice with a bile acid binding resin. Moreover, when key metabolic signal transduction pathways in the liver were investigated, those of Mek1/2-Erk1/2 and Akt were blunted after treatment of ob/ob mice with the Slc10a2 inhibitor. It is concluded that abrogation of Slc10a2 reduces hepatic Srebp1c activity and serum TGs, and in the diabetic ob/ob model it also reduces glucose and insulin levels. Hence, targeting of Slc10a2 may be a promising strategy to treat hypertriglyceridemia and diabetes.

  7. Serum uric acid is more strongly associated with impaired fasting glucose in women than in men from a community-dwelling population.

    Directory of Open Access Journals (Sweden)

    Ryuichi Kawamoto

    Full Text Available Serum uric acid (SUA levels are associated with metabolic syndrome (MetS and its components such as glucose intolerance and type 2 diabetes. It is unknown whether there are gender-specific differences regarding the relationship between SUA levels, impaired fasting glucose (IFG and newly detected diabetes. We recruited 1,209 men aged 60±15 (range, 19-89 years and 1,636 women aged 63±12 (range, 19-89 years during their annual health examination from a single community. We investigated the association between SUA levels and six categories according to fasting plasma glucose (FPG level {normal fasting glucose (NFG, <100 mg/dL; high NFG-WHO, 100 to 109 mg/dL; IFG-WHO, 110 to 125 mg/dL; IFG-ADA, 100 to 125 mg/dL; newly detected diabetes, ≥126 mg/dL; known diabetes} SUA levels were more strongly associated with the different FPG categories in women compared with men. In women, the associations remained significant for IFG-WHO (OR, 1.23, 95% CI, 1.00-1.50 and newly detected diabetes (OR, 1.33, 95% CI, 1.03-1.72 following multivariate adjustment. However, in men all the associations were not significant. Thus, there was a significant interaction between gender and SUA level for newly detected diabetes (P = 0.005. SUA levels are associated with different categories of impaired fasting glucose in participants from community-dwelling persons, particularly in women.

  8. Effects of Omega-3 Fatty Acid Supplementation on Glucose Control and Lipid Levels in Type 2 Diabetes: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Cai Chen

    Full Text Available Many studies assessed the impact of marine omega-3 fatty acids on glycemic homeostasis and lipid profiles in patients with type 2 diabetes (T2DM, but reported controversial results. Our goal was to systematically evaluate the effects of omega-3 on glucose control and lipid levels.Medline, Pubmed, Cochrane Library, Embase, the National Research Register, and SIGLE were searched to identify eligible randomized clinical trials (RCTs. Extracted data from RCTs were analyzed using STATA 11.0 statistical software with fixed or random effects model. Effect sizes were presented as weighted mean differences (WMD with 95% confidence intervals (95% CI. Heterogeneity was assessed using the Chi-square test with significance level set at p < 0.1.20 RCT trials were included into this meta-analysis. Among patients with omega-3 supplementation, triglyceride (TG levels were significantly decreased by 0.24 mmol/L. No marked change in total cholesterol (TC, HbA1c, fasting plasma glucose, postprandial plasma glucose, BMI or body weight was observed. High ratio of EPA/DHA contributed to a greater decreasing tendency in plasma insulin, HbAc1, TC, TG, and BMI measures, although no statistical significance was identified (except TG. FPG levels were increased by 0.42 mmol/L in Asians. No evidence of publication bias was observed in this meta-analysis.The ratio of EPA/DHA and early intervention with omega 3 fatty acids may affect their effects on glucose control and lipid levels, which may serve as a dietary reference for clinicians or nutritionists who manage diabetic patients.

  9. Polyphenol fraction of extra virgin olive oil protects against endothelial dysfunction induced by high glucose and free fatty acids through modulation of nitric oxide and endothelin-1

    Directory of Open Access Journals (Sweden)

    Carolina Emilia Storniolo

    2014-01-01

    Full Text Available Epidemiological and clinical studies have reported that olive oil reduces the incidence of cardiovascular disease. However, the mechanisms involved in this beneficial effect have not been delineated. The endothelium plays an important role in blood pressure regulation through the release of potent vasodilator and vasoconstrictor agents such as nitric oxide (NO and endothelin-1 (ET-1, respectively, events that are disrupted in type 2 diabetes. Extra virgin olive oil contains polyphenols, compounds that exert a biological action on endothelial function. This study analyzes the effects of olive oil polyphenols on endothelial dysfunction using an in vitro model that simulates the conditions of type 2 diabetes. Our findings show that high glucose and linoleic and oleic acids decrease endothelial NO synthase phosphorylation, and consequently intracellular NO levels, and increase ET-1 synthesis by ECV304 cells. These effects may be related to the stimulation of reactive oxygen species production in these experimental conditions. Hydroxytyrosol and the polyphenol extract from extra virgin olive oil partially reversed the above events. Moreover, we observed that high glucose and free fatty acids reduced NO and increased ET-1 levels induced by acetylcholine through the modulation of intracellular calcium concentrations and endothelial NO synthase phosphorylation, events also reverted by hydroxytyrosol and polyphenol extract. Thus, our results suggest a protective effect of olive oil polyphenols on endothelial dysfunction induced by hyperglycemia and free fatty acids.

  10. Acute effects of sodium valproate and gamma-vinyl GABA on regional amino acid metabolism in the rat brain: incorporation of 2-[14C]glucose into amino acids.

    Science.gov (United States)

    Chapman, A G; Riley, K; Evans, M C; Meldrum, B S

    1982-09-01

    Amino acid concentrations have been determined in rat brain regions (cortex, striatum, cerebellum, and hippocampus) by HPLC after administration of acute anticonvulsant doses of sodium valproate (400 mg/kg, i.p.) and gamma-vinyl-GABA (1 g/kg, i.p.). After valproate administration the GABA level increases only in the cortex; aspartic acid concentration decreases in the cortex and hippocampus, and glutamic acid decreases in the hippocampus and striatum and increases in the cortex and cerebellum. There are no changes in the concentrations of glutamine, taurine, glycine, serine, and alanine following valproate administration. Only the GABA level increases in all the regions after gamma-vinyl-GABA administration. Cortical analyses 2, 4 and 10 minutes after pulse labeling with 2-[14C]glucose, i.v., show no change in the rate of cortical glucose utilization in the valproate treated group. The rate of labeling of glutamic acid is also unchanged, but the rate of labeling of GABA is reduced following valproate administration. After gamma-vinyl-GABA administration there is no change in the rate of labeling of GABA. These biochemical findings can be interpreted in terms of a primary anticonvulsant action of valproate on membrane receptors with secondary effects on the metabolism of amino acid neurotransmitters. This contrasts with the primary action of gamma-vinyl-GABA on GABA-transaminase activity.

  11. Second trimester amniotic fluid glucose, uric acid, phosphate, potassium, and sodium concentrations in relation to maternal pre-pregnancy BMI and birth weight centiles.

    Science.gov (United States)

    Fotiou, Maria; Michaelidou, Alexandra Maria; Athanasiadis, Apostolos P; Menexes, Georgios; Symeonidou, Maria; Koulourida, Vasiliki; Ganidou, Maria; Theodoridis, Theodoros D; Tarlatzis, Basil C

    2015-05-01

    To study the evolution profile of amniotic fluid (AF) glucose, uric acid, phosphate, potassium, and sodium, in the second trimester of pregnancy, and explore the possible relations between the concentration of these components and maternal, as well as neonatal characteristics. AF of 52 pregnant women was analyzed using an automatic multichannel analyzer. Maternal age, pre-pregnancy Body Mass Index (BMI), inter-pregnancy intervals, and smoking status were derived from questionnaires. Information on pregnancy and delivery was collected from medical records. Uric acid increased (r = 0.423, p pregnancy (r = -0.590, p pregnancy BMI was significantly correlated with AF uric acid concentration (r = 0.460, p sodium (r = 0.254, p = 0.070) levels. Multiple linear regression indicated that mid-trimester AF uric acid and phosphate levels were significantly related to birth weight centiles (R(2)( )= 0.345, p pregnancy BMI is significantly correlated with AF uric acid concentration, and (c) in appropriate for gestational age infants, AF phosphate and uric acid levels may serve as potential biomarkers of birth weight centiles. Further studies on AF composition may help to unravel the biochemical pathways underlying fetal development and could offer insight on the potential impact of maternal nutritional management on fetal growth regulation.

  12. Is forest management a significant source of monoterpenes into the boreal atmosphere?

    Science.gov (United States)

    Haapanala, S.; Hakola, H.; Hellén, H.; Vestenius, M.; Levula, J.; Rinne, J.

    2012-04-01

    Volatile organic compounds (VOCs) including terpenoids are emitted into the atmosphere from various natural sources. Damaging the plant tissue is known to strongly increase their monoterpene release. We measured the terpenoid emissions caused by timber felling, i.e. those from stumps and logging residue. The emissions from stumps were studied using enclosures and those from the whole felling area using an ecosystem-scale micrometeorological method, disjunct eddy accumulation (DEA). The compounds analyzed were isoprene, monoterpenes and sesquiterpenes. Strong emissions of monoterpenes were measured from both the stumps and from the whole felling area. The emission rate decreased rapidly within a few months after the logging. In addition to fresh logging residue, the results suggest also other strong monoterpene sources may be present in the felling area. These could include pre-existing litter, increased microbial activity and remaining undergrowth. In order to evaluate the possible importance of monoterpenes emitted annually from cut Scots pine forests in Finland, we conducted a rough upscaling calculation. The resulting monoterpene release was approximated to be on the order of 15 kilotonnes per year, which corresponds to about one tenth of the monoterpene release from intact forests in Finland.

  13. Is forest management a significant source of monoterpenes into the boreal atmosphere?

    Directory of Open Access Journals (Sweden)

    S. Haapanala

    2012-04-01

    Full Text Available Volatile organic compounds (VOCs including terpenoids are emitted into the atmosphere from various natural sources. Damaging the plant tissue is known to strongly increase their monoterpene release. We measured the terpenoid emissions caused by timber felling, i.e. those from stumps and logging residue. The emissions from stumps were studied using enclosures and those from the whole felling area using an ecosystem-scale micrometeorological method, disjunct eddy accumulation (DEA. The compounds analyzed were isoprene, monoterpenes and sesquiterpenes. Strong emissions of monoterpenes were measured from both the stumps and from the whole felling area. The emission rate decreased rapidly within a few months after the logging. In addition to fresh logging residue, the results suggest also other strong monoterpene sources may be present in the felling area. These could include pre-existing litter, increased microbial activity and remaining undergrowth. In order to evaluate the possible importance of monoterpenes emitted annually from cut Scots pine forests in Finland, we conducted a rough upscaling calculation. The resulting monoterpene release was approximated to be on the order of 15 kilotonnes per year, which corresponds to about one tenth of the monoterpene release from intact forests in Finland.

  14. Changes in monoterpene mixing ratios during summer storms in rural New Hampshire (USA

    Directory of Open Access Journals (Sweden)

    K. B. Haase

    2011-11-01

    Full Text Available Monoterpenes are an important class of biogenic hydrocarbons that influence ambient air quality and are a principle source of secondary organic aerosol (SOA. Emitted from vegetation, monoterpenes are a product of photosynthesis and act as a response to a variety of environmental factors. Most parameterizations of monoterpene emissions are based on clear weather models that do not take into account episodic conditions that can drastically change production and release rates into the atmosphere. Here, the monoterpene dataset from the rural Thompson Farm measurement site in Durham, New Hampshire is examined in the context of a set of known severe storm events. While some storm systems had a negligible influence on ambient monoterpene mixing ratios, the average storm event increased mixing ratios by 0.59 ± 0.21 ppbv, a factor of 93% above pre-storm levels. In some events, mixing ratios reached the 10's of ppbv range and persisted overnight. These mixing ratios correspond to increases in the monoterpene emission rate, ranging from 120 to 1240 g km−2 h−1 compared to an estimated clear weather rate of 116 to 193 g km−2 h−1. Considering the regularity of storm events over most forested areas, this could be an important factor to consider when modeling global monoterpene emissions and their resulting influence on the formation of organic aerosols.

  15. Changes in monoterpene mixing ratios during summer storms in rural New Hampshire (USA)

    Science.gov (United States)

    Haase, K.B.; Jordan, C.; Mentis, E.; Cottrell, L.; Mayne, H.R.; Talbot, R.; Sive, B.C.

    2011-01-01

    Monoterpenes are an important class of biogenic hydrocarbons that influence ambient air quality and are a principle source of secondary organic aerosol (SOA). Emitted from vegetation, monoterpenes are a product of photosynthesis and act as a response to a variety of environmental factors. Most parameterizations of monoterpene emissions are based on clear weather models that do not take into account episodic conditions that can drastically change production and release rates into the atmosphere. Here, the ongoing monoterpene dataset from the rural Thompson Farm measurement site in Durham, New Hampshire is examined in the context of a set of known severe storm events. While some storm systems had a negligible influence on ambient monoterpene mixing ratios, the average storm event increased mixing ratios by 0.59 ?? 0.21 ppbv, a factor of 93 % above pre-storm levels. In some events, mixing ratios reached the 10's of ppbv range and persisted overnight. These mixing ratios correspond to increases in the monoterpene emission rate, ranging from 120 to 1240 g km-2 h -1 compared to an estimated clear weather rate of 116 to 193 g km-2 h-1. Considering the regularity of storm events over most forested areas, this could be an important factor to consider when modeling global monoterpene emissions and their resulting influence on the formation of organic aerosols. ?? 2011 Author(s).

  16. Glucose oxidase variants with improved properities

    OpenAIRE

    Fischer, Rainer; Ostafe, Raluca; Prodanovic, Radivoje

    2014-01-01

    Source: WO14173822A3 [EN] The technology provided herein relates to novel variants of microbial glucose oxidase with improved properties, more specifically to polypeptides having glucose oxidase activity as their major enzymatic activity; to nucleic acid molecules encoding said glucose oxidases; vectors and host cells containing the nucleic acids and methods for producing the glucose oxidase; compositions comprising said glucose oxidase; methods for the preparation and production of such enzy...

  17. Glucose-dependent insulinotropic polypeptide may enhance fatty acid re-esterification in subcutaneous abdominal adipose tissue in lean humans

    DEFF Research Database (Denmark)

    Asmar, Meena; Simonsen, Lene; Madsbad, Sten

    2010-01-01

    Glucose-dependent insulinotropic polypeptide (GIP) has been implicated in lipid metabolism in animals. In humans, however, there is no clear evidence of GIP effecting lipid metabolism. The present experiments were performed in order to elucidate the effects of GIP on regional adipose tissue metab...

  18. Challenges in modelling isoprene and monoterpene emission dynamics of Arctic plants

    DEFF Research Database (Denmark)

    Tang, Jing; Schurgers, Guy; Valolahti, Hanna Maritta

    2016-01-01

    test. The model showed reasonable agreement to the observed vegetation CO2 fluxes in the main growing season as well as day-to-day variability of isoprene and monoterpene emissions. The observed relatively high WRs were better captured by the adjusted T response curve than by the common one. During...... 1999-2012, the modelled annual mean isoprene and monoterpene emissions were 20 and 8 mg C mg-2 yrg-1, with an increase by 55 and 57 % for 2 °C summertime warming, respectively. Warming by 4 and 8 °C for the same period further elevated isoprene emission for all years, but the impacts on monoterpene...

  19. Isolation and characterization of three new monoterpene synthases from Artemisia annua

    OpenAIRE

    Ju-Xin eRuan; Jian-Xu eLi; Xin eFang; Ling-Jian eWang; Wen-Li eHu; Xiao-Ya eChen; Changqing eYang

    2016-01-01

    Artemisia annua, an annual herb used in traditional Chinese medicine, produces a wealth of monoterpenes and sesquiterpenes, including the well-known sesquiterpene lactone artemisinin, an active ingredient in the treatment for malaria. Here we report three new monoterpene synthases of A. annua. From a glandular trichome cDNA library, monoterpene synthases of AaTPS2, AaTPS5 and AaTPS6, were isolated and characterized. The recombinant proteins of AaTPS5 and AaTPS6 produced multiple products with...

  20. L-Lactic acid production from glucose and xylose with engineered strains of Saccharomyces cerevisiae: aeration and carbon source influence yields and productivities.

    Science.gov (United States)

    Novy, Vera; Brunner, Bernd; Nidetzky, Bernd

    2018-04-11

    Saccharomyces cerevisiae, engineered for L-lactic acid production from glucose and xylose, is a promising production host for lignocellulose-to-lactic acid processes. However, the two principal engineering strategies-pyruvate-to-lactic acid conversion with and without disruption of the competing pyruvate-to-ethanol pathway-have not yet resulted in strains that combine high lactic acid yields (Y LA ) and productivities (Q LA ) on both sugar substrates. Limitations seemingly arise from a dependency on the carbon source and the aeration conditions, but the underlying effects are poorly understood. We have recently presented two xylose-to-lactic acid converting strains, IBB14LA1 and IBB14LA1_5, which have the L-lactic acid dehydrogenase from Plasmodium falciparum (pfLDH) integrated at the pdc1 (pyruvate decarboxylase) locus. IBB14LA1_5 additionally has its pdc5 gene knocked out. In this study, the influence of carbon source and oxygen on Y LA and Q LA in IBB14LA1 and IBB14LA1_5 was investigated. In anaerobic fermentation IBB14LA1 showed a higher Y LA on xylose (0.27 g g Xyl -1 ) than on glucose (0.18 g g Glc -1 ). The ethanol yields (Y EtOH , 0.15 g g Xyl -1 and 0.32 g g Glc -1 ) followed an opposite trend. In IBB14LA1_5, the effect of the carbon source on Y LA was less pronounced (~ 0.80 g g Xyl -1 , and 0.67 g g Glc -1 ). Supply of oxygen accelerated glucose conversions significantly in IBB14LA1 (Q LA from 0.38 to 0.81 g L -1  h -1 ) and IBB14LA1_5 (Q LA from 0.05 to 1.77 g L -1  h -1 ) at constant Y LA (IBB14LA1 ~ 0.18 g g Glc -1 ; IBB14LA1_5 ~ 0.68 g g Glc -1 ). In aerobic xylose conversions, however, lactic acid production ceased completely in IBB14LA1 and decreased drastically in IBB14LA1_5 (Y LA aerobic ≤ 0.25 g g Xyl -1 and anaerobic ~ 0.80 g g Xyl -1 ) at similar Q LA (~ 0.04 g L -1  h -1 ). Switching from aerobic to microaerophilic conditions (pO 2  ~ 2%) prevented lactic acid metabolization, observed for

  1. Effect of docosahexaenoic acid on hippocampal neurons in high-glucose condition: involvement of PI3K/AKT/nuclear factor-κB-mediated inflammatory pathways.

    Science.gov (United States)

    Yang, R-H; Lin, J; Hou, X-H; Cao, R; Yu, F; Liu, H-Q; Ji, A-L; Xu, X-N; Zhang, L; Wang, F

    2014-08-22

    Accumulating evidence suggested that hyperglycemia played a critical role in hippocampus dysfunction in patients with diabetes mellitus. However, the multifactorial pathogenesis of hyperglycemia-induced impairments of hippocampal neurons has not been fully elucidated. Docosahexaenoic acid (DHA) has been shown to enhance learning and memory and affect neural function in various experimental conditions. The present study investigated the effects of DHA on the lipid peroxidation, the level of inflammatory cytokines and neuron apoptosis in the hippocampal neurons in high-glucose condition. High-glucose administration increased the level of tumor necrosis factor α (TNF-α) and IL-6, induced oxidative stress and apoptosis of hippocampal neurons in vitro. DHA treatment reduced oxidative stress and TNF-α expression, protected the hippocampal neurons by increasing AKT phosphorylation and decreasing caspase-3 and caspase-9 expression. These results suggested that high-glucose exposure induced injury of hippocampal neurons in vitro, and the principle mechanisms involved in the neuroprotective effect of DHA were its antioxidant and anti-apoptotic potential. DHA may thus be of use in preventing or treating neuron-degeneration resulting from hyperglycemia. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Capturing of the monoterpene olefin limonene produced in Saccharomyces cerevisiae.

    Science.gov (United States)

    Jongedijk, Esmer; Cankar, Katarina; Ranzijn, Jorn; van der Krol, Sander; Bouwmeester, Harro; Beekwilder, Jules

    2015-01-01

    Monoterpene olefins such as limonene are plant compounds with applications as flavouring and fragrance agents, as solvents and potentially also in polymer and fuel chemistry. We engineered baker's yeast Saccharomyces cerevisiae to express a (-)-limonene synthase from Perilla frutescens and a (+)-limonene synthase from Citrus limon. Both proteins were expressed either with their native plastid targeting signal or in a truncated form in which the plastidial sorting signal was removed. The yeast host strain for expression was AE9 K197G, which expresses a mutant Erg20 enzyme. This enzyme catalyses the formation of geranyl diphosphate, which is the precursor for monoterpenes. Several methods were tested to capture limonene produced by the yeast. Extraction from the culture medium by pentane, or by the addition of CaCl2 followed by solid-phase micro-extraction, did not lead to detectable limonene, indicating that limonene is rapidly lost from the culture medium. Volatile terpenes such as limonene may also be trapped in a dodecane phase added to the medium during fermentation. This method resulted in recovery of 0.028 mg/l (+)-limonene and 0.060 mg/l (-)-limonene in strains using the truncated Citrus and Perilla synthases, respectively. Trapping the headspace during culture of the limonene synthase-expressing strains resulted in higher titres, at 0.12 mg/l (+)-limonene and 0.49 mg/l (-)-limonene. These results show that the volatile properties of the olefins produced require specific methods for efficient recovery of these molecules from biotechnological production systems. Copyright © 2014 John Wiley & Sons, Ltd.

  3. Glucose concentration and blood acid-basis status in high-yielding dairy cows during heat stress

    Directory of Open Access Journals (Sweden)

    Vujanac Ivan

    2011-01-01

    Full Text Available The objective of this work was to examine the effect of heat stress on glucose and pH values in blood of high-yielding dairy cows in the early stage of lactation, as well as to determine whether the changes in these parameters are interdependent under such conditions. An experiment was performed on high-yielding dairy cows during the summer and the spring periods. Forty cows were selected, twenty each for the two periods under investigation. In the course of the experiment, the temperature humidity index (THI was determined for the entire period of investigations, and then also the average daily THI, nightmorning THI (average value of hourly THI measured from 22h on the previous day until 10h of the current day, as well as the day-night THI (average value of hourly THI measured during the period from 10h to 22h of the current day. The pH and glucose concentration were determined in blood samples taken in the morning and afternoon of days 30, 60, and 90 of lactation during the spring and summer periods of the investigations. Based on the results for the THI, it was established that the animals were not exposed to the effect of extreme heat stress during the spring period of investigations, while they were periodically exposed to moderate but also extreme heat stress during the summer, in particular in the afternoon hours. It can be concluded from the results obtained for the blood pH that the cows were in respiratory alkalosis during the summer in the morning and afternoon hours on day 30, in the afternoon hours of days 60 and 90 of lactation, as well as in the afternoon on day 90 of lactation during the spring period of investigations. During the summer period, there were no statistically significant differences between the pH value determined in the morning and afternoon hours on day 30 of lactation, while the pH value was significantly higher in the afternoon hours than in the morning hours on days 60 and 90 of lactation. There were no

  4. On the interaction of uranium with the bioligands citric acid and glucose; Zur Wechselwirkung von Uran mit den Bioliganden Citronensaeure und Glucose

    Energy Technology Data Exchange (ETDEWEB)

    Steudtner, Robin

    2011-10-26

    , 591.8 nm, 513.5 nm, 537.0 nm and 561.9 nm for the 1:0:1-complex and at 483.6 nm, 502.7 nm, 524.5 nm, 548.1 and 574.0 nm for the 2:0:2-complex. The respective fluorescence lifetimes determined at 153 K were 79 {+-} 15 {mu}s (1:0:1) and 10 {+-} 3 {mu}s (2:0:2). In this work not only the model complexation of the hexavalent uranium but also the complex behaviour of the tetravalent uranium in presence of citric acid were studied. In all samples the uranium citrate complexes were detected as dissolved species. In addition to the spectroscopy detection of the new forming uranium citrate species the complex formation could be analyzed the complex formation constant and the single component spectrum for all complexes. Complex formation constant for the citrate species of the hexavalent uranium of log {beta}{sub 203} = 22.67 {+-} 0.34 ([(UO{sub 2}){sub 2}(Cit){sub 3}]{sup 5-}) and of log {beta}{sub 103} = 12.35 {+-} 0.22 ([UO{sub 2}(Cit){sub 3}]{sup 7-}) and for the complexes of the tetravalent uranium of log {beta}{sub 1-21} = -9.74 {+-} 0.23 ([U(OH){sub 2}Cit]{sup -}) und log {beta}{sub 1-31} = -20.36 {+-} 0.22 ([U(OH){sub 3}Cit]{sup 2-}) were calculated for the first time. Also to the complex behaviour and the redox behaviour of uranium in presence of citric acid were investigated. The photochemical reduction of uranium(VI) by citric acid at aerobic and anaerobic conditions was detected by UV-Vis spectroscopy. The reaction at aerobic conditions showed which unknown influence organic ligands can have on the chemical behaviour of uranium. The highest reduction rate could be determinate between pH 3.5 and 4 with 52 % at aerobic conditions and 66 % at anaerobic conditions. With increase of the pH the amount of reduced uranium(VI) decreases. In the oxygen system a reduction above pH 7 wasn't detectable. These results are in a very good correspondence with model calculation of the uranium(VI) speciation in urine.

  5. Technical note: comparison of 3 methods for analyzing areas under the curve for glucose and nonesterified fatty acids concentrations following epinephrine challenge in dairy cows.

    Science.gov (United States)

    Cardoso, F C; Sears, W; LeBlanc, S J; Drackley, J K

    2011-12-01

    The objective of the study was to compare 3 methods for calculating the area under the curve (AUC) for plasma glucose and nonesterified fatty acids (NEFA) after an intravenous epinephrine (EPI) challenge in dairy cows. Cows were assigned to 1 of 6 dietary niacin treatments in a completely randomized 6 × 6 Latin square with an extra period to measure carryover effects. Periods consisted of a 7-d (d 1 to 7) adaptation period followed by a 7-d (d 8 to 14) measurement period. On d 12, cows received an i.v. infusion of EPI (1.4 μg/kg of BW). Blood was sampled at -45, -30, -20, -10, and -5 min before EPI infusion and 2.5, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min after. The AUC was calculated by incremental area, positive incremental area, and total area using the trapezoidal rule. The 3 methods resulted in different statistical inferences. When comparing the 3 methods for NEFA and glucose response, no significant differences among treatments and no interactions between treatment and AUC method were observed. For glucose and NEFA response, the method was statistically significant. Our results suggest that the positive incremental method and the total area method gave similar results and interpretation but differed from the incremental area method. Furthermore, the 3 methods evaluated can lead to different results and statistical inferences for glucose and NEFA AUC after an EPI challenge. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Type 1 cannabinoid receptor mapping with [18F]MK-9470 PET in the rat brain after quinolinic acid lesion: a comparison to dopamine receptors and glucose metabolism

    International Nuclear Information System (INIS)

    Casteels, Cindy; Martinez, Emili; Camon, Lluisa; Vera, Nuria de; Planas, Anna M.; Bormans, Guy; Baekelandt, Veerle; Laere, Koen van

    2010-01-01

    Several lines of evidence imply early alterations in metabolic, dopaminergic and endocannabinoid neurotransmission in Huntington's disease (HD). Using [ 18 F]MK-9470 and small animal PET, we investigated cerebral changes in type 1 cannabinoid (CB 1 ) receptor binding in the quinolinic acid (QA) rat model of HD in relation to glucose metabolism, dopamine D 2 receptor availability and amphetamine-induced turning behaviour. Twenty-one Wistar rats (11 QA and 10 shams) were investigated. Small animal PET acquisitions were conducted on a Focus 220 with approximately 18 MBq of [ 18 F]MK-9470, [ 18 F]FDG and [ 11 C]raclopride. Relative glucose metabolism and parametric CB 1 receptor and D 2 binding images were anatomically standardized to Paxinos space and analysed voxel-wise using Statistical Parametric Mapping (SPM2). In the QA model, [ 18 F]MK-9470 uptake, glucose metabolism and D 2 receptor binding were reduced in the ipsilateral caudate-putamen by 7, 35 and 77%, respectively (all p -5 ), while an increase for these markers was observed on the contralateral side (>5%, all p -4 ). [ 18 F]MK-9470 binding was also increased in the cerebellum (p = 2.10 -5 ), where it was inversely correlated to the number of ipsiversive turnings (p = 7.10 -6 ), suggesting that CB 1 receptor upregulation in the cerebellum is related to a better functional outcome. Additionally, glucose metabolism was relatively increased in the contralateral hippocampus, thalamus and sensorimotor cortex (p = 1.10 -6 ). These data point to in vivo changes in endocannabinoid transmission, specifically for CB 1 receptors in the QA model, with involvement of the caudate-putamen, but also distant regions of the motor circuitry, including the cerebellum. These data also indicate the occurrence of functional plasticity on metabolism, D 2 and CB 1 neurotransmission in the contralateral hemisphere. (orig.)

  7. Recovery of manganese and zinc from spent Zn-C cell powder: Experimental design of leaching by sulfuric acid solution containing glucose.

    Science.gov (United States)

    Biswas, Ranjit K; Karmakar, Aneek K; Kumar, Sree L

    2016-05-01

    The spent Zn-C cell powder, containing ZnMn2O4, ZnO, MnO(OH) and possibly Mn2O3 and Mn3O4, can be leached by a sulfuric acid solution mixed with some glucose. The leaching is found to be dependent on solid to liquid (S/L) ratio, amount of glucose, concentration of sulfuric acid solution, time and pulp agitation speed. For 5g powder (S), 1h leaching time and 300rpm pulp agitation speed, two-level four-factor (2(4)) experimental designs have been carried out to derive models for extraction of both Mn(II) and Zn(II). Amount of glucose (G, g), concentration of H2SO4 solution (C, mol/L), volume of H2SO4 solution as leachant (L, mL) and leaching temperature (T, °C) are considered as factors (variables). The model in both cases consists of mean, factor effects and interaction effects. The four-factor interaction effect is observed in neither of the cases. Some two-factor and three-factor effects are found to have produced positive or negative contributions to dissolution percentage in both cases. The models are examined for comparison with experimental results with good fits and also used for optimization of factors. At optimized condition (G=0.50g, C=2mol/L, L=250mL and T=100°C), an aliquot of 5g powder in 1h and at 300rpm produces a solution containing (7.08±0.10)g/L Mn(II) and (2.20±0.06)g/L Zn(II) corresponding to almost 100% extraction of both metal ions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. The effects of feeding rats diets deficient in folic acid and related methyl donors on the blood pressure and glucose tolerance of the offspring.

    Science.gov (United States)

    Maloney, Christopher A; Hay, Susan M; Rees, William D

    2009-05-01

    In humans poor maternal folate status is associated with a decrease in infant birth weight. As low birth weight increases the risk of cardiovascular and metabolic disease in adults, an inadequate supply of folic acid in the mother's diet may increase the susceptibility of the offspring to disease. We have fed laboratory rats diets deficient in folic acid and the related methyl donors methionine and choline to examine the effects on growth, blood pressure and insulin action in the offspring. Poor folate status transiently increased fetal growth but did not produce a long-term change in body weight. There were, however, small changes in the hearts of the female offspring. When folate deficiency was combined with low intakes of methionine and choline, the kidneys of the male offspring were proportionately smaller, probably because of the limited availability of methionine. There was no effect on the blood pressure of either the male or female offspring. The pancreatic insulin content of fetuses from animals fed the folate-deficient diets were higher than those of the controls. Following an oral glucose challenge, there was a weak trend for glucose-stimulated insulin release to be increased in the offspring of dams fed the folate-deficient diet. The changes in insulin concentrations were, however, much smaller than the corresponding changes observed in the offspring of animals fed protein-deficient diets. These results suggest that folate deficiency during gestation causes modest changes to the insulin axis of the fetus.

  9. Glucose Sensing

    CERN Document Server

    Geddes, Chris D

    2006-01-01

    Topics in Fluorescence Spectroscopy, Glucose Sensing is the eleventh volume in the popular series Topics in Fluorescence Spectroscopy, edited by Drs. Chris D. Geddes and Joseph R. Lakowicz. This volume incorporates authoritative analytical fluorescence-based glucose sensing reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. Glucose Sensing is an essential reference for any lab working in the analytical fluorescence glucose sensing field. All academics, bench scientists, and industry professionals wishing to take advantage of the latest and greatest in the continuously emerging field of glucose sensing, and diabetes care & management, will find this volume an invaluable resource. Topics in Fluorescence Spectroscopy Volume 11, Glucose Sensing Chapters include: Implantable Sensors for Interstitial Fluid Smart Tattoo Glucose Sensors Optical Enzyme-based Glucose Biosensors Plasmonic Glucose Sens...

  10. An NPF transporter exports a central monoterpene indole alkaloid intermediate from the vacuole

    DEFF Research Database (Denmark)

    Payne, Richard; Xu, Deyang; Foureau, Emilien

    2017-01-01

    Plants sequester intermediates of metabolic pathways into different cellular compartments, but the mechanisms by which these molecules are transported remain poorly understood. Monoterpene indole alkaloids, a class of specialized metabolites that includes the anticancer agent vincristine, antimal......Plants sequester intermediates of metabolic pathways into different cellular compartments, but the mechanisms by which these molecules are transported remain poorly understood. Monoterpene indole alkaloids, a class of specialized metabolites that includes the anticancer agent vincristine...

  11. Structure Odour Relationship Study of Acyclic Monoterpene Alcohols, their Acetates and Synthesized Oxygenated Derivatives

    OpenAIRE

    Elsharif, Shaimaa

    2017-01-01

    The replacement of synthetic conventional compounds by natural ingredients; whether in medicine, food, or cosmetics; has been increasingly requested by consumers, especially since the last decade. Terpenes in general and monoterpenes in particular are secondary metabolites in plants, and they may be a promising natural alternative. Monoterpenes, the main constituents of plants’ essential oils, are odorous compounds that play a significant ecological role in plant evolution. The...

  12. Monoterpenes as inhibitors of digestive enzymes and counter-adaptations in a specialist avian herbivore.

    Science.gov (United States)

    Kohl, Kevin D; Pitman, Elizabeth; Robb, Brecken C; Connelly, John W; Dearing, M Denise; Forbey, Jennifer Sorensen

    2015-05-01

    Many plants produce plant secondary metabolites (PSM) that inhibit digestive enzymes of herbivores, thus limiting nutrient availability. In response, some specialist herbivores have evolved digestive enzymes that are resistant to inhibition. Monoterpenes, a class of PSMs, have not been investigated with respect to the interference of specific digestive enzymes, nor have such interactions been studied in avian herbivores. We investigated this interaction in the Greater Sage-Grouse (Phasianidae: Centrocercus urophasianus), which specializes on monoterpene-rich sagebrush species (Artemisia spp.). We first measured the monoterpene concentrations in gut contents of free-ranging sage-grouse. Next, we compared the ability of seven individual monoterpenes present in sagebrush to inhibit a protein-digesting enzyme, aminopeptidase-N. We also measured the inhibitory effects of PSM extracts from two sagebrush species. Inhibition of aminopeptidase-N in sage-grouse was compared to inhibition in chickens (Gallus gallus). We predicted that sage-grouse enzymes would retain higher activity when incubated with isolated monoterpenes or sagebrush extracts than chicken enzymes. We detected unchanged monoterpenes in the gut contents of free-ranging sage-grouse. We found that three isolated oxygenated monoterpenes (borneol, camphor, and 1,8-cineole) inhibited digestive enzymes of both bird species. Camphor and 1,8-cineole inhibited enzymes from chickens more than from sage-grouse. Extracts from both species of sagebrush had similar inhibition of chicken enzymes, but did not inhibit sage-grouse enzymes. These results suggest that specific monoterpenes may limit the protein digestibility of plant material by avian herbivores. Further, this work presents additional evidence that adaptations of digestive enzymes to plant defensive compounds may be a trait of specialist herbivores.

  13. Monoterpene ‘thermometer’ of tropical forest-atmosphere response to climate warming

    OpenAIRE

    Jardine, KJ; Jardine, AB; Holm, JA; Lombardozzi, DL; Negron-Juarez, RI; Martin, ST; Beller, HR; Gimenez, BO; Higuchi, N; Chambers, JQ

    2017-01-01

    © 2016 John Wiley & Sons Ltd Tropical forests absorb large amounts of atmospheric CO 2 through photosynthesis but elevated temperatures suppress this absorption and promote monoterpene emissions. Using 13 CO 2 labeling, here we show that monoterpene emissions from tropical leaves derive from recent photosynthesis and demonstrate distinct temperature optima for five groups (Groups 1–5), potentially corresponding to different enzymatic temperature-dependent reaction mechanisms within β-ocimen...

  14. Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Haofei; Guenther, Alex; Gu, Dasa; Warneke, Carsten; Geron, Chris; Goldstein, Allen; Graus, Martin; Karl, Thomas; Kaser, Lisa; Misztal, Pawel; Yuan, Bin

    2017-10-01

    Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance were comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or

  15. Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests.

    Science.gov (United States)

    Yu, Haofei; Guenther, Alex; Gu, Dasa; Warneke, Carsten; Geron, Chris; Goldstein, Allen; Graus, Martin; Karl, Thomas; Kaser, Lisa; Misztal, Pawel; Yuan, Bin

    2017-10-01

    Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance were comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or

  16. Synergistic effect of Aspergillus tubingensis CTM 507 glucose oxidase in presence of ascorbic acid and alpha amylase on dough properties, baking quality and shelf life of bread.

    Science.gov (United States)

    Kriaa, Mouna; Ouhibi, Rabeb; Graba, Héla; Besbes, Souhail; Jardak, Mohamed; Kammoun, Radhouane

    2016-02-01

    The impact of Aspergillus tubingensis glucose oxidase (GOD) in combination with α-amylase and ascorbic acid on dough properties, qualities and shelf life of bread was investigated. Regression models of alveograph and texture parameters of dough and bread were adjusted. Indeed, the mixture of GOD (44 %) and ascorbic acid (56 %) on flour containing basal improver showed its potential as a corrective action to get better functional and rheological properties of dough and bread texture. Furthermore, wheat flour containing basal additives and enriched with GOD (63.8 %), ascorbic acid (32 %) and α- amylase (4.2 %) led to high technological bread making parameters, to decrease the crumb firmness and chewiness and to improve elasticity, adhesion, cohesion and specific volume of bread. In addition to that, the optimized formulation addition significantly reduced water activity and therefore decreased bread susceptibility to microbial spoilage. These findings demonstrated that GOD could partially substitute not only ascorbic acid but also α-amylase. The generated models allowed to predict the behavior of wheat flour containing additives in the range of values tested and to define the additives formula that led to desired rheological and baking qualities of dough. This fact provides new perspectives to compensate flour quality deficiencies at the moment of selecting raw materials and technological parameters reducing the production costs and facilitating gluten free products development. Graphical abstractᅟ.

  17. Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

    Science.gov (United States)

    Yassaa, N.; Custer, T.; Song, W.; Pech, F.; Kesselmeier, J.; Williams, J.

    2010-11-01

    A headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS), 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS). Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m-2 s-1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

  18. Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

    Directory of Open Access Journals (Sweden)

    N. Yassaa

    2010-11-01

    Full Text Available A headspace solid-phase microextraction (HS-SPME and gas chromatography/mass spectrometry (GC/MS system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS, 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS. Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m−2 s−1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

  19. Metabolism of monoterpenes in cell cultures of common sage (Salvia officinalis)

    International Nuclear Information System (INIS)

    Falk, K.L.; Gershenzon, J.; Croteau, R.

    1990-01-01

    Leaves of common sage (Salvia officinalis) accumulate monoterpenes in glandular trichomes at levels exceeding 15 milligrams per gram fresh weight at maturity, whereas sage cells in suspension culture did not accumulate detectable levels of monoterpenes ( 14 C]sucrose was also virtually undetectable in this cell culture system. In vitro assay of each of the enzymes required for the sequential conversion of the ubiquitous isoprenoid precursor geranyl pyrophosphate to (+)-camphor (a major monoterpene product of sage) in soluble extracts of the cells revealed the presence of activity sufficient to produce (+)-camphor at a readily detectable level (>0.3 micrograms per gram fresh weight) at the late log phase of growth. Other monoterpene synthetic enzymes were present as well. In vivo measurement of the ability to catabolize (+)-camphor in these cells indicated that degradative capability exceeded biosynthetic capacity by at least 1,000-fold. Therefore, the lack of monoterpene accumulation in undifferentiated sage cultures could be attributed to a low level of biosynthetic activity (relative to the intact plant) coupled to a pronounced capacity for monoterpene catabolism

  20. Borneol, a Bicyclic Monoterpene Alcohol, Reduces Nociceptive Behavior and Inflammatory Response in Mice

    Directory of Open Access Journals (Sweden)

    Jackson Roberto Guedes da Silva Almeida

    2013-01-01

    Full Text Available Borneol, a bicyclic monoterpene, has been evaluated for antinociceptive and anti-inflammatory activities. Antinociceptive and anti-inflammatory activities were studied by measuring nociception by acetic acid, formalin, hot plate, and grip strength tests, while inflammation was prompted by carrageenan-induced peritonitis. The rotarod test was used to evaluate motor coordination. Borneol produced a significant (P<0.01 reduction of the nociceptive behavior at the early and late phases of paw licking and reduced the writhing reflex in mice (formalin and writhing tests, resp.. When the hot plate test was conducted, borneol (in higher dose produced an inhibition (P<0.05 of the nociceptive behavior. Such results were unlikely to be provoked by motor abnormality. Additionally, borneol-treated mice reduced the carrageenan-induced leukocytes migration to the peritoneal cavity. Together, our results suggest that borneol possess significant central and peripheral antinociceptive activity; it has also anti-inflammatory activity. In addition, borneol did not impair motor coordination.

  1. Abomasal amino acid infusion in postpartum dairy cows: Effect on whole-body, splanchnic, and mammary glucose metabolism

    DEFF Research Database (Denmark)

    Galindo, C; Larsen, Mogens; Ouellet, D R

    2015-01-01

    -OH-butyrate (BHBA) in postpartum dairy cows according to a generalized randomized incomplete block design with repeated measures in time. At calving, cows were blocked according to parity (second and third or greater) and were allocated to 2 treatments: abomasal infusion of water (n=4) or abomasal infusion of free...... AA with casein profile (AA-CN; n=5) in addition to the same basal diet. The AA-CN infusion started with half the maximal dose at 1 d in milk (DIM) and then steadily decreased from 791 to 226 g/d from DIM 2 to 29 to cover the estimated essential AA deficit. On DIM 5, 15, and 29, D[6,6-(2)H2]-glucose...... (23.7 mmol/h) was infused into a jugular vein for 5h, and 6 blood samples were taken from arterial, portal, hepatic, and mammary sources at 45-min intervals, starting 1h after the initiation of the D[6,6-(2)H2]glucose infusion. Trans-organ fluxes were calculated as veno-arterial differences times...

  2. Impaired maternal glucose homeostasis during pregnancy is associated with low status of long-chain polyunsaturated fatty acids (LCP) and essential fatty acids (EFA) in the fetus

    NARCIS (Netherlands)

    Dijck-Brouwer, DAJ; Hadders-Algra, M; Bouwstra, H; Decsi, T; Boehm, G; Martini, IA; Boersma, ER; Muskiet, FAJ

    Low status of long-chain polyunsaturated fatty acids (LCP) and essential fatty acids (EFA) in the fetus is associated with less favorable neonatal neurological condition. A 'relative', rather than 'absolute' EFA deficiency might explain this finding. A relative EFA deficiency may derive from

  3. Branched Chain Amino Acids Are Associated with Insulin Resistance Independent of Leptin and Adiponectin in Subjects with Varying Degrees of Glucose Tolerance.

    Science.gov (United States)

    Connelly, Margery A; Wolak-Dinsmore, Justyna; Dullaart, Robin P F

    2017-05-01

    Branched chain amino acids (BCAA) may be involved in the pathogenesis of insulin resistance and are associated with type 2 diabetes mellitus (T2DM) development. Adipokines such as leptin and adiponectin influence insulin resistance and reflect adipocyte dysfunction. We examined the extent to which the association of BCAA with insulin resistance is attributable to altered leptin and adiponectin levels in individuals with varying degrees of glucose tolerance. BCAA were measured by nuclear magnetic resonance, whereas leptin and adiponectin were measured by immunoassay, in subjects with normal fasting glucose (n = 30), impaired fasting glucose (n = 25), and T2DM (n = 15). Insulin resistance was estimated by homeostasis model assessment (HOMAir). BCAA were higher in men than in women (P BCAA were correlated with HOMAir (r = 0.46; P  0.05). Multivariable linear regression analysis, adjusting for age, sex, T2DM, and body mass index (BMI), demonstrated that BCAA were positively associated with HOMAir (β = 0.242, P = 0.023). When BCAA, leptin, and adiponectin were included together, the positive relationship of HOMAir with BCAA (β = 0.275, P = 0.012) remained significant. Insulin resistance was associated with BCAA. This association remained after adjusting for age, sex, T2DM, BMI, as well as leptin and adiponectin. It is unlikely that the relationship of insulin resistance with BCAA is to a major extent attributable to effects of leptin and adiponectin.

  4. Abscisic acid synergizes with rosiglitazone to improve glucose tolerance, down-modulate macrophage accumulation in adipose tissue: possible action of the cAMP/PKA/PPAR γ axis

    Science.gov (United States)

    Guri, Amir J; Hontecillas, Raquel; Bassaganya-Riera, Josep

    2010-01-01

    Background & Aims Abscisic acid (ABA) is effective in preventing insulin resistance and obesity-related inflammation through a PPAR γ-dependent mechanism. The objective of this study was to assess the efficacy ABA in improving glucose homeostasis and suppress inflammation when administered in combination with rosiglitazone (Ros) and to determine whether PPAR γ activation by ABA is initiated via cAMP/protein kinase A (PKA) signaling. Methods Obese db/db mice were fed high-fat diets containing 0, 10, or 70 mg/kg Ros with and without racemic ABA (100 mg/kg) for 60 days. Glucose tolerance and fasting insulin levels were assessed at 6 and 8 weeks, respectively, and adipose tissue macrophage (ATM) infiltration was examined by flow cytometry. Gene expression was examined on white adipose tissue (WAT) and stromal vascular cells (SVCs) cultured with ABA, Ros, or an ABA/Ros combination. Results Both Ros and ABA improved glucose tolerance, and ABA decreased plasma insulin levels while having no effect on Ros-induced weight gain. ABA in combination with low-dose Ros (10 mg/kg; Roslo) synergistically inhibited ATM infiltration. Treatment of SVCs with Ros, ABA or ABA/Ros suppressed expression of the M1 marker CCL17. ABA and Ros synergistically increased PPAR γ activity and pretreatment with a cAMP-inhibitor or a PKA-inhibitor abrogated ABA-induced PPAR γ activation. Conclusions ABA and Ros act synergistically to modulate PPAR γ activity and macrophage accumulation in WAT and ABA enhances PPAR γ activity through a membrane-initiated mechanism dependent on cAMP/PKA signaling. PMID:20207056

  5. Intact pituitary function is decisive for the catabolic response to TNF-α: studies of protein, glucose and fatty acid metabolism in hypopituitary and healthy subjects.

    Science.gov (United States)

    Bach, Ermina; Møller, Andreas B; Jørgensen, Jens O L; Vendelbo, Mikkel H; Jessen, Niels; Olesen, Jonas F; Pedersen, Steen B; Nielsen, Thomas S; Møller, Niels

    2015-02-01

    TNF-α generates inflammatory responses and insulin resistance, lipolysis, and protein breakdown. It is unclear whether these changes depend on intact hypothalamo-pituitary stress hormone responses to trigger the release of cortisol and growth hormone. To define differential effects of TNF-α on glucose, protein, and lipid metabolism in hypopituitary patients (without intact hypothalamo-pituitary axis) and healthy controls. Randomized, placebo controlled, single-blinded. Setting, Participants, and Intervention: We studied eight hypopituitary (HP) patients and eight matched control subjects [control volunteers (CTR)] twice during 4-h basal and 2-h hyperinsulinemic clamp conditions with isotope dilution during infusion of saline or TNF-α(12 ng/kg/h) for 6 h. Phenylalanine, urea, palmitate, and glucose fluxes and fat biopsies in basal and clamp periods. TNF-α infusion significantly increased cortisol and GH levels in CTR but not in HP. TNF-α increased phenylalanine fluxes in both groups, with the increase being significantly greater in CTR, and raised urea flux by 40 % in CTR without any alteration in HP. Endogenous glucose production (EGP) was elevated in CTR compared to HP after TNF-α administration, whereas insulin sensitivity remained similarly unaffected in both groups. TNF-α increased whole body palmitate fluxes and decreased palmitate specific activity in CTR, but not in HP without statistical difference between groups. We did not detect significant effects TNF-α on lipase expression or regulation in fat. TNF-α increased both urea and amino acid fluxes and EGP significantly more in CTR compared to HP, suggesting that increases in endogenous cortisol and GH release are significant components of the metabolic response to TNF-α.

  6. Effect of pertussis and cholera toxins administered supraspinally on CA3 hippocampal neuronal cell death and the blood glucose level induced by kainic acid in mice.

    Science.gov (United States)

    Kim, Chea-Ha; Park, Soo-Hyun; Sim, Yun-Beom; Sharma, Naveen; Kim, Sung-Su; Lim, Su-Min; Jung, Jun-Sub; Suh, Hong-Won

    2014-12-01

    The effect of cholera toxin (CTX) or pertussis toxin (PTX) administered supraspinally on hippocampal neuronal cell death in CA3 region induced by kainic acid (KA) was examined in mice. After the pretreatment with either PTX or CTX intracerebroventricularly (i.c.v.), mice were administered i.c.v. with KA. The i.c.v. treatment with KA caused a neuronal cell death in CA3 region and PTX, but not CTX, attenuated the KA-induced neuronal cell death. In addition, i.c.v. treatment with KA caused an elevation of the blood glucose level. The i.c.v. PTX pretreatment alone caused a hypoglycemia and inhibited KA-induced hyperglycemic effect. However, i.c.v. pretreatment with CTX did not affect the basal blood glucose level and KA-induced hyperglycemic effect. Moreover, KA administered i.c.v. caused an elevation of corticosterone level and reduction of the blood insulin level. Whereas, i.c.v. pretreatment with PTX further enhanced KA-induced up-regulation of corticosterone level. Furthermore, i.c.v. administration of PTX alone increased the insulin level and KA-induced hypoinsulinemic effect was reversed. In addition, PTX pretreatment reduces the KA-induced seizure activity. Our results suggest that supraspinally administered PTX, exerts neuroprotective effect against KA-induced neuronal cells death in CA3 region and neuroprotective effect of PTX is mediated by the reduction of KA-induced blood glucose level. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  7. The chemopreventive properties of chlorogenic acid reveal a potential new role for the microsomal glucose-6-phosphate translocase in brain tumor progression

    Directory of Open Access Journals (Sweden)

    Desgagnés Julie

    2006-03-01

    Full Text Available Abstract Background Chlorogenic acid (CHL, the most potent functional inhibitor of the microsomal glucose-6-phosphate translocase (G6PT, is thought to possess cancer chemopreventive properties. It is not known, however, whether any G6PT functions are involved in tumorigenesis. We investigated the effects of CHL and the potential role of G6PT in regulating the invasive phenotype of brain tumor-derived glioma cells. Results RT-PCR was used to show that, among the adult and pediatric brain tumor-derived cells tested, U-87 glioma cells expressed the highest levels of G6PT mRNA. U-87 cells lacked the microsomal catalytic subunit glucose-6-phosphatase (G6Pase-α but expressed G6Pase-β which, when coupled to G6PT, allows G6P hydrolysis into glucose to occur in non-glyconeogenic tissues such as brain. CHL inhibited U-87 cell migration and matrix metalloproteinase (MMP-2 secretion, two prerequisites for tumor cell invasion. Moreover, CHL also inhibited cell migration induced by sphingosine-1-phosphate (S1P, a potent mitogen for glioblastoma multiform cells, as well as the rapid, S1P-induced extracellular signal-regulated protein kinase phosphorylation potentially mediated through intracellular calcium mobilization, suggesting that G6PT may also perform crucial functions in regulating intracellular signalling. Overexpression of the recombinant G6PT protein induced U-87 glioma cell migration that was, in turn, antagonized by CHL. MMP-2 secretion was also inhibited by the adenosine triphosphate (ATP-depleting agents 2-deoxyglucose and 5-thioglucose, a mechanism that may inhibit ATP-mediated calcium sequestration by G6PT. Conclusion We illustrate a new G6PT function in glioma cells that could regulate the intracellular signalling and invasive phenotype of brain tumor cells, and that can be targeted by the anticancer properties of CHL.

  8. Embryonic protein undernutrition by albumen removal programs the hepatic amino acid and glucose metabolism during the perinatal period in an avian model.

    Directory of Open Access Journals (Sweden)

    Els Willems

    Full Text Available Different animal models have been used to study the effects of prenatal protein undernutrition and the mechanisms by which these occur. In mammals, the maternal diet is manipulated, exerting both direct nutritional and indirect hormonal effects. Chicken embryos develop independent from the hen in the egg. Therefore, in the chicken, the direct effects of protein deficiency by albumen removal early during incubation can be examined. Prenatal protein undernutrition was established in layer-type eggs by the partial replacement of albumen by saline at embryonic day 1 (albumen-deprived group, compared to a mock-treated sham and a non-treated control group. At hatch, survival of the albumen-deprived group was lower compared to the control and sham group due to increased early mortality by the manipulation. No treatment differences in yolk-free body weight or yolk weight could be detected. The water content of the yolk was reduced, whereas the water content of the carcass was increased in the albumen-deprived group, compared to the control group, indicating less uptake of nutrients from the yolk. At embryonic day 16, 20 and at hatch, plasma triiodothyronine (T3, corticosterone, lactate or glucose concentrations and hepatic glycogen content were not affected by treatment. At embryonic day 20, the plasma thyroxine (T4 concentrations of the albumen-deprived embryos was reduced compared to the control group, indicating a decreased metabolic rate. Screening for differential protein expression in the liver at hatch using two-dimensional difference gel electrophoresis revealed not only changed abundance of proteins important for amino acid metabolism, but also of enzymes related to energy and glucose metabolism. Interestingly, GLUT1, a glucose transporter, and PCK2 and FBP1, two out of three regulatory enzymes of the gluconeogenesis were dysregulated. No parallel differences in gene expressions causing the differences in protein abundance could be detected

  9. Effects of trans fatty acids on glucose homeostasis: a meta-analysis of randomized, placebo-controlled clinical trials123

    OpenAIRE

    Aronis, Konstantinos N; Khan, Sami M; Mantzoros, Christos S

    2012-01-01

    Background: Although evidence from cohort studies has suggested that trans fatty acid (TFA) consumption may be associated with insulin resistance and diabetes, randomized placebo-controlled trials (RCTs) have yielded conflicting results.

  10. Microbial Reduction of Fe(III) in Acidic Sediments: Isolation of Acidiphilium cryptum JF-5 Capable of Coupling the Reduction of Fe(III) to the Oxidation of Glucose

    OpenAIRE

    Küsel, Kirsten; Dorsch, Tanja; Acker, Georg; Stackebrandt, Erko

    1999-01-01

    To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12°C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H2 was consumed by acid...

  11. Effects of soil water content and elevated CO2 concentration on the monoterpene emission rate of Cryptomeria japonica.

    Science.gov (United States)

    Mochizuki, Tomoki; Amagai, Takashi; Tani, Akira

    2018-04-11

    Monoterpenes emitted from plants contribute to the formation of secondary pollution and affect the climate system. Monoterpene emission rates may be affected by environmental changes such as increasing CO 2 concentration caused by fossil fuel burning and drought stress induced by climate change. We measured monoterpene emissions from Cryptomeria japonica clone saplings grown under different CO 2 concentrations (control: ambient CO 2 level, elevated CO 2 : 1000μmolmol -1 ). The saplings were planted in the ground and we did not artificially control the SWC. The relationship between the monoterpene emissions and naturally varying SWC was investigated. The dominant monoterpene was α-pinene, followed by sabinene. The monoterpene emission rates were exponentially correlated with temperature for all measurements and normalized (35°C) for each measurement day. The daily normalized monoterpene emission rates (E s0.10 ) were positively and linearly correlated with SWC under both control and elevated CO 2 conditions (control: r 2 =0.55, elevated CO 2 : r 2 =0.89). The slope of the regression line of E s0.10 against SWC was significantly higher under elevated CO 2 than under control conditions (ANCOVA: P<0.01), indicating that the effect of CO 2 concentration on monoterpene emission rates differed by soil water status. The monoterpene emission rates estimated by considering temperature and SWC (Improved G93 algorithm) better agreed with the measured monoterpene emission rates, when compared with the emission rates estimated by considering temperature alone (G93 algorithm). Our results demonstrated that the combined effects of SWC and CO 2 concentration are important for controlling the monoterpene emissions from C. japonica clone saplings. If these relationships can be applied to the other coniferous tree species, our results may be useful to improve accuracy of monoterpene emission estimates from the coniferous forests as affected by climate change in the present and

  12. Monoterpenes released from fruit, plant, and vegetable systems.

    Science.gov (United States)

    Iqbal, Mohammad Asif; Kim, Ki-Hyun; Ahn, Jeong Hyeon

    2014-09-29

    To quantify the emission rate of monoterpenes (MTs) from diverse natural sources, the sorbent tube (ST)-thermal desorption (TD) method was employed to conduct the collection and subsequent detection of MTs by gas chromatography. The calibration of MTs, when made by both mass spectrometric (MS) and flame ionization detector (FID), consistently exhibited high coefficient of determination values (R2 > 0.99). This approach was employed to measure their emission rate from different fruit/plant/vegetable (F/P/V) samples with the aid of an impinger-based dynamic headspace sampling system. The results obtained from 10 samples (consisting of carrot, pine needle (P. sylvestris), tangerine, tangerine peel, strawberry, sepals of strawberry, plum, apple, apple peel, and orange juice) marked α-pinene, β-pinene, myrcene, α-terpinene, R-limonene, γ-terpinene, and p-cymene as the most common MTs. R-limonene was the major species emitted from citrus fruits and beverages with its abundance exceeding 90%. In contrast, α-pinene was the most abundant MT (37%) for carrot, while it was myrcene (31%) for pine needle. The overall results for F/P/V samples confirmed α-pinene, β-pinene, myrcene, α-terpinene, and γ-terpinene as common MTs. Nonetheless, the types and magnitude of MTs released from fruits were distinguished from those of vegetables and plants.

  13. A new bioactive monoterpene-flavonoid from Satureja khuzistanica.

    Science.gov (United States)

    Malmir, Maryam; Gohari, Ahmad Reza; Saeidnia, Soodabeh; Silva, Olga

    2015-09-01

    A new monoterpene-flavonoid, saturejin (3'-(2,5-dihydroxy-p-cymene) 5,7,4'-trihydroxy flavone) (4), together with twelve known flavonoids consist of two flavanonols (aromadendrin (8) and taxifolin (12)), two flavanones (naringenin (3) and 5,7,3',5'-tetrahydroxy flavanone (9)) and eight flavones (xanthomicrol (1), acacetin (2), cirsimaritin (5), 7-methoxy luteolin (6), apigenin (7), cirsilineol (10), diosmetin (11) and 6-hydroxyluteolin 7,3'-dimethyl ether (13)), were isolated from an ethyl acetate extract and identified for the first time in the dried aerial parts of Satureja khuzistanica Jamzad, an endemic medicinal plant traditionally used as dental anesthetic, oral antiseptic and anti-inflammatory among the nomadic inhabitants of southwestern Iran. The structures of these compounds were determined using the usual spectroscopic methods including 2D-NMR and MS analyses. Saturejin showed a significant β-glucosidase inhibitory activity at concentration of 10 μg as well as positive antioxidant activity at the amount of 1 μg. These results could be correlated with the in vitro and in vivo anti-inflammatory, anti-oxidant and anti-diabetic properties reported from this medicinal plant. Similar activities were also described for some of the other isolated compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Monoterpenes Released from Fruit, Plant, and Vegetable Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Asif Iqbal

    2014-09-01

    Full Text Available To quantify the emission rate of monoterpenes (MTs from diverse natural sources, the sorbent tube (ST-thermal desorption (TD method was employed to conduct the collection and subsequent detection of MTs by gas chromatography. The calibration of MTs, when made by both mass spectrometric (MS and flame ionization detector (FID, consistently exhibited high coefficient of determination values (R2 > 0.99. This approach was employed to measure their emission rate from different fruit/plant/vegetable (F/P/V samples with the aid of an impinger-based dynamic headspace sampling system. The results obtained from 10 samples (consisting of carrot, pine needle (P. sylvestris, tangerine, tangerine peel, strawberry, sepals of strawberry, plum, apple, apple peel, and orange juice marked α-pinene, β-pinene, myrcene, α-terpinene, R-limonene, γ-terpinene, and p-cymene as the most common MTs. R-limonene was the major species emitted from citrus fruits and beverages with its abundance exceeding 90%. In contrast, α-pinene was the most abundant MT (37% for carrot, while it was myrcene (31% for pine needle. The overall results for F/P/V samples confirmed α-pinene, β-pinene, myrcene, α-terpinene, and γ-terpinene as common MTs. Nonetheless, the types and magnitude of MTs released from fruits were distinguished from those of vegetables and plants.

  15. Suppression of new particle formation from monoterpene oxidation by NOx

    Science.gov (United States)

    Wildt, J.; Mentel, T. F.; Kiendler-Scharr, A.; Hoffmann, T.; Andres, S.; Ehn, M.; Kleist, E.; Müsgen, P.; Rohrer, F.; Rudich, Y.; Springer, M.; Tillmann, R.; Wahner, A.

    2014-03-01

    The impact of nitrogen oxides (NOx = NO + NO2) on new particle formation (NPF) and on photochemical ozone production from real plant volatile organic compound (BVOC) emissions was studied in a laboratory setup. At high NOx conditions ([BVOC] / [NOx] 23 ppb) new particle formation was suppressed. Instead, photochemical ozone formation was observed resulting in higher hydroxyl radical (OH) and lower nitrogen monoxide (NO) concentrations. When [NO] was reduced back to levels below 1 ppb by OH reactions, NPF was observed. Adding high amounts of NOx caused NPF to be slowed by orders of magnitude compared to analogous experiments at low NOx conditions ([NOx] ~300 ppt), although OH concentrations were higher. Varying NO2 photolysis enabled showing that NO was responsible for suppression of NPF. This suggests that peroxy radicals are involved in NPF. The rates of NPF and photochemical ozone production were related by power law dependence with an exponent approaching -2. This exponent indicated that the overall peroxy radical concentration must have been similar when NPF occurred. Thus, permutation reactions of first-generation peroxy radicals cannot be the rate limiting step in NPF from monoterpene oxidation. It was concluded that permutation reactions of higher generation peroxy-radical-like intermediates limit the rate of new particle formation. In contrast to the strong effects on the particle numbers, the formation of particle mass was substantially less sensitive to NOx concentrations. If at all, yields were reduced by about an order of magnitude only at very high NOx concentrations.

  16. The effect of a pre-anesthetic infusion of amino acids on body temperature, venous blood pH, glucose, creatinine, and lactate of healthy dogs during anesthesia.

    Science.gov (United States)

    Clark-Price, Stuart C; Dossin, Olivier; Ngwenyama, Thandeka R; O'Brien, Mauria A; McMichael, Maureen; Schaeffer, David J

    2015-05-01

    To evaluate the effect of preanesthetic, intravenous (IV) amino acids on body temperature of anesthetized healthy dogs. Randomized, experimental, crossover study. Eight mixed-breed dogs approximately 2 years of age weighing 20.7 ± 2.1 kg. Dogs received 10% amino acid solution (AA) or 0.9% saline (SA) IV at 5 mL kg(-1) over 60 minutes. Body temperature (BT) was recorded at 5 minute intervals during infusions. Dogs were then anesthetized with sevoflurane for 90 minutes. BT was recorded at 5 minute intervals during anesthesia. Jugular blood samples were analyzed for pH, glucose, creatinine, and lactate concentrations at baseline, after infusion, after anesthesia and after 24 hours. BT at conclusion of infusion decreased -0.34 ± 0.42 °C in group AA and -0.40 ± 0.38 °C in group SA and was not different between groups (p = 0.072). BT decreased 2.72 ± 0.37 °C in group AA and 2.88 ± 0.26 °C in group SA after anesthesia and was different between groups (p dogs, preanesthetic IV infusion of amino acids attenuated heat loss compared to controls, however, the amount attenuated may not be clinically useful. Further studies are warranted to determine if nutrient-induced thermogenesis is beneficial to dogs undergoing anesthesia. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  17. Amino Acid and Biogenic Amine Profile Deviations in an Oral Glucose Tolerance Test: A Comparison between Healthy and Hyperlipidaemia Individuals Based on Targeted Metabolomics

    Directory of Open Access Journals (Sweden)

    Qi Li

    2016-06-01

    Full Text Available Hyperlipidemia (HLP is characterized by a disturbance in lipid metabolism and is a primary risk factor for the development of insulin resistance (IR and a well-established risk factor for cardiovascular disease and atherosclerosis. The aim of this work was to investigate the changes in postprandial amino acid and biogenic amine profiles provoked by an oral glucose tolerance test (OGTT in HLP patients using targeted metabolomics. We used ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry to analyze the serum amino acid and biogenic amine profiles of 35 control and 35 HLP subjects during an OGTT. The amino acid and biogenic amine profiles from 30 HLP subjects were detected as independent samples to validate the changes in the metabolites. There were differences in the amino acid and biogenic amine profiles between the HLP individuals and the healthy controls at baseline and after the OGTT. The per cent changes of 13 metabolites from fasting to the 2 h samples during the OGTT in the HLP patients were significantly different from those of the healthy controls. The lipid parameters were associated with the changes in valine, isoleucine, creatine, creatinine, dimethylglycine, asparagine, serine, and tyrosine (all p < 0.05 during the OGTT in the HLP group. The postprandial changes in isoleucine and γ-aminobutyric acid (GABA during the OGTT were positively associated with the homeostasis model assessment of insulin resistance (HOMA-IR; all p < 0.05 in the HLP group. Elevated oxidative stress and disordered energy metabolism during OGTTs are important characteristics of metabolic perturbations in HLP. Our findings offer new insights into the complex physiological regulation of metabolism during the OGTT in HLP.

  18. Simultaneous demonstration of acid phosphatase and glucose-6-phosphate dehydrogenase in mouse hepatocytes. A novel electron-microscopic dual staining enzyme-cytochemistry

    Directory of Open Access Journals (Sweden)

    S Matsubara

    2010-01-01

    Full Text Available Acid phosphatase (ACPase and glucose-6-phosphate dehydrogenase (G6PD play important roles in cell biology/disease pathophysiology in various organs including the liver. The purpose of the present report is to introduce a new enzymecytochemical method to simultaneously demonstrate the subcellular localization of ACPase and G6PD within the same hepatocyte in the mouse liver. The ultrastructural localization of ACPase and G6PD were demonstrated, with concomitant use of the cerium method and the copper-ferrocyanide method, respectively. ACPase labelings were localized in the lysosomes, and G6PD labelings were visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of the hepatocyte. This novel double staining procedure may be a useful histochemical tool for the study of liver functions in both physiological and pathological conditions.

  19. Quantitative importance of the pentose phosphate pathway determined by incorporation of 13C from [2-13C]- and [3-13C]glucose into TCA cycle intermediates and neurotransmitter amino acids in functionally intact neurons.

    Science.gov (United States)

    Brekke, Eva M F; Walls, Anne B; Schousboe, Arne; Waagepetersen, Helle S; Sonnewald, Ursula

    2012-09-01

    The brain is highly susceptible to oxidative injury, and the pentose phosphate pathway (PPP) has been shown to be affected by pathological conditions, such as Alzheimer's disease and traumatic brain injury. While this pathway has been investigated in the intact brain and in astrocytes, little is known about the PPP in neurons. The activity of the PPP was quantified in cultured cerebral cortical and cerebellar neurons after incubation in the presence of [2-(13)C]glucose or [3-(13)C]glucose. The activity of the PPP was several fold lower than glycolysis in both types of neurons. While metabolism of (13)C-labeled glucose via the PPP does not appear to contribute to the production of releasable lactate, it contributes to labeling of tricarboxylic acid (TCA) cycle intermediates and related amino acids. Based on glutamate isotopomers, it was calculated that PPP activity accounts for ~6% of glucose metabolism in cortical neurons and ~4% in cerebellar neurons. This is the first demonstration that pyruvate generated from glucose via the PPP contributes to the synthesis of acetyl CoA for oxidation in the TCA cycle. Moreover, the fact that (13)C labeling from glucose is incorporated into glutamate proves that both the oxidative and the nonoxidative stages of the PPP are active in neurons.

  20. Responses of plasma glucose and nonesterified fatty acids to intravenous insulin tolerance tests in dairy cows during a 670-day lactation.

    Science.gov (United States)

    Marett, L C; Auldist, M J; Wales, W J; Macmillan, K L; Dunshea, F R; Leury, B J

    2017-04-01

    The metabolic response of dairy cows undergoing an extended lactation to an insulin tolerance test (ITT) was investigated. Twelve multiparous Holstein-Friesian cows that calved in late winter in a pasture-based system were managed for a 670-d lactation by delaying rebreeding. Four 5-wk experimental periods commenced at approximately 73, 217, 422, and 520 d in milk (DIM). Cows were offered a diet of perennial ryegrass (73 and 422 DIM) or pasture hay and silage (217 and 520 DIM) supplemented with 1 kg dry matter (DM) of grain (control; CON) or 6 kg DM of grain (GRN). Daily energy intake was approximately 160 and 215 MJ of metabolizable energy/cow for CON and GRN, respectively. At all other times, cows were managed as a single herd and grazed pasture supplemented with grain to an estimated daily intake of 180 MJ of metabolizable energy/cow. Cows were fitted with a jugular catheter during the final week of each experimental period. An ITT using 0.12 IU of insulin/kg of body weight (BW) was conducted on each cow at approximately 100, 250, 460, and 560 DIM. Cows in the GRN treatment had greater milk yield, milk solids yield, and BW than cows in the CON treatment. Within treatment, individual cow responses to the ITT were highly variable. Plasma glucose and nonesterified fatty acid (NEFA) concentrations declined at all stages of lactation. The clearance rate of plasma glucose was slower before 300 DIM than after 300 DIM, which indicates greater inhibition of hepatic glucose synthesis and uptake of glucose by insulin-dependent tissues later in the lactation. The clearance rate, area under the curve, and recovery of plasma NEFA were greatest at 100 DIM, indicating greater responsiveness to the antilipolytic effect of insulin in early lactation, but also greater lipolytic responsiveness. The variation in response to the ITT was mostly a result of DIM rather than diet. However, the plasma NEFA response showed interactions between diet and DIM, indicating that energy intake

  1. Acidic preconditioning of endothelial colony-forming cells (ECFC) promote vasculogenesis under proinflammatory and high glucose conditions in vitro and in vivo.

    Science.gov (United States)

    Mena, Hebe Agustina; Zubiry, Paula Romina; Dizier, Blandine; Schattner, Mirta; Boisson-Vidal, Catherine; Negrotto, Soledad

    2018-05-02

    We have previously demonstrated that acidic preconditioning of human endothelial colony-forming cells (ECFC) increased proliferation, migration, and tubulogenesis in vitro, and increased their regenerative potential in a murine model of hind limb ischemia without baseline disease. We now analyze whether this strategy is also effective under adverse conditions for vasculogenesis, such as the presence of ischemia-related toxic molecules or diabetes, one of the main target diseases for cell therapy due to their well-known healing impairments. Cord blood-derived CD34 + cells were seeded in endothelial growth culture medium (EGM2) and ECFC colonies were obtained after 14-21 days. ECFC were exposed at pH 6.6 (preconditioned) or pH 7.4 (nonpreconditioned) for 6 h, and then pH was restored at 7.4. A model of type 2 diabetes induced by a high-fat and high-sucrose diet was developed in nude mice and hind limb ischemia was induced in these animals by femoral artery ligation. A P value < 0.05 was considered statistically significant (by one-way analysis of variance). We found that acidic preconditioning increased ECFC adhesion and the release of pro-angiogenic molecules, and protected ECFC from the cytotoxic effects of monosodium urate crystals, histones, and tumor necrosis factor (TNF)α, which induced necrosis, pyroptosis, and apoptosis, respectively. Noncytotoxic concentrations of high glucose, TNFα, or their combination reduced ECFC proliferation, stromal cell-derived factor (SDF)1-driven migration, and tubule formation on a basement membrane matrix, whereas almost no inhibition was observed in preconditioned ECFC. In type 2 diabetic mice, intravenous administration of preconditioned ECFC significantly induced blood flow recovery at the ischemic limb as measured by Doppler, compared with the phosphate-buffered saline (PBS) and nonpreconditioned ECFC groups. Moreover, the histologic analysis of gastrocnemius muscles showed an increased vascular density and reduced

  2. The effect of different treatments for early-lactation hyperketonemia on blood β-hydroxybutyrate, plasma nonesterified fatty acids, glucose, insulin, and glucagon in dairy cattle.

    Science.gov (United States)

    Mann, S; Yepes, F A Leal; Behling-Kelly, E; McArt, J A A

    2017-08-01

    Despite increased efforts in preventing the occurrence of metabolic disorders in transition cows, hyperketonemia remains a frequent early-lactation metabolic disease affecting an average of 40% of cows in herds in the United States. Despite the demonstrated economic effect of this disorder, controlled clinical trials comparing different treatment strategies in affected cows are lacking. The objective of our study was to investigate the effect of treatment with intravenous glucose, oral propylene glycol, or a combination of both on the reduction in blood β-hydroxybutyrate (BHB) concentrations of early-lactation hyperketonemic dairy cows. Multiparous Holstein cows between 3 to 9 d in milk were screened for hyperketonemia using a handheld meter 3 times per week, and enrolled at whole blood BHB concentration ≥1.2 mmol/L to 1 of 4 treatment groups: (1) 500 mL of a 50% dextrose solution i.v. once daily for 3 d (GLU, n = 9), (2) 300 mL of propylene glycol as a drench once daily for 3 d (PG, n = 9), (3) a combination treatment of a 500 mL of 50% dextrose solution i.v. and 300 mL of propylene glycol orally once daily for 3 d (GLU+PG, n = 8), or (4) an untreated control group (CTRL, n = 8). Blood samples were collected immediately before as well as at 1, 2, 4, 8, 12, 24, 36, 48, 60, and 72 h after administration of the first treatment through a jugular catheter and 3 times per week thereafter from coccygeal vessels. Concentrations of BHB were measured in whole blood, and plasma samples were analyzed for glucose, fatty acid (NEFA), insulin, glucagon, and electrolyte concentrations. The EDTA-anticoagulated blood samples were assessed for red blood cell indices, and smears were made for evaluation of red blood cell morphology. Outcomes were analyzed using repeated measures analysis. Overall least squares means (95% CI) of whole blood BHB concentrations between 1 h and d 11 relative to first treatment were 1.11 (0.95 to 1.30), 1.26 (1.07 to 1.47), 0.96 (0.81 to 1.13), and 1

  3. Global isoprene and monoterpene emissions under changing climate, vegetation, CO2 and land use

    DEFF Research Database (Denmark)

    Hantson, Stijn; Knorr, Wolfgang; Schurgers, Guy

    2017-01-01

    Plants emit large quantities of isoprene and monoterpenes, the main components of global biogenic volatile organic compound (BVOC) emissions. BVOCs have an important impact on the atmospheric composition of methane, and of short-lived radiative forcing agents (e.g. ozone, aerosols etc.). It is th......Plants emit large quantities of isoprene and monoterpenes, the main components of global biogenic volatile organic compound (BVOC) emissions. BVOCs have an important impact on the atmospheric composition of methane, and of short-lived radiative forcing agents (e.g. ozone, aerosols etc.......). It is therefore necessary to know how isoprene and monoterpene emissions have changed over the past and how future changes in climate, land-use and other factors will impact them. Here we present emission estimates of isoprene and monoterpenes over the period 1901–2 100 based on the dynamic global vegetation...... model LPJ-GUESS, including the effects of all known important drivers. We find that both isoprene and monoterpene emissions at the beginning of the 20th century were higher than at present. While anthropogenic land-use change largely drives the global decreasing trend for isoprene over the 20th century...

  4. Antifungal activity and mechanism of action of monoterpenes against dermatophytes and yeasts

    Directory of Open Access Journals (Sweden)

    Diogo Miron

    Full Text Available Dermatomycosis causes highly frequent dermal lesions, and volatile oils have been proven to be promising as antifungal agents. The antifungal activity of geraniol, nerol, citral, neral and geranial (monoterpenes, and terbinafine and anidulafungin (control drugs against seven opportunistic pathogenic yeasts and four dermatophyte species was evaluated by the Clinical and Laboratory Standards Institute microdilution tests. Monoterpenes were more active against dermatophytes than yeasts (geometric mean of minimal inhibitory concentration (GMIC of 34.5 and 100.4 µg.ml-1, respectively. Trichophyton rubrum was the fungal species most sensitive to monoterpenes (GMIC of 22.9 µg.ml-1. The trans isomers showed higher antifungal activity than the cis. The mechanism of action was investigated evaluating damage in the fungal cell wall (Sorbitol Protection Assay and in the cell membrane (Ergosterol Affinity Assay. No changes were observed in the MIC of monoterpenes in the sorbitol protection assay.The MIC of citral and geraniol was increased from 32 to 160 µg.ml-1 when the exogenous ergosterol concentrations was zero and 250 µg.ml-1, respectively. The monoterpenes showed an affinity for ergosterol relating their mechanism of action to cell membrane destabilization.

  5. PDK2 and ABCG2 genes polymorphisms are correlated with blood glucose levels and uric acid in Tibetan gout patients.

    Science.gov (United States)

    Ren, Y C; Jin, T B; Sun, X D; Geng, T T; Zhang, M X; Wang, L; Feng, T; Kang, L L; Chen, C

    2016-02-11

    Previous studies have shown that the PDK2 and ABCG2 genes play important roles in many aspects of gout development in European populations. However, a detailed genotype-phenotype analysis was not performed. The aim of the present study was to investigate the potential association between variants in these two genes and metabolism-related quantitative phenotypes relevant to gout in a Chinese Tibetan population. In total, 316 Chinese Tibetan gout patients were recruited from rheumatology outpatient clinics and 6 single nucleotide polymorphisms in PDK2 and ABCG2 were genotyped, which were possible etiologic variants as identified in the HapMap Chinese Han Beijing population. A significant difference in blood glucose levels was detected between different genotypes of rs2728109 (P = 0.005) in the PDK2 gene. We also detected a significant difference in the mean serum uric levels between different genotypes of rs3114018 (P = 0.004) in the ABCG2 gene. All P values remained significant after Bonferroni's correction for multiple testing. Our data demonstrate potential roles for PDK2 and ABCG2 polymorphisms in the metabolic phenotypes of Tibetan gout patients, which may provide new insights into the etiology of gout. Further studies are required to confirm these findings.

  6. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats. A pharmacological study with the chlorogenic acid derivative S4048

    NARCIS (Netherlands)

    van Dijk, T. H.; van der Sluijs, F. H.; Wiegman, C. H.; Baller, J. F.; Gustafson, L. A.; Burger, H. J.; Herling, A. W.; Kuipers, F.; Meijer, A. J.; Reijngoud, D. J.

    2001-01-01

    Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in

  7. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats - A pharmacological study with the chlorogenic acid derivative S4048

    NARCIS (Netherlands)

    van Dijk, TH; van der Sluijs, FH; Wiegman, CH; Baller, JFW; Gustafson, LA; Burger, HJ; Herling, AW; Kuipers, F; Meijer, AJ; Reijngoud, DJ

    2001-01-01

    Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in

  8. Odd Chain Fatty Acids, New Insights of the Relationship Between the Gut Microbiota, Dietary Intake, Biosynthesis and Glucose Intolerance

    Czech Academy of Sciences Publication Activity Database

    Jenkins, B.J.; Seyssel, K.; Chiu, S.; Pan, P.-H.; Lin, S.-Y.; Stanley, E.; Ament, Z.; West, J.A.; Summerhill, K.; Griffin, J.L.; Vetter, W.; Autio, K.J.; Hiltunen, K.; Hazebrouck, S.; Štěpánková, Renata; Chen, C.-J.; Alligier, M.; Laville, M.; Moore, M.; Kraft, G.; Cherrington, A.; King, S.; Krauss, R.M.; de Schryver, E.; Van Veldhoven, P.P.; Ronis, M.; Koulman, A.

    2017-01-01

    Roč. 7, MAR 23 (2017), s. 1-8, č. článku 44845. ISSN 2045-2322 R&D Projects: GA ČR(CZ) GA15-09518S; GA ČR(CZ) GA16-06326S Institutional support: RVO:61388971 Keywords : fatty acids * gut * microbiota Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.259, year: 2016

  9. Synthesis and evaluation of temperature- and glucose-sensitive nanoparticles based on phenylboronic acid and N-vinylcaprolactam for insulin delivery

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jun-zi [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620 (China); Bremner, David H. [School of Science, Engineering and Technology, Kydd Building, Abertay University, Dundee DD1 1HG, Scotland (United Kingdom); Li, He-yu; Sun, Xiao-zhu [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620 (China); Zhu, Li-Min, E-mail: lzhu@dhu.edu.cn [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620 (China)

    2016-12-01

    Poly N-vinylcaprolactam-co-acrylamidophenylboronic acid p(NVCL-co-AAPBA) was prepared from N-vinylcaprolactam (NVCL) and 3-acrylamidophenylboronic acid (AAPBA), using 2,2-azobisisobutyronitrile (AIBN) as initiator. The synthesis and structure of the polymer were examined by Fourier Transform infrared spectroscopy (FT-IR) and {sup 1}H-NMR. Dynamic light scattering (DLS), lower critical solution temperature (LCST) and transmission electron microscopy (TEM) were utilized to characterize the nanoparticles, CD spectroscopy was used to determine if there were any changes to the conformation of the insulin, and cell and animal toxicity were also investigated. The prepared nanoparticles were found to be monodisperse submicron particles and were glucose- and temperature-sensitive. In addition, the nanoparticles have good insulin-loading characteristics, do not affect the conformation of the insulin and show low-toxicity to cells and animals. These p(NVCL-co-AAPBA) nanoparticles may have some value for insulin or other hypoglycemic protein delivery. - Highlights: • A comprehensive study of a nanoparticles may have some value for insulin or other hypoglycemic protein delivery. • p(NVCL-co-AAPBA)'s synthetic method is simple, convenient to carry out. • NVCL is low toxic and safe. • The evaluation of acute toxicity and chronic toxicity is the most highlight.

  10. Piracetam ameliorated oxygen and glucose deprivation-induced injury in rat cortical neurons via inhibition of oxidative stress, excitatory amino acids release and P53/Bax.

    Science.gov (United States)

    He, Zhi; Hu, Min; Zha, Yun-hong; Li, Zi-cheng; Zhao, Bo; Yu, Ling-ling; Yu, Min; Qian, Ying

    2014-05-01

    Our previous work has demonstrated that piracetam inhibited the decrease in amino acid content induced by chronic hypoperfusion, ameliorated the dysfunction of learning and memory in a hypoperfusion rat model, down-regulated P53, and BAX protein, facilitated the synaptic plasticity, and may be helpful in the treatment of vascular dementia. To explore the precise mechanism, the present study further evaluated effects of piracetam on Oxygen and glucose deprivation (OGD)-induced neuronal damage in rat primary cortical cells. The addition of piracetam to the cultured cells 12 h before OGD for 4 h significantly reduced neuronal damage as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and lactate dehydrogenase release experiments. Piracetam also lowered the levels of malondialdehyde, nitrogen monoxidum, and xanthine oxidase which was increased in the OGD cells, and enhanced the activities of superoxide dismutase and glutathione peroxidase, which were decreased in the OGD cells. We also demonstrated that piracetam could decrease glutamate and aspartate release when cortical cells were subjected to OGD. Furthermore, Western blot study demonstrated that piracetam attenuated the increased expression of P53 and BAX protein in OGD cells. These observations demonstrated that piracetam reduced OGD-induced neuronal damage by inhibiting the oxidative stress and decreasing excitatory amino acids release and lowering P53/Bax protein expression in OGD cells.

  11. Combined Function of Brønsted and Lewis Acidity in the Zeolite-Catalyzed Isomerization of Glucose to Fructose in Alcohols

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Riisager, Anders; Taarning, Esben

    2016-01-01

    Glucose conversion via fructose to useful chemicals and fuels has attracted considerable attention. Isomerization of glucose to fructose can proceed along several different reaction pathways involving different sugar intermediates and isomeric forms. Presently, the roles of the substrate isomeric...

  12. Increased and Altered Fragrance of Tobacco Plants after Metabolic Engineering Using Three Monoterpene Synthases from Lemon

    Science.gov (United States)

    Lücker, Joost; Schwab, Wilfried; van Hautum, Bianca; Blaas, Jan; van der Plas, Linus H. W.; Bouwmeester, Harro J.; Verhoeven, Harrie A.

    2004-01-01

    Wild-type tobacco (Nicotiana tabacum) plants emit low levels of terpenoids, particularly from the flowers. By genetic modification of tobacco cv Petit Havana SR1 using three different monoterpene synthases from lemon (Citrus limon L. Burm. f.) and the subsequent combination of these three into one plant by crossings, we show that it is possible to increase the amount and alter the composition of the blend of monoterpenoids produced in tobacco plants. The transgenic tobacco plant line with the three introduced monoterpene synthases is emitting β-pinene, limonene, and γ-terpinene and a number of side products of the introduced monoterpene synthases, from its leaves and flowers, in addition to the terpenoids emitted by wild-type plants. The results show that there is a sufficiently high level of substrate accessible for the introduced enzymes. PMID:14718674

  13. Co-expression of peppermint geranyl diphosphate synthase small subunit enhances monoterpene production in transgenic tobacco plants.

    Science.gov (United States)

    Yin, Jun-Lin; Wong, Woon-Seng; Jang, In-Cheol; Chua, Nam-Hai

    2017-02-01

    Monoterpenes are important for plant survival and useful to humans. In addition to their function in plant defense, monoterpenes are also used as flavors, fragrances and medicines. Several metabolic engineering strategies have been explored to produce monoterpene in tobacco but only trace amounts of monoterpenes have been detected. We investigated the effects of Solanum lycopersicum 1-deoxy-d-xylulose-5-phosphate synthase (SlDXS), Arabidopsis thaliana geranyl diphosphate synthase 1 (AtGPS) and Mentha × piperita geranyl diphosphate synthase small subunit (MpGPS.SSU) on production of monoterpene and geranylgeranyl diphosphate (GGPP) diversities, and plant morphology by transient expression in Nicotiana benthamiana and overexpression in transgenic Nicotiana tabacum. We showed that MpGPS.SSU could enhance the production of various monoterpenes such as (-)-limonene, (-)-linalool, (-)-α-pinene/β-pinene or myrcene, in transgenic tobacco by elevating geranyl diphosphate synthase (GPS) activity. In addition, overexpression of MpGPS.SSU in tobacco caused early flowering phenotype and increased shoot branching by elevating contents of GA 3 and cytokinins due to upregulated transcript levels of several plastidic 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway genes, geranylgeranyl diphosphate synthases 3 (GGPPS3) and GGPPS4. Our method would allow the identification of new monoterpene synthase genes using transient expression in N. benthamiana and the improvement of monoterpene production in transgenic tobacco plants. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  14. Impact of drought stress on specialised metabolism: Biosynthesis and the expression of monoterpene synthases in sage (Salvia officinalis).

    Science.gov (United States)

    Radwan, Alzahraa; Kleinwächter, Maik; Selmar, Dirk

    2017-09-01

    In previous experiments, we demonstrated that the amount of monoterpenes in sage is increased massively by drought stress. Our current study is aimed to elucidate whether this increase is due, at least in part, to elevated activity of the monoterpene synthases responsible for the biosynthesis of essential oils in sage. Accordingly, the transcription rates of the monoterpene synthases were analyzed. Salvia officinalis plants were cultivated under moderate drought stress. The concentrations of monoterpenes as well as the expression of the monoterpene synthases were analyzed. The amount of monoterpenes massively increased in response to drought stress; it doubled after just two days of drought stress. The observed changes in monoterpene content mostly match with the patterns of monoterpene synthase expressions. The expression of bornyl diphosphate synthase was strongly up-regulated; its maximum level was reached after two days. Sabinene synthase increased gradually and reached a maximum after two weeks. In contrast, the transcript level of cineole synthase continuously declined. This study revealed that the stress related increase of biosynthesis is not only due to a "passive" shift caused by the stress related over-reduced status, but also is due - at least in part-to an "active" up-regulation of the enzymes involved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Genetic and biochemical characterization of a novel monoterpene epsilon-lactone hydrolase from Rhodococcus erythropolis DCL14

    NARCIS (Netherlands)

    Vlugt-Bergmans, van der C.J.B.; Werf, van der M.J.

    2001-01-01

    A monoterpene ε-lactone hydrolase (MLH) from Rhodococcus erythropolis DCL14, catalyzing the ring opening of lactones which are formed during degradation of several monocyclic monoterpenes, including carvone and menthol, was purified to apparent homogeneity. It is a monomeric enzyme of 31 kDa that is

  16. Genetic and biochemical characterization of a novel monoterpene e-lactone hydrolase from Rhodococcus erythropolis DCL14

    NARCIS (Netherlands)

    Vlugt-Bergmans, C.J.B. van der; Werf, M.J. van der

    2001-01-01

    A monoterpene ε-lactone hydrolase (MLH) from Rhodococcus erythropolis DCL14, catalyzing the ring opening of lactones which are formed during degradation of several monocyclic monoterpenes, including carvone and menthol, was purified to apparent homogeneity. It is a monomeric enzyme of 31 kDa that is

  17. Characterization and application of expanded graphite modified with phosphoric acid and glucose for the removal of Ni(II) from aqueous solution

    Science.gov (United States)

    Jiang, Li; Zhang, Jian; Xu, Xiaoli; Zhang, Jie; Liu, Hai; Guo, Zizhang; Kang, Yan; Li, Yiran; Xu, Jingtao

    2015-12-01

    Three kinds of modified expanded graphite (EG), impregnated with phosphoric acid (H3PO4) (P-EG), impregnated with glucose (G-EG), and impregnated with H3PO4 and glucose (G-P-EG), were prepared under a low temperature (150 °C). The adsorption capacity of G-P-EG (Qm = 7.016 mg/g) is much higher than original expanded graphite (EG Qm = 0.423 mg/g) and other two kinds of modified expanded graphite (P-EG Qm = 0.770 mg/g; G-EG Qm = 0.507 mg/g). The physicochemical properties of EG and G-P-EG were characterized by N2 adsorption/desorption, Boehm's titration and X-ray photoelectron spectroscopy (XPS). EG exhibited higher values of BET surface area (11.357 m2/g) and total pore volume (0.0303 cm3/g) than that of G-P-EG (4.808 m3/g and 0.0109 cm3/g). However, the results of Bohm's titration and XPS showed that G-P-EG contained more surface oxygen-containing functional groups. The Ni(II) adsorption equilibrium data agreed well with the Langmuir model. And the experimental data of EG and G-P-EG fitted better by pseudo-second order model. Based on the results of batch adsorption experiments and XPS analysis, there were several possible mechanisms for Ni(II) adsorption on the G-P-EG, including chemical adsorption, cation exchange, electrostatic attraction and surface complication.

  18. Effect of Functional Bread Rich in Potassium, γ-Aminobutyric Acid and Angiotensin-Converting Enzyme Inhibitors on Blood Pressure, Glucose Metabolism and Endothelial Function

    Science.gov (United States)

    Becerra-Tomás, Nerea; Guasch-Ferré, Marta; Quilez, Joan; Merino, Jordi; Ferré, Raimon; Díaz-López, Andrés; Bulló, Mònica; Hernández-Alonso, Pablo; Palau-Galindo, Antoni; Salas-Salvadó, Jordi

    2015-01-01

    Abstract Because it has been suggested that food rich in γ-aminobutyric acid (GABA) or angiotensin-converting enzyme inhibitor (ACEI) peptides have beneficial effects on blood pressure (BP) and other cardiovascular risk factors, we tested the effects of low-sodium bread, but rich in potassium, GABA, and ACEI peptides on 24-hour BP, glucose metabolism, and endothelial function. A randomized, double-blind, crossover trial was conducted in 30 patients with pre or mild-to-moderate hypertension, comparing three 4-week nutritional interventions separated by 2-week washout periods. Patients were randomly assigned to consume 120 g/day of 1 of the 3 types of bread for each nutritional intervention: conventional wheat bread (CB), low-sodium wheat bread enriched in potassium (LSB), and low-sodium wheat bread rich in potassium, GABA, and ACEI peptides (LSB + G). For each period, 24-hour BP measurements, in vivo endothelial function, and biochemical samples were obtained. After LSB + G consumption, 24-hour ambulatory BP underwent a nonsignificant greater reduction than after the consumption of CB and LSB (0.26 mm Hg in systolic BP and −0.63 mm Hg in diastolic BP for CB; −0.71 mm Hg in systolic BP and −1.08 mm Hg in diastolic BP for LSB; and −0.75 mm Hg in systolic BP and −2.12 mm Hg in diastolic BP for LSB + G, respectively). Diastolic BP at rest decreased significantly during the LSB + G intervention, although there were no significant differences in changes between interventions. There were no significant differences between interventions in terms of changes in in vivo endothelial function, glucose metabolism, and peripheral inflammatory parameters. Compared with the consumption of CB or LSB, no greater beneficial effects on 24-hour BP, endothelial function, or glucose metabolism were demonstrated after the consumption of LSB + G in a population with pre or mild-to-moderate hypertension. Further studies are warranted to clarify the

  19. Characterization and application of expanded graphite modified with phosphoric acid and glucose for the removal of Ni(II) from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Li [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Zhang, Jian, E-mail: zhangjian00@sdu.edu.cn [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Xu, Xiaoli [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Zhang, Jie [Shandong Experimental High School, Jinan 250100 (China); Liu, Hai; Guo, Zizhang; Kang, Yan; Li, Yiran [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Xu, Jingtao [School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250100 (China)

    2015-12-01

    Highlights: • Glucose and H{sub 3}PO{sub 4}, single or together, were used to modify expanded graphite. • The modified condition was at a low temperature (150 °C). • The properties of EG and the highest adsorption ability modified EG were compared. • G-P-EG has the highest adsorption ability, which is much higher than that of EG. - Abstract: Three kinds of modified expanded graphite (EG), impregnated with phosphoric acid (H{sub 3}PO{sub 4}) (P-EG), impregnated with glucose (G-EG), and impregnated with H{sub 3}PO{sub 4} and glucose (G-P-EG), were prepared under a low temperature (150 °C). The adsorption capacity of G-P-EG (Q{sub m} = 7.016 mg/g) is much higher than original expanded graphite (EG Q{sub m} = 0.423 mg/g) and other two kinds of modified expanded graphite (P-EG Q{sub m} = 0.770 mg/g; G-EG Q{sub m} = 0.507 mg/g). The physicochemical properties of EG and G-P-EG were characterized by N{sub 2} adsorption/desorption, Boehm's titration and X-ray photoelectron spectroscopy (XPS). EG exhibited higher values of BET surface area (11.357 m{sup 2}/g) and total pore volume (0.0303 cm{sup 3}/g) than that of G-P-EG (4.808 m{sup 3}/g and 0.0109 cm{sup 3}/g). However, the results of Bohm's titration and XPS showed that G-P-EG contained more surface oxygen-containing functional groups. The Ni(II) adsorption equilibrium data agreed well with the Langmuir model. And the experimental data of EG and G-P-EG fitted better by pseudo-second order model. Based on the results of batch adsorption experiments and XPS analysis, there were several possible mechanisms for Ni(II) adsorption on the G-P-EG, including chemical adsorption, cation exchange, electrostatic attraction and surface complication.

  20. Characterization and application of expanded graphite modified with phosphoric acid and glucose for the removal of Ni(II) from aqueous solution

    International Nuclear Information System (INIS)

    Jiang, Li; Zhang, Jian; Xu, Xiaoli; Zhang, Jie; Liu, Hai; Guo, Zizhang; Kang, Yan; Li, Yiran; Xu, Jingtao

    2015-01-01

    Highlights: • Glucose and H 3 PO 4 , single or together, were used to modify expanded graphite. • The modified condition was at a low temperature (150 °C). • The properties of EG and the highest adsorption ability modified EG were compared. • G-P-EG has the highest adsorption ability, which is much higher than that of EG. - Abstract: Three kinds of modified expanded graphite (EG), impregnated with phosphoric acid (H 3 PO 4 ) (P-EG), impregnated with glucose (G-EG), and impregnated with H 3 PO 4 and glucose (G-P-EG), were prepared under a low temperature (150 °C). The adsorption capacity of G-P-EG (Q m = 7.016 mg/g) is much higher than original expanded graphite (EG Q m = 0.423 mg/g) and other two kinds of modified expanded graphite (P-EG Q m = 0.770 mg/g; G-EG Q m = 0.507 mg/g). The physicochemical properties of EG and G-P-EG were characterized by N 2 adsorption/desorption, Boehm's titration and X-ray photoelectron spectroscopy (XPS). EG exhibited higher values of BET surface area (11.357 m 2 /g) and total pore volume (0.0303 cm 3 /g) than that of G-P-EG (4.808 m 3 /g and 0.0109 cm 3 /g). However, the results of Bohm's titration and XPS showed that G-P-EG contained more surface oxygen-containing functional groups. The Ni(II) adsorption equilibrium data agreed well with the Langmuir model. And the experimental data of EG and G-P-EG fitted better by pseudo-second order model. Based on the results of batch adsorption experiments and XPS analysis, there were several possible mechanisms for Ni(II) adsorption on the G-P-EG, including chemical adsorption, cation exchange, electrostatic attraction and surface complication.

  1. Glucose allostasis

    DEFF Research Database (Denmark)

    Stumvoll, Michael; Tataranni, P Antonio; Stefan, Norbert

    2003-01-01

    individuals with normal glucose tolerance, normoglycemia can always be maintained by compensatorily increasing AIR in response to decreasing M (and vice versa). This has been mathematically described by the hyperbolic relationship between AIR and M and referred to as glucose homeostasis, with glucose......In many organisms, normoglycemia is achieved by a tight coupling of nutrient-stimulated insulin secretion in the pancreatic beta-cell (acute insulin response [AIR]) and the metabolic action of insulin to stimulate glucose disposal (insulin action [M]). It is widely accepted that in healthy...... concentration assumed to remain constant along the hyperbola. Conceivably, glucose is one of the signals stimulating AIR in response to decreasing M. Hypothetically, as with any normally functioning feed-forward system, AIR should not fully compensate for worsening M, since this would remove the stimulus...

  2. Effects of chicory inulin on serum metabolites of uric acid, lipids, glucose, and abdominal fat deposition in quails induced by purine-rich diets.

    Science.gov (United States)

    Lin, Zhijian; Zhang, Bing; Liu, Xiaoqing; Jin, Rui; Zhu, Wenjing

    2014-11-01

    Inulin, a group of dietary fibers, is reported to improve the metabolic disorders. In the present study, we investigated the effects of chicory inulin on serum metabolites of uric acid (UA), lipids, glucose, and abdominal fat deposition in quail model induced by a purine-rich diet. In this study, 60 male French quails were randomly allocated to five groups: CON (control group), MOD (model group), BEN (benzbromarone-treated group), CHI-H (high-dosage chicory inulin-treated group), and CHI-L (low-dosage chicory inulin-treated group). The serum UA level was significantly increased in the model group from days 7 to 28, as well as triglyceride (TG) and free fatty acid (FFA) increased later in the experimental period. The abdominal fat ratio was increased on day 28. Benzbromarone can decrease UA levels on days 14 and 28. The high and low dosage of chicory inulin also decreased serum UA levels on days 7, 14, and 28. The abdominal fat ratio, activity, and protein of acetyl-CoA carboxylase (ACC) were decreased in chicory inulin-treated groups. The activities of xanthine oxidase (XOD) and fatty acid synthase (FAS) were increased in the model group and decreased in the benzbromarone and chicory inulin groups. This study evaluated a quail model of induced hyperuricemia with other metabolic disorders caused by a high-purine diet. The results indicated that a purine-rich diet might contribute to the development of hyperuricemia, hypertriglyceridemia, and abdominal obesity. Chicory inulin decreased serum UA, TG, and abdominal fat deposition in a quail model of hyperuricemia by altering the ACC protein expression and FAS and XOD activities.

  3. effects of caffeine and ethanolic extract of kolanut on glucose uptake

    African Journals Online (AJOL)

    Daniel Owu

    calculated as the product of (A-V) glucose and blood flow. ... Key words: Caffeine, kolanut, dog, glucose uptake, hindlimb ...... free fatty acids, and amino acids. ... involved in glucose homeostasis. ... independent of obesity and type 2 diabetes.

  4. Bornyl-diphosphate synthase from Lavandula angustifolia: A major monoterpene synthase involved in essential oil quality.

    Science.gov (United States)

    Despinasse, Yolande; Fiorucci, Sébastien; Antonczak, Serge; Moja, Sandrine; Bony, Aurélie; Nicolè, Florence; Baudino, Sylvie; Magnard, Jean-Louis; Jullien, Frédéric

    2017-05-01

    Lavender essential oils (EOs) of higher quality are produced by a few Lavandula angustifolia cultivars and mainly used in the perfume industry. Undesirable compounds such as camphor and borneol are also synthesized by lavender leading to a depreciated EO. Here, we report the cloning of bornyl diphosphate synthase of lavender (LaBPPS), an enzyme that catalyzes the production of bornyl diphosphate (BPP) and then by-products such as borneol or camphor, from an EST library. Compared to the BPPS of Salvia officinalis, the functional characterization of LaBPPS showed several differences in amino acid sequence, and the distribution of catalyzed products. Molecular modeling of the enzyme's active site suggests that the carbocation intermediates are more stable in LaBPPS than in SoBPPS leading probably to a lower efficiency of LaBPPS to convert GPP into BPP. Quantitative RT-PCR performed from leaves and flowers at different development stages of L. angustifolia samples show a clear correlation between transcript level of LaBPPS and accumulation of borneol/camphor, suggesting that LaBPPS is mainly responsible of in vivo biosynthesis of borneol/camphor in fine lavender. A phylogenetic analysis of terpene synthases (TPS) pointed out the basal position of LaBPPS in the TPSb clade, suggesting that LaBPPS could be an ancestor of others lavender TPSb. Finally, borneol could be one of the first monoterpenes to be synthesized in the Lavandula subgenus. Knowledge gained from these experiments will facilitate future studies to improve the lavender oils through metabolic engineering or plant breeding. Accession numbers: LaBPPS: KM015221. Copyright © 2017. Published by Elsevier Ltd.

  5. Engineered protein degradation of farnesyl pyrophosphate synthase is an effective regulatory mechanism to increase monoterpene production in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Peng, Bingyin; Nielsen, Lars K.; Kampranis, Sotirios C

    2018-01-01

    Monoterpene production in Saccharomyces cerevisae requires the introduction of heterologous monoterpene synthases (MTSs). The endogenous farnesyl pyrosphosphate synthase (FPPS; Erg20p) competes with MTSs for the precursor geranyl pyrophosphate (GPP), which limits the production of monoterpenes. ERG......20 is an essential gene that cannot be deleted and transcriptional down-regulation of ERG20 has failed to improve monoterpene production. Here, we investigated an N-degron-dependent protein degradation strategy to down-regulate Erg20p activity. Degron tagging decreased GFP protein half......-life drastically to 1 h (degron K3K15) or 15 min (degrons KN113 and KN119). Degron tagging of ERG20 was therefore paired with a sterol responsive promoter to ensure sufficient metabolic flux to essential downstream sterols despite the severe destabilisation effect of degron tagging. A dual monoterpene...

  6. Monoterpene persistence in the sapwood and heartwood of longleaf pine stumps: assessment of differences in composition and stability under field conditions

    Science.gov (United States)

    Thomas L. Eberhardt; Philip M. Sheridan; Jolie M. Mahfouz

    2009-01-01

    Monoterpenes in exudates, phloem and sapwood have received considerable attention relative to the active defenses of pine trees. However, little is known about the composition and function of the heartwood monoterpenes. To address this deficiency, monoterpene contents and relative compositions were determined for sapwood and heartwood samples from longleaf pine (Pinus...

  7. The altered glucose metabolism in tumor and a tumor acidic microenvironment associated with extracellular matrix metalloproteinase inducer and monocarboxylate transporters

    Science.gov (United States)

    Li, Xiaofeng; Yu, Xiaozhou; Dai, Dong; Song, Xiuyu; Xu, Wengui

    2016-01-01

    Extracellular matrix metalloproteinase inducer, also knowns as cluster of differentiation 147 (CD147) or basigin, is a widely distributed cell surface glycoprotein that is involved in numerous physiological and pathological functions, especially in tumor invasion and metastasis. Monocarboxylate transporters (MCTs) catalyze the proton-linked transport of monocarboxylates such as L-lactate across the plasma membrane to preserve the intracellular pH and maintain cell homeostasis. As a chaperone to some MCT isoforms, CD147 overexpression significantly contributes to the metabolic transformation of tumor. This overexpression is characterized by accelerated aerobic glycolysis and lactate efflux, and it eventually provides the tumor cells with a metabolic advantage and an invasive phenotype in the acidic tumor microenvironment. This review highlights the roles of CD147 and MCTs in tumor cell metabolism and the associated molecular mechanisms. The regulation of CD147 and MCTs may prove to be with a therapeutic potential for tumors through the metabolic modification of the tumor microenvironment. PMID:27009812

  8. Simple proxies for estimating the concentrations of monoterpenes and their oxidation products at a boreal forest site

    Directory of Open Access Journals (Sweden)

    J. Kontkanen

    2016-10-01

    Full Text Available The oxidation products of monoterpenes likely have a crucial role in the formation and growth of aerosol particles in boreal forests. However, the continuous measurements of monoterpene concentrations are usually not available on decadal timescales, and the direct measurements of the concentrations of monoterpene oxidation product have so far been scarce. In this study we developed proxies for the concentrations of monoterpenes and their oxidation products at a boreal forest site in Hyytiälä, southern Finland. For deriving the proxies we used the monoterpene concentration measured with a proton transfer reaction mass spectrometer (PTR-MS during 2006–2013. Our proxies for the monoterpene concentration take into account the temperature-controlled emissions from the forest ecosystem, the dilution caused by the mixing within the boundary layer and different oxidation processes. All the versions of our proxies captured the seasonal variation of the monoterpene concentration, the typical proxy-to-measurements ratios being between 0.8 and 1.3 in summer and between 0.6 and 2.6 in winter. In addition, the proxies were able to describe the diurnal variation of the monoterpene concentration rather well, especially in summer months. By utilizing one of the proxies, we calculated the concentration of oxidation products of monoterpenes by considering their production in the oxidation and their loss due to condensation on aerosol particles. The concentration of oxidation products was found to have a clear seasonal cycle, with a maximum in summer and a minimum in winter. The concentration of oxidation products was lowest in the morning or around noon and highest in the evening. In the future, our proxies for the monoterpene concentration and their oxidation products can be used, for example, in the analysis of new particle formation and growth in boreal environments.

  9. The role of ecophysiology in determining monoterpene concentrations and emissions from pinyon pine under drought conditions

    Science.gov (United States)

    Trowbridge, A. M.; Adams, H. D.; Breshears, D. D.; Stoy, P.; Monson, R. K.

    2012-12-01

    While much research has focused on the primary metabolic mechanisms underlying pinyon pine's sensitivity to severe and abrupt drought conditions, there remains a gap in our knowledge concerning how the resulting shift in carbon allocation toward plant secondary compounds, particularly monoterpenes, affects both atmospheric process and ecological species interactions. Because of the large global emission rate of monoterpenes and their effect on atmospheric chemistry, identifying the primary controls over and sensitivities to environmental change is critical for global emission models. Furthermore, monoterpenes are also known to impact insect behavior and act as defense compounds against herbivores, contributing to fluctuations in the population densities of herbivores either directly through toxicity, or indirectly by influencing an insect's susceptibility to parasitism. While pinyon mortality events are thought to be exacerbated by their susceptibility to herbivores resulting from weakened secondary chemical defenses, the impact of current and predicted drought on the chemical defense status of pinyons and the potential consequences for atmospheric composition and ecological interactions remains unknown. We performed a manipulative field study to untangle the effects of drought on plant carbon assimilation, growth, and defense throughout the year. Transplanting pinyons from their natural habitat into a desert environment, we were able to increase mean annual temperature by ~4 degrees C. Throughout the growing season, we measured pinyon physiology and monoterpene composition and emissions under different water (well-watered, ambient, or drought-stresed) and temperature (natural pinyon habitat or desert transplants) regimes. We hypothesized that increased drought would increase tissue concentrations in accordance with the carbon-nutrient balance hypothesis (CNBH). Furthermore, we predicted that higher temperatures and lower water availability together would influence

  10. Effects of 4-phenyl butyric acid on high glucose-induced alterations in dorsal root ganglion neurons.

    Science.gov (United States)

    Sharma, Dilip; Singh, Jitendra Narain; Sharma, Shyam S

    2016-12-02

    Mechanisms and pathways involving in diabetic neuropathy are still not fully understood but can be unified by the process of overproduction of reactive oxygen species (ROS) such as superoxide, endoplasmic reticulum (ER) stress, downstream intracellular signaling pathways and their modulation. Susceptibility of dorsal root ganglion (DRG) to internal/external hyperglycemic environment stress contributes to the pathogenesis and progression of diabetic neuropathy. ER stress leads to abnormal ion channel function, gene expression, transcriptional regulation, metabolism and protein folding. 4-phenyl butyric acid (4-PBA) is a potent and selective chemical chaperone; which may inhibit ER stress. It may be hypothesized that 4-PBA could attenuate via channels in DRG in diabetic neuropathy. Effects of 4-PBA were determined by applying different parameters of oxidative stress, cell viability, apoptosis assays and channel expression in cultured DRG neurons. Hyperglycemia-induced apoptosis in the DRG neuron was inhibited by 4-PBA. Cell viability of DRG neurons was not altered by 4-PBA. Oxidative stress was significantly blocked by the 4-PBA. Sodium channel expression was not altered by the 4-PBA. Our data provide evidence that the hyperglycemia-induced alteration may be reduced by the 4-PBA without altering the sodium channel expression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Protection against Oxygen-Glucose Deprivation/Reperfusion Injury in Cortical Neurons by Combining Omega-3 Polyunsaturated Acid with Lyciumbarbarum Polysaccharide.

    Science.gov (United States)

    Shi, Zhe; Wu, Di; Yao, Jian-Ping; Yao, Xiaoli; Huang, Zhijian; Li, Peng; Wan, Jian-Bo; He, Chengwei; Su, Huanxing

    2016-01-13

    Ischemic stroke, characterized by the disturbance of the blood supply to the brain, is a severe worldwide health threat with high mortality and morbidity. However, there is no effective pharmacotherapy for ischemic injury. Currently, combined treatment is highly recommended for this devastating injury. In the present study, we investigated neuroprotective effects of the combination of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and Lyciumbarbarum polysaccharide (LBP) on cortical neurons using an in vitro ischemic model. Our study demonstrated that treatment with docosahexaenoic acid (DHA), a major component of the ω-3 PUFAs family, significantly inhibited the increase of intracellular Ca(2+) in cultured wild type (WT) cortical neurons subjected to oxygen-glucose deprivation/reperfusion (OGD/R) injury and promoted their survival compared with the vehicle-treated control. The protective effects were further confirmed in cultured neurons with high endogenous ω-3 PUFAs that were isolated from fat-1 mice, in that a higher survival rate was found in fat-1 neurons compared with wild-type neurons after OGD/R injury. Our study also found that treatment with LBP (50 mg/L) activated Trk-B signaling in cortical neurons and significantly attenuated OGD/R-induced cell apoptosis compared with the control. Notably, both combining LBP treatment with ω-3 PUFAs administration to WT neurons and adding LBP to fat-1 neurons showed enhanced effects on protecting cortical neurons against OGD/R injury via concurrently regulating the intracellular calcium overload and neurotrophic pathway. The results of the study suggest that ω-3 PUFAs and LBP are promising candidates for combined pharmacotherapy for ischemic stroke.

  12. Effects of exercise training and diet on lipid kinetics during free fatty acid-induced insulin resistance in older obese humans with impaired glucose tolerance

    DEFF Research Database (Denmark)

    Solomon, Thomas; Haus, Jacob M; Marchetti, Christine M

    2009-01-01

    Elevated free fatty acids (FFA) are implicated with insulin resistance at the cellular level. However, the contribution of whole body lipid kinetics to FFA-induced insulin resistance is not well understood, and the effect of exercise and diet on this metabolic defect is not known. We investigated...... the effect of 12 wk of exercise training with and without caloric restriction on FFA turnover and oxidation (FFA(ox)) during acute FFA-induced insulin resistance. Sixteen obese subjects with impaired glucose tolerance were randomized to either a hypocaloric (n = 8; -598 +/- 125 kcal/day, 66 +/- 1 yr, 32.......8 +/- 1.8 kg/m(2)) or a eucaloric (n = 8; 67 +/- 2 yr, 35.3 +/- 2.1 kg/m(2)) diet and aerobic exercise (1 h/day at 65% of maximal oxygen uptake) regimen. Lipid kinetics ([1-(14)C]palmitate) were assessed throughout a 7-h, 40 mU x m(-2) x min(-1) hyperinsulinemic euglycemic clamp, during which insulin...

  13. Molecular Interaction between Lipoteichoic Acids and Lactobacillus delbrueckii Phages Depends on d-Alanyl and α-Glucose Substitution of Poly(Glycerophosphate) Backbones▿

    Science.gov (United States)

    Räisänen, Liisa; Draing, Christian; Pfitzenmaier, Markus; Schubert, Karin; Jaakonsaari, Tiina; von Aulock, Sonja; Hartung, Thomas; Alatossava, Tapani

    2007-01-01

    Lipoteichoic acids (LTAs) have been shown to act as bacterial counterparts to the receptor binding proteins of LL-H, LL-H host range mutant LL-H-a21, and JCL1032. Here we have used LTAs purified by hydrophobic interaction chromatography from different phage-resistant and -sensitive strains of Lactobacillus delbrueckii subsp. lactis. Nuclear magnetic resonance analyses revealed variation in the degree of α-glucosyl and d-alanyl substitution of the 1,3-linked poly(glycerophosphate) LTAs between the phage-sensitive and phage-resistant strains. Inactivation of phages was less effective if there was a high level of d-alanine residues in the LTA backbones. Prior incubation of the LTAs with α-glucose-specific lectin inhibited the LL-H phage inactivation. The overall level of decoration or the specific spatial combination of α-glucosyl-substituted, d-alanyl-substituted, and nonsubstituted glycerol residues may also affect phage adsorption. PMID:17416656

  14. Two pear glutathione S-transferases genes are regulated during fruit development and involved in response to salicylic acid, auxin, and glucose signaling.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Shi

    Full Text Available Two genes encoding putative glutathione S-transferase proteins were isolated from pear (Pyrus pyrifolia and designated PpGST1 and PpGST2. The deduced PpGST1 and PpGST2 proteins contain conserved Glutathione S-transferase N-terminal domain (GST_N and Glutathione S-transferase, C-terminal domain (GST_C. Using PCR amplification technique, the genomic clones corresponding to PpGST1 and PpGST2 were isolated and shown to contain two introns and a singal intron respectively with typical GT/AG boundaries defining the splice junctions. Phylogenetic analysis clearly demonstrated that PpGST1 belonged to Phi class of GST superfamilies and had high homology with apple MdGST, while PpGST2 was classified into the Tau class of GST superfamilies. The expression of PpGST1 and PpGST2 genes was developmentally regulated in fruit. Further study demonstrated that PpGST1 and PpGST2 expression was remarkably induced by glucose, salicylic acid (SA and indole-3-aceticacid (IAA treatments in pear fruit, and in diseased fruit. These data suggested that PpGST1 and PpGST2 might be involved in response to sugar, SA, and IAA signaling during fruit development of pear.

  15. AtRH57, a DEAD-box RNA helicase, is involved in feedback inhibition of glucose-mediated abscisic acid accumulation during seedling development and additively affects pre-ribosomal RNA processing with high glucose.

    Science.gov (United States)

    Hsu, Yi-Feng; Chen, Yun-Chu; Hsiao, Yu-Chun; Wang, Bing-Jyun; Lin, Shih-Yun; Cheng, Wan-Hsing; Jauh, Guang-Yuh; Harada, John J; Wang, Co-Shine

    2014-01-01

    The Arabidopsis thaliana T-DNA insertion mutant rh57-1 exhibited hypersensitivity to glucose (Glc) and abscisic acid (ABA). The other two rh57 mutants also showed Glc hypersensitivity similar to rh57-1, strongly suggesting that the Glc-hypersensitive feature of these mutants results from mutation of AtRH57. rh57-1 and rh57-3 displayed severely impaired seedling growth when grown in Glc concentrations higher than 3%. The gene, AtRH57 (At3g09720), was expressed in all Arabidopsis organs and its transcript was significantly induced by ABA, high Glc and salt. The new AtRH57 belongs to class II DEAD-box RNA helicase gene family. Transient expression of AtRH57-EGFP (enhanced green fluorescent protein) in onion cells indicated that AtRH57 was localized in the nucleus and nucleolus. Purified AtRH57-His protein was shown to unwind double-stranded RNA independent of ATP in vitro. The ABA biosynthesis inhibitor fluridone profoundly redeemed seedling growth arrest mediated by sugar. rh57-1 showed increased ABA levels when exposed to high Glc. Quantitative real time polymerase chain reaction analysis showed that AtRH57 acts in a signaling network downstream of HXK1. A feedback inhibition of ABA accumulation mediated by AtRH57 exists within the sugar-mediated ABA signaling. AtRH57 mutation and high Glc conditions additively caused a severe defect in small ribosomal subunit formation. The accumulation of abnormal pre-rRNA and resistance to protein synthesis-related antibiotics were observed in rh57 mutants and in the wild-type Col-0 under high Glc conditions. These results suggested that AtRH57 plays an important role in rRNA biogenesis in Arabidopsis and participates in response to sugar involving Glc- and ABA signaling during germination and seedling growth. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  16. Monoterpene composition of pine species and hybrids...some preliminary findings

    Science.gov (United States)

    Richard H. Smith

    1967-01-01

    Xylem resin samples, obtained from 72 freshly cut pine stumps at the Institute of Forest Genetics, Placerville, Calif., were analyzed for monoterpenes by gasliquid chromatography. Very little or no qualitative or quantitative variation could be attributed to annual ring, time of securing sample, and period of storage of sample up to 1 year. The 34 hybrids sampled...

  17. The Use of Monoterpenes as Kairomones by Ips latidens (LeConte) (Coleoptera: Scolytidae)

    Science.gov (United States)

    D.R. Miller; J.H. Borden

    1990-01-01

    The responses of Ips lutidens (LeConte) to multiple-funnel traps baited with various monoterpenes were determined in stands of lodgepole pine in British Columbia. ß-Phellandrene was attractive to I. lutidens in the absence of the pheromone ipsenol ß-Phellandrene increased the attraction of I. lutidens to...

  18. Variation in monoterpene content among geographic sources of eastern white pine

    Science.gov (United States)

    A.R. Gilmore; J.J. Jokela

    1977-01-01

    Variations of monoterpenes in cortical oleoresins and foliar samples were determined for seed from 16 provenances of eastern white pine (Pinus strobus L.). The experiment was analyzed using the "raw" and the arcsine "transformed" data. Alpha-pinene, camphene, and β-pinene varied between seed sources when "raw" data were analyzed...

  19. Alpha-Terpineol, a natural monoterpene: A review of its biological properties

    Science.gov (United States)

    Terpineols are monocyclic monoterpene tertiary alcohols and they are naturally present in plant species. There are five common isomers of terpineols, alpha-, beta-, gamma-, delta- and terpinen-4-ol, of which alpha-terpineol and its isomer terpinen-4-ol are the most common terpineols found in nature....

  20. Field Bioassays of Synthetic Pheromones and Host Monoterpenes for Conophthorus coniperda (Coleoptera: Scolytidae)

    Science.gov (United States)

    Peter de Groot; Gary L. DeBarr; Goran Birgersson

    1998-01-01

    Four major monoterpenes, (±)-a-pinene,1 (S)-(-)-ß-pinene,(R)-(+)-limonene, and myrcene are found in the cones of eastern white pines, Pinus strobus L. Mixtures ofthese, as well as. a-pinene or ß-pinene alone. increased catches of male white pine cone...

  1. Gene Coexpression Analysis Reveals Complex Metabolism of the Monoterpene Alcohol Linalool in Arabidopsis FlowersW

    NARCIS (Netherlands)

    Ginglinger, J.F.; Boachon, B.; Hofer, R.; Paetz, C.; Kollner, T.G.; Miesch, L.; Lugan, R.; Baltenweck, R.; Mutterer, J.; Ullman, P.; Verstappen, F.W.A.; Bouwmeester, H.J.

    2013-01-01

    The cytochrome P450 family encompasses the largest family of enzymes in plant metabolism, and the functions of many of its members in Arabidopsis thaliana are still unknown. Gene coexpression analysis pointed to two P450s that were coexpressed with two monoterpene synthases in flowers and were thus

  2. Comparative study of the antitumor effect of natural monoterpenes: relationship to cell cycle analysis

    Directory of Open Access Journals (Sweden)

    Abdeslam Jaafari

    2012-06-01

    Full Text Available Monoterpenes have been identified as responsible of important therapeutic effects of plant-extracts. In this work, we try to compare the cytotoxic effect of six monoterpenes (carvacrol, thymol, carveol, carvone, eugenol and isopulegol as well as their molecular mechanisms. The in vitro antitumor activity of the tested products, evaluated against five tumor cell lines, show that the carvacrol is the most cytotoxic monoterpene. The investigation of an eventual synergistic effect of the six natural monoterpenes with two anticancer drugs revealed that there is a significant synergy between them (p<5%. On the other hand, the effect of the tested products on cell cycle progression was examined by flow cytometry after DNA staining in order to investigate the molecular mechanism of their cytotoxic activity. The results revealed that carvacrol and carveol stopped the cell cycle progression in S phase; however, thymol and isopulegol stopped it in G0/G1 phase. Regarding carvone and eugenol, no effect on cell cycle was observed.

  3. Increased and altered fragrance of tobacco plants after metabolic engineering using three monoterpene synthases from lemon

    NARCIS (Netherlands)

    Lücker, J.; Schwab, W.; Hautum, van B.; Blaas, J.; Plas, van der L.H.W.; Bouwmeester, H.J.; Verhoeven, H.A.

    2004-01-01

    Wild-type tobacco (Nicotiana tabacum) plants emit low levels of terpenoids, particularly from the flowers. By genetic modification of tobacco cv Petit Havana SR1 using three different monoterpene synthases from lemon (Citrus limon L. Burm. f.) and the subsequent combination of these three into one

  4. Monoterpene engineering in a woody plant Eucalyptus camaldulensis using a limonene synthase cDNA.

    Science.gov (United States)

    Ohara, Kazuaki; Matsunaga, Etsuko; Nanto, Kazuya; Yamamoto, Kyoko; Sasaki, Kanako; Ebinuma, Hiroyasu; Yazaki, Kazufumi

    2010-01-01

    Metabolic engineering aimed at monoterpene production has become an intensive research topic in recent years, although most studies have been limited to herbal plants including model plants such as Arabidopsis. The genus Eucalyptus includes commercially important woody plants in terms of essential oil production and the pulp industry. This study attempted to modify the production of monoterpenes, which are major components of Eucalyptus essential oil, by introducing two expression constructs containing Perilla frutescens limonene synthase (PFLS) cDNA, whose gene products were designed to be localized in either the plastid or cytosol, into Eucalyptus camaldulensis. The expression of the plastid-type and cytosol-type PFLS cDNA in transgenic E. camaldulensis was confirmed by real-time polymerase chain reaction (PCR). Gas chromatography with a flame ionization detector analyses of leaf extracts revealed that the plastidic and cytosolic expression of PFLS yielded 2.6- and 4.5-times more limonene than that accumulated in wild-type E. camaldulensis, respectively, while the ectopic expression of PFLS had only a small effect on the emission of limonene from the leaves of E. camaldulensis. Surprisingly, the high level of PFLS in Eucalyptus was accompanied by a synergistic increase in the production of 1,8-cineole and alpha-pinene, two major components of Eucalyptus monoterpenes. This genetic engineering of monoterpenes demonstrated a new potential for molecular breeding in woody plants.

  5. Biocatalytic conversion of turpentine - a wood processing waste - into oxygenated monoterpenes

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, Marcela; Valterová, Irena; Vaněk, Tomáš

    2011-01-01

    Roč. 29, č. 5 (2011), s. 204-211 ISSN 1024-2422 R&D Projects: GA MŠk ME08070; GA MŠk 2B08058 Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z40550506 Keywords : biotransformation * monoterpene * Picea abies Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.905, year: 2011

  6. Inhibition of the NorA multi-drug transporter by oxygenated monoterpenes.

    Science.gov (United States)

    Coêlho, Mayara Ladeira; Ferreira, Josie Haydée Lima; de Siqueira Júnior, José Pinto; Kaatz, Glenn W; Barreto, Humberto Medeiros; de Carvalho Melo Cavalcante, Ana Amélia

    2016-10-01

    The aim of this study was to investigate intrinsic antimicrobial activity of three monoterpenes nerol, dimethyl octanol and estragole, against bacteria and yeast strains, as well as, investigate if these compounds are able to inhibit the NorA efflux pump related to fluoroquinolone resistance in Staphylococcus aureus. Minimal inhibitory concentrations (MICs) of the monoterpenes against Staphylococcus aureus, Escherichia coli and Candida albicans strains were determined by micro-dilution assay. MICs of the norfloxacin against a S. aureus strain overexpressing the NorA protein were determined in the absence or in the presence of the monoterpenes at subinhibitory concentrations, aiming to verify the ability of this compounds act as efflux pump inhibitors. The monoterpenes were inactive against S. aureus however the nerol was active against E. coli and C. albicans. The addition of the compounds to growth media at sub-inhibitory concentrations enhanced the activity of norfloxacin against S. aureus SA1199-B. This result shows that bioactives tested, especially the nerol, are able to inhibit NorA efflux pump indicating a potential use as adjuvants of norfloxacin for therapy of infections caused by multi-drug resistant S. aureus strains. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Two new monoterpene glucosides from Xanthium strumarium subsp. sibiricum with their anti-inflammatory activity.

    Science.gov (United States)

    Jiang, Hai; Xing, Xudong; Yan, Meiling; Guo, Xinyue; Yang, Lin; Yang, Liu

    2018-06-01

    Two new monoterpene glucosides: xanmonoter A (1) and xanmonoter B (2) were isolated from Xanthium strumarium. Their structures were elucidated on the basis of 1D and 2D NMR, MS and CD analysis. Compounds 1 and 2 were tested for their anti-inflammatory activity with IC 50 values of 17.4, 22.1 μM, respectively.

  8. Wet effluent diffusion denuder: The tool for determination of monoterpenes in forest

    Czech Academy of Sciences Publication Activity Database

    Křůmal, Kamil; Mikuška, Pavel; Večeřová, Kristýna; Urban, Otmar; Pallozzi, E.; Večeřa, Zbyněk

    2016-01-01

    Roč. 153, JUN (2016), s. 260-267 ISSN 0039-9140 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:68081715 ; RVO:67179843 Keywords : diffusion denuder * monoterpene * biogenic volatile organic compounds * tenax tubes Subject RIV: CB - Analytical Chemistry , Separation; EH - Ecology, Behaviour (UEK-B) Impact factor: 4.162, year: 2016

  9. Analysis of trends in isoprene and monoterpenes in a remote forest and an anthropogenic influenced forest

    Science.gov (United States)

    Usenko, S.; Sheesley, R. J.; Winfield, Z.; Yoon, S.; Erickson, M.; Flynn, J. H., III; Alvarez, S. L.; Wallace, H. W., IV; Griffin, R. J.

    2017-12-01

    The University of Houston Mobile Air Quality Laboratory (MAQL) was deployed to the University of Michigan Biological Station (UMBS) in July 2016 as part of the PROPHET-AMOS study and then was deployed to Jones Forest located north of Houston, TX from August 12 through September 23, 2016. Both sites are heavily forested, but UMBS is remote with no anthropogenic influence while Jones Forest sees frequent pollution transport from Houston. UMBS experienced periods of high isoprene:monoterpenes and periods of equivalent isoprene:monoterpenes, while Jones Forest had a consistently high isoprene:monoterpenes. This provided for a test bed to look at the interactions within two forested environments as well as the influence of anthropogenic sources. The MAQL was outfitted to measure O3 (2B Technology), NOy and SO2 (Thermo Scientific), NO/NOx (Air Quality Design), CO (Los Gatos), and select biogenic volatile organic carbon (BVOC) with their oxidation products (Ionicon PTR-MS). The instruments sampled from MAQL's 6 m tower at both sites. The UMBS site was below canopy and the Jones Forest site was in an open field surrounded by forest. The trends in isoprene and monoterpenes were explored in relation to time-of-day, temperature, and precipitation for both locations. In addition, the production of methyl vinyl ketone and methacrolein under these different conditions of meteorology, trace gas composition and BVOC composition was explored.

  10. Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest

    Directory of Open Access Journals (Sweden)

    R. Taipale

    2011-08-01

    Full Text Available Monoterpene emissions from Scots pine have traditionally been assumed to originate as evaporation from specialized storage pools. More recently, the significance of de novo emissions, originating directly from monoterpene biosynthesis, has been recognized. To study the role of biosynthesis at the ecosystem scale, we measured monoterpene emissions from a Scots pine dominated forest in southern Finland using the disjunct eddy covariance method combined with proton transfer reaction mass spectrometry. The interpretation of the measurements was based on a correlation analysis and a hybrid emission algorithm describing both de novo and pool emissions. During the measurement period May–August 2007, the monthly medians of daytime emissions were 200, 290, 180, and 200 μg m−2 h−1. The emissions were partly light dependent, probably due to de novo biosynthesis. The emission potential for both de novo and pool emissions exhibited a decreasing summertime trend. The ratio of the de novo emission potential to the total emission potential varied between 30 % and 46 %. Although the monthly changes were not significant, the ratio always differed statistically from zero, suggesting that the role of de novo biosynthesis was observable. Given the uncertainties in this study, we conclude that more accurate estimates of the contribution of de novo emissions are required for improving monoterpene emission algorithms for Scots pine dominated forests.

  11. Wet effluent diffusion denuder: The tool for determination of monoterpenes in forest

    Czech Academy of Sciences Publication Activity Database

    Křůmal, Kamil; Mikuška, Pavel; Večeřová, Kristýna; Urban, Otmar; Pallozzi, E.; Večeřa, Zbyněk

    2016-01-01

    Roč. 153, JUN (2016), s. 260-267 ISSN 0039-9140 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:68081715 ; RVO:67179843 Keywords : diffusion denuder * monoterpene * biogenic volatile organic compounds * tenax tubes Subject RIV: CB - Analytical Chemistry, Separation; EH - Ecology, Behaviour (UEK-B) Impact factor: 4.162, year: 2016

  12. Xylem monoterpenes of some hard pines of Western North America: three studies

    Science.gov (United States)

    Richard H. Smith

    1982-01-01

    Monoterpene composition was studied in a number of hard pine species and results were compared with earlier work. (1) Intratree measurements showed strong constancy of composition in both single-stemmed and forked trees of ponderosa, Jeffrey, Coulter, and Jeffrey x ponderosa pines. In grafts of these and other pines, the scion influenced the root stock, but not the...

  13. A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air

    Science.gov (United States)

    Jones, C. E.; Kato, S.; Nakashima, Y.; Kajii, Y.

    2014-05-01

    Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in ambient air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C9-C15 BVOC composition of single plant emissions may be characterised within a 14.5 min analysis time. Moreover, in-situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an 11.7 min chromatographic separation time (increasing to 19.7 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). These analysis times potentially allow for a twofold to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in-situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC (OBVOC) linalool in ambient air. During this field deployment within a suburban forest

  14. Dehydroeburicoic Acid from Antrodia camphorata Prevents the Diabetic and Dyslipidemic State via Modulation of Glucose Transporter 4, Peroxisome Proliferator-Activated Receptor α Expression and AMP-Activated Protein Kinase Phosphorylation in High-Fat-Fed Mice

    Directory of Open Access Journals (Sweden)

    Yueh-Hsiung Kuo

    2016-06-01

    Full Text Available This study investigated the potential effects of dehydroeburicoic acid (TT, a triterpenoid compound from Antrodia camphorata, in vitro and examined the effects and mechanisms of TT on glucose and lipid homeostasis in high-fat-diet (HFD-fed mice. The in vitro study examined the effects of a MeOH crude extract (CruE of A. camphorata and Antcin K (AnK; the main constituent of fruiting body of this mushroom on membrane glucose transporter 4 (GLUT4 and phospho-Akt in C2C12 myoblasts cells. The in vitro study demonstrated that treatment with CruE, AnK and TT increased the membrane levels of glucose transporter 4 (GLUT4 and phospho-Akt at different concentrations. The animal experiments were performed for 12 weeks. Diabetic mice were randomly divided into six groups after 8 weeks of HFD-induction and treated with daily oral gavage doses of TT (at three dose levels, fenofibrate (Feno (at 0.25 g/kg body weight, metformin (Metf (at 0.3 g/kg body weight or vehicle for another 4 weeks while on an HFD diet. HFD-fed mice exhibited increased blood glucose levels. TT treatment dramatically lowered blood glucose levels by 34.2%~43.4%, which was comparable to the antidiabetic agent-Metf (36.5%. TT-treated mice reduced the HFD-induced hyperglycemia, hypertriglyceridemia, hyperinsulinemia, hyperleptinemia, and hypercholesterolemia. Membrane levels of GLUT4 were significantly higher in CruE-treated groups in vitro. Skeletal muscle membrane levels of GLUT4 were significantly higher in TT-treated mice. These groups of mice also displayed lower mRNA levels of glucose-6-phosphatase (G6 Pase, an inhibitor of hepatic glucose production. The combination of these agents produced a net hypoglycemic effect in TT-treated mice. TT treatment enhanced the expressions of hepatic and skeletal muscle AMP-activated protein kinase (AMPK phosphorylation in mice. TT-treated mice exhibited enhanced expression of hepatic fatty acid oxidation enzymes, including peroxisome proliferator

  15. Glycosyltransferase glycosylating flavokermesic acid and/or kermesic acid

    DEFF Research Database (Denmark)

    2016-01-01

    An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

  16. GLYCOSYLTRANSFERASE GLYCOSYLATING FLAVOKERMESIC ACID AND/OR KERMESIC ACID

    DEFF Research Database (Denmark)

    2015-01-01

    An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

  17. The PPARα/γ Agonist, Tesaglitazar, Improves Insulin Mediated Switching of Tissue Glucose and Free Fatty Acid Utilization In Vivo in the Obese Zucker Rat

    Directory of Open Access Journals (Sweden)

    Kristina Wallenius

    2013-01-01

    Full Text Available Metabolic flexibility was assessed in male Zucker rats: lean controls, obese controls, and obese rats treated with the dual peroxisome proliferator activated receptor (PPAR agonist, tesaglitazar, 3 μmol/kg/day for 3 weeks. Whole body glucose disposal rate ( and hepatic glucose output (HGO were assessed under basal fasting and hyperinsulinemic isoglycemic clamp conditions using [3,3H]glucose. Indices of tissue specific glucose utilization ( were measured at basal, physiological, and supraphysiological levels of insulinemia using 2-deoxy-D-[2,6-3H]glucose. Finally, whole body and tissue specific FFA and glucose utilization and metabolic fate were evaluated under basal and hyperinsulinemic conditions using a combination of [U-13C]glucose, 2-deoxy-D-[U-14C]glucose, [U-14C]palmitate, and [9,10-3H]-(R-bromopalmitate. Tesaglitazar improved whole body insulin action by greater suppression of HGO and stimulation of compared to obese controls. This involved increased insulin stimulation of in fat and skeletal muscle as well as increased glycogen synthesis. Tesaglitazar dramatically improved insulin mediated suppression of plasma FFA level, whole body turnover (, and muscle, liver, and fat utilization. At basal insulin levels, tesaglitazar failed to lower HGO or compared to obese controls. In conclusion, the results demonstrate that tesaglitazar has a remarkable ability to improve insulin mediated control of glucose and FFA fluxes in obese Zucker rats.

  18. De novo production of six key grape aroma monoterpenes by a geraniol synthase-engineered S. cerevisiae wine strain.

    Science.gov (United States)

    Pardo, Ester; Rico, Juan; Gil, José Vicente; Orejas, Margarita

    2015-09-16

    Monoterpenes are important contributors to grape and wine aroma. Moreover, certain monoterpenes have been shown to display health benefits with antimicrobial, anti-inflammatory, anticancer or hypotensive properties amongst others. The aim of this study was to construct self-aromatizing wine yeasts to overproduce de novo these plant metabolites in wines. Expression of the Ocimum basilicum (sweet basil) geraniol synthase (GES) gene in a Saccharomyces cerevisiae wine strain substantially changed the terpene profile of wine produced from a non-aromatic grape variety. Under microvinification conditions, and without compromising other fermentative traits, the recombinant yeast excreted geraniol de novo at an amount (~750 μg/L) well exceeding (>10-fold) its threshold for olfactory perception and also exceeding the quantities present in wines obtained from highly aromatic Muscat grapes. Interestingly, geraniol was further metabolized by yeast enzymes to additional monoterpenes and esters: citronellol, linalool, nerol, citronellyl acetate and geranyl acetate, resulting in a total monoterpene concentration (~1,558 μg/L) 230-fold greater than that of the control. We also found that monoterpene profiles of wines derived from mixed fermentations were found to be determined by the composition of the initial yeast inocula suggesting the feasibility of producing 'à la carte' wines having predetermined monoterpene contents. Geraniol synthase-engineered yeasts demonstrate potential in the development of monoterpene enhanced wines.

  19. Stomatal uptake and stomatal deposition of ozone in isoprene and monoterpene emitting plants.

    Science.gov (United States)

    Fares, S; Loreto, F; Kleist, E; Wildt, J

    2008-01-01

    Volatile isoprenoids were reported to protect plants against ozone. To understand whether this could be the result of a direct scavenging of ozone by these molecules, the stomatal and non-stomatal uptake of ozone was estimated in plants emitting isoprene or monoterpenes. Ozone uptake by holm oak (Quercus ilex, a monoterpene emitter) and black poplar (Populus nigra, an isoprene emitter) was studied in whole plant enclosures (continuously stirred tank reactors, CSTR). The ozone uptake by plants was estimated measuring ozone concentration at the inlet and outlet of the reactors, after correcting for the uptake of the enclosure materials. Destruction of ozone at the cuticle or at the plant stems was found to be negligible compared to the ozone uptake through the stomata. For both plant species, a relationship between stomatal conductance and ozone uptake was found. For the poplar, the measured ozone losses were explained by the uptake of ozone through the stomata only, and ozone destruction by gas phase reactions with isoprene was negligible. For the oak, gas phase reactions of ozone with the monoterpenes emitted by the plants contributed significantly to ozone destruction. This was confirmed by two different experiments showing a) that in cases of high stomatal conductance but under low CO(2) concentration, a reduction of monoterpene emission was still associated with reduced O(3) uptake; and b) that ozone losses due to the gas phase reactions only can be measured when using the exhaust from a plant chamber to determine the gas phase reactivity in an empty reaction chamber. Monoterpenes can therefore relevantly scavenge ozone at leaf level contributing to protection against ozone.

  20. Laboratory and field measurements of enantiomeric monoterpene emissions as a function of chemotype, light and temperature

    Science.gov (United States)

    Song, W.; Staudt, M.; Bourgeois, I.; Williams, J.

    2014-03-01

    Plants emit significant amounts of monoterpenes into the earth's atmosphere, where they react rapidly to form a multitude of gas phase species and particles. Many monoterpenes exist in mirror-image forms or enantiomers. In this study the enantiomeric monoterpene profile for several representative plants (Quercus ilex L., Rosmarinus officinalis L., and Pinus halepensis Mill.) was investigated as a function of chemotype, light and temperature both in the laboratory and in the field. Analysis of enantiomeric monoterpenes from 19 Quercus ilex individuals from Southern France and Spain revealed four regiospecific chemotypes (genetically fixed emission patterns). In agreement with previous work, only Quercus ilex emissions increased strongly with light. However, for all three plant species no consistent enantiomeric variation was observed as a function of light, and the enantiomeric ratio of α-pinene was found to vary by less than 20% from 100 and 1000 μmol m-2 s-1 PAR (photosynthetically active radiation). The rate of monoterpene emission increased with temperature from all three plant species, but little variation in the enantiomeric distribution of α-pinene was observed with temperature. There was more enantiomeric variability between individuals of the same species than could be induced by either light or temperature. Field measurements of α-pinene enantiomer mixing ratios in the air, taken at a Quercus ilex forest in Southern France, and several other previously reported field enantiomeric ratio diel cycle profiles are compared. All show smoothly varying diel cycles (some positive and some negative) even over changing wind directions. This is surprising in comparison with variations of enantiomeric emission patterns shown by individuals of the same species.

  1. Measurement and Correlation on Viscosity and Apparent Molar Volume of Ternary System for L-ascorbic Acid in Aqueous D-Glucose and Sucrose Solutions%L-抗坏血酸在葡萄糖和蔗糖溶液中的黏度及其热力学性质的研究

    Institute of Scientific and Technical Information of China (English)

    赵长伟; 马沛生

    2003-01-01

    Viscosities and densities at several temperatures from 293.15 K to 313.15 K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations. The parameters of density, viscosity coefficient B and partial molar volume are calculated by regression. The experimental results show that densities and viscosities decrease as temperature increases at the same solute and solvent (glucose and sucrose aqueous solution) concentrations, and increase with concentration of glucose and sucrose at the same solute concentration and temperature. B increases with concentration of glucose and sucrose and temperature. L-ascorbic acid is structure-breaker or structure-making for the glucose and sucrose aqueous solutions. Furthermore, the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

  2. Dietary n-3 long-chain polyunsaturated fatty acids modify phosphoenolpyruvate carboxykinase activity and lipid synthesis from glucose in adipose tissue of rats fed a high-sucrose diet.

    Science.gov (United States)

    Londero, Lisiane G; Rieger, Débora K; Hansen, Fernanda; Silveira, Simone L; Martins, Tiago L; Lulhier, Francisco; da Silva, Roselis S; Souza, Diogo O; Perry, Marcos L S; de Assis, Adriano M

    2013-12-01

    Long-chain polyunsaturated n-3 fatty acids (n-3 LCPUFAs) have hypolipidemic effects and modulate intermediary metabolism to prevent or reverse insulin resistance in a way that is not completely elucidated. Here, effects of these fatty acids on the lipid profile, phosphoenolpyruvate carboxykinase (PEPCK) activity, lipid synthesis from glucose in epididymal adipose tissue (Ep-AT) and liver were investigated. Male rats were fed a high-sucrose diet (SU diet), containing either sunflower oil or a mixture of sunflower and fish oil (SU-FO diet), and the control group was fed a standard diet. After 13 weeks, liver, adipose tissue and blood were harvested and analysed. The dietary n-3 LCPUFAs prevented sucrose-induced increase in adiposity and serum free fat acids, serum and hepatic triacylglycerol and insulin levels. Furthermore, these n-3 LCPUFAs decreased lipid synthesis from glucose and increased PEPCK activity in the Ep-AT of rats fed the SU-FO diet compared to those fed the SU diet, besides reducing lipid synthesis from glucose in hepatic tissue. Thus, the inclusion of n-3 LCPUFAs in the diet may be beneficial for the prevention or attenuation of dyslipidemia and insulin resistance, and for reducing the risk of related chronic diseases. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Changes of glucose utilization by erythrocytes, lactic acid concentration in the serum and blood cells, and haematocrit value during one hour rest after maximal effort in individuals differing in physical efficiency.

    Science.gov (United States)

    Tomasik, M

    1982-01-01

    Glucose utilization by the erythrocytes, lactic acid concentration in the blood and erythrocytes, and haematocrit value were determined before exercise and during one hour rest following maximal exercise in 97 individuals of either sex differing in physical efficiency. In the investigations reported by the author individuals with strikingly high physical fitness performed maximal work one-third greater than that performed by individuals with medium fitness. The serum concentration of lactic acid was in all individuals above the resting value still after 60 minutes of rest. On the other hand, this concentration returned to the normal level in the erythrocytes but only in individuals with strikingly high efficiency. Glucose utilization by the erythrocytes during the restitution period was highest immediately after the exercise in all studied individuals and showed a tendency for more rapid return to resting values again in individuals with highest efficiency. The investigation of very efficient individuals repeated twice demonstrated greater utilization of glucose by the erythrocytes at the time of greater maximal exercise. This was associated with greater lactic acid concentration in the serum and erythrocytes throughout the whole one-hour rest period. The observed facts suggest an active participation of erythrocytes in the process of adaptation of the organism to exercise.

  4. Prediction of Glucose Tolerance without an Oral Glucose Tolerance Test

    Directory of Open Access Journals (Sweden)

    Rohit Babbar

    2018-03-01

    Full Text Available IntroductionImpaired glucose tolerance (IGT is diagnosed by a standardized oral glucose tolerance test (OGTT. However, the OGTT is laborious, and when not performed, glucose tolerance cannot be determined from fasting samples retrospectively. We tested if glucose tolerance status is reasonably predictable from a combination of demographic, anthropometric, and laboratory data assessed at one time point in a fasting state.MethodsGiven a set of 22 variables selected upon clinical feasibility such as sex, age, height, weight, waist circumference, blood pressure, fasting glucose, HbA1c, hemoglobin, mean corpuscular volume, serum potassium, fasting levels of insulin, C-peptide, triglyceride, non-esterified fatty acids (NEFA, proinsulin, prolactin, cholesterol, low-density lipoprotein, HDL, uric acid, liver transaminases, and ferritin, we used supervised machine learning to estimate glucose tolerance status in 2,337 participants of the TUEF study who were recruited before 2012. We tested the performance of 10 different machine learning classifiers on data from 929 participants in the test set who were recruited after 2012. In addition, reproducibility of IGT was analyzed in 78 participants who had 2 repeated OGTTs within 1 year.ResultsThe most accurate prediction of IGT was reached with the recursive partitioning method (accuracy = 0.78. For all classifiers, mean accuracy was 0.73 ± 0.04. The most important model variable was fasting glucose in all models. Using mean variable importance across all models, fasting glucose was followed by NEFA, triglycerides, HbA1c, and C-peptide. The accuracy of predicting IGT from a previous OGTT was 0.77.ConclusionMachine learning methods yield moderate accuracy in predicting glucose tolerance from a wide set of clinical and laboratory variables. A substitution of OGTT does not currently seem to be feasible. An important constraint could be the limited reproducibility of glucose tolerance status during a

  5. Untangling the primary drivers of pinyon monoterpene production and emissions under predicted drought

    Science.gov (United States)

    Trowbridge, A. M.; Adams, H. D.; Breshears, D. D.; Monson, R. K.

    2012-04-01

    Climate and insect herbivory have important consequences for plant function, atmospheric composition, and the functioning of ecosystems and ecological communities. Within the last decade, pinyon-juniper woodlands throughout the southwestern U.S. have suffered large-scale mortality, especially of pinyon pine, due to drought and associated insect outbreaks. While much research has focused on the primary metabolic mechanisms underlying pinyon's sensitivity to drought, there remains a gap in our knowledge concerning how the resulting shift in carbon allocation toward plant secondary compounds, particularly monoterpenes, affects atmospheric process and ecological interactions. Monoterpenes are the principal constituents of pinyon resin. Because of their large global emission rates and effect on atmospheric chemistry, particularly ozone creation, identifying controls over emissions and sensitivities to environmental change is critical for global emission models. Furthermore, monoterpenes are known to impact insect behavior and act as defense compounds against herbivores, contributing to insect population fluctuations either directly through toxicity, or indirectly by influencing parasitism susceptibility. Pinyon mortality events are thought to be exacerbated by their susceptibility to herbivores resulting from weakened secondary chemical defenses, but the impact of current and predicted drought on the chemical defense status of pinyons and subsequent atmospheric and ecological consequences remain unknown. A field study was developed to examine the impact of seasonality and climate, particularly drought, on pinyon pine physiology and chemistry in the context of tiger moth (Lophocampa ingens) herbivory in pinyon-juniper woodlands. We demonstrate the importance of geography and seasonality, particularly mid-summer drought and late summer monsoons, in driving physiology and monoterpene concentrations and emissions. Emission rates significantly decreased throughout the summer

  6. Associations between Forkhead Box O1 (FoxO1) Expression and Indicators of Hepatic Glucose Production in Transition Dairy Cows Supplemented with Dietary Nicotinic Acid.

    Science.gov (United States)

    Kinoshita, Asako; Locher, Lena; Tienken, Reka; Meyer, Ulrich; Dänicke, Sven; Rehage, Jürgen; Huber, Korinna

    2016-01-01

    Forkhead box protein O1 (FoxO1) is a transcription factor which promotes hepatic glucose production (HGP) by up-regulating the transcription of gluconeogenic enzymes in monogastric species. The activity of FoxO1 is inhibited by insulin-induced phosphorylation. The aims of the present study were to find associations between FoxO1 expression and variables associated with HGP as affected by feeding regimen in dairy cows during the transition period. Twenty one healthy German Holstein cows were allocated to four groups (LC-CON, HC-CON, LC-NA with 5 cows/group and HC-NA with 6 cows/group, respectively). Cows received 0 (LC-CON and HC-CON) or 24 (LC-NA and HC-NA) g/d nicotinic acid with high (HC) or low (LC) concentrate proportion from -42 days (-41.8 + 4.8; mean + standard deviation) relative to expected calving date (d-42) to d24. Liver biopsy was taken at d-42, 1, 21, and 100. The total protein expression of FoxO1 (tFoxO1) and the extent of phosphorylation of FoxO1 at serine 256 (pFoxO1) were analysed semiquantitatively by Western Blotting. The expression of hepatic mRNA of FoxO1 and seven genes associated with HGP was measured by real-time RT-PCR. Mixed model and Pearson's correlation were used for statistical evaluation with the level of significance at Pdairy cows in early lactation.

  7. Tetranuclear copper(II) complexes bridged by alpha-D-glucose-1-phosphate and incorporation of sugar acids through the Cu4 core structural changes.

    Science.gov (United States)

    Kato, Merii; Sah, Ajay Kumar; Tanase, Tomoaki; Mikuriya, Masahiro

    2006-08-21

    Tetranuclear copper(II) complexes containing alpha-D-glucose-1-phosphate (alpha-D-Glc-1P), [Cu4(mu-OH){mu-(alpha-D-Glc-1P)}2(bpy)4(H2O)2]X3 [X = NO3 (1a), Cl (1b), Br (1c)], and [Cu4(mu-OH){mu-(alpha-D-Glc-1P)}2(phen)4(H2O)2](NO3)3 (2) were prepared by reacting the copper(II) salt with Na2[alpha-D-Glc-1P] in the presence of diimine ancillary ligands, and the structure of 2 was characterized by X-ray crystallography to comprise four {Cu(phen)}2+ fragments connected by the two sugar phosphate dianions in 1,3-O,O' and 1,1-O mu4-bridging fashion as well as a mu-hydroxo anion. The crystal structure of 2 involves two chemically independent complex cations in which the C2 enantiomeric structure for the trapezoidal tetracopper(II) framework is switched according to the orientation of the alpha-D-glucopyranosyl moieties. Temperature-dependent magnetic susceptibility data of 1a indicated that antiferromagnetic spin coupling is operative between the two metal ions joined by the hydroxo bridge (J = -52 cm(-1)) while antiferromagnetic interaction through the Cu-O-Cu sugar phosphate bridges is weak (J = -13 cm(-1)). Complex 1a readily reacted with carboxylic acids to afford the tetranuclear copper(II) complexes, [Cu4{mu-(alpha-D-Glc-1P)}2(mu-CA)2(bpy)4](NO3)2 [CA = CH3COO (3), o-C6H4(COO)(COOH) (4)]. Reactions with m-phenylenediacetic acid [m-C6H4(CH2COOH)2] also gave the discrete tetracopper(II) cationic complex [Cu4{mu-(alpha-D-Glc-1P)}2(mu-m-C6H4(CH2COO)(CH2COOH))2(bpy)4](NO3)2 (5a) as well as the cluster polymer formulated as {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-m-C6H4(CH2COO)2)(bpy)4](NO3)2}n (5b). The tetracopper structure of 1a is converted into a symmetrical rectangular core in complexes 3, 4, and 5b, where the hydroxo bridge is dissociated and, instead, two carboxylate anions bridge another pair of Cu(II) ions in a 1,1-O monodentate fashion. The similar reactions were applied to incorporate sugar acids onto the tetranuclear copper(II) centers. Reactions of 1a with delta

  8. Herbivory and climate interact serially to control monoterpene emissions from pinyon pine forests.

    Science.gov (United States)

    Trowbridge, Amy M; Daly, Ryan W; Helmig, Detlev; Stoy, Paul C; Monson, Russell K

    2014-06-01

    The emission of volatile monoterpenes from coniferous trees impacts the oxidative state of the troposphere and multi-trophic signaling between plants and animals. Previous laboratory studies have revealed that climate anomalies and herbivory alter the rate of tree monoterpene emissions. However, no studies to date have been conducted to test these relations in situ. We conducted a two-year field experiment at two semiarid sites dominated by pinyon pine (Pinus edulis) during outbreaks of a specialist herbivore, the southwestern tiger moth (Lophocampa ingens: Arctiidae). We discovered that during the early spring, when herbivory rates were highest, monoterpene emission rates were approximately two to six times higher from undamaged needles on damaged trees, with this increase in emissions due to alpha-pinene, beta-pinene, and camphene at both sites. During mid-summer, emission rates did not differ between previously damaged and undamaged trees at the site on the Western Slope of the Rocky Mountains, but rather tracked changes in the temperature and precipitation regime characteristic of the region. As the mid-summer drought progressed at the Eastern Slope site, emission rates were low, but differences between previously damaged and undamaged trees were not statistically significant. Despite no difference in emissions, mid-summer tissue monoterpene concentrations were significantly lower in previously damaged trees at both sites. With the onset of monsoon rains during late summer, emission rates from previously damaged trees increased to levels higher than those of undamaged trees despite the lack of herbivory. We conclude that (1) herbivory systemically increases the flux of terpenes to the atmosphere during the spring, (2) drought overrides the effect of past herbivory as the primary control over emissions during the mid-summer, and (3) a release from drought and the onset of late-summer rains is correlated with a secondary increase in emissions, particularly from

  9. Low-protein diet induces, whereas high-protein diet reduces hepatic FGF21 production in mice, but glucose and not amino acids up-regulate FGF21 in cultured hepatocytes.

    Science.gov (United States)

    Chalvon-Demersay, Tristan; Even, Patrick C; Tomé, Daniel; Chaumontet, Catherine; Piedcoq, Julien; Gaudichon, Claire; Azzout-Marniche, Dalila

    2016-10-01

    Fibroblast growth factor 21 (FGF21) is a polypeptide secreted by the liver and involved in several metabolic processes such as thermogenesis and lipid oxidation. The nutritional mechanisms controlling FGF21 production are poorly understood. This study aimed to investigate how dietary carbohydrates and proteins impact FGF21 production and how in turn, FGF21 is involved in the metabolic adaptation to changes in the carbohydrate and protein contents of the diet. For that purpose, we fed 25 male C57BL/6 mice diets composed of different protein and carbohydrate contents (normal-protein and carbohydrate diet (N=9, NPNC), low-protein high-carbohydrate diet (N=8, LPHC), high-protein low-carbohydrate diet (N=8, HPLC) for 3 weeks. We measured liver Fgf21 gene expression, synthesis and secretion as well as different parameters related to energy and glucose metabolism. We also investigated the direct role of amino acids and glucose in the control of Fgf21 gene expression in hepatocyte primary cultures (n=6). In vivo, FGF21 responds acutely to LPHC intake whereas under an HPLC diet, plasma FGF21 circulating levels are low in the fasted and refed states. In hepatocytes, Fgf21 expression was controlled by glucose but not amino acids. Both diets increased the thermic effect of feeding (TEF) and ketogenesis was increased in fasted HPLC mice. The results presented suggest that dietary glucose, rather than amino acids, directly controls FGF21 secretion, and that FGF21 may be involved in the increased TEF response to LPHC. The effects of the HPLC diet on ketogenesis and TEF are probably controlled by other metabolic pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Structural Basis of Catalysis in the Bacterial Monoterpene Synthases Linalool Synthase and 1,8-Cineole Synthase

    OpenAIRE

    Karuppiah, Vijaykumar; Ranaghan, Kara E.; Leferink, Nicole G. H.; Johannissen, Linus O.; Shanmugam, Muralidharan; Ní Cheallaigh, Aisling; Bennett, Nathan J.; Kearsey, Lewis J.; Takano, Eriko; Gardiner, John M.; van der Kamp, Marc W.; Hay, Sam; Mulholland, Adrian J.; Leys, David; Scrutton, Nigel S.

    2017-01-01

    Terpenoids form the largest and stereochemically most diverse class of natural products, and there is considerable interest in producing these by biocatalysis with whole cells or purified enzymes, and by metabolic engineering. The monoterpenes are an important class of terpenes and are industrially important as flavors and fragrances. We report here structures for the recently discovered Streptomyces clavuligerus monoterpene synthases linalool synthase (bLinS) and 1,8-cineole synthase (bCinS)...

  11. Optimization of glucose oxidase production by Aspergillus niger

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... manganese, cobalt, thioglycolic acid, and gluconic acid according to (Liu et al., .... In this experiment duplicate media of glucose 10% were adjusted at different ... Glucose oxidase as a pharmaceutical anti oxidant Drug. Devt. ... Plush KS, Hellmuth K, Rinas U (1996). kinetics of glucose oxidase excretion by ...

  12. Inhibition of cholinergic potentiation of insulin secretion from pancreatic islets by chronic elevation of glucose and fatty acids: Protection by casein kinase 2 inhibitor

    Directory of Open Access Journals (Sweden)

    Nicolai M. Doliba

    2017-10-01

    Conclusions: These results show that chronic FA treatment decreases acetylcholine potentiation of insulin secretion and that this effect is strictly glucose dependent and might involve CK2 phosphorylation of β-cell M3 muscarinic receptors.

  13. Metabolomic analysis reveals amino-acid responses to an oral glucose tolerance test in women with prior history of gestational diabetes mellitus

    Directory of Open Access Journals (Sweden)

    R. Bentley-Lewis, MD, MBA, MMSc

    2014-06-01

    Conclusions: Greater change in metabolite levels after a glucose challenge was significantly associated with a longer duration of breastfeeding and higher BMI. Further exploration of these preliminary observations and closer examination of the specific pathways implicated are warranted.

  14. Development of an enzyme free glucose sensor based on copper oxide-graphene composite by using green reducing agent ascorbic acid

    Science.gov (United States)

    Palve, Yogesh Pandit; Jha, Neetu

    2018-05-01

    In this research work we have developed high sensitive and selective glucose sensor based on copper oxide-graphene composite which is prepared by green synthesis method and used for nonenzymatic glucose sensor. In present paper we report that present method highly selective, simple, efficient, accurate, ecofriendly, less toxic. The prepared composite were characterized by material characterization like SEM, XRD and also by electrochemical characterization like CV, chronoamperometry represents that copper oxide-graphene shows excellent electrocatalytic activity towards glucose, exhibiting a good sensitivity of 103.84 µA mM-1 cm-2, a fast response time 2s, a low detection limit 0.00033µM and linear range from 10 µM-3000 µM. The present sensor can successfully apply for determination of glucose concentration in human blood sample.

  15. Microbial Reduction of Fe(III) in Acidic Sediments: Isolation of Acidiphilium cryptum JF-5 Capable of Coupling the Reduction of Fe(III) to the Oxidation of Glucose

    Science.gov (United States)

    Küsel, Kirsten; Dorsch, Tanja; Acker, Georg; Stackebrandt, Erko

    1999-01-01

    To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12°C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H2 was consumed by acidic sediments and yielded additional amounts of Fe(II) in a ratio of approximately 1:2. In contrast, supplemental lactate did not stimulate the formation of Fe(II). Supplemental acetate was not consumed and inhibited the formation of Fe(II). Most-probable-number estimates demonstrated that glucose-utilizing acidophilic Fe(III)-reducing bacteria approximated to 1% of the total direct counts of 4′,6-diamidino-2-phenylindole-stained bacteria. From the highest growth-positive dilution of the most-probable-number series at pH 2.3 supplemented with glucose, an isolate, JF-5, that could dissimilate Fe(III) was obtained. JF-5 was an acidophilic, gram-negative, facultative anaerobe that completely oxidized the following substrates via the dissimilation of Fe(III): glucose, fructose, xylose, ethanol, glycerol, malate, glutamate, fumarate, citrate, succinate, and H2. Growth and the reduction of Fe(III) did not occur in the presence of acetate. Cells of JF-5 grown under Fe(III)-reducing conditions formed blebs, i.e., protrusions that were still in contact with the cytoplasmic membrane. Analysis of the 16S rRNA gene sequence of JF-5 demonstrated that it was closely related to an Australian isolate of Acidiphilium cryptum (99.6% sequence similarity), an organism not previously shown to couple the complete oxidation of sugars to the reduction of Fe(III). These collective results indicate that the in situ reduction of Fe(III) in acidic sediments can be mediated by heterotrophic Acidiphilium

  16. Microbial reduction of Fe(III) in acidic sediments: isolation of Acidiphilium cryptum JF-5 capable of coupling the reduction of Fe(III) to the oxidation of glucose.

    Science.gov (United States)

    Küsel, K; Dorsch, T; Acker, G; Stackebrandt, E

    1999-08-01

    To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12 degrees C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H(2) was consumed by acidic sediments and yielded additional amounts of Fe(II) in a ratio of approximately 1:2. In contrast, supplemental lactate did not stimulate the formation of Fe(II). Supplemental acetate was not consumed and inhibited the formation of Fe(II). Most-probable-number estimates demonstrated that glucose-utilizing acidophilic Fe(III)-reducing bacteria approximated to 1% of the total direct counts of 4', 6-diamidino-2-phenylindole-stained bacteria. From the highest growth-positive dilution of the most-probable-number series at pH 2. 3 supplemented with glucose, an isolate, JF-5, that could dissimilate Fe(III) was obtained. JF-5 was an acidophilic, gram-negative, facultative anaerobe that completely oxidized the following substrates via the dissimilation of Fe(III): glucose, fructose, xylose, ethanol, glycerol, malate, glutamate, fumarate, citrate, succinate, and H(2). Growth and the reduction of Fe(III) did not occur in the presence of acetate. Cells of JF-5 grown under Fe(III)-reducing conditions formed blebs, i.e., protrusions that were still in contact with the cytoplasmic membrane. Analysis of the 16S rRNA gene sequence of JF-5 demonstrated that it was closely related to an Australian isolate of Acidiphilium cryptum (99.6% sequence similarity), an organism not previously shown to couple the complete oxidation of sugars to the reduction of Fe(III). These collective results indicate that the in situ reduction of Fe(III) in acidic sediments can be mediated by heterotrophic

  17. Pheromone Production by an Invasive Bark Beetle Varies with Monoterpene Composition of its Naïve Host.

    Science.gov (United States)

    Taft, Spencer; Najar, Ahmed; Erbilgin, Nadir

    2015-06-01

    The secondary chemistry of host plants can have cascading impacts on the establishment of new insect herbivore populations, their long-term population dynamics, and their invasion potential in novel habitats. Mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) has recently expanded its range into forests of jack pine, Pinus banksiana Lamb., in western Canada. We investigated whether variations in jack pine monoterpenes affect beetle pheromone production, as the primary components of the beetle's aggregation pheromone, (-)-trans-verbenol and anti-aggregation pheromone (-)-verbenone, are biosynthesized from the host monoterpene α-pinene. Jack pine bolts were collected from five Canadian provinces east of the beetle's current range, live D. ponderosae were introduced into them, and their monoterpene compositions were characterized. Production of (-)-trans-verbenol and (-)-verbenone emitted by beetles was measured to determine whether pheromone production varies with monoterpene composition of jack pines. Depending on particular ratios of major monoterpenes in host phloem, jack pine could be classified into three monoterpenoid groups characterized by high amounts of (+)-α-pinene, 3-carene, or a more moderate blend of monoterpenes, and beetle pheromone production varied among these groups. Specifically, beetles reared in trees characterized by high (+)-α-pinene produced the most (-)-trans-verbenol and (-)-verbenone, while beetles in trees characterized by high 3-carene produced the least. Our results indicate that pheromone production by D. ponderosae will remain a significant aspect and important predictor of its survival and persistence in the boreal forest.

  18. Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate.

    Science.gov (United States)

    Schilmiller, Anthony L; Schauvinhold, Ines; Larson, Matthew; Xu, Richard; Charbonneau, Amanda L; Schmidt, Adam; Wilkerson, Curtis; Last, Robert L; Pichersky, Eran

    2009-06-30

    We identified a cis-prenyltransferase gene, neryl diphosphate synthase 1 (NDPS1), that is expressed in cultivated tomato (Solanum lycopersicum) cultivar M82 type VI glandular trichomes and encodes an enzyme that catalyzes the formation of neryl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. mRNA for a terpene synthase gene, phellandrene synthase 1 (PHS1), was also identified in these glands. It encodes an enzyme that uses neryl diphosphate to produce beta-phellandrene as the major product as well as a variety of other monoterpenes. The profile of monoterpenes produced by PHS1 is identical with the monoterpenes found in type VI glands. PHS1 and NDPS1 map to chromosome 8, and the presence of a segment of chromosome 8 derived from Solanum pennellii LA0716 causes conversion from the M82 gland monoterpene pattern to that characteristic of LA0716 plants. The data indicate that, contrary to the textbook view of geranyl diphosphate as the "universal" substrate of monoterpene synthases, in tomato glands neryl diphosphate serves as a precursor for the synthesis of monoterpenes.

  19. Successful Colonization of Lodgepole Pine Trees by Mountain Pine Beetle Increased Monoterpene Production and Exhausted Carbohydrate Reserves.

    Science.gov (United States)

    Roth, Marla; Hussain, Altaf; Cale, Jonathan A; Erbilgin, Nadir

    2018-02-01

    Lodgepole pine (Pinus contorta) forests have experienced severe mortality from mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) in western North America for the last several years. Although the mechanisms by which beetles kill host trees are unclear, they are likely linked to pine defense monoterpenes that are synthesized from carbohydrate reserves. However, how carbohydrates and monoterpenes interact in response to MPB colonization is unknown. Understanding this relationship could help to elucidate how pines succumb to bark beetle attack. We compared concentrations of individual and total monoterpenes and carbohydrates in the phloem of healthy pine trees with those naturally colonized by MPB. Trees attacked by MPB had nearly 300% more monoterpenes and 40% less carbohydrates. Total monoterpene concentrations were most strongly associated with the concentration of sugars in the phloem. These results suggest that bark beetle colonization likely depletes carbohydrate reserves by increasing the production of carbon-rich monoterpenes, and other carbon-based secondary compounds. Bark beetle attacks also reduce water transport causing the disruption of carbon transport between tree foliage and roots, which restricts carbon assimilation. Reduction in carbohydrate reserves likely contributes to tree mortality.

  20. The Antibacterial Activity of Chitosan Products Blended with Monoterpenes and Their Biofilms against Plant Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Mohamed E. I. Badawy

    2016-01-01

    Full Text Available This study focuses on the biological activities of eleven chitosan products with a viscosity-average molecular weight ranging from 22 to 846 kDa in combination with the most active monoterpenes (geraniol and thymol, out of 10 tested, against four plant pathogenic bacteria, Agrobacterium tumefaciens, Erwinia carotovora, Corynebacterium fascians, and Pseudomonas solanacearum. The antibacterial activity was evaluated in vitro by the agar dilution technique as a minimum inhibitory concentration (MIC that was found to be dependent on the type of the microorganism tested. The most active product of chitosan was used for biofilm production enriched with geraniol and thymol (0.1 and 0.5% and the films were also evaluated against the tested bacteria. The biological bioactivities summarized here may provide novel insights into the functions of chitosan and some monoterpenes and potentially allow their use for food protection from microbial attack.

  1. Secondary organic aerosols over oceans via oxidation of isoprene and monoterpenes from Arctic to Antarctic.

    Science.gov (United States)

    Hu, Qi-Hou; Xie, Zhou-Qing; Wang, Xin-Ming; Kang, Hui; He, Quan-Fu; Zhang, Pengfei

    2013-01-01

    Isoprene and monoterpenes are important precursors of secondary organic aerosols (SOA) in continents. However, their contributions to aerosols over oceans are still inconclusive. Here we analyzed SOA tracers from isoprene and monoterpenes in aerosol samples collected over oceans during the Chinese Arctic and Antarctic Research Expeditions. Combined with literature reports elsewhere, we found that the dominant tracers are the oxidation products of isoprene. The concentrations of tracers varied considerably. The mean average values were approximately one order of magnitude higher in the Northern Hemisphere than in the Southern Hemisphere. High values were generally observed in coastal regions. This phenomenon was ascribed to the outflow influence from continental sources. High levels of isoprene could emit from oceans and consequently have a significant impact on marine SOA as inferred from isoprene SOA during phytoplankton blooms, which may abruptly increase up to 95 ng/m³ in the boundary layer over remote oceans.

  2. Above Canopy Emissions of Isoprene and Monoterpenes from a Southeast Asian Tropical Forest

    Science.gov (United States)

    Baker, B.; Johnson, C.; Cai, Z.; Guenther, A.; Greenberg, J.; Bai, J.; Li, Q.

    2003-12-01

    Fluxes of isoprene were measured using the eddy covariance technique and an ozone chemiluminescence isoprene sensor above a secondary tropical forest/rubber tree plantation located in the Xishuangbanna region of southern China during the wet and dry seasons. Fluxes of monoterpenes were inferred from ambient boundary layer concentrations (wet season) and from relaxed eddy accumulation measurements (dry season). Isoprene emissions were comparable to what has been observed from other tropical forests in Africa and South America. In this forest, monoterpene emissions were much higher during the wet season due to the senescence of the rubber trees during the dry season. These flux measurements represent the first ecosystem level flux measurements reported from Southeast Asian tropical forests.

  3. Seasonal influence on gene expression of monoterpene synthases in Salvia officinalis (Lamiaceae).

    Science.gov (United States)

    Grausgruber-Gröger, Sabine; Schmiderer, Corinna; Steinborn, Ralf; Novak, Johannes

    2012-03-01

    Garden sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants and possesses antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, formed mainly in very young leaves, is in part responsible for these activities. It is mainly composed of the monoterpenes 1,8-cineole, α- and β-thujone and camphor synthesized by the 1,8-cineole synthase, the (+)-sabinene synthase and the (+)-bornyl diphosphate synthase, respectively, and is produced and stored in epidermal glands. In this study, the seasonal influence on the formation of the main monoterpenes in young, still expanding leaves of field-grown sage plants was studied in two cultivars at the level of mRNA expression, analyzed by qRT-PCR, and at the level of end-products, analyzed by gas chromatography. All monoterpene synthases and monoterpenes were significantly influenced by cultivar and season. 1,8-Cineole synthase and its end product 1,8-cineole remained constant until August and then decreased slightly. The thujones increased steadily during the vegetative period. The transcript level of their corresponding terpene synthase, however, showed its maximum in the middle of the vegetative period and declined afterwards. Camphor remained constant until August and then declined, exactly correlated with the mRNA level of the corresponding terpene synthase. In summary, terpene synthase mRNA expression and respective end product levels were concordant in the case of 1,8-cineole (r=0.51 and 0.67 for the two cultivars, respectively; p<0.05) and camphor (r=0.75 and 0.82; p<0.05) indicating basically transcriptional control, but discordant for α-/β-thujone (r=-0.05 and 0.42; p=0.87 and 0.13, respectively). Copyright © 2011 Elsevier GmbH. All rights reserved.

  4. Remote sensing estimation of isoprene and monoterpene emissions generated by natural vegetation in Monterrey, Mexico.

    Science.gov (United States)

    Gastelum, Sandra L; Mejía-Velázquez, G M; Lozano-García, D Fabián

    2016-06-01

    In addition to oxygen, hydrocarbons are the most reactive chemical compounds produced by plants into the atmosphere. These compounds are part of the family of volatile organic compounds (VOCs) and are discharged in a great variety of forms. Among the VOCs produced by natural sources such as vegetation, the most studied until today are the isoprene and monoterpene. These substances can play an important role in the chemical balance of the atmosphere of a region. In this project, we develop a methodology to estimate the natural (vegetation) emission of isoprene and monoterpenes and applied it to the Monterrey Metropolitan Area, Mexico and its surrounding areas. Landsat-TM data was used to identify the dominant vegetation communities and field work to determine the foliage biomass density of key species. The studied communities were submontane scrub, oak, and pine forests and a combination of both. We carried out the estimation of emissions for isoprene and monoterpenes compounds in the different plant communities, with two different criteria: (1) taking into account the average foliage biomass density obtained from the various sample point in each vegetation community, and (2) using the foliage biomass density obtained for each transect, associated to an individual spectral class within a particular vegetation type. With this information, we obtained emission maps for each case. The results show that the main producers of isoprene are the communities that include species of the genus Quercus, located mainly on the Sierra Madre Oriental and Sierra de Picachos, with average isoprene emissions of 314.6 ton/day and 207.3 ton/day for the two methods utilized. The higher estimates of monoterpenes were found in the submontane scrub areas distributed along the valley of the metropolitan zone, with an estimated average emissions of 47.1 ton/day and 181.4 tons for the two methods respectively.

  5. Biotransformation of a monoterpene mixture by in vitro cultures of selected conifer species

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, Marcela; Valterová, Irena; Vaněk, Tomáš

    2007-01-01

    Roč. 2, č. 3 (2007), s. 233-238 ISSN 1934-578X R&D Projects: GA MŠk 1P04OC926.001; GA MŠk 1P05ME731 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50380511 Keywords : biotransformation * monoterpenes * P. abies * P. baccata Subject RIV: CC - Organic Chemistry Impact factor: 0.435, year: 2007

  6. Monoterpene and herbivore-induced emissions from cabbage plants grown at elevated atmospheric CO 2 concentration

    Science.gov (United States)

    Vuorinen, Terhi; Reddy, G. V. P.; Nerg, Anne-Marja; Holopainen, Jarmo K.

    The warming of the lower atmosphere due to elevating CO 2 concentration may increase volatile organic compound (VOC) emissions from plants. Also, direct effects of elevated CO 2 on plant secondary metabolism are expected to lead to increased VOC emissions due to allocation of excess carbon on secondary metabolites, of which many are volatile. We investigated how growing at doubled ambient CO 2 concentration affects emissions from cabbage plants ( Brassica oleracea subsp. capitata) damaged by either the leaf-chewing larvae of crucifer specialist diamondback moth ( Plutella xylostella L.) or generalist Egyptian cotton leafworm ( Spodoptera littoralis (Boisduval)). The emission from cabbage cv. Lennox grown in both CO 2 concentrations, consisted mainly of monoterpenes (sabinene, limonene, α-thujene, 1,8-cineole, β-pinene, myrcene, α-pinene and γ-terpinene). ( Z)-3-Hexenyl acetate, sesquiterpene ( E, E)- α-farnesene and homoterpene ( E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) were emitted mainly from herbivore-damaged plants. Plants grown at 720 μmol mol -1 of CO 2 had significantly lower total monoterpene emissions per shoot dry weight than plants grown at 360 μmol mol -1 of CO 2, while damage by both herbivores significantly increased the total monoterpene emissions compared to intact plants. ( Z)-3-Hexenyl acetate, ( E, E)- α-farnesene and DMNT emissions per shoot dry weight were not affected by the growth at elevated CO 2. The emission of DMNT was significantly enhanced from plants damaged by the specialist P. xylostella compared to the plants damaged by the generalist S. littoralis. The relative proportions of total monoterpenes and total herbivore-induced compounds of total VOCs did not change due to the growth at elevated CO 2, while insect damage increased significantly the proportion of induced compounds. The results suggest that VOC emissions that are induced by the leaf-chewing herbivores will not be influenced by elevated CO 2 concentration.

  7. Wet effluent diffusion denuder technique and the determination of volatile organic compounds in air. II. Monoterpenes

    Czech Academy of Sciences Publication Activity Database

    Sklenská, Jana; Broškovičová, Anna; Večeřa, Zbyněk

    2002-01-01

    Roč. 973, 1-2 (2002), s. 211-216 ISSN 0021-9673 R&D Projects: GA ČR GA203/98/0943 Grant - others:SPSDII(XE) EV/02/11 Institutional research plan: CEZ:AV0Z4031919 Keywords : wet effluent denuder technique * volatile organic compounds * monoterpenes Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.098, year: 2002

  8. Onset of photosynthesis in spring speeds up monoterpene synthesis and leads to emission bursts.

    Science.gov (United States)

    Aalto, J; Porcar-Castell, A; Atherton, J; Kolari, P; Pohja, T; Hari, P; Nikinmaa, E; Petäjä, T; Bäck, J

    2015-11-01

    Emissions of biogenic volatile organic compounds (BVOC) by boreal evergreen trees have strong seasonality, with low emission rates during photosynthetically inactive winter and increasing rates towards summer. Yet, the regulation of this seasonality remains unclear. We measured in situ monoterpene emissions from Scots pine shoots during several spring periods and analysed their dynamics in connection with the spring recovery of photosynthesis. We found high emission peaks caused by enhanced monoterpene synthesis consistently during every spring period (monoterpene emission bursts, MEB). The timing of the MEBs varied relatively little between the spring periods. The timing of the MEBs showed good agreement with the photosynthetic spring recovery, which was studied with simultaneous measurements of chlorophyll fluorescence, CO2 exchange and a simple, temperature history-based proxy for state of photosynthetic acclimation, S. We conclude that the MEBs were related to the early stages of photosynthetic recovery, when the efficiency of photosynthetic carbon reactions is still low whereas the light harvesting machinery actively absorbs light energy. This suggests that the MEBs may serve a protective functional role for the foliage during this critical transitory state and that these high emission peaks may contribute to atmospheric chemistry in the boreal forest in springtime. © 2015 John Wiley & Sons Ltd.

  9. Direct suppression of a rice bacterial blight (Xanthomonas oryzae pv. oryzae) by monoterpene (S)-limonene.

    Science.gov (United States)

    Lee, Gun Woong; Chung, Moon-Soo; Kang, Mihyung; Chung, Byung Yeoup; Lee, Sungbeom

    2016-05-01

    Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile