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Sample records for pyrogallol

  1. Highly sensitive flow-injection chemiluminescence determination of pyrogallol compounds

    Science.gov (United States)

    Kanwal, Shamsa; Fu, Xiaohong; Su, Xingguang

    2009-12-01

    A highly sensitive flow-injection chemiluminescent method for the direct determination of pyrogallol compounds has been developed. Proposed method is based on the enhanced effect of pyrogallol compounds on the chemiluminescence signals of KMnO 4-H 2O 2 system in slightly alkaline medium. Three important pyrogallol compounds, pyrogallic acid, gallic acid and tannic acid, have been detected by this method, and the possible mechanism of the CL reaction is also discussed. The proposed method is simple, convenient, rapid (60 samples h -1), and sensitive, has a linear range of 8 × 10 -10 mol L -1 to 1 × 10 -5 mol L -1, for pyrogallic acid, with a detection limit of 6 × 10 -11 mol L -1, 4 × 10 -8 mol L -1 to 5 × 10 -3 mol L -1 for gallic acid with a detection limit of 9 × 10 -10 mol L -1, and 8 × 10 -8 mol L -1 to 5 × 10 -2 mol L -1 for tannic acid, with a detection limit of 2 × 10 -9 mol L -1, respectively. The relative standard deviation (RSD, n = 15) was 0.8, 1.1 and 1.3% for 5 × 10 -6 mol L -1 pyrogallic acid, gallic acid and tannic acid, respectively. The proposed method was successfully applied to the determination of pyrogallol compounds in tea and coffee samples.

  2. Solution superstructures: truncated cubeoctahedron structures of pyrogallol[4]arene nanoassemblies.

    Science.gov (United States)

    Kumari, Harshita; Kline, Steven R; Fowler, Drew A; Mossine, Andrew V; Deakyne, Carol A; Atwood, Jerry L

    2014-01-04

    Giant nanocapsules: the solution-phase structures of PgC1Ho and PgC3Ho have been investigated using in situ neutron scattering measurements. The SANS results show the presence of spherical nanoassemblies of radius 18.2 Å, which are larger than the previously reported metal-seamed PgC3 hexamers (radius = 10 Å). The spherical architectures conform to a truncated cubeoctahedron geometry, indicating formation of the first metal-containing pyrogallol[4]arene-based dodecameric nanoassemblies in solution.

  3. Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

    Science.gov (United States)

    Jaén, J. A.; González, L.; Vargas, A.; Olave, G.

    2003-06-01

    The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

  4. Theoretical indications on the relationship between pyrogallol[4]arenes dynamics of assembling and geometry

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    Robert A. Cazar

    2014-05-01

    Full Text Available Pyrogallol[4]arenes are macrocycles with high potential as building blocks for nanocapsules. We theoretically studied the dimeric precursors of 2,8,14,20-tetramethylpyrogallol[4]arene and 2,8,10,14-tetraphenylpyrogallol[4] arene to understand the dynamics of assembly of these compounds, and calculated the potential energy curves along the torsion angle of the (R-pyrogallolCH–(R-pyrogallol dimeric bond at the B3LYP/6-311G(d,p level of theory. We found that the energy barriers for free rotation around the selected bond are 0.00133 Hartrees for the alkyl-substituted dimer and 0.77879 Hartrees for the aryl-substituted dimer. These values imply that the free rotation around the selected bond exists for the first dimer but not for the second one. Because the orientation of the substituent and the pyrogallol ring around this bond are likely to determine the geometry of the final structure, we propose that the alkyl-substituted compound will most likely adopt a crown-shaped geometry whereas the aryl-substituted compound will adopt a chair-shaped geometry. These predictions concur with experimental evidence, which shows that the geometry of pyrogallol[4]arenes depends on the substituents attached to them.

  5. Solution structures of nanoassemblies based on pyrogallol[4]arenes.

    Science.gov (United States)

    Kumari, Harshita; Deakyne, Carol A; Atwood, Jerry L

    2014-10-21

    Nanoassemblies of hydrogen-bonded and metal-seamed pyrogallol[4]arenes have been shown to possess novel solution-phase geometries. Further, we have demonstrated that both guest encapsulation and structural rearrangements may be studied by solution-phase techniques such as small-angle neutron scattering (SANS) and diffusion NMR. Application of these techniques to pyrogallol[4]arene-based nanoassemblies has allowed (1) differentiation among spherical, ellipsoidal, toroidal, and tubular structures in solution, (2) determination of factors that control the preferred geometrical shape and size of the nanoassemblies, and (3) detection of small variations in metric dimensions distinguishing similarly and differently shaped nanoassemblies in a given solution. Indeed, we have shown that the solution-phase structure of such nanoassemblies is often quite different from what one would predict based on solid-state studies, a result in disagreement with the frequently made assumption that these assemblies have similar structures in the two phases. We instead have predicted solid-state architectures from solution-phase structures by combining the solution-phase analysis with solid-state magnetic and elemental analyses. Specifically, the iron-seamed C-methylpyrogallol[4]arene nanoassembly was found to be tubular in solution and predicted to be tubular in the solid state, but it was found to undergo a rearrangement from a tubular to spherical geometry in solution as a function of base concentration. The absence of metal within a tubular framework affects its stability in both solution and the solid state; however, this instability is not necessarily characteristic of hydrogen-bonded capsular entities. Even metal seaming of the capsules does not guarantee similar solid-state and solution-phase architectures. The rugby ball-shaped gallium-seamed C-butylpyrogallol[4]arene hexamer becomes toroidal on dissolution, as does the spherically shaped gallium/zinc-seamed C-butylpyrogallol[4

  6. The Three Catecholics Benserazide, Catechol and Pyrogallol are GPR35 Agonists

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    Huayun Deng

    2013-04-01

    Full Text Available Nearly 1% of all clinically used drugs are catecholics, a family of catechol-containing compounds. Using label-free dynamic mass redistribution and Tango β-arrestin translocation assays, we show that several catecholics, including benserazide, catechol, 3-methoxycatechol, pyrogallol, (+-taxifolin and fenoldopam, display agonistic activity against GPR35.

  7. Electrochemical treatment of aqueous wastes containing pyrogallol by BDD-anodic oxidation.

    Science.gov (United States)

    Nasr, Bensalah; Hsen, Trabelsi; Abdellatif, Gadri

    2009-01-01

    In this work, the electrochemical oxidation of pyrogallol (1,2,3-trihydroxybenzene) on boron-doped diamond anodes has been studied. The voltammetric results showed that pyrogallol oxidation takes place in the same potential region as that of phenol where the supporting electrolyte is stable. Synthetic wastewaters containing pyrogallol have been treated in a bench-scale electrolysis plant. This plant operates in a discontinuous mode by recirculating the waste continuously through a single-chamber electrochemical flow cell. The complete mineralization of pyrogallol and the electro-generated pollutants is obtained in the electrolytic device. HPLC analyses show the formation of carboxylic acids as the main intermediates. The efficiency of the electrochemical process was found to depend mainly on the pollutant concentration present in the waste and on the applied current density. The high efficiency of this technology can be explained in terms of the direct electro-oxidation at the BDD surface and the oxidation carried out by hydroxyl radicals and other electro-generated oxidants.

  8. Microwave Assisted Efficient Synthesis and Crystal Structures of O-Hexadecalkylated Pyrogallol[4]arenes

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiao; CHEN Weifeng; YAN Chaoguo

    2009-01-01

    Under microwave irradiation alkylation reactions of sixteen phenolic hydroxyl groups in tetrap-hydroxyphenylpyrogallol[4]arene with alkylating reagents such as n-butyl iodide,benzyl chloride,and ethyl a-chloroacetate were finished quickly in one step to give the fully O-alkylated products.The X-ray single crystal diffraction showed that the three peralkylated pyrogallol[4]arenes existed in rcttcis-trans-transconfiguration.

  9. The synthesis, structure and activity evaluation of pyrogallol and catechol derivatives as Helicobacter pylori urease inhibitors.

    Science.gov (United States)

    Xiao, Zhu-Ping; Ma, Tao-Wu; Fu, Wei-Chang; Peng, Xiao-Chun; Zhang, Ai-Hua; Zhu, Hai-Liang

    2010-11-01

    Some pyrogallol and catechol derivatives were synthesized, and their urease inhibitory activity was evaluated by using acetohydroxamic acid (AHA), a well known Helicobacter pylori urease inhibitor, as positive control. The assay results indicate that many compounds have showed potential inhibitory activity against H. pylori urease. 4-(4-Hydroxyphenethyl)phen-1,2-diol (2a) was found to be the most potent urease inhibitor with IC(50)s of 1.5±0.2 μM for extracted fraction and 4.2±0.3 μM for intact cell, at least 10 times and 20 times lower than those of AHA (IC(50) of 17.2±0.9 μM, 100.6±13 μM), respectively. This finding indicate that 2a would be a potential urease inhibitor deserves further research. Molecular dockings of 2a into H. pylori urease active site were performed for understanding the good activity observed.

  10. A novel pyrogallol red-based assay to assess catalase activity: Optimization by response surface methodology.

    Science.gov (United States)

    Abderrahim, Mohamed; Arribas, Silvia M; Condezo-Hoyos, Luis

    2017-05-01

    Pyrogallol red (PGR) was identified as a novel optical probe for the detection of hydrogen peroxide (H2O2) based on horseradish peroxidase (HRP)-catalyzed oxidation. Response surface methodology (RSM) was applied as a tool to optimize the concentrations of PGR (100µmolL(-1)), HRP (1UmL(-1)) and H2O2 (250µmolL(-1)) and used to develop a sensitive PGR-based catalase (CAT) activity assay (PGR-CAT assay). N-ethylmaleimide -NEM- (102mmolL(-1)) was used to avoid interference produced by thiol groups while protecting CAT activity. Incubation time (30min) for samples or CAT used as standard and H2O2 as well as signal stability (stable between 5 and 60min) were also evaluated. PGR-CAT assay was linear within the range of 0-4UmL(-1) (R(2)=0.993) and very sensitive with limits of detection (LOD) of 0.005UmL(-1) and quantitation (LOQ) of 0.01UmL(-1). PGR-CAT assay showed an adequate intra-day RSD=0.6-9.5% and inter-day RSD=2.4-8.9%. Bland-Altman analysis and Passing-Bablok and Pearson correlation analysis showed good agreement between CAT activity as measured by the PRG-CAT assay and the Amplex Red assay. The PGR-CAT assay is more sensitive than all the other colorimetric assays reported, particularly the Amplex Red assay, and the cost of PGR is a small fraction (about 1/1000) of that of an Amplex Red probe, so it can be expected to find wide use among scientists studying CAT activity in biological samples.

  11. The gnotobiotic brine shrimp (Artemia franciscana) model system reveals that the phenolic compound pyrogallol protects against infection through its prooxidant activity.

    Science.gov (United States)

    Baruah, Kartik; Duy Phong, Ho Phuong Pham; Norouzitallab, Parisa; Defoirdt, Tom; Bossier, Peter

    2015-12-01

    The phenolic compound pyrogallol is the functional unit of many polyphenols and currently there has been a growing interest in using this compound in human and animal health owing to its health-promoting effects. The biological actions of pyrogallol moiety (and polyphenols) in inducing health benefitting effects have been studied; however, the mechanisms of action remain unclear yet. Here, we aimed at unravelling the underlying mechanism of action behind the protective effects of pyrogallol against bacterial infection by using the gnotobiotically-cultured brine shrimp Artemia franciscana and pathogenic bacteria Vibrio harveyi as host-pathogen model system. The gnotobiotic test system represents an exceptional system for carrying out such studies because it eliminates any possible interference of microbial communities (naturally present in the experimental system) in mechanistic studies and furthermore facilitates the interpretation of the results in terms of a cause effect relationship. We provided clear evidences suggesting that pyrogallol pretreament, at an optimum concentration, induced protective effects in the brine shrimp against V. harveyi infection. By pretreating brine shrimp with pyrogallol in the presence or absence of an antioxidant enzyme mixture (catalase and superoxide dismutase), we showed that the Vibrio-protective effect of the compound was caused by its prooxidant action (e.g. generation of hydrogen peroxide, H2O2). We showed further that generation of prooxidant is linked to the induction of heat shock protein Hsp70, which is involved in eliciting the prophenoloxidase and transglutaminase immune responses. The ability of pyrogallol to induce protective immunity makes it a potential natural protective agent that might be a potential preventive modality for different host-pathogen systems.

  12. Hexameric Capsules Studied by Magic Angle Spinning Solid-State NMR Spectroscopy: Identifying Solvent Molecules in Pyrogallol[4]arene Capsules.

    Science.gov (United States)

    Avram, Liat; Goldbourt, Amir; Cohen, Yoram

    2016-01-18

    Powders of pyrogallol[4]arene hexamers were produced by evaporation from organic solvents and were studied, for the first time, by magic angle spinning solid-state NMR (MAS ssNMR). Evaporation selectively removed non-encapsulated solvent molecules leaving stable hexameric capsules encapsulating solvent molecules. After exposure of the powder to solvent vapors, (1)H/(13)C heteronuclear correlation MAS ssNMR experiments were used to assign the signals of the external and encapsulated solvent molecules. The formed capsules were stable for months and the process of solvent encapsulation was reversible. According to the ssNMR experiments, the encapsulated solvent molecules occupy different sites and those sites differ in their mobility. The presented approach paves the way for studying guest exchange, guest affinity, and gas storage in hexamers of this type in the solid state.

  13. A Sensitive Voltammetric Sensor for Determination of Glutathione Based on Multiwall Carbon Nanotubes Paste Electrode Incorporating Pyrogallol Red

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    Mohsen Keyvanfard

    2014-06-01

    Full Text Available A new sensitive and selective electrochemical sensor was developed for determination of glutathione (GSH at the surface of carbon paste electrode (CPE modified with multi-wall carbon nanotubes (MWCNTs as a sensor and pyrogallol red (PGR as a mediator. The mechanism of GSH electrochemical behavior at the modified electrode surface was investigated by various electrochemical techniques including chronoamperometry, cyclic voltammetry (CV and square wave voltammetry (SWV. A linear calibration curve was obtained in the concentration range of GSH of 0.3–500 μmol L–1, with a limit of detection of 0.19 μmol L–1. The method was applied to the determination of GSH in urine samples with satisfactory results.

  14. Glycine Betaine Recognition through Cation−π Interactions in Crystal Structures of Glycine Betaine Complexes with C-Ethyl-pyrogallol[4]arene and C-Ethyl-resorcin[4]arene as Receptors

    OpenAIRE

    Ikuhide Fujisawa; Katsuyuki Aoki

    2013-01-01

    The glycine betaine (betaine), interacts with several types of proteins with diverse structures in vivo, and in the contact regions, the aromatic rings of protein residues are frequently found beside the trimethylammonium group of betaine, implying the importance of the cation−π interactions in recognition of this molecule. The crystal structures determined by X-ray crystallography of the complexes of betaine and C-ethyl-pyrogallol[4]arene (pyrogallol cyclic tetramer: PCT) and betaine and C-e...

  15. Trace and selective determination of cobalt(II in water and salt samples using cathodic adsorptive stripping voltammetry in the presence of pyrogallol red

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    Hasanpour Foroozan

    2013-01-01

    Full Text Available A sensitive and selective procedure is presented for voltammetric determination of cobalt. The procedure involves an adsorptive accumulation of cobalt pyrogallol red (PGR complex on stationary mercury drop electrode, followed by cathodic stripping voltammetry measurement of reduction current of adsorbed complex at -1.17 V (vs. Ag/AgCl. The optimum conditions for determination of cobalt include pH 11.0, 35 μM pyrogallol red, an accumulation potential of -0.9 V (vs. Ag/AgCl and scan rate 80 mVs-1. The peak current is proportional to the concentration of cobalt over the concentration range of 5.0 to 280 ng mL-1 with a detection limit of 1 ng mL-1 with an accumulation time of 140 s. The method was applied for the determination of cobalt in analytical grade NaCl and water samples.

  16. 高效液相色谱法测定焦性没食子酸%A HPLC Method for the Determination of Pyrogallol

    Institute of Scientific and Technical Information of China (English)

    邓自西; 刘林; 李文娟

    2012-01-01

    A simple but effective HPLC method for the quantitative determination of pyrogallol using gallic acid as internal standard was explored. A regression model was established between the peak area ratio and the concentration ratio of pyrogallol and gallic acid. The results showed that the proposed method could accurately determine pyrogallol content The standard deviation, coefficient of variation, recovery and linear relative coefficient were 0.059, 0.036%, 101.2% and 0.999 9, respectively.%在选定高效液相色谱操作条件下,研究了使用没食子酸作为标准测定焦性没食子酸含量的方法,对两者的浓度比值与其色谱响应值比值的关系进行了回归分析,方法标准偏差0.059,变异系数0.036,线性相关系数0.9999,回收率101.2%.

  17. Structural, quantum chemical, vibrational and thermal studies of a hydrogen bonded zwitterionic co-crystal (nicotinic acid: pyrogallol)

    Science.gov (United States)

    Prabha, E. Arockia Jeya Yasmi; Kumar, S. Suresh; Athimoolam, S.; Sridhar, B.

    2017-02-01

    In the present work, a new co-crystal of nicotinic acid with pyrogallol (NICPY) has been grown in the zwitterionic form and the corresponding structural, vibrational, thermal, solubility and anti-cancer characteristics have been reported. The single crystal X-ray diffraction analysis confirms that the structural molecular packing of the crystal stabilized through N-H⋯O and O-H⋯O hydrogen bond. The stabilization energy of the hydrogen bond motifs were calculated in the solid state. Vibrational spectral studies such as Fourier transform-infrared (FT-IR) and FT-Raman were adopted to understand the zwitterionic co-crystalline nature of the compound, which has been compared with theoretically calculated vibrational frequencies. The thermal stability of the grown co-crystal was analyzed by TG/DTA study. The solubility of the NICPY co-crystal was investigated in water at different temperature and compared with that of the nicotinic acid, which is the parent compound of NICPY co-crystal. The grown crystals were treated with human cervical cancer cell line (HeLa) to analyze the cytotoxicity of NICPY crystals and compared with the parent compound, which shows that NICPY has moderate activity against human cervical cancer cell line.

  18. Glycine Betaine Recognition through Cation−π Interactions in Crystal Structures of Glycine Betaine Complexes with C-Ethyl-pyrogallol[4]arene and C-Ethyl-resorcin[4]arene as Receptors

    Directory of Open Access Journals (Sweden)

    Ikuhide Fujisawa

    2013-04-01

    Full Text Available The glycine betaine (betaine, interacts with several types of proteins with diverse structures in vivo, and in the contact regions, the aromatic rings of protein residues are frequently found beside the trimethylammonium group of betaine, implying the importance of the cation−π interactions in recognition of this molecule. The crystal structures determined by X-ray crystallography of the complexes of betaine and C-ethyl-pyrogallol[4]arene (pyrogallol cyclic tetramer: PCT and betaine and C-ethyl-resorcin[4]arene (resorcinol cyclic tetramer: RCT mimic the conformations of betaine and protein complexes and show that the clathrate conformations are retained by the cation−π interactions. The difference of the conformation feature of betaine in the Protein Data Bank and in the Cambridge Structural Database was found by chance during the research and analyzed with the torsion angles.

  19. ŸKinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of Ÿ•NO and •NO2

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    Estefania Hugo

    2015-06-01

    Full Text Available In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR, a polyphenolic dye, with nitrous acid (HONO. PGR has been used as a model polyphenol due to its strong UV-visible absorption and its high reactivity towards reactive species (radicals and non-radicals, RS. The reaction was followed by UV-visible spectroscopy and high performance liquid chromatography (HPLC. A clear decrease of the PGR absorbance at 465 nm was observed, evidencing an efficient bleaching of PGR by HONO. In the initial stages of the reaction, each HONO molecule nearly consumed 2.6 PGR molecules while, at long reaction times, ca. 7.0 dye molecules were consumed per each reacted HONO. This result is interpreted in terms of HONO recycling. During the PGR-HONO reaction, nitric oxide was generated in the micromolar range. In addition, the rate of PGR consumption induced by HONO was almost totally abated by argon bubbling, emphasising the role that critical volatile intermediates, such as ŸNO and/or nitrogen dioxide (ŸNO2, play in the bleaching of this phenolic compound.

  20. Determination of aluminium in water samples by adsorptive cathodic stripping voltammetry in the presence of pyrogallol red and a quaternary ammonium salt.

    Science.gov (United States)

    Arancibia, Verónica; Muñoz, Carolina

    2007-09-30

    A fast, sensitive and selective method for the determination of aluminium based on the reaction of the metal with pyrogallol red (PR) in the presence of tetrabutylammonium tetrafluoroborate (TBATFB) to form an Al(PR)(3)x9TBATFB complex which is adsorbed on the mercury electrode is presented. Under these conditions complexation of aluminium is rapid and no waiting period or heating of the sample is required. The reduction current of the accumulated complex is measured by scanning the potential in the cathodic direction. The variation of peak current with pH, adsorption time, adsorption potential, ligand and quaternary ammonium salt concentration, and some instrumental parameters, such as stirring rate in the accumulation stage, and step amplitude, pulse amplitude and step duration while obtaining the square wave voltamperograms were optimized. The best experimental parameters were pH 8.5, (NH(4)Ac-NH(3) buffer), C(PR)=25mumolL(-1), C(TBATFB) over 75mumolL(-1), t(ads)=60s, and E(ads)=-0.60V versus Ag/AgCl. A linear response is observed over the 0.0-30.0mugL(-1) concentration range, with a detection limit of 1.0mugL(-1). Reproducibility for 9.0mugL(-1) aluminium solution was 2.3% (n=6). Synthetic sea water and sea water reference material CRM-SW were used for validation measurements. Aluminium in urine samples of a volunteer who ingested 800mg of Al(OH)(3) was analyzed.

  1. Correlation of electronic transitions and redox potentials measured for pyrocatechol, resorcinol, hydroquinone, pyrogallol, and gallic acid with results of semi-empirical molecular orbital computations A useful interpretation tool

    Science.gov (United States)

    Carter, Melvin Keith

    2007-04-01

    Cyclic voltammogram (CV) electrochemical measurements for pyrocatechol, resorcinol, hydroquinone, pyrogallol, and gallic acid in strong alkaline solution produced observable oxidation-reduction potentials for each hydroxy group present except for resorcinol. UV absorption spectra were also observed for the diluted solutions. Semi-empirical molecular orbital computations were conducted for these molecules of C2 v point group symmetry to determine the character and energies to aid interpretation of the experimental results. CV oxidation removed a π-electron by a radiationless π-π* transition followed by an electron shift from a negative oxygen to the positive aromatic π-system indicated by an observable σ-π* transition. Simple semi-empirical computations correlated with measured excited electronic states during electron transfer.

  2. Crystal structures of resorcin[4]arene and pyrogallol[4]arene complexes with DL-pipecolinic acid. Model compounds for the recognition of the pipecolinyl ring, a key fragment of FK506, through C-H⋯π interaction

    Science.gov (United States)

    Fujisawa, Ikuhide; Kitamura, Yuji; Kato, Ryo; Murayama, Kazutaka; Aoki, Katsuyuki

    2014-01-01

    Resorcin[4]arene (resorcinol cyclic tetramer, abbreviated as RCT) or pyrogallol[4]arene (pyrogallol cyclic tetramer, PCT) form host-guest 1:1 complexes with DL-pipecolinic acid (DL-pipeH), RCT·DL-pipeH·EtOH·8H2O (1), PCT DL-pipeH·EtOH·4H2O (2), and PCT·DL-pipeH·3H2O (3), whose crystal structures have been determined. In each complex, the pipeH ligand is incorporated into the bowl-shaped cavity of the RCT or PCT host molecules through C-H⋯π interactions between alkyl protons of the piperidine ring of pipeH and π-rings of RCT or PCT, forming an [(RCT/PCT)·pipeH] structural fragment. In 1 and 3, two [(RCT/PCT) pipeH] fragments self-associate across an inversion center to form a guest-mediated, obliquely declined dimeric structure [(RCT/PCT)·L-pipeH·D-pipeH (RCT/PCT)]. In 2, each PCT-capped pipeH ligand bridges to two adjacent PCT molecules to form guest-mediated, optically-discrete helical polymers [PCT·L-pipeH]n or [PCT·D-pipeH]n. An 1H NMR experiment shows that the complexation through C-H⋯π interaction between the piperidine ring of pipeH and π-rings of RCT or PCT occurs also in solution, with the binding constants of 9.7 ± 0.6 M-1 for RCT and 26.5 ± 1.5 M-1 for PCT. These complexes provide a synthetic model for the recognition of the pipecolinyl-ring moiety, a key constituent of immunosuppressant drugs such as FK506, FK520 or rapamycin, by their binding proteins through C-H⋯π interaction.

  3. Superoxide generated by pyrogallol reduces highly water-soluble tetrazolium salt to produce a soluble formazan: a simple assay for measuring superoxide anion radical scavenging activities of biological and abiological samples.

    Science.gov (United States)

    Xu, Chen; Liu, Shu; Liu, Zhiqiang; Song, Fengrui; Liu, Shuying

    2013-09-02

    Superoxide anion radical (O2(˙-)) plays an important role in several human diseases. The xanthine/xanthine oxidase system is frequently utilized to produce O2(˙-). However, false positive results are easily got by using this system. The common spectrophotometric probes for O2(˙-) are nitroblue tetrazolium (NBT) and cytochrome c. Nevertheless, the application of NBT method is limited because of the water-insolubility of NBT formazan and the assay using cytochrome c lacks sensitivity and is not suitable for microplate measurement. We overcome these problems by using 1,2,3-trihydroxybenzene (pyrogallol) as O2(˙-)-generating system and a highly water-soluble tetrazolium salt, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium sodium salt (WST-1) which can be reduced by superoxide anion radical to a stable water-soluble formazan with a high absorbance at 450 nm. The method is simple, rapid and sensitive. Moreover, it can be adapted to microplate format. In this study, the O2(˙-) scavenging activities of superoxide dismutase (SOD), L-ascorbic acid, N-acetyl-L-cysteine (NAC), albumin from human serum, flavonoids and herbal extracts were assessed by using this method. Meanwhile, the activities of tissue homogenates and serum were determined by using this validated method. This method, applicable to tissue homogenates, serum and herbal extracts, proved to be efficient for measuring O2(˙-) scavenging activities of biological and abiological samples.

  4. 邻苯三酚与亚甲蓝舒张大鼠肠系膜动脉的不同机制%Mechanisms of relaxation by pyrogallol and methylthioninium chloride in perfused rat mesenteric artery

    Institute of Scientific and Technical Information of China (English)

    李元建; Sue Piper DUCKLES

    1994-01-01

    In perfused rat mesenteric arteries without endothelium, pyrogallol (Pyr) or methylthioninium chloride (methylene blue,Met) produced a concentration-dependent re-laxation. Superoxide dismutase abolished in-hibition by Pyr, but not Met, of vasoconstric-tor responses to transmural nerve stimulation(TNS). Neither catalase nor deferoxamine had any effect on vasodilator responses to Pyr or Met. Vasodilator responses to Pyr were unaltered by Nω-nitro-L-arginine methyl ester(L-NAME), indomethacin, or capsaicin.Similarly, the relaxing effect of Met was unaf-fected by indomethacin or capsaicin. These findings suggest that vasodilator responses to Pyr may be due to endothelial-independent generation of superoxide anion. In contrast the relaxation produced by Met appears to be due to a direct action on vascular smooth muscle independent of superoxide anion generation.%在去内皮肠系膜血管,邻苯三酚与亚甲蓝产生浓度依赖性舒张,SOD可取消邻苯三酚对TNS所致缩血管效应的抑制作用,但不影响亚甲蓝的效应.邻苯三酚与亚甲蓝的舒血管效应不被过氧化氢酶、去铁胺、吲哚美辛和辣椒素所影响.结果提示,邻苯三酚的舒血管效应是其产生超氧阴离子所致,而亚甲蓝的效应为直接作用于血管平滑肌.

  5. 21 CFR 73.1375 - Pyrogallol.

    Science.gov (United States)

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... material. (3) When the sutures are used for the purposes specified in their labeling, there is no migration... drug application, pursuant to section 505 of the act, is in effect for it. (d) Labeling. The label...

  6. Use of Pyrogallol Red and Pyranine as Probes to Evaluate Antioxidant Capacities towards Hypochlorite

    Directory of Open Access Journals (Sweden)

    Fernanda Pérez-Cruz

    2013-01-01

    Full Text Available Hypochlorite is a strong oxidant able to induce deleterious effects in biological systems. The goal of this work was to investigate the use of PGR and PYR as probes in assays aimed at evaluating antioxidant activities towards hypochorite and apply it to plant extracts employed in Chilean folk medicine. The consumption of PGR and PYR was evaluated from the decrease in the visible absorbance and fluorescence intensity, respectively. Total phenolic content was determined by the Folin Ciocalteau assay. PGR and PYR react with hypochlorite with different kinetics, being considerably faster the consumption of PGR. Different stoichiometric values were also determined: 0.7 molecules of PGR and 0.33 molecules of PYR were bleached per each molecule of added hypochlorite. Both probes were protected by antioxidants, but the rate of PGR bleaching was too fast to perform a kinetic analysis. For PYR, the protection took place without changes in its initial consumption rate, suggesting a competition between the dye and the antioxidant for hypochlorite. Plant extracts protected PYR giving a PYR-HOCl index that follows the order: Fuchsia magellanica » Marrubium vulgare » Tagetes minuta > Chenopodium ambrosoides » Satureja montana > Thymus praecox. Based on both the kinetic data and the protection afforded by pure antioxidants, we selected PYR as the best probe. The proposed methodology allows evaluating an antioxidant capacity index of plant extracts related to the reactivity of the samples towards hypochlorite.

  7. Understanding the self-assembly process and behavior of metal-seamed pyrogallol[4]arene nanocapsules

    Science.gov (United States)

    Mossine, Andrew V.

    C-alkylpyrogallol[4]arenes (PgCs) are bowl-shaped compounds that are commonly used as supramolecular building blocks in the construction of larger entities such as capsules, nanotubes, and layered networks. Many of these assemblies are constructed using non-covalent means and, as such, are inherently unstable in polar media. Although metal coordination with the hydroxyl-rich PgC upper rim can be exploited to synthesize assemblies with enhanced stability, few reports of this can be found in the literature. Thus, a thorough investigation of these metal-seamed assemblies and their manipulation is of importance. Prior work in the Atwood lab has produced three examples of metal-organic nanocapsules (MONCs) based on PgCs. These include two hexameric MONCs (based on Cu2+ and Ga3+) as well as a single example of a dimeric MONC (based on Zn2+). As it was unknown whether other metal cations could lead to the formation of similar entities, PgC complexation experiments were conducted with other first series transition metal cations, notably Ni2+, Co2+ and Mn2+. All of these led to nanocapsular materials, which were identified and studied using single crystal X-ray diffraction (scXRD). Once the foundational studies were complete, syntheses were also performed under varied conditions, specifically with Ni2+ and Cu2+. This led to the characterization of both dimeric and hexameric MONCs with these two metals, as well as the characterization of many other capsular materials. The information collected from these experiments also led to an intriguing question: which specific conditions lead to the formation of dimeric vs. hexameric MONCs? To answer this question, solid-state analysis using scXRD was coupled to in situ analysis utilizing small angle neutron scattering (SANS). This work showed that the formation of the dimer is typically favored at higher temperatures while the formation of the hexamer is favored at lower temperatures for both of the metals tested. Studies that varied time of measurement as well as the solvent system during synthesis were also performed. Furthermore, SANS was also used to study Fe3+-PgC complexes. These complexes are difficult if not impossible to crystallize, and therefore cannot be studied using scXRD. SANS was used in conjunction with elemental analysis to deduce a structure for these materials. In addition to understanding the synthesis of MONCs, another goal was to also use them for other (possibly practical) purposes. To this end, PgC-based MONCs were used as building blocks in metal-organic frameworks (MOFs). This involved the use of divergent ligands to "link" capsular monomers together, resulting in one and two dimensional frameworks. This work not only produced functional materials that may be useful in future research efforts, but also showed that exo-ligand exchange can be used to derivatize MONCs into potentially useful and functional materials. The introduction of radioisotopes into the nanocapsule was another method by which functionality could theoretically be imparted into MONCs. It was envisioned that MONCs could potentially be used as carrier systems for radioisotopes, and thereby function as agents for therapy or medical imaging. Copper hexamers constructed from 64Cu2+ were therefore prepared and studied in a living system. However, these studies were unsuccessful at showing that the copper-seamed MONCs differed in behavior from 64Cu in vivo, either due to poor labeling efficiency or metabolism. Nevertheless, radiolabeling of hexameric nanocapsules was helpful in broadening our understanding of these materials. Some of the studies that were conducted include those that gauge the solubility and stability of nanocapsules, as well as others that explore the conditions required for cationic uptake and exchange.

  8. Cascading electron and hole transfer dynamics in a CdS/CdTe core-shell sensitized with bromo-pyrogallol red (Br-PGR): slow charge recombination in type II regime.

    Science.gov (United States)

    Maity, Partha; Debnath, Tushar; Chopra, Uday; Ghosh, Hirendra Nath

    2015-02-14

    Ultrafast cascading hole and electron transfer dynamics have been demonstrated in a CdS/CdTe type II core-shell sensitized with Br-PGR using transient absorption spectroscopy and the charge recombination dynamics have been compared with those of CdS/Br-PGR composite materials. Steady state optical absorption studies suggest that Br-PGR forms strong charge transfer (CT) complexes with both the CdS QD and CdS/CdTe core-shell. Hole transfer from the photo-excited QD and QD core-shell to Br-PGR was confirmed by both steady state and time-resolved emission spectroscopy. Charge separation was also confirmed by detecting electrons in the conduction band of the QD and the cation radical of Br-PGR as measured from femtosecond transient absorption spectroscopy. Charge separation in the CdS/Br-PGR composite materials was found to take place in three different pathways, by transferring the photo-excited hole of CdS to Br-PGR, electron injection from the photo-excited Br-PGR to the CdS QD, and direct electron transfer from the HOMO of Br-PGR to the conduction band of the CdS QD. However, in the CdS/CdTe/Br-PGR system hole transfer from the photo-excited CdS to Br-PGR and electron injection from the photo-excited Br-PGR to CdS take place after cascading through the CdTe shell QD. Charge separation also takes place via direct electron transfer from the Br-PGR HOMO to the conduction band of CdS/CdTe. Charge recombination (CR) dynamics between the electron in the conduction band of the CdS QD and the Br-PGR cation radical were determined by monitoring the bleach recovery kinetics. The CR dynamics were found to be much slower in the CdS/CdTe/Br-PGR system than in the CdS/Br-PGR system. The formation of the strong CT complex and the separation of charges cascading through the CdTe shell help to slow down charge recombination in the type II regime.

  9. Polyphenolics from mango (Mangifera indica L.) suppress breast cancer ductal carcinoma in situ proliferation through activation of AMPK pathway and suppression of mTOR in athymic nude mice.

    Science.gov (United States)

    Nemec, Matthew J; Kim, Hyemee; Marciante, Alexandria B; Barnes, Ryan C; Hendrick, Erik D; Bisson, William H; Talcott, Stephen T; Mertens-Talcott, Susanne U

    2017-03-01

    The objective of this study was to assess the underlying mechanisms of mango polyphenol decreased cell proliferation and tumor volume in ductal carcinoma in situ breast cancer. We hypothesized that mango polyphenols suppress signaling along the AKT/mTOR axis while up-regulating AMPK. To test this hypothesis, mango polyphenols (0.8 mg gallic acid equivalents per day) and pyrogallol (0.2 mg/day) were administered for 4 weeks to mice xenografted with MCF10DCIS.com cells subcutaneously (n=10 per group). Tumor volumes were significantly decreased, both mango and pyrogallol groups displayed greater than 50% decreased volume compared to control. There was a significant reduction of phosphorylated protein levels of IR, IRS1, IGF-1R, and mTOR by mango; while pyrogallol significantly reduced the phosphorylation levels of IR, IRS1, IGF-1R, p70S6K, and ERK. The protein levels of Sestrin2, which is involved in AMPK-signaling, were significantly elevated in both groups. Also, mango significantly elevated AMPK phosphorylation and pyrogallol significantly elevated LKB1 protein levels. In an in vitro model, mango and pyrogallol increased reactive oxygen species (ROS) generation and arrested cells in S phase. In silico modeling indicates that pyrogallol has the potential to bind directly to the allosteric binding site of AMPK, inducing activation. When AMPK expression was down-regulated using siRNA in vitro, pyrogallol reversed the reduced expression of AMPK. This indicates that pyrogallol not only activates AMPK, but also increases constitutive protein expression. These results suggest that mango polyphenols and their major microbial metabolite, pyrogallol, inhibit proliferation of breast cancer cells through ROS-dependent up-regulation of AMPK and down-regulation of the AKT/mTOR pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Enhanced functional properties of tannic acid after thermal hydrolysis

    Science.gov (United States)

    Thermal hydrolysis processing of fresh tannic acid was carried out in a closed reactor at four different temperatures (65, 100, 150 and 200°C). Pressures reached in the system were 1.3 and 4.8 MPa at 150 and 200°C, respectively. Hydrolysis products (gallic acid and pyrogallol) were separated and qua...

  11. Use of Moessbauer spectroscopy to study reaction products of polyphenols and iron compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gust, J. (Building Research Inst., Warsaw (Poland)); Suwalski, J. (Atomic Energy Inst., Otwock-Swierk (Poland))

    1994-05-01

    Moessbauer spectroscopy was used to study parameters of the reaction products of iron compounds (Fe[sup III]) and polyphenols with hydroxyl (OH) groups in ortho positions. Polyphenols used in the reaction were catechol, pyrogallol, gallic acid, and oak tannin. The Fe-containing compounds were hydrated ferric sulfate (Fe[sub 2][SO[sub 4

  12. Stability of dietary polyphenols under the cell culture conditions: avoiding erroneous conclusions.

    Science.gov (United States)

    Xiao, Jianbo; Högger, Petra

    2015-02-11

    Most data of bioactivity from dietary polyphenols have been derived from in vitro cell culture experiments. In this context, little attention is paid to potential artifacts due to chemical instability of these natural antioxidants. An early degradation time ((C)T10) and half-degradation time ((C)T50) were defined to characterize the stability of 53 natural antioxidants incubated in Dulbecco's modified Eagle's medium (DMEM) at 37 °C. The degree of hydroxylation of flavones and flavonols significantly influenced the stability in order resorcinol-type > catechol-type > pyrogallol-type, with the pyrogallol-type being least stable. In contrast, any glycosylation of polyphenols obviously enhanced their stability. However, the glycosylation was less important compared to the substitution pattern of the nucleus rings. Methoxylation of flavonoids with more than three hydroxyl groups typically improved their stability as did the hydrogenation of the C2═C3 double bond of flavonoids to corresponding flavanoids. There was no significant correlation between the antioxidant potential of polyphenols and their stability. Notably, the polyphenols were clearly more stable in human plasma than in DMEM, which may be caused by polyphenol-protein interactions. It is strongly suggested to carry out stability tests in parallel with cell culture experiments for dietary antioxidants with catechol or pyrogallol structures and pyrogallol-type glycosides in order to avoid artifacts.

  13. Biosynthesis of reduced graphene oxide and its in-vitro cytotoxicity against cervical cancer (HeLa) cell lines.

    Science.gov (United States)

    Luo, Lan; Xu, Lina; Zhao, Haibo

    2017-09-01

    The present work proposed a simple, one pot, and green approach for the deoxygenation of graphene oxide (GO) using pyrogallol as reducing and stabilizing agent. This synthetic strategy prevents the utilization of toxic reducing reagents during synthesis. The characterization results of Ultra violet visible (UV-Vis), X-ray diffraction (XRD), X-ray photo electron spectroscopy (XPS), Transmission electron microscopy (TEM) for the synthesized GO and reduced graphene oxide (RGO) indicated the strong removal of oxygen groups after reduction which followed by stabilization with oxidized form of pyrogallol. TEM analysis showed the thin transparent silk like sheets of graphene. FTIR analysis confirmed the stabilization of graphene sheets with oxidized pyrogallol molecules. XRD and XPS analysis represented the deoxygenation of GO to RGO. The in-vitro cytotoxicity of RGO towards HeLa cells is dose dependant. The prepared RGO also exhibited the percent cell viability of about 80% even at higher concentrations indicating the less toxic nature of the RGO stabilized with pyrogallol. These results have represented that this synthetic approach is effective for the preparation of bulk scale RGO in a simple, less expensive and eco-friendly method. Since this method avoids the use of chemical reagents that are toxic in nature, the produced graphene are likely to offer several potential biomedical applications. Copyright © 2017. Published by Elsevier B.V.

  14. Essential Structural Requirements and Additive Effects for Flavonoids to Scavenge Methylglyoxal.

    Science.gov (United States)

    Shao, Xi; Chen, Huadong; Zhu, Yingdong; Sedighi, Rashin; Ho, Chi-Tang; Sang, Shengmin

    2014-04-01

    Reactive dicarbonyl species, such as methylglyoxal (MGO), are considered as the major precursors of advanced glycation end products (AGEs), which are believed to be one of the physiological causes of diabetes and its complications. Scavenging of reactive dicarbonyl species using naturally occurring flavonoids has been proposed as an effective way to prevent diabetic complications. To elucidate the structural requirements of flavonoids in scavenging MGO, seven flavonoids (quercetin, luteolin, epicatechin, genistein, daidzein, apigenin, and phloretin) and five sub-components of the flavonoids (gallic acid, phloroglucinol, pyrogallol, pyrocatechol, and resorcinol) were examined in this study. Our results showed the following: (1) 1,2,3-trihydroxybenzene (pyrogallol) has higher MGO scavenging activity than 1,3,5-trihydroxybenzene and 1,2- and 1,3-dihydroxybenzene, and substitution at position 5 of pyrogallol diminished the scavenging activity, indicating that position 5 is the active site of pyrogallol; (2) the A ring is the active site of flavonoids in contributing the MGO-trapping efficacy, and the hydroxyl group at C-5 on the A ring enhances the trapping efficacy; (3) the double bond between C-2 and C-3 on the C ring could facilitate the trapping efficacy; and (4) the number of hydroxyl groups on the B ring does not significantly influence the trapping efficacy. In addition, we found there is an additive effect in MGO trapping by two common flavonoids, quercetin and phloretin, indicating that flavonoid-enriched foods and beverages hold great promise to prevent the development of diabetic complications.

  15. Purification and characterization of Ocimum basilicum L. polyphenol oxidase.

    Science.gov (United States)

    Dogan, Serap; Turan, Pinar; Dogan, Mehmet; Arslan, Oktay; Alkan, Mahir

    2005-12-28

    A partial characterization of polyphenol oxidase (PPO) activity in Ocimum basilicum L. is described. PPO in O. basilicum L. was extracted and purified through (NH4)2SO4 precipitation, dialysis, and a Sepharose 4B-l-tyrosine-p-aminobenzoic acid affinity column. The samples obtained from (NH4)2SO4 precipitation and dialysis were used for the characterization of PPO. At the end of purification by affinity chromatography, 11.5-fold purification was achived. The purified enzyme exhibited a clear single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular mass of the enzyme was estimated to be approximately 54 kDa. The contents of total phenolic and protein of O. basilicum L. extracts were determined. The total phenolic content of O. basilicum L. was determined spectrophotometrically according to the Folin-Ciocalteu procedure and was found to be 280 mg 100 g(-1) on a fresh weight basis. The protein content was determined according to the Bradford method. The enzyme showed activity to 4-methylcatechol, catechol, and pyrogallol substrates, but not to tyrosine. Therefore, of these three substrates, 4-methylcatecol was the best substrate due to the highest V(max)/K(m) value, followed by pyrogallol and catechol. The optimum pH was at 6, 8, and 9 for 4-methylcatechol, catechol, and pyrogallol, respectively. The enzyme had an optimum temperature of 20, 40, and 50 degrees C for 4-methylcatechol, catechol, and pyrogallol, respectively. It was found that optimum temperature and pH were dependent on the substrates studied. The enzyme activity with increasing temperature and inactivation time for 4-methylcatechol, catechol, and pyrogallol substrates decreased due to heat denaturation of the enzyme.

  16. The influence of natural and synthetic antioxidant on oxidation stability and emission of sapota oil methyl ester as fuel in CI engine

    Directory of Open Access Journals (Sweden)

    Ramalingam Senthil

    2016-01-01

    Full Text Available In this present study oxidation stability of sapota oil methyl ester with synthetic and natural antioxidant additives using Rancimat test is investigate. The performance and emission characteristics of the B20 blend of sapota oil methyl ester with different antioxidant additive are evaluated in a Diesel engine. The natural antioxidants namely citric acid, rosemary extract and leaf extract and synthetic antioxidants namely pyrogallol, propyl gallate and butylated hydroxylanisole are selected. Addition of all the antioxidant additive found to have improved the oxidation stability of the biodiesel to the required level. Pyrogallol is found to be the best among the synthetic antioxidant, while leaf extract is the best among the natural antioxidant. From the emission test it is found that B20 has better emission characters compared to diesel except NOx. Further the addition of leaf extract slightly reduces the NOx emission of B20 and appreciably suppresses smoke emission.

  17. Determination of Bioactive Components of Ethyl Acetate Fraction of Punica granatum Rind Extract

    OpenAIRE

    J. Sangeetha; K. Vijayalakshmi

    2011-01-01

    Punica granatum belongs to a Punicaceae family. The Punica granatum is valued as a powerful medicinal plant and used in folk medicines. Hence the present investigation was carried out to determine the possible chemical components from ethyl acetate fraction of Punica granatum rind extract by GC-MS Technique. This analysis revealed that ethyl acetate fraction of Punica granatum rind extract contain Pyrogallol (41.88%), 5-Hydroxymethylfurfural (14.10%), D-Allose (9.17%), 2-Methoxy-1, 4-Benzened...

  18. Extraction, gas chromatography-mass spectrometry analysis and screening of fruits of Terminalia chebula Retz. for its antimicrobial potential

    Directory of Open Access Journals (Sweden)

    Geeta Singh

    2013-01-01

    Full Text Available Background: Terminalia chebula is called the "king of medicines" in Tibet and is always listed first in the Ayurvedic meteria medica because of its extraordinary powers of healing. Objective: Identification, isolation and screening of pyrogallol which are responsible for antimicrobial property of fruits of Terminalia chebula. Materials and Methods: Ethyl acetate fraction of fruits of Terminalia chebula was subjected to Gas chromatography-mass spectrometry (GC-MS for the components present in the extract. Results: Sixty four constituents were identified out of which kaempferol-3-O-rutinoside flavonoid and Vitamin E has been detected for the first time in fruits of this plant. Pyrogallol (46.26% which was the major component of the extract in GC-MS analysis was isolated and screened for antimicrobial activity against selected test pathogens by Disc Diffusion Assay. Crude ethyl acetate fraction of the fruits was showing the same activity potential as was observed for pure pyrogallol which was the major component as per GC-MS analysis. The most sensitive species among the bacteria was Enterobacter aerogenes with highest inhibition zone (IZ = 31 mm; AI = 1.409 ± 0.046 even at minimum inhibitory concentration (0.039 mg/ml. Conclusion: Hence activity shown by crude ethyl acetate fraction might be due to pyrogallol present in the extract. On the basis of results it can be advocate that achieved crude ethyl acetate fraction can be explored for preparing antimicrobial drugs in future for the infectious caused by the pathogens tested in the study.

  19. Differential Sensitivities of Pulmonary and Coronary Arteries to Hemoglobin-Based Oxygen Carriers and Nitrovasodilators: Study in a Bovine Ex Vivo Model of Vascular Strips

    Science.gov (United States)

    2010-01-01

    lsev ier.c omflocate/ vph Differential sensitivities of pulmonary and coronary arteries to hemoglobin-based oxygen carriers and nitrovasodilators...preparation has been used extensively in multiple studies that led to the discovery of NO as endothelium-derived relaxing factor (lgnarro et al., 1984...G.M .• Wood, K.S., Chaudhuri, G., 1988a. Pharmacological evidence that endothelium-derived relaxing factor is nitric oxide: use or pyrogallol and

  20. Antioxidant Activities of Total Pigment Extract from Blackberries

    OpenAIRE

    Jiao, Zhonggao; Liu, Jiechao; Wang, Sixin

    2005-01-01

    Total pigment has been extracted from blackberries and its antioxidant activity against lipid peroxidation and scavenging capacities towards superoxide anion radicals, hydroxyl radicals and nitrite in different in vitro systems have been investigated. The total pigment extract from blackberries (TPEB) exhibited strong antioxidant activity against lipid peroxidation in a linoleic acid model system and scavenging capacities towards superoxide anion radicals, generated by a pyrogallol autoxidati...

  1. Partículas de CoO(OH) Dispersas em Pasta de Carbono Aplicado na Eletrooxidação de Compostos Fenólicos

    OpenAIRE

    Janaina Sartori Bonini; Filipe Quadros Mariani; Eryza Guimarães de Castro; Andressa Galli; Rafael Marangoni; Fauze Jacó Anaissi

    2015-01-01

    In this work, particles of cobalt oxyhydroxide (III), CoO (OH), synthesized by alkaline precipitation were used in a carbon paste electrode modified [CPEM_CoO(OH)] for the detection of phenolic compounds (catechol, guiacol, pyrogallol and salicylic acid). The cobalt-based electrode acts as the electron mediator, where the ion Co (III) acts effectively in the oxidation/reduction of analyte, via reductive dissolution. As a result, the modified carbon paste electrode [CPEM_CoO(OH)] exhibited goo...

  2. A novel fiber optic spectrophotometric determination of nitrite using Safranin O and cloud point extraction.

    Science.gov (United States)

    Filik, Hayati; Giray, Derya; Ceylan, Burak; Apak, Reşat

    2011-09-30

    A novel fiber optic spectrophotometric method for nitrite determination in different samples is suggested, based on the reaction of nitrite with Safranin O in acidic medium to form a diazo-safranin, which is subsequently coupled with pyrogallol in alkaline medium to form a highly stable, red azo dye, followed by cloud point extraction (CPE) using a mixed micelle of a nonionic surfactant, Triton X-114, with an anionic surfactant, sodium dodecyl sulphate (SDS). The reaction and extraction conditions (e.g., acidity for diazotization and alkalinity for pyrogallol coupling, and other reagent concentrations, time, and tolerance to other ions) were optimized. Linearity was obeyed in a concentration range up to 230 μg L(-1), and the detection limit of the method is 0.5 μg L(-1) of nitrite ion. The molar absorptivity for nitrite of the Safranin-diazonium salt (ɛ(610 nm) =4 × 10(3) L mol(-1)cm(-1)) existing in literature was greatly enhanced by pyrogallol coupling and CPE enrichment (ɛ(592 nm)=1.39 × 10(5) L mol(-1)cm(-1)). The method was applied to the determination of nitrite in tap water, lake water and milk samples with an optimal preconcentration factor of 20.

  3. Role of GLUT1 in regulation of reactive oxygen species

    Directory of Open Access Journals (Sweden)

    Stanley Andrisse

    2014-01-01

    Full Text Available In skeletal muscle cells, GLUT1 is responsible for a large portion of basal uptake of glucose and dehydroascorbic acid, both of which play roles in antioxidant defense. We hypothesized that conditions that would decrease GLUT1-mediated transport would cause increased reactive oxygen species (ROS levels in L6 myoblasts, while conditions that would increase GLUT1-mediated transport would result in decreased ROS levels. We found that the GLUT1 inhibitors fasentin and phloretin increased the ROS levels induced by antimycin A and the superoxide generator pyrogallol. However, indinavir, which inhibits GLUT4 but not GLUT1, had no effect on ROS levels. Ataxia telangiectasia mutated (ATM inhibitors and activators, previously shown to inhibit and augment GLUT1-mediated transport, increased and decreased ROS levels, respectively. Mutation of an ATM target site on GLUT1 (GLUT1-S490A increased ROS levels and prevented the ROS-lowering effect of the ATM activator doxorubicin. In contrast, expression of GLUT1-S490D lowered ROS levels during challenge with pyrogallol, prevented an increase in ROS when ATM was inhibited, and prevented the pyrogallol-induced decrease in insulin signaling and insulin-stimulated glucose transport. Taken together, the data suggest that GLUT1 plays a role in regulation of ROS and could contribute to maintenance of insulin action in the presence of ROS.

  4. Structural characteristics of green tea catechins for formation of protein carbonyl in human serum albumin.

    Science.gov (United States)

    Ishii, Takeshi; Mori, Taiki; Ichikawa, Tatsuya; Kaku, Maiko; Kusaka, Koji; Uekusa, Yoshinori; Akagawa, Mitsugu; Aihara, Yoshiyuki; Furuta, Takumi; Wakimoto, Toshiyuki; Kan, Toshiyuki; Nakayama, Tsutomu

    2010-07-15

    Catechins are polyphenolic antioxidants found in green tea leaves. Recent studies have reported that various polyphenolic compounds, including catechins, cause protein carbonyl formation in proteins via their pro-oxidant actions. In this study, we evaluate the formation of protein carbonyl in human serum albumin (HSA) by tea catechins and investigate the relationship between catechin chemical structure and its pro-oxidant property. To assess the formation of protein carbonyl in HSA, HSA was incubated with four individual catechins under physiological conditions to generate biotin-LC-hydrazide labeled protein carbonyls. Comparison of catechins using Western blotting revealed that the formation of protein carbonyl in HSA was higher for pyrogallol-type catechins than the corresponding catechol-type catechins. In addition, the formation of protein carbonyl was also found to be higher for the catechins having a galloyl group than the corresponding catechins lacking a galloyl group. The importance of the pyrogallol structural motif in the B-ring and the galloyl group was confirmed using methylated catechins and phenolic acids. These results indicate that the most important structural element contributing to the formation of protein carbonyl in HSA by tea catechins is the pyrogallol structural motif in the B-ring, followed by the galloyl group. The oxidation stability and binding affinity of tea catechins with proteins are responsible for the formation of protein carbonyl, and consequently the difference in these properties of each catechin may contribute to the magnitude of their biological activities.

  5. Characterization and purification of polyphenol oxidase from artichoke (Cynara scolymus L.).

    Science.gov (United States)

    Dogan, Serap; Turan, Yusuf; Ertürk, Hatibe; Arslan, Oktay

    2005-02-09

    In this study, the polyphenol oxidase (PPO) of artichoke (Cynara scolymus L.) was first purified by a combination of (NH(4))(2)SO(4) precipitation, dialysis, and a Sepharose 4B-L-tyrosine-p-aminobenzoic acid affinity column. At the end of purification, 43-fold purification was achieved. The purified enzyme migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Polyacrylamide gel electrophoresis indicated that PPO had a 57 kDa molecular mass. Second, the contents of total phenolic and protein of artichoke head extracts were determined. The total phenolic content of artichoke head was determined spectrophotometrically according to the Folin-Ciocalteu procedure and was found to be 425 mg 100 g(-1) on a fresh weight basis. Protein content was determined according to Bradford method. Third, the effects of substrate specificity, pH, temperature, and heat inactivation were investigated on the activity of PPO purified from artichoke. The enzyme showed activity to 4-methylcatechol, pyrogallol, catechol, and L-dopa. No activity was detected toward L-tyrosine, resorsinol, and p-cresol. According to V(max)/K(m) values, 4-methylcatechol (1393 EU min(-1) mM(-1)) was the best substrate, followed by pyrogallol (1220 EU min(-1) mM(-1)), catechol (697 EU min(-1) mM(-1)), and L-dopa (102 EU min(-1) mM(-1)). The optimum pH values for PPO were 5.0, 8.0, and 7.0 using 4-methylcatechol, pyrogallol, and catechol as substrate, respectively. It was found that optimum temperatures were dependent on the substrates studied. The enzyme activity decreased due to heat denaturation of the enzyme with increasing temperature and inactivation time for 4-methylcatechol and pyrogallol substrates. However, all inactivation experiments for catechol showed that the activity of artichoke PPO increased with mild heating, reached a maximum, and then decreased with time. Finally, inhibition of artichoke PPO was investigated with inhibitors such as L-cysteine, EDTA, ascorbic

  6. Different influences of extracellular and intracellular superoxide on relaxation through the NO/sGC/cGMP pathway in isolated rat iliac arteries.

    Science.gov (United States)

    Tawa, Masashi; Shimosato, Takashi; Iwasaki, Hirotaka; Imamura, Takeshi; Okamura, Tomio

    2015-02-01

    Superoxide production is increased in diseased blood vessels, which is considered to lead to impairment of the nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP pathway. To investigate the respective influence of extracellular and intracellular superoxide on vascular function through the NO/sGC/cGMP pathway, mechanical responses of rat external iliac arteries without endothelium were studied under exposure to a superoxide-generating agent, pyrogallol, or menadione. Exposure to pyrogallol impaired the relaxation induced by acidified NaNO2 (exogenous NO) but not that by nitroglycerin (organic nitrate), BAY 41-2272 (sGC stimulator), BAY 60-2770 (sGC activator), or 8-Br-cGMP (cGMP analog). Superoxide dismutase (SOD) and tempol restored the impaired relaxation by acidified NaNO2. Superoxide production in the bathing solution, but not in artery segments, was significantly increased by exposure to pyrogallol, which was abolished in the presence of SOD or tempol. However, exposure to menadione impaired the relaxant response to acidified NaNO2, nitroglycerin, or BAY 41-2272, whereas it augmented that to BAY 60-2770. Also, this exposure had no effect on the 8-Br-cGMP-induced vasorelxation. Superoxide production in artery segments was dramatically enhanced by exposure to menadione, whereas that in the bathing solution was not affected. This increase in vascular superoxide production was normalized by tempol but not by SOD. These findings suggest that extracellular superoxide reacts with NO only outside the cell, whereas intracellular superoxide not only scavenges NO inside the cell but also shifts the sGC redox equilibrium.

  7. Properties and quality verification of biodiesel produced from tobacco seed oil

    Energy Technology Data Exchange (ETDEWEB)

    Usta, N., E-mail: n_usta@pau.edu.t [Pamukkale University, Mechanical Engineering Department, 20070 Denizli (Turkey); Aydogan, B. [Pamukkale University, Mechanical Engineering Department, 20070 Denizli (Turkey); Con, A.H. [Pamukkale University, Food Engineering Department, 20070 Denizli (Turkey); Uguzdogan, E. [Pamukkale University, Chemical Engineering Department, 20070 Denizli (Turkey); Ozkal, S.G. [Pamukkale University, Food Engineering Department, 20070 Denizli (Turkey)

    2011-05-15

    Research highlights: {yields} High quality biodiesel fuel can be produced from tobacco seed oil. {yields} Pyrogallol was found to be effective antioxidant improving the oxidation stability. {yields} The iodine number was reduced with a biodiesel including more saturated fatty acids. {yields} Octadecene-1-maleic anhydride copolymer was an effective cold flow improver. {yields} The appropriate amounts of the additives do not affect the properties negatively. -- Abstract: Tobacco seed oil has been evaluated as a feedstock for biodiesel production. In this study, all properties of the biodiesel that was produced from tobacco seed oil were examined and some solutions were derived to bring all properties of the biodiesel within European Biodiesel Standard EN14214 to verify biodiesel quality. Among the properties, only oxidation stability and iodine number of the biodiesel, which mainly depend on fatty acid composition of the oil, were not within the limits of the standard. Six different antioxidants that are tert-butylhydroquinone, butylated hydroxytoluene, propyl gallate, pyrogallol, {alpha}-tocopherol and butylated hydroxyanisole were used to improve the oxidation stability. Among them, pyrogallol was found to be the most effective antioxidant. The iodine number was improved with blending the biodiesel produced from tobacco seed oil with a biodiesel that contains more saturated fatty acids. However, the blending caused increasing the cold filter plugging point. Therefore, four different cold flow improvers, which are ethylene-vinyl acetate copolymer, octadecene-1-maleic anhydride copolymer and two commercial cold flow improvers, were used to decrease cold filter plugging point of the biodiesel and the blends. Among the improvers, the best improver is said to be octadecene-1-maleic anhydride copolymer. In addition, effects of temperature on the density and the viscosity of the biodiesel were investigated.

  8. The microbiota is essential for the generation of black tea theaflavins-derived metabolites.

    Directory of Open Access Journals (Sweden)

    Huadong Chen

    Full Text Available BACKGROUND: Theaflavins including theaflavin (TF, theaflavin-3-gallate (TF3G, theaflavin-3'-gallate (TF3'G, and theaflavin-3,3'-digallate (TFDG, are the most important bioactive polyphenols in black tea. Because of their poor systemic bioavailability, it is still unclear how these compounds can exert their biological functions. The objective of this study is to identify the microbial metabolites of theaflavins in mice and in humans. METHODS AND FINDINGS: In the present study, we gavaged specific pathogen free (SPF mice and germ free (GF mice with 200 mg/kg TFDG and identified TF, TF3G, TF3'G, and gallic acid as the major fecal metabolites of TFDG in SPF mice. These metabolites were absent in TFDG- gavaged GF mice. The microbial bioconversion of TFDG, TF3G, and TF3'G was also investigated in vitro using fecal slurries collected from three healthy human subjects. Our results indicate that TFDG is metabolized to TF, TF3G, TF3'G, gallic acid, and pyrogallol by human microbiota. Moreover, both TF3G and TF3'G are metabolized to TF, gallic acid, and pyrogallol by human microbiota. Importantly, we observed interindividual differences on the metabolism rate of gallic acid to pyrogallol among the three human subjects. In addition, we demonstrated that Lactobacillus plantarum 299v and Bacillus subtilis have the capacity to metabolize TFDG. CONCLUSIONS: The microbiota is important for the metabolism of theaflavins in both mice and humans. The in vivo functional impact of microbiota-generated theaflavins-derived metabolites is worthwhile of further study.

  9. The Microbiota Is Essential for the Generation of Black Tea Theaflavins-Derived Metabolites

    Science.gov (United States)

    Chen, Huadong; Hayek, Saeed; Rivera Guzman, Javier; Gillitt, Nicholas D.; Ibrahim, Salam A.; Jobin, Christian; Sang, Shengmin

    2012-01-01

    Background Theaflavins including theaflavin (TF), theaflavin-3-gallate (TF3G), theaflavin-3′-gallate (TF3′G), and theaflavin-3,3′-digallate (TFDG), are the most important bioactive polyphenols in black tea. Because of their poor systemic bioavailability, it is still unclear how these compounds can exert their biological functions. The objective of this study is to identify the microbial metabolites of theaflavins in mice and in humans. Methods and Findings In the present study, we gavaged specific pathogen free (SPF) mice and germ free (GF) mice with 200 mg/kg TFDG and identified TF, TF3G, TF3′G, and gallic acid as the major fecal metabolites of TFDG in SPF mice. These metabolites were absent in TFDG- gavaged GF mice. The microbial bioconversion of TFDG, TF3G, and TF3′G was also investigated in vitro using fecal slurries collected from three healthy human subjects. Our results indicate that TFDG is metabolized to TF, TF3G, TF3′G, gallic acid, and pyrogallol by human microbiota. Moreover, both TF3G and TF3′G are metabolized to TF, gallic acid, and pyrogallol by human microbiota. Importantly, we observed interindividual differences on the metabolism rate of gallic acid to pyrogallol among the three human subjects. In addition, we demonstrated that Lactobacillus plantarum 299v and Bacillus subtilis have the capacity to metabolize TFDG. Conclusions The microbiota is important for the metabolism of theaflavins in both mice and humans. The in vivo functional impact of microbiota-generated theaflavins-derived metabolites is worthwhile of further study. PMID:23227227

  10. Effects of superoxide generating systems on muscle tone, cholinergic and NANC responses in cat airway.

    Science.gov (United States)

    Bauer, V; Nakajima, T; Pucovsky, V; Onoue, H; Ito, Y

    2000-02-14

    To study the possible role of reactive oxygen species in airway hyperreactivity, we examined the effects of the superoxide anion radical (O(2)(-)) generating systems, pyrogallol and xanthine with xanthine oxidase, on muscle tone, excitatory and inhibitory neurotransmission in the cat airway. Smooth muscle contraction or non-adrenergic non-cholinergic (NANC) relaxation evoked by electrical field stimulation (EFS) were measured before or after O(2)(-) generating systems with or without diethydithiocarbamic acid (DEDTCA), an inhibitor of endogenous superoxide dismutase (SOD). Resting membrane potential or excitatory junction potential (EJP) were also measured in vitro. Both pyrogallol and xanthine/xanthine oxidase produced biphasic changes in basal and elevated (by 5-HT) muscle tone. After SOD pretreatment, both systems consistently produced a prolonged contraction, thereby indicating that O(2)(-) was converted to H(2)O(2) by the action of SOD and as a result the actions of O(2)(-) were lost but those of H(2)O(2) introduced. The O(2)(-) showed no significant effect on smooth muscle contraction or EJP evoked by EFS, however after DEDTCA pretreatment, it evoked initial enhancement followed by suppression of the contraction and EJP. DEDTCA pretreatment ameliorated the inhibitory action of pyrogallol and xanthine/xanthine oxidase on the NANC relaxation, probably because O(2)(-) could combine with endogenous NO to form peroxynitrite. These results indicate that the O(2)(-) generating systems have multiple actions, presumably due to the presence and simultaneous action of at least two different reactive oxygen species (O(2)(-) and H(2)O(2)). While H(2)O(2) seems to be responsible for elevation of muscle tone and augmentation of smooth muscle contraction by EFS, O(2)(-) inhibits muscle tone, cholinergic and NANC neurotransmission.

  11. Aqueous thermal degradation of gallic acid

    Science.gov (United States)

    Snow Boles, Jennifer; Crerar, David A.; Grissom, Grady; Key, Tonalee C.

    1988-02-01

    Aqueous thermal degradation experiments show gallic acid, a naturally occurring aromatic carboxylic compound, decomposes rapidly at temperatures between 105° and 150°C, with an activation energy of 22.9 or 27.8 kcal/ mole, depending on pH of the starting solution. Pyrogallol is the primary product identified, indicating degradation via decarboxylation and a carbanion transition state. Relatively rapid degradation of vanillic, phthalic, ellagic and tannic acids has also been observed, suggesting that these and perhaps other aromatic acids could be short-lived in deep formation waters.

  12. Use of auxin, fungicides and rooting cofactors to induce adventitious root formation in softwood cuttings of apple, gooseberry and some ornamental plants

    Directory of Open Access Journals (Sweden)

    M. G. Piątkowski

    2015-06-01

    Full Text Available Cuttings of apple rootstocks MM 106, Alnarp 2, M VII and M 26, of the ornamental plants Pyracantha coccinea Roem., Syringa Meyeri Schneid., and Weigela cv. Vanhouttei formed a larger numbers of adventitious roots with a mixture of naphthaleneacetic acid and the fungicide Captan than with auxin alone. Boric acid, vitamin B1 as well as pyrogallol and vanilic acid in rather high concentrations showed no effect on rooting when used separately or in a mixture with an auxin. Intermittent mist and bottom heat were used.

  13. Development of a UV/Vis spectrophotometric method for analysis of total polyphenols from Caesalpinia peltophoroides Benth

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    Fernanda G. Bueno

    2012-01-01

    Full Text Available Caesalpinia peltophoroides is a domesticated tree found in Brazil. It was necessary to develop an analytical method to determine the content of total polyphenols (TP in this herbal drug. The pre-analytical method was standardized for analysis time, wavelength, and the best standard to use. The optimum conditions were: pyrogallol, 760 nm, and 30 min respectively. Under these conditions, validation by UV/Vis spectrophotometry proved to be reliable for TP of the crude extract and semipurified fractions from C. peltophoroides. Standardization is required for every herbal drug, and this method proved to be linear, precise, accurate, reproducible, robust, and easy to perform.

  14. How Many Drugs Are Catecholics

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    Da-Peng Yang

    2007-04-01

    Full Text Available By examination of the 8659 drugs recorded in the Comprehensive Medicinal Chemistry (CMC database, 78 catecholics (including five pyrogallolics were identified, of which 17 are currently prescribed by FDA. Through analyzing the substitutent patterns, ClogPs and O-H bond dissociation enthalpies(BDEs of the catecholic drugs, some molecular features that may benefit circumventing the toxicity of catecholics were revealed: i strong electron-donating substituents are excluded; ii ClogP 3; iii an energy penalty exists for quinone formation. Besides, the present analyses also suggest that the clinical usage and dosage of currently prescribed catecholic drugs are of importance in designing or screening catecholic antioxidants.

  15. Differential pH sensitivity of tissue superoxide dismutases

    OpenAIRE

    Patel, Samir P.; Katyare, Surendra S.

    2006-01-01

    Superoxide dismutase (SOD) activities in the human and rat RBCs and rat liver, kidney, brain and heart mitochondria as well as cytosolic fractions were determined by the pyrogallol assay procedure with slight modifications. Measurements were carried out in 0.1 M potassium phosphate buffer pH 8.0 and 9.2 to assess the pH stability of the SODs from various systems. Under these conditions the SODs from different systems including RBCs exhibited differential pH stability i.e. they displayed diffe...

  16. Tunicate-Inspired Gallic Acid/Metal Ion Complex for Instant and Efficient Treatment of Dentin Hypersensitivity.

    Science.gov (United States)

    Prajatelistia, Ekavianty; Ju, Sung-Won; Sanandiya, Naresh D; Jun, Sang Ho; Ahn, Jin-Soo; Hwang, Dong Soo

    2016-04-20

    Dentin hypersensitivity is sharp and unpleasant pains caused by exposed dentinal tubules when enamel outside of the tooth wears away. The occlusion of dentinal tubules via in situ remineralization of hydroxyapatite is the best method to alleviate the symptoms caused by dentin hypersensitivity. Commercially available dental desensitizers are generally effective only on a specific area and are relatively toxic, and their performance usually depends on the skill of the clinician. Here, a facile and efficient dentin hypersensitivity treatment with remarkable aesthetic improvement inspired by the tunicate-self-healing process is reported. As pyrogallol groups in tunicate proteins conjugate with metal ions to heal the torn body armor of a tunicate, the ingenious mechanism by introducing gallic acid (GA) as a cheap, abundant, and edible alternative to the pyrogallol groups of the tunicate combined with a varied daily intake of metal ion sources is mimicked. In particular, the GA/Fe(3+) complex exhibits the most promising results, to the instant ≈52% blockage in tubules within 4 min and ≈87% after 7 d of immersion in artificial saliva. Overall, the GA/metal ion complex-mediated coating is facile, instant, and effective, and is suggested as an aesthetic solution for treating dentin hypersensitivity.

  17. Punicalagin and catechins contain polyphenolic substructures that influence cell viability and can be monitored by radical chemosensors sensitive to electron transfer.

    Science.gov (United States)

    Carreras, Anna; Mateos-Martín, María Luisa; Velázquez-Palenzuela, Amado; Brillas, Enric; Sánchez-Tena, Susana; Cascante, Marta; Juliá, Luis; Torres, Josep Lluís

    2012-02-22

    Plant polyphenols may be free radical scavengers or generators, depending on their nature and concentration. This dual effect, mediated by electron transfer reactions, may contribute to their influence on cell viability. This study used two stable radicals (tris(2,3,5,6-tetrachloro-4-nitrophenyl)methyl (TNPTM) and tris(2,4,6-trichloro-3,5-dinitrophenyl)methyl (HNTTM)) sensitive only to electron transfer reduction reactions to monitor the redox properties of polyphenols (punicalagin and catechins) that contain phenolic hydroxyls with different reducing capacities. The use of the two radicals reveals that punicalagin's substructures consisting of gallate esters linked together by carbon-carbon (C-C) bonds are more reactive than simple gallates and less reactive than the pyrogallol moiety of green tea catechins. The most reactive hydroxyls, detected by TNPTM, are present in the compounds that affect HT-29 cell viability the most. TNPTM reacts with C-C-linked gallates and pyrogallol and provides a convenient way to detect potentially beneficial polyphenols from natural sources.

  18. Equine digital veins are more sensitive to superoxide anions than digital arteries.

    Science.gov (United States)

    Lapo, Rock Allister; Gogny, Marc; Chatagnon, Gérard; Lalanne, Valérie; Harfoush, Khaled; Assane, Moussa; Desfontis, Jean-Claude; Mallem, Mohamed Yassine

    2014-10-05

    This work was designed to investigate (i) the effect of superoxide dismutase (SOD) inhibition on endothelial function and (ii) the free radical-induced endothelial dysfunction in equine digital veins (EDVs) and equine digital arteries (EDAs) isolated from healthy horses. EDV and EDA rings were suspended in a 5 ml organ bath containing Krebs solution. After a 60 min equilibration period, EDV and EDA rings were contracted with phenylephrine. Then, cumulative concentration-response curves (CCRCs) to acetylcholine were performed. In both EDVs and EDAs, acetylcholine (1 nM to 10 µM) produced concentration-dependent relaxation. We investigated the influence of SOD inhibition by diethyldithiocarbamate (DETC; 100 µM), a CuZnSOD inhibitor, on EDAs and EDVs relaxant responses to acetylcholine. Acetylcholine -mediated relaxation was impaired by DETC only in EDVs. SOD activity assayed by a xanthine-xanthine oxidase method was higher in EDAs compared with EDVs (Psuperoxide anions generating systems showed that in both EDVs and EDAs, the acetylcholine-mediated relaxation was significantly impaired by pyrogallol and homocysteine. This impairment was more pronounced in EDVs than in EDAs. Moreover, the pyrogallol-induced impairment of acetylcholine-mediated relaxation was potentiated by DETC to a greater extent in EDVs. We concluded that due to the lower activity of SOD, EDVs are more sensitive to superoxide anions than EDAs. So, any alteration of superoxide anions metabolism is likely to have a more important impact on venous rather than arterial relaxation.

  19. Purification and partial biochemical characterization of polyphenol oxidase from mamey (Pouteria sapota).

    Science.gov (United States)

    Palma-Orozco, Gisela; Ortiz-Moreno, Alicia; Dorantes-Alvarez, Lidia; Sampedro, José G; Nájera, Hugo

    2011-01-01

    While a long shelf life for fruit products is highly desired, enzymatic browning is the main cause of quality loss in fruits and is therefore a main problem for the food industry. In this study polyphenol oxidase (PPO), the main enzyme responsible for browning was isolated from mamey fruit (Pouteria sapota) and characterized biochemically. Two isoenzymes (PPO 1 and PPO 2) were obtained upon ammonium sulfate precipitation and hydrophobic and ion exchange chromatography; PPO 1 was purified up to 6.6-fold with 0.28% yield, while PPO 2 could not be characterized as enzyme activity was completely lost after 24 h of storage. PPO 1 molecular weight was estimated to be 16.1 and 18 kDa by gel filtration and SDS-PAGE, respectively, indicating that the native state of the PPO 1 is a monomer. The optimum pH for PPO 1 activity was 7. The PPO 1 was determined to be maximum thermally stable up to 35°C. Kinetic constants for PPO 1 were K(m)=44 mM and K(m)=1.3 mM using catechol and pyrogallol as substrate, respectively. The best substrates for PPO 1 were pyrogallol, 4-methylcatechol and catechol, while ascorbic acid and sodium metabisulfite were the most effective inhibitors.

  20. In vitro anti-oxidative activities of the various parts of Parkia biglobosa and GC-MS analysis of extracts with high activity.

    Science.gov (United States)

    Ibrahim, M A; Koorbanally, N A; Islam, M S

    2013-01-01

    The anti-oxidative activities of sequentially extracted solvent fractions of different parts of P. biglobosa were evaluated in a series of in vitro assays. Our findings indicated that all extracts had electron donating and free radical scavenging activities. But the ethanol (EtOH) extracts from all the parts demonstrated more promising anti-oxidative effects in these experimental models. Apart from the aqueous extracts of the stem bark and leaves, all other extracts exhibited hydroxyl radical scavenging (HRS) activity but the ethyl acetate (EtOAc) extract of the stem bark and EtOH extracts of the root and leaves possessed more powerful HRS activity than other corresponding extracts in the parts. Further, nitric oxide (NO) inhibition activities were observed in all the extracts except the EtOAc extract of the stem bark which showed pro-oxidative activity. However, the EtOH extract of the stem bark and root as well as the EtOAc extract of the leaves displayed more potent anti-NO activity than other extracts in the parts. The GC-MS analysis of the EtOH extracts revealed that the most abundant phytochemicals are pyrogallol derivatives. Data from this study suggest that the EtOH extracts from different parts of P. biglobosa contained potent anti-oxidative agents and pyrogallol could be the main bioactive constituent.

  1. Identification of coffee components that stimulate dopamine release from pheochromocytoma cells (PC-12).

    Science.gov (United States)

    Walker, J; Rohm, B; Lang, R; Pariza, M W; Hofmann, T; Somoza, V

    2012-02-01

    Coffee and caffeine are known to affect the limbic system, but data on the influence of coffee and coffee constituents on neurotransmitter release is limited. We investigated dopamine release and Ca(2+)-mobilization in pheochromocytoma cells (PC-12 cells) after stimulation with two lyophilized coffee beverages prepared from either Coffea arabica (AR) or Coffea canephora var. robusta (RB) beans and constituents thereof. Both coffee lyophilizates showed effects in dilutions between 1:100 and 1:10,000. To identify the active coffee compound, coffee constituents were tested in beverage and plasma representative concentrations. Caffeine, trigonelline, N-methylpyridinium, chlorogenic acid, catechol, pyrogallol and 5-hydroxytryptamides increased calcium signaling and dopamine release, although with different efficacies. While N-methylpyridinium stimulated the Ca(2+)-mobilization most potently (EC(200): 0.14±0.29μM), treatment of the cells with pyrogallol (EC(200): 48±14nM) or 5-hydroxytryptamides (EC(200): 10±3nM) lead to the most pronounced effect on dopamine release. In contrast, no effect was seen for the reconstituted biomimetic mixture. We therefore conclude that each of the coffee constituents tested stimulated the dopamine release in PC-12 cells. Since no effect was found for their biomimetic mixture, we hypothesize other coffee constituents being responsible for the dopamine release demonstrated for AR and RB coffee brews. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Immobilized Horseradish Peroxidase on Discs of Polyvinyl Alcohol-Glutaraldehyde Coated with Polyaniline

    Science.gov (United States)

    Caramori, Samantha Salomão; Fernandes, Kátia Flávia; de Carvalho Junior, Luiz Bezerra

    2012-01-01

    Discs of network polyvinyl alcohol-glutaraldehyde (PVAG) were synthesized and coated with polyaniline (PANI) using glutaraldehyde as a chemical arm (PVAG-PANIG-HRP disc). The best conditions for the immobilization were established as about 1.0 mg mL−1 of protein, for 60 min and pH 5.5. The soluble enzyme lost all of its activity after incubation at 70°C for 15 min, whereas the PVAG-PANIG-HRP disc retained about half of the initial activity for pyrogallol. The same PVAG-PANIG-HRP disc was used consecutively three times without any activity lossbut presented 25% of the initial activity after the 7th use. PVAG-PANIG-HRP disc retained approximately 80% and 60% of its initial activity after 60 and 80 days of storage, respectively. Resorcinol, m-cresol, catechol, pyrogallol, α-naphthol, βnaphthol, and 4, 4′-diaminodiphenyl benzidine were efficiently oxidized by the PVAG-PANIG-HRP disc (from about 70% to 90%), and it was less efficient towards aniline, phenol, and 2-nitrosonaphthol. PMID:22619582

  3. Preparative isolation and purification of phlorotannins from Ecklonia cava using centrifugal partition chromatography by one-step.

    Science.gov (United States)

    Lee, Ji-Hyeok; Ko, Ju-Young; Oh, Jae-Young; Kim, Chul-Young; Lee, Hee-Ju; Kim, Jaeil; Jeon, You-Jin

    2014-09-01

    Various bioactive phlorotannins of Ecklonia cava (e.g., dieckol, eckol, 6,6-bieckol, phloroglucinol, phloroeckol, and phlorofucofuroeckol-A) are reported. However, their isolation and purification are not easy. Centrifugal partition chromatography (CPC) can be used to efficiently purify the various bioactive-compounds efficiently from E. cava. Phlorotannins are successfully isolated from the ethyl acetate (EtOAc) fraction of E. cava by CPC with a two-phase solvent system comprising n-hexane:EtOAc:methanol:water (2:7:3:7, v/v) solution. The dieckol (fraction I, 40.2mg), phlorofucofuroeckol-A (fraction III, 31.1mg), and fraction II (34.1mg) with 2,7-phloroglucinol-6,6-bieckol and pyrogallol-phloroglucinol-6,6-bieckol are isolated from the crude extract (500 mg) by a one-step CPC system. The purities of the isolated dieckol and phlorofucofuroeckol-A are ⩾90% according to high performance liquid chromatography (HPLC) and electrospray ionization multi stage tandem mass spectrometry analyses. The purified 2,7-phloroglucinol-6,6-bieckol and pyrogallol-phloroglucinol-6,6-bieckol are collected from fraction II by recycle-HPLC. Thus, the CPC system is useful for easy and simple isolation of phlorotannins from E. cava. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Structure-activity relationship of polyphenols on inhibition of chemical mediator release from rat peritoneal exudate cells.

    Science.gov (United States)

    Yamada, K; Shoji, K; Mori, M; Ueyama, T; Matsuo, N; Oka, S; Nishiyama, K; Sugano, M

    1999-03-01

    The effect of phenolic compounds in foodstuffs on histamine and leukotriene B4 (LTB4) release from rat peritoneal exudate cells and their antioxidative activity were examined to assess their antiallergenic activities. Among them, triphenols such as pyrogallol and gallic acid inhibited histamine release from the cells, but diphenols did not. On the other hand, o- and p-diphenols such as catechol and hydroquinone with strong antioxidative activity inhibited LTB4 release as strongly as pyrogallol, but an m-derivative resorcinol with weak antioxidative activity did not. Though carboxylated compounds and their noncarboxylated counterparts were antioxidative, the former exerted a much weaker inhibitory effect on the LTB4 release than the latter. In flavonols, only myricetin with a triphenolic B ring strongly inhibited histamine release, but all flavonols strongly suppressed LTB4 release irrespective of the number of OH groups in the B ring. Among flavonoids with an o-diphenolic B ring, flavonol and flavone with a C4-carbonyl group strongly inhibited LTB4 release, whereas the activity of anthocyan without C4-carbonyl was much weaker than the above compounds. These results suggest that triphenolic structure is essential for the inhibition of histamine release. On the other hand, antioxidative activity and membrane permeability of phenolic compounds seemed to be essential for the inhibition of LTB4 release. In addition, the C4-carbonyl group seemed to be important for strongly inhibiting LTB4 release.

  5. Use of pruned computational neural networks for processing the response of oscillating chemical reactions with a view to analyzing nonlinear multicomponent mixtures.

    Science.gov (United States)

    Hervás, C; Toledo, R; Silva, M

    2001-01-01

    The suitability of pruned computational neural networks (CNNs) for resolving nonlinear multicomponent systems involving synergistic effects by use of oscillating chemical reaction-based methods implemented using the analyte pulse perturbation technique is demonstrated. The CNN input data used for this purpose are estimates provided by the Levenberg-Marquardt method in the form of a three-parameter Gaussian curve associated with the singular profile obtained when the oscillating system is perturbed by an analyte mixture. The performance of the proposed method was assessed by applying it to the resolution of mixtures of pyrogallol and gallic acid based on their perturbating effect on a classical oscillating chemical system, viz. the Belousov-Zhabotinskyi reaction. A straightforward network topology (3:3:2, with 18 connections after pruning) allowed the resolution of mixtures of the two analytes in concentration ratios from 1:7 to 6:2 with a standard error of prediction for the testing set of 4.01 and 8.98% for pyrogallol and gallic acid, respectively. The reduced dimensions of the selected CNN architecture allowed a mathematical transformation of the input vector into the output one that can be easily implemented via software. Finally, the suitability of response surface analysis as an alternative to CNNs was also tested. The results were poor (relative errors were high), which confirms that properly selected pruned CNNs are effective tools for solving the analytical problem addressed in this work.

  6. Differential behaviors of tea catechins under thermal processing: Formation of non-enzymatic oligomers.

    Science.gov (United States)

    Fan, Fang-Yuan; Shi, Meng; Nie, Ying; Zhao, Yue; Ye, Jian-Hui; Liang, Yue-Rong

    2016-04-01

    Tea catechins as a member of flavan-3-ols subclass with the same skeleton may behave differentially. This study investigated the chemical conversions of 8 catechins under heat treatment with the involvement of epimerization, hydrolysis and oxidation/condensation reactions. Three reactions were enhanced as temperature increased from 30 °C to 90 °C. The epimerization of non-gallated catechins was favored by epi-configuration but hindered by pyrogallol moiety, and the hydrolysis reaction of gallated catechins was facilitated by pyrogallol moiety. Epicatechin and epigallocatechin had the lowest thermostabilities due to epimerization and oxidation/condensation reactions respectively. Sufficient O2 was not a precondition for the occurrence of chemical conversions of catechins under heat treatment. Non-enzymatic oligomerization occurred to epi type catechins and catechin under heat treatment, and dehydrodicatechins A were mainly responsible for the browning of epicatechin and catechin solutions. The evidence of generation of catechin oligomers provides a novel way to explain sensory change of tea and relevant products during thermal processing.

  7. Mean centering of ratio kinetic profiles for the simultaneous kinetic determination of binary mixtures in electroanalytical methods.

    Science.gov (United States)

    Zarei, K; Atabati, M; Karami, M

    2009-09-01

    In this work, the applicability of mean centering (MC) of ratio kinetic profiles method to the kinetic voltammetry data is verified. For this purpose, a procedure is described for the determination of Sb(III) and Sb(V) by adsorptive linear sweep voltammetry using pyrogallol (py) as a complexing agent. The method is based on the differences between the rate of complexation of pyrogallol with Sb(V) and Sb(III) at pH 1.2. The results show that the mean centering of ratio kinetic profiles method is suitable for the speciation of antimony. Sb(III) and Sb(V) can be determined in the ranges of 3.0-120.0 and 10.0-240.0 ng mL(-1), respectively. Moreover, the solution is analyzed for any possible effects of foreign ions. The obtained results show that the method of MC in combination to electroanalytical techniques is a powerful method with high sensitivity and selectivity. The procedure is successfully applied to the speciation of antimony in pharmaceutical preparations.

  8. Determination of Total Germanium in Chinese Herbal Remedies by Square-Wave Catalytic Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode

    Directory of Open Access Journals (Sweden)

    Shangwei Zhong

    2013-01-01

    Full Text Available A catalytic adsorptive cathodic stripping voltammetric method on an improved bismuth film electrode (BiFE for the determination of trace germanium in the presence of pyrogallol has been investigated. A well-defined and sensitive stripping peak of Ge(IV-pyrogallol complex was observed at −0.79 V (versus SCE in a 0.1 M acetate buffer solution (pH 4.8 at a deposition potential of −0.34 V. The reduction current is catalytically enhanced by adding KBrO3. The experimental variables and potential interference were studied. Compared with the BiFE plated in the solution prepared based on HAc-NaAc without trisodium citrate, the improved BiFE electrodeposited in the solution of HAc-NaAc containing trisodium citrate displayed a better electroanalytical performance for the determination of germanium(IV. Under the optimized conditions, the detection limit of Ge(IV was 60 ng L−1, and the relative standard deviation (RSD was 3.73% at 5 μg L−1 level (n=9. This method was successfully applied to determine the total germanium in several Chinese herbal remedies.

  9. Bioconversion of Biomass-Derived Phenols Catalyzed by Myceliophthora thermophila Laccase

    Directory of Open Access Journals (Sweden)

    Anastasia Zerva

    2016-04-01

    Full Text Available Biomass-derived phenols have recently arisen as an attractive alternative for building blocks to be used in synthetic applications, due to their widespread availability as an abundant renewable resource. In the present paper, commercial laccase from the thermophilic fungus Myceliophthora thermophila was used to bioconvert phenol monomers, namely catechol, pyrogallol and gallic acid in water. The resulting products from catechol and gallic acid were polymers that were partially characterized in respect to their optical and thermal properties, and their average molecular weight was estimated via solution viscosity measurements and GPC. FT-IR and 1H-NMR data suggest that phenol monomers are connected with ether or C–C bonds depending on the starting monomer, while the achieved molecular weight of polycatechol is found higher than the corresponding poly(gallic acid. On the other hand, under the same condition, pyrogallol was dimerized in a pure red crystalline compound and its structure was confirmed by 1H-NMR as purpurogallin. The herein studied green synthesis of enzymatically synthesized phenol polymers or biological active compounds could be exploited as an alternative synthetic route targeting a variety of applications.

  10. Reactivity of phenolic compounds towards free radicals under in vitro conditions.

    Science.gov (United States)

    Mathew, Sindhu; Abraham, T Emilia; Zakaria, Zainul Akmar

    2015-09-01

    The free radical scavenging activity and reducing power of 16 phenolic compounds including four hydroxycinnamic acid derivatives namely ferulic acid, caffeic acid, sinapic acid and p-coumaric acid, benzoic acid and its derivatives namely protocatechuic acid, gallic acid and vanillic acid, benzene derivatives namely vanillin, vanillyl alcohol, veratryl alcohol, veratraldehyde, pyrogallol, guaiacol and two synthetic antioxidants, butylated hydroxy anisole (BHA) and propyl gallate were evaluated using 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH(•)), 2,2'-Azinobis-3- ethylbenzothiazoline-6-sulfonic acid radical (ABTS(+•)), Hydroxyl radical ((•)OH) and Superoxide radical (O2 (•-)) scavenging assays and reduction potential assay. By virtue of their hydrogen donating ability, phenolic compounds with multiple hydroxyl groups such as protocatechuic acid, pyrogallol, caffeic acid, gallic acid and propyl gallate exhibited higher free radical scavenging activity especially against DPPH(•) and O2 (•-). The hydroxylated cinnamates such as ferulic acid and caffeic acid were in general better scavengers than their benzoic acid counter parts such as vanillic acid and protocatechuic acid. All the phenolic compounds tested exhibited more than 85 % scavenging due to the high reactivity of the hydroxyl radical. Phenolic compounds with multiple hydroxyl groups also exhibited high redox potential. Exploring the radical scavenging and reducing properties of antioxidants especially those which are found naturally in plant sources are of great interest due to their protective roles in biological systems.

  11. Cocarcinogenic and tumor-promoting agents in tobacco carcinogenesis.

    Science.gov (United States)

    Van Duuren, B L; Goldschmidt, B M

    1976-06-01

    A series of 21 tobacco smoke components and related compounds werere applied to mouse skin (50 female ICR/Ha Swiss mice/group) three times weekly with a low dose (5 mug/application) of benzo[a]pyrene (B[a]P). The test compounds were of five classes: aliphatic hydrocarbons, aromatic hydrocarbons, phenols, and long-chain acids and alcohols. The following compounds enhanced remarkably the carcinogenicity of B[a]P: catechol, pyrogallol, decane, undecane, pyrene, benzo[e]pyrene, and fluoranthene. The following compounds inhibited B[a]P carcinogenicity completely: esculin, quercetin, squalene, and oleic acid. Phenol, eugenol, resorcinol, hydroquinone, hexadecane, and limonene partially inhibited B[a]P carcinogenicity. Six of the 21 compounds were also tested as tumor promoters im two-stage carcinogenesis. No direct correlation existed between tumor-promoting activity and cocarcinogenic activity. The cocarcinogens pyrogallol and catechol did not show tumor-promoting activity. Decane, tetradecane, anthralin, and phorbol myristate acetate showed both types of activity. Structure-activity relationships and possible modes of action were described.

  12. New Hybrid Properties of TiO2 Nanoparticles Surface Modified With Catecholate Type Ligands

    Science.gov (United States)

    Janković, Ivana A.; Šaponjić, Zoran V.; Džunuzović, Enis S.; Nedeljković, Jovan M.

    2010-01-01

    Surface modification of nanocrystalline TiO2 particles (45 Å) with bidentate benzene derivatives (catechol, pyrogallol, and gallic acid) was found to alter optical properties of nanoparticles. The formation of the inner-sphere charge-transfer complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites. The binding structures were investigated by using FTIR spectroscopy. The investigated ligands have the optimal geometry for chelating surface Ti atoms, resulting in ring coordination complexes (catecholate type of binuclear bidentate binding-bridging) thus restoring in six-coordinated octahedral geometry of surface Ti atoms. From the Benesi-Hildebrand plot, the stability constants at pH 2 of the order 103 M-1 have been determined.

  13. 1,4-Anhydro-4-seleno-d-talitol (SeTal) protects endothelial function in the mouse aorta by scavenging superoxide radicals under conditions of acute oxidative stress

    DEFF Research Database (Denmark)

    Ng, Hooi Hooi; Leo, Chen Huei; O'Sullivan, Kelly

    2016-01-01

    . Aortae were isolated from C57BL/6 male mice and mounted on a wire-myograph to assess vascular function. In the presence of a superoxide radical generator, pyrogallol, 300μM and 1mM of SeTal effectively prevented endothelial dysfunction compared to other selenium-containing compounds. In a second set...... of ex vivo experiments, mouse aortae were incubated for three days with either normal or high glucose, and co-incubated with SeTal at 37°C in 5% CO2. High glucose significantly reduced the sensitivity to the endothelium-dependent agonist, acetylcholine (ACh), increased superoxide production......, but had no effect in SeTal-treated aortae. Our data show that SeTal has potent antioxidant activity in isolated mouse aortae and prevents high glucose-induced endothelial dysfunction by decreasing superoxide levels, increasing basal NO availability and normalising the contribution of vasoconstrictor...

  14. Urinary metabolites from mango (Mangifera indica L. cv. Keitt) galloyl derivatives and in vitro hydrolysis of gallotannins in physiological conditions.

    Science.gov (United States)

    Barnes, Ryan C; Krenek, Kimberly A; Meibohm, Bernd; Mertens-Talcott, Susanne U; Talcott, Stephen T

    2016-03-01

    The absorption, metabolism, and excretion of mango galloyl derivatives (GD) has not yet been investigated in humans, and studies investigating repeated dosages of polyphenols are limited. In this human pilot trial, healthy volunteers (age = 21-38 y, n = 11) consumed 400 g/day of mango-pulp (cv. Keitt) for 10 days, and seven metabolites of gallic acid (GA) were characterized and quantified in urine excreted over a 12 h period. Pyrogallol-O-sulfate and deoxypyrogallol-O-sulfate were found to be significantly more excreted between days 1 and 10 (p mango consumption. Mango GTs were also found to release free GA in conditions similar to the intestines. GTs may serve as a pool of pro-GA compounds that can be absorbed or undergo microbial metabolism. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Stabilization of coacervate systems by products of abiogenic oxidation of low-molecular-weight compounds using the energy of. gamma. radiation

    Energy Technology Data Exchange (ETDEWEB)

    Evreinova, T.N.; Kuzin, A.M.; Kryukova, L.M.; Kameneva, T.G.; Khrust, Yu.R.

    1976-01-01

    The purpose of the study was to determine the possibility of stabilization of protein-carbohydrate and protein-nucleic acid systems by products of the abiogenic oxidation of pyrocatechol, pyrogallol, and o-dianisidine using the energy of gamma radiation. The protein-nucleic acid system was produced by mixing the following reagents: histone, DNA, acetate buffer, and a solution of oxidized compounds. The protein-carbohydrate system was produced by mixing the following reagents: histone, gum arabic, acetate buffer, and a solution of oxidized compounds. Results indicated that the stabilization of coacervate systems occurs when stabilizing low-molecular-weight compounds of the type of quinones and the imino form of o-dianisidine are included in them. These compounds may be formed under the action of physical factors without the participation of enzymes. (HLW)

  16. Immobilization of chemically modified horse radish peroxidase within activated alginate beads

    Directory of Open Access Journals (Sweden)

    Spasojević Dragica

    2014-01-01

    Full Text Available Immobilization of horse radish peroxidase (HRP within alginate beads was improved by chemical modification of the enzyme and polysaccharide chains. HRP and alginate were oxidized by periodate and subsequently modified with ethylenediamine. Highest specific activity of 0.43 U/ml of gel and 81 % of bound enzyme activity was obtained using aminated HRP and alginate oxidized by periodate. Immobilized enzyme retained 75 % of original activity after 2 days of incubation in 80 % (v/v dioxane and had increased activity at basic pH values compared to native enzyme. During repeated use in batch reactor for pyrogallol oxidation immobilized peroxidase retained 75 % of original activity. [Projekat Ministarstva nauke Republike Srbije, br. ON173017 i br. ON172049

  17. Effectiveness of various phenolic compounds (commercial and non-commercial) on biodiesel oxidation stability

    Energy Technology Data Exchange (ETDEWEB)

    Anastasakos, A.; Deligiannis, A.; Dodos, G.S.; Karonis, D.; Zannikos, F. [National Technical Univ. of Athens (Greece). Lab. of Fuels Technology and Lubricants

    2013-06-01

    This study investigates the effectiveness of seven phenolic compounds, including pyrogallol (PY), butylated hydroxytoluene (BHT), 2,5-di-tert-butylhydroquinone (DTBHQ), 4-tert-Butylcatechol (TBC), 2,5- bis(dimethylaminomethyl) hydroquinone, 2,5-bis(piperidinomethyl) hydroquinone and 2,5-bis(morpholinomethyl) hydroquinone on the oxidation stability of sunflower and soybean oil methyl esters. The seven phenolic compounds were dissolved in the base fuels at the same concentration levels, i.e., 200, 600, 800, 1000 and 1200 ppm. The oxidation stability measurements were carried out by employing a Rancimat accelerated oxidation unit according to EN 14214. Most of the antioxidants had a measurable positive impact on the oxidation stability in all concentrations of the additives. (orig.)

  18. Kinetics of non-catalyzed hydrolysis of tannin in high temperature liquid water

    Institute of Scientific and Technical Information of China (English)

    Li-li LU; Xiu-yang LU; Nan MA

    2008-01-01

    High temperature liquid water (HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions,especially acid-/base-catalyzed reactions.Non-catalyzed hydrolyses of gallotannin and tara tannin in HTLW for the simultaneous preparation of gallic acid (GA) and pyrogallol (PY) are under investigation in our laboratory.In this study,the hydrolysis kinetics of gallotannin and tara tannin were determined.The reaction is indicated to be a typical consecutive first-order one in which GA has formed as a main intermediate and PY as the final product.Selective decomposition of tannin in HTLW was proved to be possible by adjusting reaction temperature and time.The present results provide an important basic data and reference for the green preparation of GA and PY.

  19. Synthesis, crystal structure and antioxidant evaluation of C-4-acetamidophenylcalix[4]pyrogallolarene

    Energy Technology Data Exchange (ETDEWEB)

    Abosadiya, Hamza M.; Hasbullah, Siti Aishah; Yamin, Bohari M. [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia)

    2015-09-25

    C-4-acetamidophenylcalix[4]pyrogallolarene was synthesized by an acid catalyzed condensation reaction of pyrogallol with 4-acetamidobenzaldehyde. The compound was characterized by IR, {sup 1}H and {sup 13}C NMR spectroscopy. Single crystal X-ray analysis revealed that the molecule crystallized in a triclinic system with space group Pī and the unit cell dimensions a= 12.2948(16) Å, b= 13.4423(17) Å, c= 13.5906(18) Å, α =107.549(4)°, β =102.034(4)°, γ =90.535(4)°, Z= 1 and V= 2088.2(5) Å{sup 3}. The macrocyclic calix adopts a chair (C{sub 2h}) conformation and the molecule is associated with eight DMSO molecules of crystallization. Antioxidant test by DPPH method showed that the compound exhibits good antioxidant activity of about 72%.

  20. Voltammetric Behavior of Sodium 7-Methoxyl-4'-hydroxylisoflavone-3'-sulfonate and Its Application

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zun-Ting张尊听; DONG She-Ying董社英; ZHENG Jian-Bin郑建斌; ZHANG Hong-Fang张宏芳; GAO Hong高鸿

    2004-01-01

    Voltammetric behavior of sodium 7-methoxyl-4'-hydroxylisoflavone-3'-sulfonate (SMHS) in the aqueous solution from pH 1 to 5 was studied by linear sweep voltammetry, cyclic voltammetry and normal pulse voltammetry.SMHS caused only one reduction wave at -1.34 V (vs. saturated calomel electrode, SCE), which was an irreversible adsorptive wave of SMHS protonized involving one electron and one proton. The peak current of SMHS on synthetic samples. In addition, its scavenging effect on superoxide anion radical was studied by the auto-oxidation of pyrogallol in HCl-tris buffer solution (pH=8.2) in order to explain its peculiar biological effects. The experimental results proved that SMHS has antioxidant quality, and it is an efficient free radical scavenger of superoxide anion radical.

  1. Effect of inducers and process parameters on laccase production by Streptomyces psammoticus and its application in dye decolourization.

    Science.gov (United States)

    Niladevi, K N; Prema, P

    2008-07-01

    The process parameters influencing the production of extracellular laccases by Streptomyces psammoticus MTCC 7334 were optimized in submerged fermentation. Coffee pulp and yeast extract were the best substrate and nitrogen source respectively for laccase production by this strain. The optimization studies revealed that the laccase yield was maximum at pH 7.5 and temperature 32 degrees C. Salinity of the medium was also observed to be influencing the enzyme production. An agitation rate of 175 rpm and 15% inoculum were the other optimized conditions for maximum laccase yield (5.9 U/mL). Pyrogallol and para-anisidine proved to be the best inducers for laccase production by this strain and the enzyme yield was enhanced by 50% with these inducers. S. psammoticus was able to decolourize various industrial dyes at different rates and 80% decolourization of Remazol Brilliant Blue R (RBBR) was observed after 10 days of incubation in dye based medium.

  2. ADSORPTION OF CAFFEINE BY HYDROGEN DONATING ADSORBENTS BASED ON HYDROGEN BONDING

    Institute of Scientific and Technical Information of China (English)

    XUMancai; SHIZuoqing; 等

    2000-01-01

    The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents-hydroxypolystyrene,polystryene-azo-pyrogallol,and D72 resin-were measured.The adsorption enthalpies calculated from the isotherms according to the Clausisu-Clapeyron equation were -24-36kJ/mol,-32-37kJ/mol,and -19-24kJ/mol respectively.These values implied that the adsorption processes were based on hydrogen bonding.Furthermore.the mechanism of the adsorption of caffeine onto D72 resin was studied by IR spectra and the small molecular model experiments,and the results showed that the adsorption of caffeine onto hydrogen donating adsorbents was based on hydrogen bonding.

  3. Depressing effect of phenoxyl acetic acids on flotation of minerals containing Ca2+/Mg2+ gangues

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Phenoxyl acetic acids were applied to determine their depressing effect on minerals containing Ca2+/Mg2+ gangues. Calcite,mixture of calcite and fluorite, and nickel ore were used in the flotation. And the depression mechanism was studied by the determination of contact angle, zeta potential, adsorptive capacity of collector, and IR analysis as well. It is found that 0.1 mmol/L of phenoxyl acetic acid derived from pyrogallol or gallic acid exhibits strong depressing ability on calcite in almost zero yields at pH value of 9.8, and calcite can be depressed in the flotation of calcite/fluorite mixture for approximate 87% yield of fluorite. The flotation result of practical nickel ore containing serpentine indicates that these two depressants may also show better depression performance to serpentine than traditional depressants such as sodium fluosilicate and carboxylmethyl cellulose. Analysis for the depression mechanism reveals that there exists strong chemical interaction between the depressants and minerals.

  4. Fetal bovine serum influences the stability and bioactivity of resveratrol analogues: A polyphenol-protein interaction approach.

    Science.gov (United States)

    Tang, Fen; Xie, Yixi; Cao, Hui; Yang, Hua; Chen, Xiaoqing; Xiao, Jianbo

    2017-03-15

    Fetal bovine serum (FBS) is a universal growth supplement of cell and tissue culture media. Herein, the influences of FBS on the stability and antioxidant activity of 21 resveratrol analogues were investigated using a polyphenol-protein interaction approach. The structure-stability relationships of resveratrol analogues in FBS showed a clear decrease in the stability of hydroxylated resveratrol analogues in the order: resorcinol-type>pyrogallol-type>catechol-type. The glycosylation and methoxylation of resveratrol analogues enhanced their stability. A linear relationship between the stability of resveratrol analogues in FBS and the affinity of resveratrol analogues-FBS interaction was found. The oxidation process is not the only factor governing the stability of resveratrol analogues in FBS. These results facilitated the insightful investigation of the role of polyphenol-protein interactions in serum, thereby providing some fundamental clues for future clinical research and pharmacological studies on natural small molecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. A Study on Anti-oxidative Activity of Soybean Peptides with Linoleic Acid Peroxidation Systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Soybean bioactive peptides(SBPs) were prepared from the isolated soybean protein by proteolysis with an alkaline protease, alcalase, at 50 ℃ and pH = 8. 0. The dependence of hydrolysis time on hydrolysis degree and molecular weight distribution were examined. The hydrolysate was fractionated on a Sephadex G-25 column and the anti-oxidative activities of the fractions were detected by the method of pyrogallol auto-oxidation. The average chain length of soybean peptides that have anti-oxidative activity was estimated to be about 7. The anti-oxidative properties of the soybean peptide were also studied by using linoleic acid peroxidation systems. The optimal condition of the peroxidation system was set up, Vc/Cu2 + as the inducer at pH = 7.4 and 25 ℃. In addition, soybean peptides show higher antioxidative activity compared with GSH.

  6. Partículas de CoO(OH Dispersas em Pasta de Carbono Aplicado na Eletrooxidação de Compostos Fenólicos

    Directory of Open Access Journals (Sweden)

    Janaina Sartori Bonini

    2015-12-01

    Full Text Available In this work, particles of cobalt oxyhydroxide (III, CoO (OH, synthesized by alkaline precipitation were used in a carbon paste electrode modified [CPEM_CoO(OH] for the detection of phenolic compounds (catechol, guiacol, pyrogallol and salicylic acid. The cobalt-based electrode acts as the electron mediator, where the ion Co (III acts effectively in the oxidation/reduction of analyte, via reductive dissolution. As a result, the modified carbon paste electrode [CPEM_CoO(OH] exhibited good performance in the detection of phenolic compounds in a concentration range between 0 to 0.15 µmol L-1, with a limit of detection (LOD of 10-8 mol L-1. The electrochemical studies were performed using the techniques of cyclic voltammetry and linear. DOI: http://dx.doi.org/10.17807/orbital.v7i4.780

  7. Extraction and Characterization of Antioxidant Compositions From Fermented Fruit Juice of Morinda citrifolia(Noni)

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-hong; XUE Ya-rong; YE Yong-hang; YUAN Feng-feng; LIU Jun-yan; SHUANG Jing-lei

    2007-01-01

    Extraction and characterization of antioxidative compositions from the extracts of fermented Xisha Noni(Morinda citrifolia L.)juice were studied.The antioxidative constituents of 184.6g freeze-dried extracts of naturally fermented Xisha Noni juice were isolated successfully by petroleum ether,EtOAc and n-BuOH solvents,and the antioxidative effects were measured according to scavenging activity against hydroxyl generated in Fenton reaction system and superoxide anion radicals in pyrogallol autoxidation system.The EtOAc extract exhibited most significantly higher(P<0.01)antioxidative activity than mannitol or vitamin C,while the petroleum ether and n-BuOH extracts showed lower activities compared to were isolated from the EtOAc extract by several chromatography techniques for the first time.The results suggest that several compounds,in particular,the phenolic compounds,contribute separately or synergistically to the antioxidative activity of fermented Noni fruit juice.

  8. Ionic liquid-based dispersive liquid-liquid microextraction and enhanced spectrophotometric determination of molybdenum (VI) in water and plant leaves samples by FO-LADS.

    Science.gov (United States)

    Gharehbaghi, Maysam; Shemirani, Farzaneh

    2011-02-01

    A new simple and rapid ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) has been applied to preconcentrate trace levels of molybdenum (VI) as a prior step to its enhanced determination by fiber optic-linear array detection spectrophotometry (FO-LADS). In this method, a small amount of [Hmim][Tf(2)N] (1-hexyl-3-methylimmidazolium bis (trifluormethylsulfonyl) imid) as an extraction solvent was applied to extract molybdenum - pyrogallol red complex, which was formed in an aqueous solution in the presence of N-cetyl-N-N-N-trimethyl ammonium chloride as a sensitizing agent. Under optimum conditions, enhancement factor, detection limit and relative standard deviation (n=5, for 30 μg L(-1) of molybdenum (VI)) in 10 mL water sample were 72.6, 1.43 μg L(-1) and 2.8%, respectively.

  9. Inhibitory activity of carbonyl compounds on alcoholic fermentation by Saccharomyces cerevisiae.

    Science.gov (United States)

    Cao, Dongxu; Tu, Maobing; Xie, Rui; Li, Jing; Wu, Yonnie; Adhikari, Sushil

    2014-01-29

    Aldehydes and acids play important roles in the fermentation inhibition of biomass hydrolysates. A series of carbonyl compounds (vanillin, syringaldehyde, 4-hydroxybenzaldehyde, pyrogallol aldehyde, and o-phthalaldehyde) were used to examine the quantitative structure-inhibitory activity relationship of carbonyl compounds on alcoholic fermentation, based on the glucose consumption rate and the final ethanol yield. It was observed that pyrogallol aldehyde and o-phthalaldehyde (5.0 mM) reduced the initial glucose consumption rate by 60 and 89%, respectively, and also decreased the final ethanol yield by 60 and 99%, respectively. Correlating the molecular descriptors to inhibition efficiency in yeast fermentation revealed a strong relationship between the energy of the lowest unoccupied molecular orbital (ELUMO) of aldehydes and their inhibitory efficiency in fermentation. On the other hand, vanillin, syringaldehyde, and 4-hydroxybenzaldehyde (5.0 mM) increased the final ethanol yields by 11, 4, and 1%, respectively. Addition of vanillin appeared to favor ethanol formation over glycerol formation and decreased the glycerol yield in yeast fermentation. Furthermore, alcohol dehydrogenase (ADH) activity dropped significantly from 3.85 to 2.72, 1.83, 0.46, and 0.11 U/mg at 6 h of fermentation at vanillin concentrations of 0, 2.5, 5.0, 10.0, and 25.0 mM correspondingly. In addition, fermentation inhibition by acetic acid and benzoic acid was pH-dependent. Addition of acetate, benzoate, and potassium chloride increased the glucose consumption rate, likely because the salts enhanced membrane permeability, thus increasing glucose consumption.

  10. Role of superoxide dismutase enzymes and ascorbate in protection of nitrergic relaxation against superoxide anions in mouse duodenum

    Institute of Scientific and Technical Information of China (English)

    M Ata SECILMIS; Olcay Ergurhan KIROGLU; Nuran OGULENER

    2008-01-01

    Aim: The aim of this study was to investigate whether superoxide dismutase (SOD) enzymes and ascorbate play a role in the protection of the nitrergic relax-ation against superoxide anion inhibition in the mouse duodenum. Methods: The effects of exogenous SOD, N,N'-bis(salicylidene) ethylenediamine chlo-ride (EUK-8; a synthetic cell-permeable mimetic of the manganese SOD [Mn SOD] and ascorbate on relaxant responses induced by nitrergic nerve stimulation), exogenous nitric oxide (NO), and nitroglycerin were investigated in isolated mouse duodenum tissues. Results: Diethyidithiocarbamate (DETCA) inhibited the relaxation to exogenous NO and nitroglycerin, but not relaxation to electri-cal field stimulation (EFS). SOD and ascorbate partially prevented the inhibi-tory effect of DETCA on relaxation to NO, abut not to nitroglycerin. The DETCA-induced inhibition on nitroglycerin was prevented by ELrK-8. Hemoglobin, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazolinel-oxyl-3-oxide, and hydroxo-cobalamin inhibited the relaxation to NO, but not to EFS and nitroglycerin in the presence of DETCA. Pyrogallol and hydroquinone inhibited the relaxation to NO, but not to EFS and nitroglycerin. This inhibition was prevented by exog-enous SOD and ascorbate, but was not prevented by EUK-8. Pyrogallol and hy-droquinone did not inhibit the EFS-induced relaxation in the presence of DETCA. Duroquinone and 6-anilino-5.8-quinolinedione inhibited the relaxation to EFS, NO, and nitroglycerin, and this inhibition was prevented by EUK-8. Conclusion: These results suggest that the nitrergic neurotransmission in the mouse duode-num is protected by endogenous tissue antioxidants against superoxide anions, and Mn SOD, in addition to copper/zinc SOD, can protect NO from attack from superoxide anion generators intracellularly. Also, the possibility that the endog-enous neurotransmitter may not be the free NO but a NO-containing or NO-generating molecule in the mouse duodenum remains open.

  11. Evaluation of Crocus sativus L. Stigma Phenolic and Flavonoid Compounds and Its Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Hawa Z.E. Jaafar

    2010-09-01

    Full Text Available Saffron (Crocus sativus L. belongs to the Iridaceae family. The stigma of saffron has been widely used as spice, medicinal plant, and food additive in the Mediterranean and Subtropical countries. Recently, attention has been paid to the identification of new sources of safe natural antioxidants for the food industry. The antioxidant activities of spices are mainly attributed to their phenolic and flavonoid compounds. Saffron is one of the spices believed to possess antioxidant properties, but information on its antioxidant activity and phenolic, flavonoids compound are rather limited, therefore this research was carried out to evaluate the antioxidant activity of saffron stigmas extracted with different solvents. The phenolic and flavonoid compounds of saffron were also examined using reversed phase (RP-HPLC. Results showed that saffron stigma possess antioxidant activity. The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of saffron stigma at a concentration of 300 μg/mL, with values of 68.2% and 78.9%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. The obtained total phenolics value for methanolic saffron extract was 6.54 ± 0.02 mg gallic acid equivalent (GAE/g dry weight (DW, and for total flavonoids, 5.88 ± 0.12 mg rutin equivalent/g DW, which were also higher than values obtained from the ethanolic and boiling water extracts. In addition, the RP-HPLC analyses indicated the presence of gallic acid and pyrogallol as two bioactive compounds. In summary, saffron stigmas showed antioxidant activity and methanol appeared to be the best solvent to extract the active components, among which the presence of gallic acid and pyrogallol might contribute towards the stigma’s antioxidant properties. Hence, saffron stigma could be applied as a natural antioxidant

  12. Adsorption and detection of some phenolic compounds by rice husk ash of Kenyan origin.

    Science.gov (United States)

    Mbui, Damaris N; Shiundu, Paul M; Ndonye, Rachel M; Kamau, Geoffrey N

    2002-12-01

    Rice husk ash (RHA) obtained from a rice mill in Kenya has been used as an inexpensive and effective adsorbent (and reagent) for the removal (and detection) of some phenolic compounds in water. The abundantly available rice mill waste was used in dual laboratory-scale batch experiments to evaluate its potential in: (i) the removal of phenol, 1,3-dihydroxybenzene (resorcinol) and 2-chlorophenol from water; and (ii) the detection of 1,2-dihydroxybenzene (pyrocatechol) and 1,2,3-trihydroxybenzene (pyrogallol) present in an aqueous medium. The studies were conducted using synthetic water with different initial concentrations of the phenolic compounds. The effects of different operating conditions (such as contact time, concentration of the phenolic compounds, adsorbent quantity, temperature, and pH) were assessed by evaluating the phenolic compound removal efficiency as well as the extent of their color formation reactions (where applicable). RHA exhibits reasonable adsorption capacity for the phenolic compounds and follows both Langmuir and Freundlich isotherm models. Adsorption capacities of 1.53 x 10(-4), 8.07 x 10(-5), and 1.63 x 10(-6) mol g(-1) were determined for phenol, resorcinol and 2-chlorophenol, respectively. Nearly 100% adsorption of the phenolic compounds was possible and this depended on the weight of RHA employed. For the detection experiments, pyrocatechol and pyrogallol present in water formed coloured complexes with RHA, with the rate of colour formation increasing with temperature, weight of RHA, concentration of the phenolic compounds and sonication. This study has proven that RHA is a useful agricultural waste product for the removal and detection of some phenolic compounds.

  13. Unprecedented access of phenolic substrates to the heme active site of a catalase: substrate binding and peroxidase-like reactivity of Bacillus pumilus catalase monitored by X-ray crystallography and EPR spectroscopy.

    Science.gov (United States)

    Loewen, Peter C; Villanueva, Jacylyn; Switala, Jacek; Donald, Lynda J; Ivancich, Anabella

    2015-05-01

    Heme-containing catalases and catalase-peroxidases catalyze the dismutation of hydrogen peroxide as their predominant catalytic activity, but in addition, individual enzymes support low levels of peroxidase and oxidase activities, produce superoxide, and activate isoniazid as an antitubercular drug. The recent report of a heme enzyme with catalase, peroxidase and penicillin oxidase activities in Bacillus pumilus and its categorization as an unusual catalase-peroxidase led us to investigate the enzyme for comparison with other catalase-peroxidases, catalases, and peroxidases. Characterization revealed a typical homotetrameric catalase with one pentacoordinated heme b per subunit (Tyr340 being the axial ligand), albeit in two orientations, and a very fast catalatic turnover rate (kcat  = 339,000 s(-1) ). In addition, the enzyme supported a much slower (kcat  = 20 s(-1) ) peroxidatic activity utilizing substrates as diverse as ABTS and polyphenols, but no oxidase activity. Two binding sites, one in the main access channel and the other on the protein surface, accommodating pyrogallol, catechol, resorcinol, guaiacol, hydroquinone, and 2-chlorophenol were identified in crystal structures at 1.65-1.95 Å. A third site, in the heme distal side, accommodating only pyrogallol and catechol, interacting with the heme iron and the catalytic His and Arg residues, was also identified. This site was confirmed in solution by EPR spectroscopy characterization, which also showed that the phenolic oxygen was not directly coordinated to the heme iron (no low-spin conversion of the Fe(III) high-spin EPR signal upon substrate binding). This is the first demonstration of phenolic substrates directly accessing the heme distal side of a catalase.

  14. Reactive Oxygen Species-Induced Impairment of Endothelium-Dependent Relaxations in Rat Aortic Rings: Protection by Methanolic Extracts of Phoebe grandis

    Directory of Open Access Journals (Sweden)

    Mohd Rais Mustafa

    2011-04-01

    Full Text Available Generation of reactive oxygen species plays a pivotal role in the development of cardiovascular diseases. The present study describes the effects of the methanolic extract of Phoebe grandis (MPG stem bark on reactive oxygen species-induced endothelial dysfunction in vitro. Endothelium-dependent (acetylcholine, ACh and -independent relaxation (sodium nitroprusside, SNP was investigated from isolated rat aorta of Sprague-Dawley (SD in the presence of the β-NADH (enzymatic superoxide inducer and MPG extract. Superoxide anion production in aortic vessels was measured by lucigen chemiluminesence. Thirty minutes incubation of the rat aorta in vitro with β-NADH increased superoxide radical production and significantly inhibited ACh-induced relaxations. Pretreatment with MPG (0.5, 5 and 50 μg/mL restored the ACh-induced relaxations (Rmax: 92.29% ± 2.93, 91.02% ± 4.54 and 88.31 ± 2.36, respectively in the presence of β-NADH. MPG was ineffective in reversing the impaired ACh-induced relaxations caused by pyrogallol, a non-enzymatic superoxide generator. Superoxide dismutase (a superoxide scavenger, however, reversed the impaired ACh relaxations induced by both β-NADH and pyrogallol. MPG also markedly inhibited the β-NADH-induced generation of the superoxide radicals. Furthermore, MPG scavenging peroxyl radicals generated by tBuOOH (10−4 M.These results indicate that MPG may improve the endothelium dependent relaxations to ACh through its scavenging activity as well as by inhibiting the NADH/NADPH oxidase induced generation of superoxide anions.

  15. Tuning solubility and stability of hydrochlorothiazide co-crystals.

    Science.gov (United States)

    Sanphui, Palash; Rajput, Lalit

    2014-02-01

    Hydrochlorothiazide (HCT), C7H8ClN3O4S2, is a diuretic BCS (Biopharmaceutics Classification System) class IV drug which has primary and secondary sulfonamide groups. To modify the aqueous solubility of the drug, co-crystals with biologically safe co-formers were screened. Multi-component molecular crystals of HCT were prepared with nicotinic acid, nicotinamide, succinamide, p-aminobenzoic acid, resorcinol and pyrogallol using liquid-assisted grinding. The co-crystals were characterized by FT-IR spectroscopy, powder X-ray diffraction (PXRD) and differential scanning calorimetry. Single crystal structures were obtained for four of them. The N-H...O sulfonamide catemer synthons found in the stable polymorph of pure HCT are replaced in the co-crystals by drug-co-former heterosynthons. Isostructural co-crystals with nicotinic acid and nicotinamide are devoid of the common sulfonamide dimer/catemer synthons. Solubility and stability experiments were carried out for the co-crystals in water (neutral pH) under ambient conditions. Among the six binary systems, the co-crystal with p-aminobenzoic acid showed a sixfold increase in solubility compared with pure HCT, and stability up to 24 h in an aqueous medium. The co-crystals with nicotinamide, resorcinol and pyrogallol showed only a 1.5-2-fold increase in solubility and transformed to HCT within 1 h of the dissolution experiment. An inverse correlation is observed between the melting points of the co-crystals and their solubilities.

  16. The ethanolic extract of Kaempferia parviflora reduces ischaemic injury in rat isolated hearts.

    Science.gov (United States)

    Malakul, Wachirawadee; Ingkaninan, Kornkanok; Sawasdee, Pattara; Woodman, Owen L

    2011-09-01

    The ethanolic extract of Kaempferia parviflora (KPE) has been reported to contain a range of flavonoids and to enhance endothelial synthesis of NO. We investigated the vascular relaxant, antioxidant and cardioprotective activities of KPE. Vascular function was assessed in rat aortic rings and superoxide generation determined using lucigenin enhanced chemiluminescence. Ischaemia and reperfusion were induced in rat isolated, perfused hearts. KPE caused vasorelaxation (R(max) 102 ± 2%), which was partly inhibited by removal of the endothelium (R(max) 91 ± 1%) or by N(G)-nitro-l-arginine (L-NNA, R(max) 83 ± 3%) or 1H-[1,2,4] oxadiazolo[4,3-a]quinoxaline-1-one (ODQ, R(max) 80 ± 2%). In addition KPE caused concentration-dependent inhibition of the contractile response to exogenous Ca(2+). KPE (10(-3)M) also significantly inhibited superoxide radical generation induced by of xanthine/xanthine oxidase (2.3 ± 0.4% of control) to a similar extent to the xanthine oxidase inhibitor allopurinol (10(-4)M, 1.6 ± 0.5%) or by rat isolated aorta in the presence of NADPH (30.0 ± 6.3% of control) similarly to the NADPH oxidase inhibitor diphenyliodonium (5 × 10(-6)M, 23.1 ± 5.6%). In the presence of oxidant stress generated by pyrogallol endothelium-dependent relaxation of rat aortic rings was impaired (ACh R(max) control 99 ± 1%; pyrogallol 44 ± 5%), an effect that was significantly reduced by KPE (10(-4)M, ACh R(max) 82 ± 4%). In addition, KPE was found to attenuate the ventricular dysfunction caused by 20 min global ischaemia and 30 min reperfusion (I/R) in rat isolated hearts (dP/dt IR 1016 ± 242, IR+KPE 2238±233 mm Hg/s). KPE is an effective vasodilator and antioxidant that is able to prevent myocardial ischaemia-reperfusion injury. We suggest that KPE may be useful as an adjunct to thrombolytic therapy in the management of reperfusion injury. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Influence of natural humic acids and synthetic phenolic polymers on fibrinolysis

    Science.gov (United States)

    Klöcking, Hans-Peter

    The influence of synthetic and natural phenolic polymers on the release of plasminogen activator was studied in an isolated, perfused, vascular preparation (pig ear). Of the tested synthetic phenolic polymers, the oxidation products of caffeic acid (KOP) and 3,4-dihydroxyphenylacetic acid (3,4-DHPOP), at a concentration of 50 µg/ml perfusate, were able to increase the plasminogen activator activity by 70%. The oxidation products of chlorogenic acid (CHOP), hydrocaffeic acid (HYKOP), pyrogallol (PYROP) and gallic acid (GALOP), at the same concentration, exerted no influence on the release of plasminogen activator. Of the naturally occurring humic acids, the influence of sodium humate was within the same order of magnitude as KOP and 3,4-DHPOP. Ammonium humate was able to increase the plasminogen activator release only at a concentration of 100 µg/ml perfusate. In rats, the t-PA activity increased after i.v. application of 10 mg/kg of KOP, Na-HS or NH4-HS.

  18. Interaction of humic acids and humic-acid-like polymers with herpes simplex virus type 1

    Science.gov (United States)

    Klöcking, Renate; Helbig, Björn

    The study was performed in order to compare the antiviral activity against herpes simplex virus type 1 (HSV-1) of synthetic humic-acid-like polymers to that of their low-molecular-weight basic compounds and naturally occurring humic acids (HA) in vitro. HA from peat water showed a moderate antiviral activity at a minimum effective concentration (MEC) of 20 µg/ml. HA-like polymers, i.e. the oxidation products of caffeic acid (KOP), hydrocaffeic acid (HYKOP), chlorogenic acid (CHOP), 3,4-dihydroxyphenylacetic acid (3,4-DHPOP), nordihydroguaretic acid (NOROP), gentisinic acid (GENOP), pyrogallol (PYROP) and gallic acid (GALOP), generally inhibit virus multiplication, although with different potency and selectivity. Of the substances tested, GENOP, KOP, 3,4-DHPOP and HYKOP with MEC values in the range of 2 to 10 µg/ml, proved to be the most potent HSV-1 inhibitors. Despite its lower antiviral potency (MEC 40 µg/ml), CHOP has a remarkable selectivity due to the high concentration of this polymer that is tolerated by the host cells (>640 µg/ml). As a rule, the antiviral activity of the synthetic compounds was restricted to the polymers and was not preformed in the low-molecular-weight basic compounds. This finding speaks in favour of the formation of antivirally active structures during the oxidative polymerization of phenolic compounds and, indirectly, of corresponding structural parts in different HA-type substances.

  19. Antimicrobial and antioxidant activities of Mimusops elengi seed extract mediated isotropic silver nanoparticles

    Science.gov (United States)

    Kiran Kumar, Hoskote Anand; Mandal, Badal Kumar; Mohan Kumar, Kesarla; Maddinedi, Sireesh babu; Sai Kumar, Tammina; Madhiyazhagan, Pavithra; Ghosh, Asit Ranjan

    2014-09-01

    The present study reports the use of Mimusops elengi (M. elengi) fruit extract for the synthesis of silver nanoparticles (Ag NPs). The synthesized Ag NPs was initially noticed through visual color change from yellow to reddish brown and further confirmed by surface plasmonic resonance (SPR) band at 429 nm using UV-Visible spectroscopy. Morphology and size of Ag NPs was determined by Transmission Electron Microscopy (TEM) analysis. X-ray Diffraction (XRD) study revealed crystalline nature of Ag NPs. The prolonged stability of Ag NPs was due to capping of oxidized polyphenols which was established by Fourier Transform Infrared Spectroscopy (FTIR) study. The polyphenols present in M. elengi fruit extract was analyzed by High Pressure Liquid Chromatography (HPLC) and the results revealed the presence of ascorbic acid, gallic acid, pyrogallol and resorcinol. In order to study the role of these polyphenols in reducing Ag+ ions to Ag NPs, analyses of extracts before reduction and after reduction were carried out. In addition, the synthesized Ag NPs were tested for antibacterial and antioxidant activities against Staphylococcus aureus (S. Aureus) and Escherichia coli (E. coli). Ag NPs showed good antimicrobial activity against both gram positive (S. aureus) and gram negative (E. coli) bacteria. It also showed good antioxidant activity as compared to ascorbic acid as standard antioxidant.

  20. Green synthesis of size controllable gold nanoparticles

    Science.gov (United States)

    Mohan Kumar, Kesarla; Mandal, Badal Kumar; Kiran Kumar, Hoskote A.; Maddinedi, Sireesh Babu

    2013-12-01

    A facile rapid green eco-friendly method to synthesize gold nanoparticles (Au NPs) of tunable size using aqueous Terminalia arjuna fruit extracts has been demonstrated herein. Formation of Au NPs was confirmed by Surface Plasmon Resonance (SPR) study at 528 nm using UV-visible spectrophotometer. The time of reduction, size and morphological variations of Au NPs were studied with varying quantities of T. arjuna fruit aqueous extracts. Synthesized Au NPs were characterized using UV-visible spectroscopy, Fourier transformed infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDAX). Polyphenols responsible for reduction of Au3+ to Au0 were identified using High Performance Liquid Chromatography (HPLC) as ascorbic acid, gallic acid and pyrogallol. The oxidized forms of polyphenols formed coordination with surface of Au NPs which protected their further growth and aggregation. We also propose a plausible mechanism how to tune size and shape of Au NPs by varying the quantity of extracts. Thus obtained Au NPs were stable for more than four months.

  1. Sporobacterium olearium gen. nov., sp. nov., a new methanethiol-producing bacterium that degrades aromatic compounds, isolated from an olive mill wastewater treatment digester.

    Science.gov (United States)

    Mechichi, T; Labat, M; Garcia, J L; Thomas, P; Patel, B K

    1999-10-01

    A strictly chemo-organotrophic, anaerobic bacterium was isolated from an olive mill wastewater treatment digester on syringate and designated strain SR1T. The cells were slightly curved rods, stained Gram-positive and possessed terminal spores. Strain SR1T utilized crotonate, methanol and a wide range of aromatic compounds including 3,4,5-trimethoxybenzoate (TMB), 3,4,5-trimethoxycinnamate (TMC), syringate, 3,4,5-trimethoxyphenylacetate (TMPA), 3,4,5-trimethoxyphenylpropionate (TMPP), ferulate, sinapate, vanillate, 3,4-dimethoxybenzoate, 2,3-dimethoxybenzoate, gallate, 2,4,6-trihydroxybenzoate (THB), pyrogallol, phloroglucinol and quercetin as carbon and energy sources. Acetate and butyrate were produced from aromatic compounds, methanol and crotonate whereas methanethiol (MT) was produced from methoxylated aromatic compounds and methanol. Strain SR1T had a G + C content of 38 mol% and grew optimally between 37 and 40 degrees C at pH 7.2 on a crotonate-containing medium. Phylogenetically, strain SR1T was a member of cluster XIVa of the Clostridiales group and shared a sequence similarity of 90% with Clostridum aminovalericum and Eubacterium fissicatena. Consequently, its precise neighbourliness to any one of them depended on the selection of strains of the cluster. On the basis of the phylogenetic and phenotypic evidence presented in this paper, the designation of strain SR1T as Sporobacterium olearium gen. nov., sp. nov. is proposed. The type strain is SR1T (= DSM 12504T).

  2. Study on Preparation of Rapeseed Peptides from Rapeseed Protein by Enzymatic Hydrolysis%18种常见水果对自由基消除作用的研究

    Institute of Scientific and Technical Information of China (English)

    陈安均; 葛焱; 郭双霜; 梁杰; 蒲彪; 刘兴艳

    2013-01-01

      采用水杨酸法产生羟基自由基和邻苯三酚自氧化法产生超氧阴离子自由基,对18种常见水果清除自由基的能力进行了测定与比较,并分析其清除能力和维生素含量之间的关系。结果表明,对羟基自由基清除率最大的是柠檬,对超氧阴离子自由基清除率最大的是猕猴桃,所测水果中自由基清除能力与水果中维生素的含量没有明显的线性关系。%  The free radical scavenging capacit of 18 kinds of fruits and it's relation with the content of Vitamin were studied using the pyrogallol autoxidation method and the Fenton method. Respectively , the kiwi fruit was found as the best fruit for the superoxide anion radical scavenging. The lemon was the best fruit for the hydroxyl radical scavenging. Finally there was no significant relation between the free radical scavenging capacit and the content of the vitamin.

  3. Chemical constituents and antioxidant activities of waste liquid extract from Apostichopus japonicus Selenka processing

    Institute of Scientific and Technical Information of China (English)

    LI Chaofeng; LI Xiancui; LI Hong; GUO Shuju; ZHU Xiaobin

    2013-01-01

    Apostichopus japonicus Selenka is an ideal tonic food that is used traditionally in many Asian countries,and it contains many bioactive substances,such as antioxidant,antimicrobial,and anticancer materials.To convert waste liquid generated during production into a useful resource,extract from waste liquid was isolated by column chromatography and studied by the pyrogallol autoxidation and 1,10-phenanthroline-Fe2+ oxidation methods.Results show that the extract scavenged about 91% of the superoxide anion radical at a concentration of 1.4 mg/mL and 24% of the hydroxyl radical at 3.3 mg/mL.Four compounds were isolated and identified from the extract:2,4-dihydroxy-5-methyl-1,3-azine; 2,4-dihydroxy-1,3-diazine; 3-O-[β-D-quinovopranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopranosyl]-holosta-9(11)-ene-3β,12t,17α-triol; and 24-ethyl-5t-cholesta-7-ene-3β-O-β-D-xylopyranoside.All of these compounds are known in A.japonicus,and were found in the waste liquid for the first time.

  4. Structural characterization of the isoenzymatic forms of human myeloperoxidase: evaluation of the iron-containing prosthetic group.

    Science.gov (United States)

    Wright, J; Bastian, N; Davis, T A; Zuo, C; Yoshimoto, S; Orme-Johnson, W H; Tauber, A I

    1990-01-01

    Myeloperoxidase (MPO) from human neutrophils has been purified and found to exist in three isoenzymatic forms, resolved by ion exchange chromatography. In addition to differences in subunit size and cellular compartmentalization of the isoenzymes, differences have been reported in their activity and susceptibility to inhibition. The structural basis of these isoenzymes is unclear; we attempted to further define their functional characteristics and structural identity. First, we measured respective enzymatic activity using a panel of substrates; MPO I was found to have lower activity with some substrates (pyrogallol, guaiacol, potassium iodide [KI]), but similar activity to the other isoenzymes with 4-aminoantipyrine. These studies confirm that MPO I is enzymatically distinct from MPO II and MPO III. Next, we examined the structural basis of these differences by evaluating the iron-containing prosthetic group in each form using electron paramagnetic resonance (EPR) and determination of the pyridine hemochrome. No significant difference between the isoenzymes was noted in these parameters, suggesting that the prosthetic group is the same in each protein. The cause for any difference in enzymatic activity must lie then in variations extrinsic to the heme, and based on previous studies of the gene and protein analysis, the posttranslational modification of MPO must account for these isoenzymatic species.

  5. Purification and characterization of a secreted laccase of Gaeumannomyces graminis var. tritici.

    Science.gov (United States)

    Edens, W A; Goins, T Q; Dooley, D; Henson, J M

    1999-07-01

    We purified a secreted fungal laccase from filtrates of Gaeumannomyces graminis var. tritici cultures induced with copper and xylidine. The active protein had an apparent molecular mass of 190 kDa and yielded subunits with molecular masses of 60 kDa when denatured and deglycosylated. This laccase had a pI of 5.6 and an optimal pH of 4.5 with 2,6-dimethoxyphenol as its substrate. Like other, previously purified laccases, this one contained several copper atoms in each subunit, as determined by inductively coupled plasma spectroscopy. The active enzyme catalyzed the oxidation of 2, 6-dimethoxyphenol (Km = 2.6 x 10(-5) +/- 7 x 10(-6) M), catechol (Km = 2.5 x 10(-4) +/- 1 x 10(-5) M), pyrogallol (Km = 3.1 x 10(-4) +/- 4 x 10(-5) M), and guaiacol (Km = 5.1 x 10(-4) +/- 2 x 10(-5) M). In addition, the laccase catalyzed the polymerization of 1, 8-dihydroxynaphthalene, a natural fungal melanin precursor, into a high-molecular-weight melanin and catalyzed the oxidation, or decolorization, of the dye poly B-411, a lignin-like polymer. These findings indicate that this laccase may be involved in melanin polymerization in this phytopathogen's hyphae and/or in lignin depolymerization in its infected plant host.

  6. Spectrophotometric determination of low levels arsenic species in beverages after ion-pairing vortex-assisted cloud-point extraction with acridine red.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan; Kır, Ufuk

    2016-01-01

    A new, low-cost, micellar-sensitive and selective spectrophotometric method was developed for the determination of inorganic arsenic (As) species in beverage samples. Vortex-assisted cloud-point extraction (VA-CPE) was used for the efficient pre-concentration of As(V) in the selected samples. The method is based on selective and sensitive ion-pairing of As(V) with acridine red (ARH(+)) in the presence of pyrogallol and sequential extraction into the micellar phase of Triton X-45 at pH 6.0. Under the optimised conditions, the calibration curve was highly linear in the range of 0.8-280 µg l(-1) for As(V). The limits of detection and quantification of the method were 0.25 and 0.83 µg l(-1), respectively. The method was successfully applied to the determination of trace As in the pre-treated and digested samples under microwave and ultrasonic power. As(V) and total As levels in the samples were spectrophotometrically determined after pre-concentration with VA-CPE at 494 nm before and after oxidation with acidic KMnO4. The As(III) levels were calculated from the difference between As(V) and total As levels. The accuracy of the method was demonstrated by analysis of two certified reference materials (CRMs) where the measured values for As were statistically within the 95% confidence limit for the certified values.

  7. Bathochromic and hyperchromic effects of aluminum salt complexation by anthocyanins from edible sources for blue color development.

    Science.gov (United States)

    Sigurdson, Gregory T; Giusti, M Monica

    2014-07-23

    Use of artificial food colorants has declined due to health concerns and consumer demand, making natural alternatives a high demand. The effects of Al(3+) salt on food source anthocyanins were evaluated with the objective to better understand blue color development of metalloanthocyanins. This is one of the first known studies to evaluate the effects of food source anthocyanin structures, including acylation, with chelation of aluminum. Cyanidin and delphinidin derivatives from different plants were treated with factorial excess of Al(3+) in pH 3-6 and evaluated by spectrophotometry and colorimetry over 28 days. Anthocyanin concentration, salt ratio, and pH determined final color and intensity. Pyrogallol moieties on delphinidin showed furthest bathochromic shifts, whereas acylation promoted higher chroma. Blue color developed at lower pH when acylated anthocyanins reacted with Al(3+); hue ∼270 occurred with acylated delphinidin at pH ≥ 2.5. Highest chelate stability was found with AlCl3100-500× anthocyanin concentration. This investigation showed anthocyanin-metal chelation can produce a variety of intense violet to blue colors under acidic pH with potential for food use.

  8. Immobilization of horseradish peroxidase onto kaolin.

    Science.gov (United States)

    Šekuljica, Nataša Ž; Prlainović, Nevena Ž; Jovanović, Jelena R; Stefanović, Andrea B; Djokić, Veljko R; Mijin, Dušan Ž; Knežević-Jugović, Zorica D

    2016-03-01

    Kaolin showed as a very perspective carrier for the enzyme immobilization and it was used for the adsorption of horseradish peroxidase (HRP). The effects of the enzyme concentration and pH on the immobilization efficiency were studied in the reaction with pyrogallol and anthraquinone dye C.I. Acid Violet 109 (AV 109). In addition, Fourier transform infrared spectroscopy, scanning electron microscopy and analysis by Brunauer-Emmett-Teller were performed for kaolin, thermally activated kaolin and the immobilized enzyme. It has been shown that 0.1 IU of HRP-kaolin decolorized 87 % of dye solution, under the optimal conditions (pH 5.0, temperature 24 °C, dye concentration 40 mg/L and 0.2 mM of H2O2) within 40 min. The immobilized HRP decolorization follows the Ping Pong Bi-Bi mechanism with dead-end inhibition by the dye. The biocatalyst retained 35 ± 0.9 % of the initial activity after seven cycles of reuse in the decolorization reaction of AV 109 under optimal conditions in a batch reactor. The obtained kinetic parameters and reusability study confirmed improvement in performances of k-HRP compared to free, indicating that k-HRP has a great potential for environmental purposes.

  9. Potentiometric titration and equivalent weight of humic acid

    Science.gov (United States)

    Pommer, A.M.; Breger, I.A.

    1960-01-01

    The "acid nature" of humic acid has been controversial for many years. Some investigators claim that humic acid is a true weak acid, while others feel that its behaviour during potentiometric titration can be accounted for by colloidal adsorption of hydrogen ions. The acid character of humic acid has been reinvestigated using newly-derived relationships for the titration of weak acids with strong base. Re-interpreting the potentiometric titration data published by Thiele and Kettner in 1953, it was found that Merck humic acid behaves as a weak polyelectrolytic acid having an equivalent weight of 150, a pKa of 6.8 to 7.0, and a titration exponent of about 4.8. Interdretation of similar data pertaining to the titration of phenol-formaldehyde and pyrogallol-formaldehyde resins, considered to be analogs for humic acid by Thiele and Kettner, leads to the conclusion that it is not possible to differentiate between adsorption and acid-base reaction for these substances. ?? 1960.

  10. Purification and partial biochemical characterization of polyphenol oxidase from mango (Mangifera indica cv. Manila).

    Science.gov (United States)

    Palma-Orozco, Gisela; Marrufo-Hernández, Norma A; Sampedro, José G; Nájera, Hugo

    2014-10-08

    Polyphenol oxidase (PPO) is an enzyme widely distributed in the plant kingdom that has been detected in most fruits and vegetables. PPO was extracted and purified from Manila mango (Mangifera indica), and its biochemical properties were studied. PPO was purified 216-fold by hydrophobic interaction and ion exchange chromatography. PPO was purified to homogeneity, and the estimated PPO molecular weight (MW) by SDS-PAGE was ≈31.5 kDa. However, a MW of 65 kDa was determined by gel filtration, indicating a dimeric structure for the native PPO. The isolated PPO showed the highest affinity to pyrogallol (Km = 2.77 mM) followed by 4-methylcatechol (Km = 3.14 mM) and catechol (Km = 15.14 mM). The optimum pH for activity was 6.0. PPO was stable in the temperature range of 20-70 °C. PPO activity was completely inhibited by tropolone, ascorbic acid, sodium metabisulfite, and kojic acid at 0.1 mM.

  11. Green synthesis of size controllable gold nanoparticles.

    Science.gov (United States)

    Mohan Kumar, Kesarla; Mandal, Badal Kumar; Kiran Kumar, Hoskote A; Maddinedi, Sireesh Babu

    2013-12-01

    A facile rapid green eco-friendly method to synthesize gold nanoparticles (Au NPs) of tunable size using aqueous Terminalia arjuna fruit extracts has been demonstrated herein. Formation of Au NPs was confirmed by Surface Plasmon Resonance (SPR) study at 528 nm using UV-visible spectrophotometer. The time of reduction, size and morphological variations of Au NPs were studied with varying quantities of T. arjuna fruit aqueous extracts. Synthesized Au NPs were characterized using UV-visible spectroscopy, Fourier transformed infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDAX). Polyphenols responsible for reduction of Au(3+) to Au(0) were identified using High Performance Liquid Chromatography (HPLC) as ascorbic acid, gallic acid and pyrogallol. The oxidized forms of polyphenols formed coordination with surface of Au NPs which protected their further growth and aggregation. We also propose a plausible mechanism how to tune size and shape of Au NPs by varying the quantity of extracts. Thus obtained Au NPs were stable for more than four months.

  12. Changes in antioxidant systems in soybean as affected by Sclerotinia sclerotiorum (Lib.) de Bary.

    Science.gov (United States)

    Malenčić, Djordje; Kiprovski, Biljana; Popović, Milan; Prvulović, Dejan; Miladinović, Jegor; Djordjević, Vuk

    2010-01-01

    Changes in antioxidant systems in soybean [Glycine max (L.) Merr., Fabaceae] genotypes infected with Sclerotinia sclerotiorum were studied 12, 24, 48 and 72h after inoculation. Generation of superoxide and hydroxyl radicals was evaluated together with the production of malonyldialdehyde, main end product of lipid peroxidation. Several enzymatic and non-enzymatic parameters were monitored as well, such as the activity of antioxidant enzymes superoxide dismutase and pyrogallol and guaiacol peroxidases, reduced glutathione, soluble proteins and total carotenoids content. Results showed that genotypes expressed oxidative burst as well as different antioxidant systems in response to biotic stress caused by pathogen invasion. It has been confirmed that, although hypersensitive cell death is efficient against biotrophic pathogens, it does not protect soybean plants against infection by the necrotrophic pathogen such as S. sclerotiorum. Still, some genotypes showed distinctive and combined activity of several biochemical parameters which may point to further directions in exploring host-pathogen relations and lead to selection and production of new genotypes with higher levels of tolerance. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  13. Phytochemical Composition, Antioxidant Activity, and Neuroprotective Effect of Terminalia chebula Retzius Extracts

    Directory of Open Access Journals (Sweden)

    Chia Lin Chang

    2012-01-01

    Full Text Available The objectives of this study were to determine phytochemical compositions, chemiluminescence antioxidant activities, and neuroprotective effects on PC12 cells for water, methanol, and 95% ethanol extracts of the air-dried fruit of Terminalia chebula Retzius. The water extract afforded the greatest yield, and total phenolic and tannin content. The methanol extract yielded the greatest total triterpenoid content. Based on four chemiluminescence antioxidant assays, the three extracts showed various degrees of antioxidant activity. The methanol extract showed good antioxidant activity based on the horseradish peroxidase-luminol-hydrogen peroxide (H2O2 assay. The water extract appeared to have good antioxidant activities in cupric sulfate-Phen-Vc-H2O2 and luminol-H2O2 assays. Pyrogallol-luminol assay showed the 95% ethanol extract to have good antioxidant activity. The methanol and water extracts presented neuroprotective activities on H2O2-induced PC12 cell death at 0.5–5.0 μg/mL. Further investigations are necessary to verify these activities in vivo.

  14. A manganese catalase from Thermomicrobium roseum with peroxidase and catecholase activity.

    Science.gov (United States)

    Baginski, Robin; Sommerhalter, Monika

    2017-01-01

    An enzyme with catechol oxidase activity was identified in Thermomicrobium roseum extracts via solution assays and activity-stained SDS-PAGE. Yet, the genome of T. roseum does not harbor a catecholase gene. The enzyme was purified with two anion exchange chromatography steps and ultimately identified to be a manganese catalase with additional peroxidase and catecholase activity. Catalase activity (6280 ± 430 IU/mg) clearly dominated over pyrogallol peroxidase (231 ± 53 IU/mg) and catecholase (3.07 ± 0.56 IU/mg) activity as determined at 70 °C. Most enzyme kinetic properties were comparable to previously characterized manganese catalase enzymes. Catalase activity was highest at alkaline pH values and showed inhibition by excess substrate and chloride. The apparent K m and k cat values were 20 mM and 2.02 × 10(4) s(-1) subunit(-1) at 25 °C and pH 7.0.

  15. Assessment of aerobic and respiratory growth in the Lactobacillus casei group.

    Directory of Open Access Journals (Sweden)

    Teresa Zotta

    Full Text Available One hundred eighty four strains belonging to the species Lactobacillus casei, L. paracasei and L. rhamnosus were screened for their ability to grow under aerobic conditions, in media containing heme and menaquinone and/or compounds generating reactive oxygen species (ROS, in order to identify respiratory and oxygen-tolerant phenotypes. Most strains were able to cope with aerobic conditions and for many strains aerobic growth and heme or heme/menaquinone supplementation increased biomass production compared to anaerobic cultivation. Only four L. casei strains showed a catalase-like activity under anaerobic, aerobic and respiratory conditions and were able to survive in presence of H2O2 (1 mM. Almost all L. casei and L. paracasei strains tolerated menadione (0.2 mM and most tolerated pyrogallol (50 mM, while L. rhamnosus was usually resistant only to the latter compound. This is the first study in which an extensive screening of oxygen and oxidative stress tolerance of members of the L. casei group has been carried out. Results allowed the selection of strains showing the typical traits of aerobic and respiratory metabolism (increased pH and biomass under aerobic or respiratory conditions and unique oxidative stress response properties. Aerobic growth and respiration may confer technological and physiological advantages in the L. casei group and oxygen-tolerant phenotypes could be exploited in several food industry applications.

  16. Stimulation of KatG catalase activity by peroxidatic electron donors.

    Science.gov (United States)

    Ndontsa, Elizabeth N; Moore, Robert L; Goodwin, Douglas C

    2012-09-15

    Catalase-peroxidases (KatGs) use a peroxidase scaffold to support robust catalase activity, an ability no other member of its superfamily possesses. Because catalase turnover requires H(2)O(2) oxidation, whereas peroxidase turnover requires oxidation of an exogenous electron donor, it has been anticipated that the latter should inhibit catalase activity. To the contrary, we report peroxidatic electron donors stimulated catalase activity up to 14-fold, particularly under conditions favorable to peroxidase activity (i.e., acidic pH and low H(2)O(2) concentrations). We observed a "low-" and "high-K(M)" component for catalase activity at pH 5.0. Electron donors increased the apparent k(cat) for the "low-K(M)" component. During stimulated catalase activity, less than 0.008 equivalents of oxidized donor accumulated for every H(2)O(2) consumed. Several classical peroxidatic electron donors were effective stimulators of catalase activity, but pyrogallol and ascorbate showed little effect. Stopped-flow evaluation showed that a Fe(III)-O(2)(·-)-like intermediate dominated during donor-stimulated catalatic turnover, and this intermediate converted directly to the ferric state upon depletion of H(2)O(2). In this respect, the Fe(III)-O(2)(·-) -like species was more prominent and persistent than in the absence of the donor. These results point toward a much more central role for peroxidase substrates in the unusual catalase mechanism of KatG.

  17. Carcinogenicity of hair dye components.

    Science.gov (United States)

    Van Duuren, B L

    1980-03-01

    The available animal carcinogenicity data on hair dye components was reviewed. From this review it became clear that certain hair dye components, some of which are still in hair dye formulations now on the market, are animal carcinogens. The compounds of concern that are still in use are: 3-amino-4-methoxyaniline, 2-nitro-4-aminoaniline and 3-nitro-4-hydroxyaniline. Certain azo dyes formerly used, and related compounds still in use, contain the benzidine moiety. Two of these compounds, Direct Blue 6 and Direct Black 38, have been shown to be metabolized in animals to the human carcinogen benzidine. Furthermore, skin absorption studies carried out with radiolabeled hair dye components applied to animal or human skin have conclusively shown that these compounds are systemically absorbed and excreted. Known cocarcinogens such as catechol and pyrogallol, which enhance benzo(a)pyrene carcinogenicity on mouse skin, are used as hair dye components. It is not known whether such compounds will enhance the carcinogenicity of substituted aniline hair dye chemicals. The available epidemiologic data are not sufficient to link hair dye use with an increased incidence in human cancer.

  18. High performance liquid chromatography, thin layer chromatography and spectrophotometric studies on the removal of biogenic amines from some Egyptian foods using organic, inorganic and natural compounds.

    Science.gov (United States)

    Mohamed, Gehad G; El-Hameed, Azza K Abd; El-Din, A M M Nezam; El-Din, Lara A M M N

    2010-04-01

    This work has been carried out to investigate the conditions which lead to removal of the biogenic amines through the model system. Also, the main goal of this research work is trying to remove biogenic amines; histamine and tyramine, from some Egyptian foods such as tomato, strawberry, banana and mango to prevent their allergy effect. Histamine and tyramine have been affected by pyrogallol, catechol, starch, ascorbic and chlorogenic acids at different levels with different conditions. Some natural additives like glucose, spices, milk, vanillin, starch, orange juice, ascorbic and citric acids, showed an effective effect on disappearance of histamine and tyramine. By studying the effect of some additives on biogenic amines, it was found that tomato showed a decrease in histamine and tyramine concentrations by adding spices. Strawberry and banana showed a clear decrease in histamine and tyramine concentrations by treating them with ascorbic acid. Treating mango by milk led to increase of histamine level while milk with chocolate increases both histamine and tyramine concentrations.

  19. Production of hydrogen peroxide by polyphenols and polyphenol-rich beverages under quasi-physiological conditions.

    Science.gov (United States)

    Akagawa, Mitsugu; Shigemitsu, Tomoko; Suyama, Kyozo

    2003-12-01

    To investigate the ability of the production of H(2)O(2) by polyphenols, we incubated various phenolic compounds and natural polyphenols under a quasi-physiological pH and temperature (pH 7.4, 37 degrees C), and then measured the formation of H(2)O(2) by the ferrous ion oxidation-xylenol orange assay. Pyrocatechol, hydroquinone, pyrogallol, 1,2,4-benzenetriol, and polyphenols such as catechins yielded a significant amount of H(2)O(2). We also examined the effects of a metal chelator, pH, and O(2) on the H(2)O(2)-generating property, and the generation of H(2)O(2) by the polyphenol-rich beverages, green tea, black tea, and coffee, was determined. The features of the H(2)O(2)-generating property of green tea, black tea, and coffee were in good agreement with that of phenolic compounds, suggesting that polyphenols are responsible for the generation of H(2)O(2) in beverages. From the results, the possible significances of the H(2)O(2)-generating property of polyphenols for biological systems are discussed.

  20. Bioactive Compounds and Antioxidant Activity of Fresh and Processed White Cauliflower

    Directory of Open Access Journals (Sweden)

    Fouad A. Ahmed

    2013-01-01

    Full Text Available Brassica species are very rich in health-promoting phytochemicals, including phenolic compounds, vitamin C, and minerals. The objective of this study was to investigate the effect of different blanching (i.e., water and steam and cooking (i.e., water boiling, steam boiling, microwaving, and stir-frying methods on the nutrient components, phytochemical contents (i.e., polyphenols, carotenoids, flavonoid, and ascorbic acid, antioxidant activity measured by DPPH assay, and phenolic profiles of white cauliflower. Results showed that water boiling and water blanching processes had a great effect on the nutrient components and caused significant losses of dry matter, protein, and mineral and phytochemical contents. However, steam treatments (blanching and cooking, stir-frying, and microwaving presented the lowest reductions. Methanolic extract of fresh cauliflower had significantly the highest antioxidant activity (68.91% followed by the extracts of steam-blanched, steam-boiled, stir-fried, and microwaved cauliflower 61.83%, 59.15%, 58.93%, and 58.24%, respectively. HPLC analysis revealed that the predominant phenolics of raw cauliflower were protocatechuic acid (192.45, quercetin (202.4, pyrogallol (18.9, vanillic acid (11.90, coumaric acid (6.94, and kaempferol (25.91 mg/100 g DW, respectively.

  1. Ultrafast excited state dynamics of S2 and S1 states of triphenylmethane dyes.

    Science.gov (United States)

    Singhal, Pallavi; Ghosh, Hirendra N

    2014-08-21

    Excited state dynamics of S2 and S1 states for a series of TPM dyes, pyrogallol red (PGR), bromopyrogallol red (Br-PGR) and aurin tricarboxylic acid (ATC), have been monitored by using ultrafast transient absorption and fluorescence up-conversion techniques. Optical absorption studies indicate that all the TPM dyes exist as keto-enol tautomers depending upon the pH of the solution. Interestingly, all the TPM dyes give S2 emission (major emitting state) in addition to weak S1 emission. S2 emission lifetimes as fast as ∼150-300 fs and S1 emission lifetimes of 2-5 ns were observed depending upon the molecular structure of the dyes. Femtosecond transient absorption studies suggest the presence of an ultrafast non-radiative decay channel from the S2 state in addition to S2 luminescence. The vibrational relaxation time from hot S1 state is found to be 2-6 ps. The heavy atom effect has been observed in ultrafast relaxation dynamics of Br-PGR.

  2. DEGRADATION OF AROMATIC COMPOUNDS USING MOVING BED BIOFILM REACTORS

    Directory of Open Access Journals (Sweden)

    B. Ayati, H. Ganjidoust, M. Mir Fattah

    2007-04-01

    Full Text Available For biological treatment of water, there are many different biofilm systems in use. Examples of them are trickling filters, rotating biological contactors, fixed media submerged biofilters, granular media biofilters and fluidized bed reactors. They all have their advantages and disadvantages. Hence, the Moving Bed Biofilm Reactor process was developed in Norway in the late 1980s and early 1990s to adopt the best features of the activated sludge process as well as those of the biofilter processes, without including the worst. Two cylindrical moving bed biofilm reactors were used in this study working in upflow stream conditions. Experiments have been done in aerobic batch flow regime. Laboratory experiments were conducted at room temperature (23–28C and synthetic wastewater comprising a composition of phenol and hydroquinone in each reactor as the main organic constituents, plus balanced nutrients and alkalinity were used to feed the reactor. The ratio of influent to effluent COD was determined at different retention times. The results indicated that the removal efficiency of each selected compound is affected by the detention time. At low phenol and hydroquinone concentration (from 700 to 1000 mg/L maximum removal efficiency (over 80 % was obtained. By further increasing in COD loading rate up to 3000 mg/L, a decrease in COD removal rate was occurred. In the reactor containing pyrogallol in COD of 1500 mg/L, the removal rate decreased to 10 percent because of its toxicity for microorganisms.

  3. Anti-Adhesive Activities of Flavan-3-ols and Proanthocyanidins in the Interaction of Group A-Streptococci and Human Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Aneta Janecki

    2010-10-01

    Full Text Available Bacterial adhesion to epithelial cells is a key step in infections, allowing subsequent colonization, invasion and internalization of pathogens into tissues. Anti-adhesive agents are therefore potential prophylactic tools against bacterial infections. The range of anti-adhesive compounds is largely confined to carbohydrate analogues. Tannins are generously recognized as potent antimicrobials, but little data exist on their anti-adherence potency. Using a model for mucosal pathogenesis with labeled group A-streptococci (GAS and human laryngeal HEp-2 cells, a series of flavan-3-ols (epicatechin, epigallocatechin, epigallocatechin-3-O-gallate and highly purified and chemically characterized proanthocyanidin samples including procyanidins based on epicatechin, catechin or ‘mixed’ constituent flavanyl units, prodelphinidins made up of (epigallocatechin monomeric unts as well as oligomers possessing A-type units in their molecules was evaluated for anti-adhesive effects. Reduced microbial adherence was observed exclusively for prodelphinidins, suggesting that pyrogallol-type elements, i.e., (epigallocatechin units are important structural features. This is the first report on structure-activity relationships regarding the anti-adhesive potency of proanthocyanidins. In addition, the structures of the first chemically defined proanthocyanidins from Pelargonium sidoides are disclosed.

  4. Analysis of commercial proanthocyanidins. Part 4: solid state (13)C NMR as a tool for in situ analysis of proanthocyanidin tannins, in heartwood and bark of quebracho and acacia, and related species.

    Science.gov (United States)

    Reid, David G; Bonnet, Susan L; Kemp, Gabre; van der Westhuizen, Jan H

    2013-10-01

    (13)C NMR is an effective method of characterizing proanthocyanidin (PAC) tannins in quebracho (Schinopsis lorentzii) heartwood and black wattle (Acacia mearnsii) bark, before and after commercial extraction. The B-rings of the constituent flavan-3-ols, catechols (quebracho) or pyrogallols (wattle), are recognized in unprocessed source materials by "marker" signals at ca. 118 or 105ppm, respectively. NMR allows the minimum extraction efficiency to be calculated; ca. 30%, and ca. 80%, for quebracho heartwood and black wattle bark, respectively. NMR can also identify PAC tannin (predominantly robinetinidin), and compare tannin content, in bark from other acacia species; tannin content decreases in the order A. mearnsii, Acacia pycnantha (87% of A. mearnsii), Acacia dealbata and Acacia decurrens (each 74%) and Acacia karroo (30%). Heartwood from an underexploited PAC tannin source, Searsia lancea, taxonomically close to quebracho, shows abundant profisetinidin and catechin PACs. NMR offers the advantage of being applicable to source materials in their native state, and has potential applications in optimizing extraction processes, identification of tannin sources, and characterization of tannin content in cultivar yield improvement programmes.

  5. Amla (Emblica officinalis Gaertn), a wonder berry in the treatment and prevention of cancer.

    Science.gov (United States)

    Baliga, Manjeshwar Shrinath; Dsouza, Jason Jerome

    2011-05-01

    Emblica officinalis Gaertn. or Phyllanthus emblica Linn, commonly known as Indian gooseberry or amla, is arguably the most important medicinal plant in the Indian traditional system of medicine, the Ayurveda. Various parts of the plant are used to treat a range of diseases, but the most important is the fruit. The fruit is used either alone or in combination with other plants to treat many ailments such as common cold and fever; as a diuretic, laxative, liver tonic, refrigerant, stomachic, restorative, alterative, antipyretic, anti-inflammatory, hair tonic; to prevent peptic ulcer and dyspepsia, and as a digestive. Preclinical studies have shown that amla possesses antipyretic, analgesic, antitussive, antiatherogenic, adaptogenic, cardioprotective, gastroprotective, antianemia, antihypercholesterolemia, wound healing, antidiarrheal, antiatherosclerotic, hepatoprotective, nephroprotective, and neuroprotective properties. In addition, experimental studies have shown that amla and some of its phytochemicals such as gallic acid, ellagic acid, pyrogallol, some norsesquiterpenoids, corilagin, geraniin, elaeocarpusin, and prodelphinidins B1 and B2 also possess antineoplastic effects. Amla is also reported to possess radiomodulatory, chemomodulatory, chemopreventive effects, free radical scavenging, antioxidant, anti-inflammatory, antimutagenic and immunomodulatory activities, properties that are efficacious in the treatment and prevention of cancer. This review for the first time summarizes the results related to these properties and also emphasizes the aspects that warrant future research to establish its activity and utility as a cancer preventive and therapeutic drug in humans.

  6. Amperometric biosensor for the determination of phenols using a crude extract of sweet potato

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Vieira, I. da; Fatibello-Filho, O. [Universidade Federal de Sa Carlos (Brazil)

    1997-03-01

    An amperometric biosensor for the determination of phenols is proposed using a crude extract of sweet potato (Ipomoea batatas (L.) Lam.) as an enzymatic source of polyphenol oxidase (PPO; tyrosinase; catechol oxidase; EC 1.14.18.1). The biosensor is constructed by the immobilization of sweet potato crude extract with glutaraldehyde and bovine serum albumin onto an oxygen membrane. This biosensor provides a linear response for catechol, pyrogallol, phenol and p-cresol in the concentration ranges of 2.0 x 10{sup -5} -4.3 x 10{sup -4} mol L{sup -1}, 2.0 x 10{sup -5} -4.3 x 10{sup -4} mol L{sup -1}, 2.0 x 10{sup -5} -4.5 x 10{sup -4} mol L{sup -1} and 2.0 x 10{sup -5} -4.5 x 10{sup -4} mol L{sup -1}, respectively. The response time was about 3-5 min for the useful response range, and the lifetime of this electrode was excellent for fifteen days (over 220 determinations for each enzymatic membrane). Application of this biosensor for the determination of phenols in industrial wastewaters is presented.

  7. Preparation of total flavonoids from loquat flower and its protective effect on acute alcohol-induced liver injury in mice

    Directory of Open Access Journals (Sweden)

    Shao-Kang Wu

    2015-03-01

    Full Text Available This study aimed to research the preparation techniques of total flavones from loquat flower (TFLF, its anti-oxidation capacity, and its protective effect on hepatic injury. The best extraction parameters by orthogonal experimentation were water at 100°C, extraction time 2.5 hours, solid/liquid ratio 1:20, and three decoctions. The chromogenic reaction to the flavones showed that loquat flowers mainly contained flavone, flavonol, and flavanone compounds combining ortho-phenolic hydroxyl group structure in the 10–30% ethanol fraction. The anti-oxidant capacity of O2−· was 26.09% and of OH−·was 83.01% by salicylic acid and pyrogallol auto-oxidation. Compared with the model group, TFLF lowered the levels of alanine aminotransferase, aspartate aminotransferase, triglyceride, and malondialdehyde and liver index significantly, and upregulated the expression of adipose triglyceride lipase and Heine oxygenase-1 mRNA. The present findings suggest that TFLF has protective effect on acute alcoholinduced liver injury in mice and may be related to its antioxidant and free-radical scavenging activity.

  8. Exploitation of the complexation reaction of ortho-dihydroxylated anthocyanins with aluminum(III) for their quantitative spectrophotometric determination in edible sources.

    Science.gov (United States)

    Bernal, Freddy A; Orduz-Diaz, Luisa L; Coy-Barrera, Ericsson

    2015-10-15

    Anthocyanins are natural pigments known for their color and antioxidant activity. These properties allow their use in various fields, including food and pharmaceutical ones. Quantitative determination of anthocyanins had been performed by non-specific methods that limit the accuracy and reliability of the results. Therefore, a novel, simple spectrophotometric method for the anthocyanins quantification based on a formation of blue-colored complexes by the known reaction between catechol- and pyrogallol-containing anthocyanins and aluminum(III) is presented. The method demonstrated to be reproducible, repetitive (RSDanthocyanins (LOD = 0.186 μg/mL). Compliance with Beer's law was also evident in a range of concentrations (2-16 μg/mL for cyanidin 3-O-glucoside). Good recoveries (98.8-103.3%) were calculated using anthocyanin-rich plant samples. The described method revealed direct correlation to pH differential method results for several common anthocyanin-containing fruits indicating its great analytical potential. The presented method was successfully validated.

  9. Study of the Stereochemistry and Oxidation Mechanism of Plant Polyphenols, Assisted by Computational Chemistry.

    Science.gov (United States)

    Matsuo, Yosuke

    2017-01-01

     In recent years, plant polyphenols have attracted great attention due to their wide range of biological activities. Certain kinds of polyphenols have complex structures; therefore, it is difficult to elucidate their total structure, including stereochemistry. In this study, we reinvestigated the stereostructures of two major C-glycosidic ellagitannins contained in Quercus plants, vescalagin and castalagin, and revised their stereostructures based on theoretical calculations of spectroscopic data. We also determined the structures of quercusnins A and B, isolated from the sapwood of Quercus crispula, based on theoretical calculations of NMR data. The oxidation mechanism of polyphenols has not been entirely elucidated. Therefore, we have also studied the oxidation mechanism of tea catechins during black tea production. Our investigation of the oxidation mechanism of black tea pigment theaflavins revealed that the difference in the position of the galloyl ester affords different oxidation products of theaflavins. In addition, oxidation products of pyrogallol-type catechins could be classified into three types-dehydrotheasinensins, theacitrins, and proepitheaflagallins; their detailed production and degradation mechanisms were also examined.

  10. The impact of the 67kDa laminin receptor on both cell-surface binding and anti-allergic action of tea catechins.

    Science.gov (United States)

    Fujimura, Yoshinori; Umeda, Daisuke; Yamada, Koji; Tachibana, Hirofumi

    2008-08-15

    Here, we investigated the structure-activity relationship of major green tea catechins and their corresponding epimers on cell-surface binding and inhibitory effect on histamine release. Galloylated catechins; (-)-epigallocatechin-3-O-gallate (EGCG), (-)-gallocatechin-3-O-gallate (GCG), (-)-epicatechin-3-O-gallate (ECG), and (-)-catechin-3-O-gallate (CG) showed the cell-surface binding to the human basophilic KU812 cells by surface plasmon resonance analysis, but their non-galloylated forms did not. Binding activities of pyrogallol-type catechins (EGCG and GCG) were higher than those of catechol-type catechins (ECG and CG). These patterns were also observed in their inhibitory effects on histamine release. Previously, we have reported that biological activities of EGCG are mediated through the binding to the cell-surface 67kDa laminin receptor (67LR). Downregulation of 67LR expression caused a reduction of both activities of galloylated catechins. These results suggest that both the galloyl moiety and the B-ring hydroxylation pattern contribute to the exertion of biological activities of tea catechins and their 67LR-dependencies.

  11. Chitosan hydrogel formation using laccase activated phenolics as cross-linkers.

    Science.gov (United States)

    Huber, Daniela; Tegl, Gregor; Baumann, Martina; Sommer, Eva; Gorji, Elham Ghorbani; Borth, Nicole; Schleining, Gerhard; Nyanhongo, Gibson S; Guebitz, Georg M

    2017-02-10

    Chitosan hydrogels are gaining increasing interest for biomedical applications due to attractive properties such as biocompatibility. In order to replace toxic chemical cross-linkers for hydrogel formation, we investigated the cross-linking potential of laccase oxidized phenolics. HPLC-TOF-MS and ATR-FTIR demonstrated that phenolics were bond to glucosamine as chitosan model substrate. Phenolics concentrations required for hydrogel formation varied from 500μM for catechol to 5000μM for sinapic acid. The hydrogels showed different swelling and release properties assessed using methylene blue release as a model. Laccase oxidized caffeic acid and pyrogallol-chitosan hydrogels showed excellent behavior in up-taking water with a swelling of 208.7% for caffeic acid. Biocompatibility results did not show any significant inhibition of growth of HEK293 cell line when phenolics like catechol or eugenol were used. Therefore, this study demonstrates that laccase oxidized phenolics are potential cross-linking agents of chitosan as a novel green approach to synthesizing chitosan hydrogels.

  12. Processing ‘Ataulfo’ Mango into Juice Preserves the Bioavailability and Antioxidant Capacity of Its Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Ana Elena Quirós-Sauceda

    2017-09-01

    Full Text Available The health-promoting effects of phenolic compounds depend on their bioaccessibility from the food matrix and their consequent bioavailability. We carried out a randomized crossover pilot clinical trial to evaluate the matrix effect (raw flesh and juice of ‘Ataulfo’ mango on the bioavailability of its phenolic compounds. Twelve healthy male subjects consumed a dose of mango flesh or juice. Blood was collected for six hours after consumption, and urine for 24 h. Plasma and urine phenolics were analyzed by electrochemical detection coupled to high performance liquid chromatography (HPLC-ECD. Five compounds were identified and quantified in plasma. Six phenolic compounds, plus a microbial metabolite (pyrogallol were quantified in urine, suggesting colonic metabolism. The maximum plasma concentration (Cmax occurred 2–4 h after consumption; excretion rates were maximum at 8–24 h. Mango flesh contributed to greater protocatechuic acid absorption (49%, mango juice contributed to higher chlorogenic acid absorption (62%. Our data suggests that the bioavailability and antioxidant capacity of mango phenolics is preserved, and may be increased when the flesh is processed into juice.

  13. Endothelium protectant and contractile effects of the antivaricose principle escin in rat aorta.

    Science.gov (United States)

    Carrasco, Omar F; Vidrio, Horacio

    2007-07-01

    The triterpene saponin escin is the active component of the extract of seeds of Aesculus hippocastanum used in the treatment of chronic venous insufficiency. Escin is also used experimentally to increase membrane permeability in isolated cells. Since endothelial dysfunction is postulated to be involved in venous insufficiency, the possible endothelium-protectant effect of escin was explored in rat aortic rings, a model widely used to study such effects with cardiovascular agents. Escin enhanced endothelium-dependent relaxation induced by acetylcholine when such relaxation had been reduced by exposure to the superoxide ion generator pyrogallol. This effect was attributed to enhanced nitric oxide production by endothelial nitric oxide synthase, a calcium-dependent enzyme, activated by the increased endothelial cell permeability to calcium induced by escin. Another effect of escin thought to contribute to its therapeutic activity is its ability to produce venous contraction. The compound was found to induce concentration-related contraction also in rat aortic rings. This response was partially inhibited by removal of the endothelium or by preincubation with indomethacin, and was completely abolished by incubation in a calcium-free perfusion fluid. Contraction was considered to be due mainly to the aforementioned effect on calcium permeability, with some mediation by release of endothelial vasoconstrictor prostanoids. It was concluded that, in rat aorta, escin possesses an endothelium-protectant action and a direct contractile effect. The former could contribute to its beneficial effect in the treatment of venous insufficiency, while the latter could constitute a limiting side effect.

  14. Determination of phenolic compounds derived from hydrolysable tannins in biological matrices by RP-HPLC.

    Science.gov (United States)

    Díez, María Teresa; García del Moral, Pilar; Resines, José Antonio; Arín, María Jesús

    2008-08-01

    An RP-HPLC method for the determination of four phenolic compounds: gallic acid (GA), pyrogallol (PY), resorcinol (RE) and ellagic acid (EA), derived from hydrolysable tannins is reported. Separation was achieved on a SunFire C18 (250 x 4.6 mm id, 5 microm) column at 40 degrees C with gradient elution. UV detection at 280 nm was applied. The developed method was validated in terms of linearity, accuracy and precision. Satisfactory repeatability and between day precision were noticed with RSD values lower than 3%. Recoveries from different biological samples ranged from 91.50 to 105.25%. The LODs were estimated as 1.70 mg/L for PY, 1.68 mg/L for GA, 1.52 mg/L for RE and 0.98 mg/L for EA with a 20 microL injection volume. The method was applied for the determination of these compounds in oak leaves and in ruminal fluid and urine samples taken from beef cattle fed with oak leaves. The proposed method could be used in ruminant nutrition studies to verify the effect that a diet rich in tannins have on ruminal fermentation and to determine the toxicity of these compounds.

  15. Effect of Additives on Liner Properties of Case-bonded Composite Propellants

    Directory of Open Access Journals (Sweden)

    S. B. Navale

    2004-07-01

    Full Text Available A thin layer of liner is applied to ensure a good bond between the insulator and the propellant in case-bonded rocket motors. It also acts as a protective shield for the insulatorby providing a limited fire protection effect. Liner compositions should preferably be based on the same binder system used in the propellant formulations. As the liner has to hold the propellant and the insulator without debond under all the environmental conditions, it plays a key role in predicted performance of a rocket motor. Hence, studies were carried out to improve the liner properties using various hydroxyl compounds, such as butanediol, cardanol, trimethylol propane, pyrogallol, etc as additives. Butanediol and phloroglucinol combination gave the best results in terms of mechanical properties and interface properties for the liner compositions. The effect of filler content on the liner properties was also studied. The results showed that higher filler content does not affect interface properties. Considering the fire retardancy effect and reinforcement of antimony trioxide (S£203, the formulation containing higher Sb2O3 was selected. The studies on pot life/castable life of liner showed that propellant could be cast up to 6 days after liner coating, without adversely affecting the bonding and the bond strength.

  16. The effect of pro-ecological procedures and insect foraging on the total content of phenol compounds in winter wheat.

    Science.gov (United States)

    Lamparski, Robert; Balcerek, Maciej; Modnicki, Daniel; Kotwica, Karol; Wawrzyniak, Maria

    2015-06-01

    In laboratory conditions, the effect of pro-ecological procedures (application of effective microorganisms and Asahi SL biostimulator) and foraging by insects [cereal leaf beetle (Oulema melanopa L.) and bird cherry-oat aphid (Rhopalosiphum padi (L.)] on the total content of phenolic compounds in winter wheat, was studied. Correlations between the total content of phenolic compounds (determined by the Folin-Ciocalteau colorimetric method) expressed as the amount of pyrogallol in wheat plants: undamaged, damaged by O. melanopa, damaged by R. padi, the length of feeding scar left by cereal leaf beetle and the number of pricks made by actively feeding insects of bird cherry-oat aphid were analysed. The wheat was treated by EM inoculant and a biostimulator. The mode of application of the preparations used had a significant effect on level the total phenolic compounds in the undamaged wheat and the wheat exposed to foraging by the above-mentioned insects. The plants not exposed to insects foraging contained greater amounts of phenolic compounds than those exposed to the insects. The correlation between the total content of phenols in the wheat damaged by the insects in the 'no-choice' conditions, proved insignificant.

  17. Purification and Characterization of Extracellular Laccase Secreted by Pleurotus sajor-caju MTCC 141

    Institute of Scientific and Technical Information of China (English)

    R. Sahay; R. S. S. Yadav; K. D. S. Yadav

    2008-01-01

    The effect of lignin containing natural substrates corn-cob, coir-dust, saw-dust, wheat straw and bagasse particles on the extracellular secretion of laccase in the liquid culture growth medium of Pleurotus sajor-caju MTCC 141 has been studied. The culture conditions for maximum secretion of laccase by Pleurotus sajor-caju MTCC 141 have been optimized. Homogeneous preparation of laccase from the culture filtrate of the fungus has been achieved using ammonium sulphate precipitation, anion exchange chromatography on DEAE and gel filtration chromatography on Sephadex G-100. The purified enzyme preparation gave a single protein band in SDS-PAGE analysis indicating a molecular weight of 90 kD. The enzymatic characteristics Km, kcat, pH and temperature optima of the purified laccase have been determined using 2, 6-dimethoxyphenol as the substrate and have been found to be 35μmol/L, 0.30 min-1, 4.5 and 37℃ respectively. The Km values for the other substrate like catechol, m-cresol, pyrogallol and syringaldazine have also been determined which were found to be 216 μmol/L, 380 μmol/L, 370 μmol/L and 260 μmol/L respectively.

  18. Efecto antioxidante y contenido polifenólico de Syringodium filiforme (Cymodoceaceae

    Directory of Open Access Journals (Sweden)

    Kethia L González García

    2011-03-01

    Full Text Available Antioxidant effect and polyphenol content of Syringodium filiforme (Cymodoceaceae. The marine phanerogam Syringodium filiforme, known as "manatee grass", is a common species that grows in coastal areas associated to Thalassia testudinum. With the aim to describe some of its possible chemical characteristics, this study was performed with a sample of 1.2kg, collected in March 2009, in Guanabo beach, Havana, Cuba. The sample was dried (less than 12% humidity and a total extract prepared; other three extracts were prepared with the use of solvents of increasing polarity. The phytochemical screening and analytical determinations of each fraction were undertaken Total polyphenol content was determined using pyrogallol as reference´s standard; chlorophyll a and b and anthocyanin content were also quantified. Total extract and fractions antioxidant activity were evaluated by using the free radical scavenging activity assay with 1,1- Diphenyl-2-Picrylhydrazyl reactive (knowing as DPPH´s method. The phytochemical screening of the different extracts detected the presence of high concentrations of flavonoids, phenols, terpenes, antocyaninns, reducing sugars and alkaloids. The total extract and methanol fraction showed significant free radical scavenging properties, while the petroleum ether fraction showed moderate activity, and the chloroform fraction and the aqueous soluble precipitate (residual salt obtained didn’t show antioxidant properties against free radicals. The results of this work confirmed the potentialities of this species for biological purposes. Rev. Biol. Trop. 59 (1: 465-472. Epub 2011 March 01.

  19. Anti-inflammatory functions of purpurogallin in LPS-activated human endothelial cells

    Directory of Open Access Journals (Sweden)

    Tae Hoon Kim

    2012-03-01

    Full Text Available Enzymatic oxidation of commercially available pyrogallol wasefficiently transformed to an oxidative product, purpurogallin.Purpurogallin plays an important role in inhibiting glutathioneS-transferase, xanthine oxidase, catechol O-methyltransferaseactivities and is effective in the cell protection of several celltypes. However, the anti-inflammatory functions of purpurogallinare not well studied. Here, we determined the effectsof purpurogallin on lipopolysaccharide (LPS-mediated proinflammatoryresponses. The results showed that purpurogallininhibited LPS-mediated barrier hyper-permeability, monocyteadhesion and migration and such inhibitory effects weresignificantly correlated with the inhibitory functions ofpurpurogallin on LPS-mediated cell adhesion molecules(vascular cell adhesion molecules, intracellular cell adhesionmolecule, E-selectin. Furthermore, LPS-mediated nuclearfactor-κB (NF-κB and tumor necrosis factor-α (TNF-α releasesfrom HUVECs were inhibited by purpurogallin. Given theseresults, purpurogallin showed its anti-inflammatory activitiesand could be a candidate as a therapeutic agent for varioussystemic inflammatory diseases. [BMB reports 2012; 45(3:200-205

  20. New identification of proanthocyanidins in cinnamon (Cinnamomum zeylanicum L.) using MALDI-TOF/TOF mass spectrometry.

    Science.gov (United States)

    Mateos-Martín, María Luisa; Fuguet, Elisabet; Quero, Carmen; Pérez-Jiménez, Jara; Torres, Josep Lluís

    2012-01-01

    The inner bark of Ceylon cinnamon (Cinnamomum zeylanicum L.) is commonly used as a spice and has also been widely employed in the treatment and prevention of disease. The positive health effects associated with the consumption of cinnamon could in part be due to its phenolic composition; proanthocyanidins (PA) are the major polyphenolic component in commercial cinnamon. We present a thorough study of the PA profile of cinnamon obtained using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. In addition to the advantages of MALDI-TOF as a sensitive technique for the analysis of high-molecular-weight compounds, the tandem arrangement allows the identification of the compounds through their fragmentation patterns from MS/MS experiments. This is the first time that this technique has been used to analyze polymeric PA. The results show that cinnamon PA are more complex than was previously thought. We show here for the first time that they contain (epi)gallocatechin and (epi)catechingallate units. As gallates (galloyl moieties) and the pyrogallol group in gallocatechins have been related to the biological activity of grape and tea polyphenols, the presence of these substructures may explain some of the properties of cinnamon extracts. MALDI-TOF/TOF reveals that cinnamon bark PA include combinations of (epi)catechin, (epi)catechingallate, (epi)gallocatechin, and (epi)afzelechin, which results in a highly heterogeneous mixture of procyanidins, prodelphinidins, and propelargonidins.

  1. Effect of Hydro Alcoholic Ginger Extracts on the Body Weight, Testis Weight and Spermatogenesis in Male Rats Undergoing Chemotherapy with Cyclophosphamide

    Directory of Open Access Journals (Sweden)

    E Sharifi

    2010-03-01

    Full Text Available Introduction: Cyclophosphamide is used as an anti cancer medicine in chemotherapy. This is an alkalizing medicine and causes the binding of DNA strands, breaking of DNA and control of protein synthesis and RNA. The side effects of this medicine include lack of appetite, nausea, reduction in activity of sexual lymph nodes, causing amenorrhea, azoospermia and oligospermia. Ginger includes many compounds, some of which are shogaols, gingerols, pyrogallols and sesquiterpenes. Ginger has anti nauseating, anti cancer, anti oxidant effects and eliminates free radicals. This medicine is used along with cyclophosphamide to reduce its destructive side effects in the body. Methods: For 21 days, the rats were fed with ginger and cyclophosphamide. After 21 days, the animals were weighed and rendered unconscious. Their testes were removed and tissue samples were provided from their testes. Results: The results showed that cyclophosphamide alone reduces body weight, testes weight and spermatogenesis as compared to the control group. In other experimental groups that were fed with ginger and cyclophosphamide, increased dosage of ginger increased the body weight, the testes weight and spermatogenesis in comparison to the other experimental groups. Conclusion: It seems that compounds present in ginger are anti tumoral and control the production of active metabolites. Therefore, if administered together with Cyclophosphamide, it can be useful and effective in patients undergoing chemotherapy.

  2. Preparation and Anti-oxidative Effects of Corn Peptides

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Corn peptides(CP) were prepared from zein via proteolysis by means of a type of alkaline protease, Alcalase, at 50 ℃ and pH 8.0. The anti-oxidative activity of the hydrolysate was examined. It was found that the anti-oxidative activity reached the maximum at the fourth hour of the hydrolysis and then decreased. The effect of the enzyme dosage on the solubility of corn protein, the dependence of hydrolysis time on the degree of the hydrolysis(DH) and molecular weight distribution were examined respectively. 30% DH was controlled on the basis of anti-oxidative activity. The hydrolysate was fractionated on a Sephadex G-15 column. The anti-oxidative activities were examined for all the fractions. The main fraction for anti-oxidative activity was collected and characterized by the methods of amino acid analysis, the measurement of average chain length and etc.. The main MW distribution of the main fraction was 300-600 Daltons. The anti-oxidative properties of the small peptides in vitro were studied. It was found that they could inhibit the auto-oxidation of pyrogallol and the oxidation of hemoglobin. The hemolysis degree of erythrocyte caused by hydroxyl free radicals was decreased greatly, indicating a protective effect of the anti-oxidative peptides on the cell membrane damage of erythrocyte.

  3. A new total antioxidant potential measurements using RP-HPLC assay with fluorescence detection.

    Science.gov (United States)

    Głód, Bronisław K; Piszcz, Paweł; Czajka, Katarzyna; Zarzycki, Paweł K

    2011-05-01

    In this paper, an improved total antioxidant potential (TAP) estimation using high-performance liquid chromatographic (HPLC) assay with fluorometric detection has been described. The principle of this method is based on the hydroxyl radicals generated in the Fenton-like reaction and subsequently detected using hydroxyterephthalic acid (HTPA), which is a reaction product of hydroxyl radicals and terephthalic acid (TPA), working as a sensing compound. HTPA quantity in the samples was measured by fluorescence detector working at excitation and emission wavelengths equal to 312 and 428 nm, respectively. A number of key experimental conditions including the influence of the reaction (incubation) time on the surface areas of HTPA peaks, concentration of Fe(II) ions as well as the influence of concentration of TPA on the surface area of the chromatographic peak of HTPA were optimized to the characteristic feature of TAP measurements. The elaborated assay has been used to evaluate TAP values of selected low-molecular mass compounds like pyrogallol, tryptamine, and n-alcohols (methanol, ethanol, and n-propanol) as well as chlorogenic and ascorbic acids and benzoic acid derivatives, which are commonly present in the food samples.

  4. Tannins in tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Doat, J.

    1978-01-01

    A preliminary study was made of the chemistry of pyrogallol- and catecholtannins, their general properties and methods of extraction and determination. Three methods of estimation - Lowenthal, powdered hide and spectrophotometry - were compared using two control solutions, four samples of wood and one of bark. Using the empirical powdered hide method, tannins of both types were estimated in wood and bark of various tropical species (some separately and some as a mixture), Moroccan oaks (Quercus suber and Q. ilex), and European oak 9Q. petraea). Further tests were made on the wood and bark of the two mangrove species, Rhizophora mangle and R. racemosa, by subjecting them to successive extraction with a range of solvents. None of the woods tested had as much as the 10% of tannins considered necessary in economic sources. The bark of the two mangroves, of Eucalyptus urophylla and of Prosopis africana had tannin contents over 10% and the latter two species had very favorable tannin/non-tannin ratios. All the tropical species, with the probable exception of E. urophylla, had only catecholtannins. Only the oaks and E. urophylla bark gave positive results when tested for gallotannins.

  5. Revisiting catechol derivatives as robust chromogenic hydrogen donors working in alkaline media for peroxidase mimetics.

    Science.gov (United States)

    Drozd, Marcin; Pietrzak, Mariusz; Pytlos, Jakub; Malinowska, Elżbieta

    2016-12-15

    Colloidal noble metal-based nanoparticles are able to catalyze oxidation of chromogenic substrates by H2O2, similarly to peroxidases, even in basic media. However, lack of robust chromogens, which work in high pH impedes their real applications. Herein we demonstrate the applicability of selected catechol derivatives: bromopyrogallol red (BPR) and pyrogallol (PG) as chromogenic substrates for peroxidase-like activity assays, which are capable of working over wide range of pH, covering also basic values. Hyperbranched polyglycidol-stabilized gold nanoparticles (HBPG@AuNPs) were used as model enzyme mimetics. Efficiency of several methods of improving stability of substrates in alkaline media by means of selective suppression of their autoxidation by molecular oxygen was evaluated. In a framework of presented studies the impact of borate anion, applied as complexing agent for PG and BPR, on their stability and reactivity towards oxidation mediated by catalytic AuNPs was investigated. The key role of high concentration of hydrogen peroxide in elimination of non-catalytic oxidation of PG and improvement of optical properties of BPR in alkaline media containing borate was underlined. Described methods of peroxidase-like activity characterization with the use of BPR and PG can become universal tools for characterization of nanozymes, which gain various applications, among others, they are used as catalytic labels in bioassays and biosensors.

  6. Critical assessment of three high performance liquid chromatography analytical methods for food carotenoid quantification.

    Science.gov (United States)

    Dias, M Graça; Oliveira, Luísa; Camões, M Filomena G F C; Nunes, Baltazar; Versloot, Pieter; Hulshof, Paul J M

    2010-05-21

    Three sets of extraction/saponification/HPLC conditions for food carotenoid quantification were technically and economically compared. Samples were analysed for carotenoids alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, lycopene, and zeaxanthin. All methods demonstrated good performance in the analysis of a composite food standard reference material for the analytes they are applicable to. Methods using two serial connected C(18) columns and a mobile phase based on acetonitrile, achieved a better carotenoid separation than the method using a mobile phase based on methanol and one C(18)-column. Carotenoids from leafy green vegetable matrices appeared to be better extracted with a mixture of methanol and tetrahydrofuran than with tetrahydrofuran alone. Costs of carotenoid determination in foods were lower for the method with mobile phase based on methanol. However for some food matrices and in the case of E-Z isomer separations, this was not technically satisfactory. Food extraction with methanol and tetrahydrofuran with direct evaporation of these solvents, and saponification (when needed) using pyrogallol as antioxidant, combined with a HPLC system using a slight gradient mobile phase based on acetonitrile and a stationary phase composed by two serial connected C(18) columns was the most technically and economically favourable method.

  7. Chromatographic analysis of phytochemicals components present in mangifera indica leaves for the synthesis of silver nanoparticles by AgNO3 reduction

    Science.gov (United States)

    Martínez-Bernett, D.; Silva-Granados, A.; Correa-Torres, S. N.; Herrera, A.

    2016-02-01

    It was studied the green synthesis of silver nanoparticles (AgNPs) from the reduction of a silver nitrate solution (1 and 10mM) in the presence of an extract of mangifera indica leaves. Phytochemicals components present in extracts of mango leaves were determined using a GC-MS chromatograph. The results showed the presence of the phenolic compound pyrogallol (26.9% wt/5mL of extract) and oleic acid (29.1% wt/5mL of extract), which are useful for the reduction of the metallic salt AgNO3 and the stabilization of silver nanoparticles. The synthesized nanoparticles were characterized by UV visible spectroscopy (UV-vis), evidencing absorbances at wavelengths of 417nm (AgNPs-1) and 414nm (AgNPs- 10), which are characteristic peaks of this metallic nanoparticles. Scanning Electron Microscopy (SEM) was used to determine the size of the synthesized nanoparticles. A particle size of about 28±7nm was observed for the AgNPs-1 sample and 26±5nm for the AgNPs-10. This suggests the advantages of green chemistry to obtain silver nanoparticles with a narrow size distribution.

  8. Fast Removal of Co2+ and Ni2+ from Aqueous Solution Using Partial Carbonized Nanoporous Resin

    Directory of Open Access Journals (Sweden)

    Imed Ghiloufi

    2015-12-01

    Full Text Available Partial carbonized nanoporous resin (PCNR-150, based on organic xerogel compounds, was prepared at 150 ºC by sol–gel method from pyrogallol and formaldehyde mixtures in water using perchloric acid as catalyst. The PCNR-150 was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infrared spectroscopy (FTIR and nitrogen porosimetry. The metal uptake characteristics were explored using well-established and effective parameters including pH, contact time, initial metal ion concentration, and temperature. Optimum adsorptions of Co2+ and Ni2+, using PCNR-150 as adsorbent, were observed at pH 5 and 7, respectively. Langmuir model gave a better fit than the other models, and kinetic studies revealed that the adsorption is fast and its data are well fitted by the pseudo-second-order kinetic model and thermodynamic properties, i.e., ΔGo, ΔHo, and ΔSo, showed that adsorption of Co2+ and Ni2+ onto PCNR-150 was endothermic, spontaneous and feasible in the temperature range of 300–328 K.

  9. The role of water in the photocatalytic degradation of acetonitrile and toluene in gas-solid and liquid-solid regimes

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Photocatalytic degradation of acetonitrile and toluene was carried out both in gas-solid and in liquid-solid regimes by using commercial TiO 2 samples (Merck and Degussa P25. The investigation was mainly aimed to study the influence of water present in the reaction environment on the mechanism and degradation rate of two probe molecules. In gas-solid regime, the reacting mixture consisted of toluene or acetonitrile, oxygen, nitrogen, and water vapour. The main degradation product of toluene was CO 2 with small amounts of benzaldehyde. In the presence of water vapour, the activity of TiO 2 Merck remained stable but greatly decreased if water was absent. TiO 2 Degussa P25 continuously deactivated, even in the presence of water vapour. With both catalysts, the photodegradation products of acetonitrile were CO 2 and HCN; the activity was stable and was independent of the presence of water vapour in the reacting mixture. The production of HCN represents a drawback of acetonitrile photocatalytic degradation but the elimination of HCN is not actually a problem. In liquid-solid regime, the main intermediates of toluene photodegradation were p -cresol and benzaldehyde; traces of pyrogallol and benzyl alcohol were also found. Benzoic acid, hydroquinone, and trans, trans muconic acid were detected only when TiO 2 Merck was used. The photodegradation products of acetonitrile were cyanide, cyanate, formate, nitrate, and carbonate ions.

  10. Peroxidase of Brazilian Cerrado grass as an alternative for agro industrial waste treatment

    Directory of Open Access Journals (Sweden)

    Raquel Pinheiro Reis Souza Ramalho

    2016-03-01

    Full Text Available Decontamination of wastewater continues to be a challenge for society and the scientific community. Despite the availability of various materials for study, enzymes stand out due to their specificity for decomposition and biodegradability for disposal. New sources of enzymes may represent efficient and low-cost alternatives compared to routinely used techniques. In this survey, the peroxidase profile from Echinolaena inflexa fruits was studied for possible applications in the treatment of wastewater. The protein content was found to be 5.33 mg g-1. The optimum reaction conditions were: 50°C, pH 7.5 at 0.1 mol L-1 of phosphate buffer for 15 min. The enzyme was inactivated after 5 min at 94°C and was inhibited when incubated with ascorbic acid at 10 mmol L-1. In tests using phenols and agro industrial waste, the peroxidase was able to oxidase 87.5% of catechol, 67.8% of pyrogallol, 39.1% of resorcinol and still presented 29.1% of the degradation capacity of raw wastewater phenolic compounds. The results showed that the Echinolaena inflexa peroxidase, a new source of enzymes, is a potential alternative to wastewater treatment.

  11. Impact of short-term intake of red wine and grape polyphenol extract on the human metabolome.

    Science.gov (United States)

    Jacobs, Doris M; Fuhrmann, Jens C; van Dorsten, Ferdinand A; Rein, Dietrich; Peters, Sonja; van Velzen, Ewoud J J; Hollebrands, Boudewijn; Draijer, Richard; van Duynhoven, John; Garczarek, Ursula

    2012-03-28

    Red wine and grape polyphenols are considered to promote cardiovascular health and are involved in multiple biological functions. Their overall impact on the human metabolome is not known. Therefore, exogenous and endogenous metabolic effects were determined in fasting plasma and 24 h urine from healthy male adults consuming a mix of red wine and grape juice extracts (WGM) for 4 days in a placebo-controlled, crossover study. Syringic acid, 3-hydroxyhippuric acid, pyrogallol, 3-hydroxyphenylacetic acid, and 3-hydroxyphenylpropionic acid were confirmed as the strongest urinary markers of WGM intake. Overall, WGM had a mild impact on the endogenous metabolism. Most noticeable were changes in several amino acids deriving from tyrosine and tryptophan. Reductions in the microbial metabolites p-cresol sulfate and 3-indoxylsulfuric acid and increases in indole-3-lactic acid and nicotinic acid were observed in urine. In plasma, tyrosine was reduced. The results suggest that short-term intake of WGM altered microbial protein fermentation and/or amino acid metabolism.

  12. Spinach thylakoid polyphenol oxidase isolation, activation, and properties of the native chloroplast enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Golbeck, J.H.; Cammarata, K.V.

    1981-05-01

    Polyphenol oxidase activity (E.C. 1.14,18.1) has been found in two enzyme species isolated from thylakoid membranes of spinach chloroplasts. The proteins were released from the membrane by sonication and purified >900-fold by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography. The enzymes appear to be the tetramer and monomer of a subunit with a molecular weight of 42,500 as determined by lithium dodecyl sulfate gel electrophoresis. Sonication releases polyphenol oxidase from the membrane largely in the latent state. In the absence of added fatty acids, the isolated enzyme spontaneously, but slowly, activates with time. Purified polyphenol oxidase utilizes o-diphenols as substrates and shows no detectable levels of monophenol or p-diphenol oxidase activities. Suitable substrates include chlorogenic acid, catechol, caffeic acid, pyrogallol, and dopamine; however, the enzyme is substrate-inhibited by the last four at concentrations near their K/sub m/. A large seasonal variation in polyphenol oxidase activity may result from a decrease in enzyme content rather than inhibition of the enzyme present.

  13. Purification and characterization of polyphenol oxidase from nettle (Urtica dioica L.) and inhibitory effects of some chemicals on enzyme activity.

    Science.gov (United States)

    Güllçin, Ilhami; Küfrevioğlu, O Irfan; Oktay, Münir

    2005-06-01

    Polyphenol oxidase (PPO) of nettle (Urtica dioica L.) was extracted and purified through (NH4)2SO4 precipitation, dialysis, and CM-Sephadex ion-exchange chromatography and was used for its characterization. The PPO showed activity to catechol, 4-methylcatechol, L-3,4-dihydroxyphenylalanine (L-DOPA), L-tyrosine, p-cresol, pyrogallol, catechin and trans-cinnamic acid. For each of these eight substrates, optimum conditions such as pH and temperature were determined and L-tyrosine was found to be one of the most suitable substrates. Optimum pH and temperature were found at pH 4.5 and 30 degrees C respectively and Km and Vmax values were 7.90 x 10(-4) M, and 11290 EU/mL for with L-tyrosine as substrate. The inhibitory effect of several inhibitors, L-cysteine chloride, sodium azide, sodium cyanide, benzoic acid, salicylic acid, L-ascorbic acid, glutathione, thiourea, sodium diethyl dithiocarbamate, beta-mercaptoethanol and sodium metabisulfite were tested. The most effective was found to be sodium diethyl dithiocarbamate which acted as a competitive inhibitor with a Ki value of 1.79 x 10(-9)M. In addition one isoenzyme of PPO was detected by native polacrylamide slab gel electrophoresis.

  14. Catalytic Kinetic Spectrophotometric Method for Determination of Phosphate Ion

    Institute of Scientific and Technical Information of China (English)

    MITIC,Snezana; ZIVANOVIC,Valentina; OBRADOVIC,Mirjana; TOSIC,Snezana; PAVLOVIC,Aleksandra

    2007-01-01

    The kinetic method for the determination of phosphate microamounts was described.The developed method is based on catalytic effect of phosphate on sodium pyrogallol-5-sulphonate(PS)by dissolved oxygen.The reaction was followed spectrophotometrically by measuring the rate of change in the values of the absorbance of the oxidation product at 437 nm.The optimum reaction conditions are PS(0.44×10-3 mol·L-1)and HClO4(3.6×10-6mol·L-1)at 25℃.Following this procedure,phosphate can be determined with a linear calibration graph up to 0.23 μg·mL-1.The interference effect of several species was also investigated and it was found that the most common cations and anions did not interfere with the determination.The developed procedure was successfully applied to the determination of phosphate in natural waters and soil.

  15. A new ternary copper(II) complex derived from 2-(2'-pyridyl)benzimidazole and glycylglycine: synthesis, characterization, DNA binding and cleavage, antioxidation and HSA interaction.

    Science.gov (United States)

    Fu, Xia-Bing; Lin, Zi-Hua; Liu, Hai-Feng; Le, Xue-Yi

    2014-03-25

    A new ternary copper(II)-dipeptide complex [Cu(glygly)(HPB)(Cl)]⋅2H2O (glygly=glycylglycine anion, HPB=2-(2'-pyridyl)benzimidazole) has been synthesized and characterized. The DNA interaction of the complex was studied by spectroscopic methods, viscosity, and electrophoresis measurements. The antioxidant activity was also investigated using the pyrogallol autoxidation assay. Besides, the interaction of the complex with human serum albumin (HSA) in vitro was examined by multispectroscopic techniques. The complex partially intercalated to CT-DNA with a high binding constant (Kb=7.28×10(5) M(-1)), and cleaved pBR322 DNA efficiently via an oxidative mechanism in the presence of Vc, with the HO· and O2(-) as the active species, and the SOD as a promoter. Furthermore, the complex shows a considerable SOD-like activity with the IC50 value of 3.8386 μM. The complex exhibits desired binding affinity to HSA, in which hydrogen bond or vander Waals force played a major role. The alterations of HSA secondary structure induced by the complex were confirmed by UV-visible, CD, synchronous fluorescence and 3D fluorescence spectroscopy.

  16. Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis.

    Science.gov (United States)

    Walter, Kyla M; Moore, Caroline E; Bozorgmanesh, Rana; Magdesian, K Gary; Woods, Leslie W; Puschner, Birgit

    2014-11-01

    Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning.

  17. Alleloppathic effects and insecticidal activity of the aqueous extract of Satureja montana L.

    Directory of Open Access Journals (Sweden)

    Šućur Jovana

    2015-01-01

    Full Text Available Extensive use of synthetic insecticides, herbicides and other pesticides has negative effects on the environment and on human and animal health. Therefore scientists are turning towards natural pesticides such as active components of plant extracts. Effect of two concentrations (0.1% and 0.2% of Satureja montana L. aqueous extract on lipid peroxidation process, as well as the activity of the antioxidant enzymes (SOD, GPX, PPX and CAT in leaves and roots of pepper and black nightshade seedlings were examined 24, 72 and 120h after the treatment. Our results showed that higher concentration of S. montana aqueous extract induced lipid peroxidation in black nightshade roots. Furthermore, significant increases of pyrogallol and guaiacol peroxidase were detected in black nightshade leaves treated with 0.2% S. montana aqueous extract. The second aim was to evaluate effectiveness of aqueous extract as contact toxicant against whitefly. It was observed that aqueous extract with concentration of 0.2% showed toxic effect with 68.33% mortality after 96h.

  18. 丹参水提物的体外抗氧化活性分析%Antioxidative Activity of Water-soluble Components from Salvia miltiorrhiza

    Institute of Scientific and Technical Information of China (English)

    秦海燕; 索志荣

    2012-01-01

    目的:对丹参水提物的抗氧化活性进行体外研究。方法:分别采用邻苯三酚自氧化法、水杨酸法比色法测定丹参水提物对超氧阴离子、羟基自由基的清除能力,并与阳性对照品VE进行比较。结果:丹参水提物还原能力随浓度增加而增强,对超氧阴离子、羟基自由基均有较强的清除作用,且呈剂量效应关系。结论:丹参水提物有显著的抗氧化活性。%Objective: To study the antioxidation activity of water-soluble components from Salvia rniltiorrhiza. Method: The scavenging effects on superoxide anion and hydroxyl radical were determined by pyrogallol autoxidation and the salicylic acid colorimetry, respectively. VE was regarded as a positive reference. Results: The reducing power of the extract was enhanced with increasing concentration, and the extract has strong inhibition to superoxide anion and hydroxyl radical. Conclusion: The results reveal that wate-soluble components of Salvia miltiorrhiza have si~aificant antioxidant activity.

  19. Close correlation between heat shock response and cytotoxicity in Neurospora crassa treated with aliphatic alcohols and phenols

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, U.; Schweim, P.; Fracella, F.; Rensing, L. [Univ. of Bremen (Germany)

    1995-03-01

    In Neurospora crassa the aliphatic alcohols methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, ethylene glycol, glycerol, and allyl alcohol and the phenolic compounds phenol, hydroquinone, resorcinol, pyrogallol, phloroglucinol, sodium salicylate, and acetylsalicylic acid were analyzed with respect to their capacities to induce heat shock proteins (HSP) and to inhibit protein synthesis. Both the alcohols and phenols showed the greatest levels of HSP induction at concentrations which inhibited the overall protein synthesis by about 50%. The abilities of the different alcohols to induce the heat shock response are proportional to their lipophilicities: the lipophilic alcohol isobutanol is maximally inductive at about 0.6 M, whereas the least lipophilic alcohol, methanol, causes maximal induction at 5.7 M. The phenols, in general, show a higher capability to induce the heat shock response. The concentrations for maximal induction range between 25 mM (sodium salicylate) and 100 mM (resorcinol). Glycerol (4.1 M) shifted the concentration necessary for maximal HSP induction by hydroquinone from 50 to 200 mM. The results reveal that the induction of HSP occurs under conditions which considerably constrain cell metabolism. The heat shock response, therefore, does not represent a sensitive marker for toxicity tests but provides a good estimate for the extent of cell damage.

  20. Determination of Trace Antimony (III by Adsorption Voltammetry at Carbon Paste Electrode

    Directory of Open Access Journals (Sweden)

    Nongyue He

    2005-05-01

    Full Text Available This work presents a sensitive method for the determination of trace antimonybased on the antimony-pyrogallol red (PGR adsorption at a carbon paste electrode (CPE.The optimal conditions were to use an electrode containing 25% paraffin oil and 75%high purity graphite powder as working electrode, a 0.10 mol/L HCl solution containing3.0×10-5 mol/L PGR as accumulation medium and a 0.20 mol/L HCl solution aselectrolyte with an accumulation time of 150 s and a reduction time of 60 s at -0.50 Vfollowed with a sweep from -0.50 V to 0.20 V. The mechanism of the electrode reactionwas discussed. Interferences of other metal ions were studied as well. The detection limitwas 1×10-9 mol/L. The linear range was from 2.0×10-9 mol/L to 5.0×10-7 mol/L.Application of the proposed method to the determination of antimony in water andhuman hair samples gave good results.

  1. New ethanol extraction improves the anti-obesity effects of black tea.

    Science.gov (United States)

    Park, Bongju; Lee, Sangjin; Lee, Bonggyeong; Kim, Ingyum; Baek, Namjoon; Lee, Tae Ho; Lee, Seok-Yong; Son, Miwon; Park, Hyunsung

    2016-03-01

    Black tea has been reported to have anti-obesity effects in both rodents and humans. Gallic acid, an active component of black tea, decomposes quickly into pyrogallol in high-temperature solutions. This study introduced a new, aqueous ethanol extraction of black tea, which resulted in extracts with higher concentrations of gallic acid than conventional black tea extracts prepared by hot-water extraction or hot-ethanol extraction. We confirmed that, compared with the hot-water extract of black tea, the cold-ethanol extract of black tea (CE-BTE) had greater effects on reducing body weight and body fat, improving fatty liver, regulating blood glucose, and reducing blood cholesterol in the high-fat diet-induced obese mouse model. Nonetheless, although CE-BTE significantly reduced fat content, it did not reduce peroxisome proliferator-activated receptor (PPARγ) protein in epididymal fat tissue of HFD mice. We also showed that CE-BTE did not inhibit the function of PPARγ protein to drive adipogenesis of mouse 3T3-L1 preadipocytes. Considering that PPARγ is a master transcription factor not only for adipocyte differentiation, but also for adipose tissue function, such as glucose and lipid metabolism and insulin sensitivity, these results suggest that CE-BTE reduced fat mass and body weight without dampening fat cell homeostasis and insulin sensitivity.

  2. Application and analysis of the folin ciocalteu method for the determination of the total phenolic content from Limonium brasiliense L.

    Science.gov (United States)

    Blainski, Andressa; Lopes, Gisely Cristiny; de Mello, João Carlos Palazzo

    2013-06-10

    Limonium brasiliense is a common plant on the southern coast of Brazil. The roots are traditionally used for treatment of premenstrual syndrome, menstrual disturbances and genito-urinary infections. Pharmaceutical preparations obtained from its roots and used for these purposes were marketed in Brazil in the 1980s and 1990s. Currently, the Brazilian Drug Agency (National Health Surveillance Agency, ANVISA) has canceled the registration of these products, and their use was discontinued because of a lack of studies to characterize the plant raw material and ensure the effectiveness and safety of its use. The aim of the present study was to develop and validate an analytical method to determine the content of total polyphenols (TP) in an extract from L. brasiliense roots, by the UV/Vis spectrophotometric method. L. brasiliense roots were extracted in acetone:water (7:3, v/v-10% w/v). The crude extract was used to develop a method for TP assay. The method was validated according to national and international guidelines. The optimum conditions for analysis time, wavelength, and standard substance were 30 min, 760 nm, and pyrogallol, respectively. Under these conditions, validation by UV/Vis spectrophotometry proved the method to be linear, specific, precise, accurate, reproducible, robust, and easy to perform. This methodology complies with the requirements for analytical application and to ensure the reliability of the results.

  3. Study on Anti-oxidative Effects of Spirulina Kinase in vitro%螺旋藻激酶的体外抗氧化作用研究Δ

    Institute of Scientific and Technical Information of China (English)

    黄媛恒; 庞辉; 王慧杰; 黎钦蓉; 纪舒妤; 黄为然; 凌家杰; 李映新

    2016-01-01

    ABSTRACT OBJECTIVE:To study the anti-oxidative effects of spirulina kinase (SPK) in vitro. METHODS:The methods of phenanthroine-Fe2+ oxidation method,DPPH and auto-oxidation of pyrogallol were used to measure the effects of different concen-trations of SPK on scavenging hydroxyl (OH-) free radical,DPPH free radical and superoxide anion (O2-) free radical;IC50 of SPK was calculated. Prussian blue reaction was used to determine total reducing ability(by absorbance)of different concentrations of SPK to Fe3+. Vitamin C(VC)was used as positive control in above trials. RESULTS:SPK could eliminate the OH-free radical, DPPH free radical and O2- free radical in concentration-dependant manner,and the maximum elimination rate of SPK to OH- free radical and DPPH free radical were 86.82% and 78.98%(IC50 were 54.31,0.636 g/L),which were higher than VC (64.77%,73.49%). The maximum elimination rate of SPK to O2- free radical was 78.31%(IC50 was 3.918 g/L),which was lower than VC (94.14%). In reducing ability test,SPK improved absorbance in reducing ability test system,and maximum absorbance was simi-lar to VC in concentration-dependant manner. CONCLUSIONS:SPK has obvious anti-oxidant activities in vitro.%OBJECTIVE:To study the anti-oxidative effects of spirulina kinase (SPK) in vitro. METHODS:The methods of phenanthroine-Fe2+ oxidation method,DPPH and auto-oxidation of pyrogallol were used to measure the effects of different concen-trations of SPK on scavenging hydroxyl (OH-) free radical,DPPH free radical and superoxide anion (O2-) free radical;IC50 of SPK was calculated. Prussian blue reaction was used to determine total reducing ability(by absorbance)of different concentrations of SPK to Fe3+. Vitamin C(VC)was used as positive control in above trials. RESULTS:SPK could eliminate the OH-free radical, DPPH free radical and O2- free radical in concentration-dependant manner,and the maximum

  4. QUANTITATIVE DETERMINATION OF MAIN GROUPS OF SUBSTANCES IN GRANULES ON THE BASIS OF MEDICINAL VEGETABLE RAW MATERIAL FOR TREATING GASTROINTESTINAL DISEASES

    Directory of Open Access Journals (Sweden)

    Spiridonov S.V.

    2014-12-01

    methanol - ethyl acetate - acetic acid environment and calculation of flavonoid content as hyperoside recalculating. For the quantitative determination of polyphenols was used the methods of State Pharmacopoeia of Ukraine "Determination of tannins in herbal drugs" or European Pharmacopoeia «Determination of tannins in herbal drugs». The method is based on the color reaction of polyphenolic substances, which including in the plant raw material, with phosphomolybdic-tungsten reagent and measuring the optical density of the resulting solution at the wavelength of 760 nm. The content of total polyphenols in the drug was determined as pyrogallol recalculating. Conclusions 1. The determination of quantitative content of biologically active substances in granules based on medicinal plant raw material for the treatment of gastrointestinal tract diseases is carried out. 2. In the studied sample of granules contents of flavonoids, calculated as hyperoside, which equal to 0.43% and the polyphenols, calculated as pyrogallol, which equal to 0.44% has been established. 3. The data obtained can be used to develop the normative and technical documentation.

  5. Research on the Antioxidant Activity of Red Pigment from Purple Eggplant Peel%紫茄皮红色素抗氧化活性的研究

    Institute of Scientific and Technical Information of China (English)

    付莉; 彭威威

    2012-01-01

    The aims were to study on the antioxidant activity of red pigment from purple eggplant peel and lay the theoretical foundation for its application. In this paper,the purple eggplant skin was used as raw materials and ascorbic acid,citric acid were used as contrasts,hydroxyl radical (o OH) from Fenton reaction and superoxide anion (O2- ) from pyrogallol autoxidation reaction were used as the test model and the radical scavenging effect of purple eggplant skin red pigment against superoxide anion and hydroxyl radical were measured by using UV spectrophotometer. The antioxidant activity of red pigment eggplant purple skin' against fat oxidation was studied when lard was used as substrate and POV value of oil was determined by the oven storage method. Red pigment from purple eggplant skin could effect on free radicals above and its effect on hydroxyl radical scavenging was better than citric acid,ascorbic acid and scavenging effect was increased with the concentration increasing and the hydroxyl radical scavenging capacity tended to the stable situation when the concentration was greater than 0.5 g/100 mL; its effect was better than citric acid,ascorbic acid,with the maximum inhibition rate 91% and the pyrogallol autoxidation effected to stable inhibition when the concentration was above 0.6 g/100 mL; the degree of inhibition of lipid peroxidation was stronger than citric acid and ascorbic acid and synergies tended to stabilize when the concentration was 0.7 g/mL. Purple eggplant skin red pigment in a certain concentration range had strong antioxidative activity.%为了研究紫茄皮红色素的抗氧化活性,为其应用奠定理论基础.以紫茄皮为原料,以抗坏血酸、柠檬酸为对照,以Fenton反应产生羟基自由基(·OH),邻苯三酚自氧化反应产生超氧阴离子自由基(O.·)为试验模型,采用紫外分光光度计测定紫茄子皮红色素对羟基自由基、超氧阴离子自由基的清除作用;以猪油作底物,采用烘箱贮

  6. Phytochemical Analysis and Antimicrobial Activities of Methanolic Extracts of Leaf, Stem and Root from Different Varieties of Labisa pumila Benth

    Directory of Open Access Journals (Sweden)

    Ehsan Karimi

    2011-05-01

    Full Text Available A local herb, Kacip Fatimah, is famous amongst Malay women for its uses in parturition; however, its phytochemical contents have not been fully documented. Therefore, a study was performed to evaluate the phenolics, flavonoids, and total saponin contents, and antibacterial and antifungal properties of the leaf, stem and root of three varieties of Labisia pumila Benth. Total saponins were found to be higher in the leaves of all three varieties, compared to the roots and stems. Leaves of var. pumila exhibited significantly higher total saponin content than var. alata and lanceolata, with values of 56.4, 43.6 and 42.3 mg diosgenin equivalent/g dry weight, respectively. HPLC analyses of phenolics and flavonoids in all three varieties revealed the presence of gallic acid, caffeic acid, rutin, and myricetin in all plant parts. Higher levels of flavonoids (rutin, quercitin, kaempferol were observed in var. pumila compared with alata and lanceolata, whereas higher accumulation of phenolics (gallic acid, pyrogallol was recorded in var. alata, followed by pumila and lanceolata. Antibacterial activities of leaf, stem and root extracts of all varieties determined against both Gram positive (Micrococcus luteus, Bacillus subtilis B145, Bacillus cereus B43, Staphylococcus aureus S1431 and Gram negative (Enterobacter aerogenes, Klebsiella pneumonia K36, Escherichia coli E256, Pseudomonas aeruginosa PI96 pathogens showed that crude methanolic extracts are active against these bacteria at low concentrations, albeit with lower antibacterial activity compared to kanamycin used as the control. Antifungal activity of methanolic extracts of all plant parts against Fusarium sp., Candida sp. and Mucor using the agar diffusion disc exhibited moderate to appreciable antifungal activities compared to streptomycin used as positive control.

  7. Phytochemical analysis and antimicrobial activities of methanolic extracts of leaf, stem and root from different varieties of Labisa pumila Benth.

    Science.gov (United States)

    Karimi, Ehsan; Jaafar, Hawa Z E; Ahmad, Sahida

    2011-05-27

    A local herb, Kacip Fatimah, is famous amongst Malay women for its uses in parturition; however, its phytochemical contents have not been fully documented. Therefore, a study was performed to evaluate the phenolics, flavonoids, and total saponin contents, and antibacterial and antifungal properties of the leaf, stem and root of three varieties of Labisia pumila Benth. Total saponins were found to be higher in the leaves of all three varieties, compared to the roots and stems. Leaves of var. pumila exhibited significantly higher total saponin content than var. alata and lanceolata, with values of 56.4, 43.6 and 42.3 mg diosgenin equivalent/g dry weight, respectively. HPLC analyses of phenolics and flavonoids in all three varieties revealed the presence of gallic acid, caffeic acid, rutin, and myricetin in all plant parts. Higher levels of flavonoids (rutin, quercitin, kaempferol) were observed in var. pumila compared with alata and lanceolata, whereas higher accumulation of phenolics (gallic acid, pyrogallol) was recorded in var. alata, followed by pumila and lanceolata. Antibacterial activities of leaf, stem and root extracts of all varieties determined against both Gram positive (Micrococcus luteus, Bacillus subtilis B145, Bacillus cereus B43, Staphylococcus aureus S1431) and Gram negative (Enterobacter aerogenes, Klebsiella pneumonia K36, Escherichia coli E256, Pseudomonas aeruginosa PI96) pathogens showed that crude methanolic extracts are active against these bacteria at low concentrations, albeit with lower antibacterial activity compared to kanamycin used as the control. Antifungal activity of methanolic extracts of all plant parts against Fusarium sp., Candida sp. and Mucor using the agar diffusion disc exhibited moderate to appreciable antifungal activities compared to streptomycin used as positive control.

  8. Pomological features, nutritional quality, polyphenol content analysis, and antioxidant properties of domesticated and 3 wild ecotype forms of raspberries (Rubus idaeus L.).

    Science.gov (United States)

    Gülçin, Ilhami; Topal, Fevzi; Çakmakçı, Ramazan; Bilsel, Mine; Gören, Ahmet C; Erdogan, Ummugulsum

    2011-05-01

    The raspberry (Rubus idaeus L.) is an economically important berry crop that contains many phenolic compounds with potential health benefits. In this study, important pomological features, including nutrient content and antioxidant properties, of a domesticated and 3 wild (Yayla, Yavuzlar, and Yedigöl) raspberry fruits were evaluated. Also, the amount of total phenolics and flavonoids in lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were calculated as gallic acid equivalents (GAEs) and quercetin equivalents (QE). The highest phenolic compounds were found in wild Yayla ecotype (26.66 ± 3.26 GAE/mg extract). Whilst, the highest flavonoids were determined in wild Yedigöl ecotype (6.09 ± 1.21 QA/mg extract). The antioxidant activity of lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were investigated as trolox equivalents using different in vitro assays including DPPH(•), ABTS(•+), DMPD(•+), and O(•-)(2) radical scavenging activities, H(2)O(2) scavenging activity, ferric (Fe(3+)) and cupric ions (Cu(2+)) reducing abilities, ferrous ions (Fe(2+)) chelating activity. In addition, quantitative amounts of caffeic acid, ferulic acid, syringic acid, ellagic acid, quercetin, α-tocopherol, pyrogallol, p-hydroxybenzoic acid, vanillin, p-coumaric acid, gallic acid, and ascorbic acid in lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were detected by high-performance liquid chromatography and tandem mass spectrometry (LC-MS-MS). The results clearly show that p-coumaric acid is the main phenolic acid responsible for the antioxidant and radical scavenging activity of lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits.

  9. 脐橙黄酮体外的抗氧化作用%Study on in vitro Antioxidation of Navel Orange Flavonoids

    Institute of Scientific and Technical Information of China (English)

    刘霞; 李伟; 范小娜

    2012-01-01

    The in vitro reactive oxygen species scavenging activity of navel orange (Citrus sinensis Osbeck) flavonoids was studied by determining the autoxidation rate of pyrogallol after different concentration of navel oranges flavonoids was added. Vitamin C and 50% alcohol was used as compare. The results revealed no significant difference (P>0.05) between the antioxidation of 1 mg/mL vitamin C and 3.01 mg/mL navel oranges flavonoids; however, the antioxidation of navel oranges flavonoids was very significantly different (P<0.01) from that of 50% ethanol and CK, indicating that navel oranges flavonoids had strong in vitro ability in scavenging reactive oxygen species.%加入不同浓度的脐橙(Citrus sinensis Osbeck)黄酮,研究脐橙黄酮体外清除活性氧自由基邻苯三酚的作用,并与维生素C、体积分数为50%的乙醇的作用进行比较.结果表明,脐橙黄酮浓度为3.01 mg/mL时对邻苯三酚的清除率与1 mg/mL维生素C相比无显著差异(P>0.05),与体积分数为50%的乙醇及去离子水相比差异极显著(P<0.01).脐橙黄酮具有较强地清除体外活性氧自由基的作用.

  10. Multi-parametric approach to identify coffee components that regulate mechanisms of gastric acid secretion.

    Science.gov (United States)

    Rubach, Malte; Lang, Roman; Seebach, Elisabeth; Somoza, Mark M; Hofmann, Thomas; Somoza, Veronika

    2012-02-01

    Chlorogenic acid (CA), caffeine (CAFF), pyrogallol (PYR), catechol (CAT), (β)N-alkanoyl-hydroxytryptamides (C5HT) and N-methylpyridinium (N-MP) were evaluated for their influence on mechanisms of gastric acid secretion as single compounds and in biomimetic mixtures. Compounds were tested in coffee representative concentrations. Human gastric cancer cells (HGT-1) were used to study the proton secretory activity by Ussing chamber experiments and FACS analysis. For activation of EGFr, Akt1, ERK1/2, ATF-2 and cAMP levels, we performed pathway screening assays. Time-dependent expression of related genes were determined by real-time PCR. Part of the data was used for neural network modeling to identify the most relevant compounds. N-MP increased the expression of the anti-secretory somatostatin receptor by 114%, whereas C5HT decreased its expression by 52%. N-MP down-regulated the pro-secretory CHRM3 receptor by 36% and the H⁺,K⁺-ATPase by 36%. CAFF stimulated the secretory activity in the functional assays, whereas N-MP and CA decreased proton secretion. After applying a pathway analysis, we were able to discriminate between CAFF, CA, CAT, C5HT, PYR and histamine-activating EGFr signaling and N-MP-associated ERK1/2 signaling. By applying a multi-parametric approach, N-MP was shown to effectively down-regulate mechanisms of gastric acid secretion in human parietal gastric cells. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Stability of vitamin E content of {gamma}-irradiated biscuits

    Energy Technology Data Exchange (ETDEWEB)

    Taipina, Magda S.; Mastro, Nelida L. del [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@ipen.br; magtaipina@ig.com.br; Lamardo, Leda C.A. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Quimica Biologica]. E-mail: llamardo@ial.sp.gov.br

    2007-07-01

    The technology of food irradiation is seen by the industry as a means of ensuring food safety, since it exposes foods to ionizing radiation that kills insects, moulds and bacteria. The need to eliminate bacterial pathogens from read-to-eat food products must always be balanced with the maintenance of product quality. In addition to determining the effective ionizing radiation doses required for pathogen elimination the effects of irradiation on product chemistry, nutritional value and quality must also been determined. Vitamin E ({alpha}-tocopherol) is one of the most potent natural lipophilic antioxidants commonly present in the human diet. As it is considered a free radical scavenger there is a growing concern that irradiation might reduce the vitamin E content of food products prepared with ingredients rich in any of the dietary source of the vitamin. This work describes the effects of ionizing radiation on the vitamin E content of some biscuits commercially found in the market. Three lots of biscuits were used. Irradiation was performed in a {sup 60}Co Gammacell 220 source, dose rate of about 3.5 kGy/h at doses of 1 kGy and 3 kGy. For vitamin E determination samples were saponified with ethanolic potassium hydroxide in the presence of pyrogallol, and the tocopherols were extracted with petroleum ether. The absorbance was measured at 520 nm. From the obtained results it is possible to conclude that there was a notorious stability of the vitamin content of the biscuits submitted to gamma-irradiation at the assayed doses. (author)

  12. Effect of pyrolysis temperature on the properties of carbon/nickel nanocomposites prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Mansour, N. Ben, E-mail: Nabil.Benmansour@fsg.rnu.tn [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabès University, Faculty of Sciences in Gabès, Gabès (Tunisia); Najeh, I.; Mansouri, S. [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabès University, Faculty of Sciences in Gabès, Gabès (Tunisia); El Mir, L. [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabès University, Faculty of Sciences in Gabès, Gabès (Tunisia); Al Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Sciences, Department of Physics, Riyadh 11623 (Saudi Arabia)

    2015-05-15

    Highlights: • Synthesis of nickel oxide nanoparticles in carbon structures. • Presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. • DC conductivity exhibited the presence of conduction percolation phenomenon and the dominance of conduction model 3D-GVRH in the studied materials. • From AC conductance PF/Ni nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. • Appearance of a negative differential resistance (NDR) at room temperature in the sample treated at 600 °C. - Abstract: Carbon–nickel nanocomposites (C/Ni) were prepared by sol–gel method after the incorporation of nickel oxide (NiO) nanoparticles in organic matrix based on pyrogallol-formaldehyde (PF). The nanocomposites heated under inert atmosphere have been characterized by various techniques such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and electrical analysis. The XRD spectra exhibited the presence of NiO or metallic Ni phase in amorphous carbon matrix at low pyrolysis temperature, while at 1000 °C the graphite structure line was observed. The TEM images indicate the presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. The AC conductance shows that our nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. The voltage–current V(I) characteristics of the compound show two different regions: an Ohmic region at low current and a negative differential resistance (NDR) region at higher current. This switching phenomenal behavior has been explained by an electrothermal model.

  13. Bioactive Compounds and Biological Activities of Jatropha curcas L. Kernel Meal Extract

    Directory of Open Access Journals (Sweden)

    Abdul Rahman Omar

    2011-09-01

    Full Text Available Defatted Jatropha curcas L. (J. curcas seed kernels contained a high percentage of crude protein (61.8% and relatively little acid detergent fiber (4.8% and neutral detergent fiber (9.7%. Spectrophotometric analysis of the methanolic extract showed the presence of phenolics, flavonoids and saponins with values of 3.9, 0.4 and 19.0 mg/g DM, respectively. High performance liquid chromatography (HPLC analyses showed the presence of gallic acid and pyrogallol (phenolics, rutin and myricetin (flavonoids and daidzein (isoflavonoid. The amount of phorbol esters in the methanolic extract estimated by HPLC was 3.0 ± 0.1 mg/g DM. Other metabolites detected by GC-MS include: 2-(hydroxymethyl-2 nitro-1,3-propanediol, β-sitosterol, 2-furancarboxaldehyde, 5-(hydroxymethy and acetic acid in the methanolic extract; 2-furancarboxaldehyde, 5-(hydroxymethy, acetic acid and furfural (2-furancarboxaldehyde in the hot water extract. Methanolic and hot water extracts of kernel meal showed antimicrobial activity against both Gram positive and Gram negative pathogenic bacteria (inhibition range: 0–1.63 cm at the concentrations of 1 and 1.5 mg/disc. Methanolic extract exhibited antioxidant activities that are higher than hot water extract and comparable to β-carotene. The extracts tended to scavenge the free radicals in the reduction of ferric ion (Fe3+ to ferrous ion (Fe2+. Cytotoxicity assay results indicated the potential of methanolic extract as a source of anticancer therapeutic agents toward breast cancer cells.

  14. Prospecting Russula senecis: a delicacy among the tribes of West Bengal

    Directory of Open Access Journals (Sweden)

    Somanjana Khatua

    2015-03-01

    Full Text Available Russula senecis, a worldwide distributed mushroom, is exclusively popular among the tribal communities of West Bengal for food purposes. The present study focuses on its reliable taxonomic identification through macro- and micro-morphological features, DNA barcoding, confirmation of its systematic placement by phylogenetic analyses, myco-chemicals and functional activities. For the first time, the complete Internal Transcribed Spacer region of R. senecis has been sequenced and its taxonomic position within subsection Foetentinae under series Ingratae of the subgen. Ingratula is confirmed through phylogenetic analysis. For exploration of its medicinal properties, dried basidiocarps were subjected for preparation of a heat stable phenol rich extract (RusePre using water and ethanol as solvent system. The antioxidant activity was evaluated through hydroxyl radical scavenging (EC50 5 µg/ml, chelating ability of ferrous ion (EC50 0.158 mg/ml, DPPH radical scavenging (EC50 1.34 mg/ml, reducing power (EC50 2.495 mg/ml and total antioxidant activity methods (13.44 µg ascorbic acid equivalent/mg of extract. RusePre exhibited antimicrobial potentiality against Listeria monocytogenes, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, different parameters were tested to investigate its chemical composition, which revealed the presence of appreciable quantity of phenolic compounds, along with carotenoids and ascorbic acid. HPLC-UV fingerprint indicated the probable existence of at least 13 phenolics, of which 10 were identified (pyrogallol > kaempferol > quercetin > chlorogenic acid > ferulic acid, cinnamic acid > vanillic acid > salicylic acid > p-coumaric acid > gallic acid. Result from the present work suggests that the fraction, RusePre, may open novel prospect as a functional ingredient in antioxidant supplements and in drugs to treat infectious disease.

  15. Pyrolysis-GC/MS of charred purified condensed tannin: towards identification of tannin-derived black carbon in environmental samples

    Science.gov (United States)

    Kaal, Joeri; Nierop, Klaas G. J.; Kraal, Peter; Preston, Caroline M.

    2010-05-01

    Tannins account for a significant proportion of plant biomass and are therefore a possible source of Black C in the charred remains from wildfires. Nonetheless, in contrast with other major biocomponents such as lignin and cellulose, the thermal degradation of tannins has not been investigated in laboratory charring experiments. We used pyrolysis-GC/MS to investigate the effects of furnace charring (30 min at fixed temperatures up to 600 °C under limited oxygen supply) on the degradation of pure condensed tannin (CT) isolated from Corsican pine (Pinus nigra) needles. The experiments showed a rapid loss (at 300 °C and higher) of the pyrogallol moieties of the B-ring of prodelphinidin-type CT, due to dehydroxylation. The relative abundance of catechols (from procyanidin-type CT) decreased at 350 °C and higher temperatures. This led to the formation of phenols that were strongly enriched between 300 and 400 °C. At higher temperatures, further dehydroxylation caused a decline in contributions of phenols producing a series of monocyclic aromatics ((alkyl)benzenes) and condensation of aromatics produced polycyclic aromatic hydrocarbons (PAHs), i.e. the typical pyrolysis fingerprint of strongly charred biomass. We conclude that (i) the thermal degradation of CT can be successfully monitored by pyrolysis-GC/MS, (ii) thermal degradation of CT is characterized by dehydroxylation of phenolic groups and condensation of aromatics that increase with temperature and (iii) CT-derived Black C may be recognized by catechol enrichments at low temperatures and possibly (relative) abundance of phenol and biphenyl at higher levels of thermal breakdown. Applying the same method to natural charcoal from gorse bushfires indicated that pyrolysis-GC/MS fingerprinting may allow for tannin identification in environmental Black C samples.

  16. Nitrogen fertilizer improves boron phytoextraction by Brassica juncea grown in contaminated sediments and alleviates plant stress.

    Science.gov (United States)

    Giansoldati, Virginia; Tassi, Eliana; Morelli, Elisabetta; Gabellieri, Edi; Pedron, Francesca; Barbafieri, Meri

    2012-06-01

    In this study we evaluated the effect of different fertilizer treatments on Brassica plants grown on boron-contaminated sediments. Experiments were conducted in the laboratory and on the lysimeter scale. At laboratory scale (microcosm), five different fertilizers were tested for a 35-d period. On the lysimeter scale, nitrogen fertilization was tested at three different doses and plants were allowed to grow until the end of the vegetative phase (70 d). Results showed that nitrogen application had effectively increased plant biomass production, while B uptake was not affected. Total B phytoextracted increased three-fold when the highest nitrogen dose was applied. Phytotoxicity on Brassica was evaluated by biochemical parameters. In plants grown in unfertilized B-contaminated sediments, the activity of antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX) and pyrogallol peroxidase (PPX) increased, whereas catalase (CAT) decreased with respect to control plants. Addition of N progressively mitigated the alteration of enzymatic activity, thus suggesting that N can aid in alleviating B-induced oxidative stress. SOD activity was restored to control levels just at the lowest N treatment, whereas the CAT inhibition was partially restored only at the highest one. N application also lowered the B-induced increase in APX and PPX activities. Increased glutathione reductase activity indicated the need to restore the oxidative balance of glutathione. Data also suggest a role of glutathione and phytochelatins in B defense mechanisms. Results suggest that the nitrogen fertilizer was effective in improving B phytoextraction by increasing Brassica biomass and by alleviating B-induced oxidative stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Reactive oxygen species scavenging activities in a chemiluminescence model and neuroprotection in rat pheochromocytoma cells by astaxanthin, beta-carotene, and canthaxanthin.

    Science.gov (United States)

    Chang, Chi-Sen; Chang, Chia-Lin; Lai, Guia-Hung

    2013-08-01

    The objective of this study was to determine chemiluminescence (CL) antioxidant activities and neuroprotective effects of astaxanthin, beta-carotene (β-carotene), and canthaxanthin on undifferentiated rat pheochromocytoma (PC12) cells. We performed three CL antioxidant assays, and the three carotenoids showed varying degrees of antioxidant activity, with astaxanthin exhibiting the highest antioxidant activity than the other two samples. Results of a pyrogallol-luminol assay revealed β-carotene to have higher antioxidant activity than canthaxanthin, whereas cupric sulfate-Phen-Vc-hydrogen peroxide (H₂O₂) assay showed canthaxanthin to have higher antioxidant activity than β-carotene. Luminol-H₂O₂ assay showed the antioxidant activity series as canthaxanthin > β-carotene at 62.5-1000 μg/mL and β-carotene > canthaxanthin at 1000-4000 μg/mL. Astaxanthin exhibited partial neuroprotective activity against H₂O₂ and the strongest neuroprotective activity against amyloid beta-peptide(25-35) [(Aβ)(25-35)]-induced undifferentiated PC12 cell deaths at 0.5-5.0 μM. Canthaxanthin showed partial neuroprotective activity in Aβ(25-35)-induced undifferentiated PC12 cell deaths at 1.0-5.0 μM. Astaxanthin protected undifferentiated PC12 cells from the damaging effects of H₂O₂ and Aβ(25-35) by the following ways: (1) scavenging superoxide anion radicals, hydroxyl radicals, and H₂O₂; (2) securing cell viability; (3) suppressing the production of reactive oxygen species; and (4) eliminating calcium ion influx. Our results conclusively show that astaxanthin has the merit as a potential neuron protectant.

  18. Tailoring Synthesis Conditions of Carbon Xerogels towards Their Utilization as Pt-Catalyst Supports for Oxygen Reduction Reaction (ORR

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    María Jesús Lázaro

    2012-10-01

    Full Text Available Carbon xerogels characterized by different textural, structural and chemical properties were synthesized and used as supports for Pt catalysts for the application in polymer electrolyte fuel cells. Synthesis conditions were varied in order to synthesize carbon xerogels following the sol-gel method. These included the reactants ratio (precursor/formaldehyde, the catalyst concentration (precursor/catalyst ratio and type (basic and acid, the precursor type (resorcinol and pyrogallol and the solvent (aqueous or acetone based. Stoichiometric mixtures of resorcinol and formaldehyde yielded well polymerized gels and highly developed structures. Slow gelation, favored by the presence of acetone as solvent in the sol and low catalyst concentration, resulted in higher polymerization extent with a highly mesoporous or even macroporous texture and more ordered structure, as evidenced by XPS and Raman spectroscopy. Small Pt particles of ca. 3.5 nm were obtained by using carbon xerogels characterized by an ordered surface structure. The specific activity towards the oxygen reduction reaction, i.e., the limiting catalytic process in low temperature fuel cells, is significantly favored by highly ordered carbon xerogels due to a metal-support enhanced interaction. Nevertheless, surface defects favor the distribution of the metallic particles on the surface of carbon, which in the end influences the effectiveness of the catalyst. Accelerated degradation tests were conducted to evaluate catalyst stability under potential cycling conditions. The observed decay of performance was considerably lower for the catalysts based on ordered carbon xerogels stabilizing Pt particles in a higher extent than the other xerogels and the commercial carbon black support.

  19. Evaluation of Some Vegetal Colloids on the Quality Attributes of Beef Sausage

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    A.S. Osheba

    2013-06-01

    Full Text Available Colloids are of vital role for improving the quality of foods including that of psyllium, locust bean and pectin which is found in orange peel albedo. These colloids are also of value for clinical nutrition. The last opinion could be confirmed by the chemical analysis which revealed that locust bean seeds had higher total phenolic compounds (485.28 mg/100 g while psyllium seeds (297.54 mg/100 g and orange peel albedo (246.11 mg/100 g showed nearly the same level. Major phenolic compound was pyrogallol for locust bean, being cholchecein for other two colloids sources. Total flavonoid compounds were higher for psyllium seeds (536.46 mg/100 g and locust bean seed (275.76 mg/100 g, being less for orange peel albedo (113.65 mg/100 g; major flavonoid in all sources was the hesperidin. The best eating qualities recoded for psyllium sausage followed by locust bean sausage. Generally, all three colloids sources improved the eating quality of beef sausage. Plasticity confirmed the results of sensory evaluation where the best sample was that of psyllium sausage. Higher pH value after 6 months storage at-18ºC was in line with the best Water Holding Capacity (WHC and plasticity levels recorded for psyllium sausage. Color intensity and TBA value were best for locust been followed by psyllium treatments. The lowest color intensity was in line with the highest TBA value. The keeping quality was better when adding the tested colloids; TVN, TBA value, Total Bacterial Count (TBC, Yeast and Mold (Y and M count was lowest for psyllium followed by locust bean treatment. Other colloids showed the same trend but at lower degree.

  20. Phytochemical study of phenolic compounds of labrador tea (Lédum palústre L.

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    Валентина Петровна Гапоненко

    2015-11-01

    Full Text Available Aim. This work is devoted a phytochemical study of biologically active substances in herb of Labrador Tea (Lédum palústre L., as well as investigation of the possibility of complex use of raw materials in order to create on its basis new herbal medicines.Methods. The object of the study served as the herb Labrador Tea. Separation of isolated substances was performed by adsorption and partition chromatography on various adsorbents. The structure of the isolated compounds was determined based on physicochemical methods: paper (PC and the thin layer (TLC chromatography, UV, IR and NMR spectroscopy in comparison with the original valid standards of flavonoids. Acid hydrolys was used for the determination of the flavonoid aglycone composition. The content of total flavonoids was determined by differential spectrophotometry at a wavelength of 412 nm from the reaction with aluminum chloride based on the hyperoside-standard (Ukrainian scientific Pharmacopoeial center for quality of medicines (Pharmacopoeial center, Kharkоv.Results. During this study we found more than 40 of phenolic compounds and identified 31compounds. The phytochemical analysis showed the presence of flavonols (11 compounds, catechins (5. Hydroxycinnamic acids represented by caffeic, ferulic, chlorogenic acids. Besides that, it were found phenolic glycoside arbutin, coumarins - coumarin, umbelliferon, scopoletin, esculetin and esculin, tannins – metyl gallate, pyrogallol.Conclusions. The following biologically active substances were defined for the first time: flavonoids – 5-methyl-kaempferol, avicularin, polistahozid, quercitrin; coumarins – esculetin, esculin; as well as hydroxycinnamic acids – ferulic, chlorogenic, neochlorogenic of Labrador Tea. The obtained data justify the prospectivefor creation of new and effective herbal medicines from Labrador Tea

  1. Study on characteristics and inhibition effects ofperoxidase from Luffa cylindrica(Linn.)Roem%丝瓜过氧化物酶的特性和抑制作用研究

    Institute of Scientific and Technical Information of China (English)

    周向军; 高义霞; 袁毅君; 张志昌; 张继

    2011-01-01

    研究丝瓜过氧化物酶最适温度、最适pH值、Km、Vmax及最适底物,同时通过正交试验探讨不同抑制剂组合对丝瓜过氧化物酶的抑制作用.结果表明,丝瓜过氧化物酶最适温度为45℃,最适pH值为5.0,以邻苯三酚为最适底物,Km=0.001516 mol/L,Vmax.=440.7U/(min·g).正交试验结果表明,最佳抑制剂组合为6mmol/L柠檬酸+6mmol/L EDTA+6mmol/L半胱氨酸+6mmol/L VC.在此条件下抑制率为58.89%.%The optimum temperature, pH value, K*, V^ and optimum substrate of peroxidase (POD) from Luffa cylindrica (Linn.) Roem were studied, and the effects of different inhibitors combination on peroxidase activity were also explored. The results shown that the optimum temperature of POD was 45t, pH value 5.0, Kn=0.001516mol/L and V^r=440.7U (min?g) using pyrogallol as optimum substrate. Orthogonal experimental results showed that the optimization inhibitors combination were as follows: 6mmol/L citric acid+6mmol/L EDTA+6mmol/L L-cys+6mmoI/L VC. Under these conditions, inhibition ratio was 58.89%.

  2. Antioxidant Activities of Phytic Acid Crude Extracts from Rapeseed Meal in Vitro%菜籽饼中植酸粗提物的体外抗氧化能力研究

    Institute of Scientific and Technical Information of China (English)

    汤务霞; 祝佳; 熊治渝; 刘超

    2011-01-01

    [目的]研究三种不同溶剂体系从菜籽饼中提取得到的植酸粗提物的体外抗氧化性能力.[方法]通过Fenton 反应体系产生羟自由基(·OH),由连苯三酚在碱性溶液中自氧化反应产生超氧阴离子自由基(O2-·);用分光光度法检测三种植酸粗提物的还原能力及对·OH、O2-·和DPPH·的清除作用.[结果]三种溶剂提取得到的植酸粗提物都具有还原能力;对羟自由基、超氧阴离子自由基、DPPH自由基也用一定的清除能力.%[ObjectiveJThe aim was to study on antioxidant activities of phytic acid crude extracts with three solvent extracts from rapeseed meal in vitro. [MethodJThe hydroxyl radical ('OH)was produced through Fenton reaction system, and the superoxide anion radical (02-*) was produced from self-oixdation reaction in alkalescent solution with the help of pyrogallol; reduction ability of phytic acid crude extract and elimination effect on -OH^02'' and DPPH-were measured with spectrophotometry. [Results]Phytic acid of crude extracts with three solvent extracts had reduction ability and some elimination effect on hydroxyl radical, superoxide anion radical, DPPH radical.

  3. Partial characterization of superoxide dismutase activity in the Barber pole worm-Haemonchus contortus infecting Capra hircus and abomasal tissue extracts

    Institute of Scientific and Technical Information of China (English)

    Sadia Rashid; Malik Irshadullah

    2014-01-01

    Objective: To determine the activity of superoxide dismutase (SOD) in the male and female haematophagous caprine worms, Haemonchus contortus infecting Capra hircus, and their E/S products and also to analyse the effect of Haemonchus infection on the level of host SOD. Methods: The SOD activity was analysed by using the pyrogallol autoxidation assay and non-denaturing polyacrylamide gel electrophoresis followed by specific enzyme staining by riboflavin-nitroblue tetrazolium method. Results: The adult females were found to have higher enzyme activity than the male worms. Appreciable amount of SOD activity was also detected in the worm culture medium and female worms secreted more SOD in comparison to the male parasites. The SOD activity was negatively correlated to the worm burden. Statistically significant decrease in SOD activity (P Conclusions:Haemonchus contortus is a key model parasite for drug and vaccine discovery. The presences of SOD activity in appreciable amount in the parasite as well as its E/S products indicate that it has a well-developed active antioxidant system to protect itself from the host immune attack. SOD could be the target for vaccine development which is the need of the hour as mass drug administration for parasite control has resulted in anthelmintic resistance across the globe and threatens the viability of sheep and goat industry in many regions of the world. The infection with Haemonchus causes a drastic reduction in SOD activity of the host tissue thus effecting its protective potential. One characteristic SOD band was found in the females which was not present in any other preparations and thus could be exploited for further studies on diagnostic/control measures.

  4. Quantitative analysis and simultaneous activity measurements of Cu, Zn-superoxide dismutase in red blood cells by HPLC-ICPMS.

    Science.gov (United States)

    Nuevo Ordoñez, Y; Montes-Bayón, M; Blanco-González, E; Sanz-Medel, A

    2010-03-15

    The interest on accurate and precise determination of metalloproteins such as Cu, Zn-superoxide dismutase (Cu, Zn-SOD) involved in the redox balance of living cells is increasing. For this purpose, analytical strategies that provide absolute protein concentration measurements have to be developed. The determination of Cu, Zn-SOD through the measurement of the Cu associated to the protein, which provides its enzymatic activity, by liquid chromatography with online inductively coupled plasma mass spectrometric (ICPMS) detection is described here. Postcolumn isotope dilution analysis (IDA) of Cu has been applied for quantification after evaluation of the column recovery for the total Cu and also Cu-SOD that turned out to be quantitative. When the concentration results obtained via IDA using high-performance liquid chromatography (HPLC)-ICPMS are plotted versus the activity measurements (using the spectrophotometric pyrogallol autoxidation method) a good correlation curve is obtained. Such results permit us, from ICPMS measurements, to obtain simultaneously the Cu, Zn-SOD absolute concentration as well as its enzymatic activity by interpolation in the previously obtained curve. This possibility was explored in real samples (red blood cells of control individuals and patients with metallic total hip arthroplasty) obtaining a good match between direct enzymatic activity measurements and those obtained by interpolation in the correlation curve. The actual protein identification in the red blood cell extract was conducted by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and two matrixes were compared in order to preserve as much as possible the protein-metal interactions during the MALDI process. Interestingly, using a solution containing trihydroxyacetophenone in citrate buffer permitted us to observe some metal-protein interactions in the MS spectrum of the intact Cu, Zn-SOD from red blood cells.

  5. Extraction and separation of total flavonoids from Flos Puerariae and its antioxidant activity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Rui-xue; OUYANG Chang-han; WU Ji-liang

    2008-01-01

    Objective To study the optimum extraction and separation process of total flavonoids in the flowers of Flos Puerariae and its antioxidative activity. Methods The total flavonoids were extracted with assistance of ultrasonic wave and the content was determined at 265 nm wavelength by Spectrophotometrie method. Orthogonal experiment L9(34) was carried out to investigate the effects of concentration of solvent, the ratio of material to liquid, time length of extraction, and frequency of extraction on extraction results of total flavonoids from Flos Puerariae. The extracted solution was purified by petroleum ether and ethanol sequently. Under these conditions, the total flavonoids was eluted gradiently with mixed mobile phase of methanol-chloroform solution in the silica gel column system, and then determined by UV scanning and HPLC. Fenton reaction was used to produce and detect hydroxyl radicals (·OH), and pyrogallol system was used to produce and detect the superoxide radical anion(O2-·). Results The optimum conditions were as follows;using 40 % (V/V) methanol as extractor with the ratio of material to liquid at 1:30, and extracting for 2.5 h a time for 3 times. The extraction yield of total flavonoids was 13.6 %. Six isoflavone compounds were isolated from the flowers of Flos Puerariae by the method of silica gel column chromatography. Antioxidative test results showed good performance of flavonoid scavenging capacity in both hydroxyl radical system and superoxide radical system and its IC50 was 7.65 μg·mL-1 and 0.18 mg·mL-1, respectively. Conclusions This study provided scientific basis for further development and utilization of Flos Puerariae and make preparation for later pharmacological research.

  6. Determinação de compostos fenólicos em amostras comerciais de chás verde e preto - Camellia sinensis (L. Kuntze, Theaceae = Determination of phenolic componds in commercial samples of green and black tea - Camellia sinensis (L. Kuntze, Theaceae

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    Airton Vicente Pereira

    2009-04-01

    Full Text Available O chá de Camellia sinensis é rico em compostos fenólicos antioxidantes, responsáveis por efeitos benéficos à saúde humana. Neste trabalho, foram realizadas as determinações da concentração de fenóis totais e flavonoides de sete amostras comerciais dos chás preto e verde. Os teores de fenóis totais variaram de 4,80 a 26,60 mg de pirogalol g-1 de amostra e os de flavonoides, de 0,46 a 1,10 mg de quercetina g-1 de amostra. A análise anatômica do conteúdo das amostras permitiu caracterizar a autenticidade dos produtos,observando-se os marcadores anatômicos típicos da espécie (estômatos anomocíticos, tricomas tectores unicelulares, mesofilo dorsiventral, drusas de oxalato de cálcio e esclereides.The tea from Camellia sinensis (green tea and black tea is rich in antioxidant phenolic compounds, responsible for beneficial effects to human health. In this work, determinations were carried out on theconcentration of total phenols and flavonoids in seven commercial samples of black tea and green tea. The samples presented concentrations of total phenols varying between 4.80 and 26.60 mg of pyrogallol g-1 and concentrations of flavonoids from 0.46 to 1.10 mg of quercetin g-1. With the purpose of characterizing the authenticity of the product contained in the sachets, the samples were fixed for histological studies. The samples presented the typical anatomical markers of the species (anomocytic stomata, unicellular non-glandulartrichomes, dorsiventral mesophyll, calcium oxalate druses and sclereids.

  7. 金丝草总黄酮的提取与抗氧化性研究%Extraction and Antioxidant Activity of Total Flavonoids from Pogonatherumcrinitum

    Institute of Scientific and Technical Information of China (English)

    林燕如; 陈宜菲; 李粉玲

    2013-01-01

    On the base of the single factor experiments,the optimal processing conditions of ultra-sound-assisted for the extraction of total flavonoids from Pogonatherum crinitum were obtained by orthogonal experiments and the antioxidation of total flavonoids by the elimination capacity on hydroxyl radical with sali-cylic acid method,superoxide anion radical with pyrogallol oxidation method and the deoxidize activity with prussian blue method were studied.The results indicated that the optimum conditions were immersed in 47℃50%ethanol with solid-liquid ratio 1∶35 for 35 min by ultrasonic power 70 W. Its yield was 3.080%.The ex-traction had certain elimination effects on hydroxyl radical and superoxide anion radical.%在单因素试验的基础上,通过正交试验对超声波辅助提取金丝草总黄酮的工艺条件进行优化.并采用水杨酸法测定其清除羟自由基能力、邻苯三酚自氧化法测定其清除超氧自由基能力和普鲁士蓝法测定还原能力.结果表明,提取金丝草总黄酮的最佳工艺条件为:乙醇浓度50%,料液比1∶35,超声波功率70 W,超声时间35 min,超声温度47℃,总黄酮得率为3.08%.金丝草黄酮提取物对羟自由基和超氧自由基呈现出清除作用,还原能力则随着浓度的增加而增强.

  8. Separation/preconcentration of ultra-trace levels of inorganic Sb and Se from different sample matrices by charge transfer sensitized ion-pairing using ultrasonic-assisted cloud point extraction prior to their speciation and determination by hydride generation AAS.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan

    2016-10-01

    In the existing study, a new, simple and low cost process for separation/preconcentration of ultra-trace level of inorganic Sb and Se from natural waters, beverages and foods using ultrasonic-assisted cloud point extraction (UA-CPE) prior to their speciation and determination by hydride generation AAS, is proposed. The process is based on charge transfer sensitized complex formations of Sb(III) and Se(IV) with 3-amino-7-dimethylamino-2-methylphenazine hydrochloride (Neutral red, NRH(+)) in presence of pyrogallol and cetyltrimethylammonium bromide (CTAB) as both sensitivity enhancement and counter ion at pH 6.0. Under the optimized reagent conditions, the calibration curves were highly linear in the ranges of 8-300ngL(-1) and 12-250ngL(-1) (r(2)≥0.993) for Se(IV) and Sb(III), respectively. The limits of detection were 2.45 and 3.60ngL(-1) with sensitivity enhancement factors of 155 and 120, respectively. The recovery rate was higher than 96% with a relative standard deviation lower than 5.3% for five replicate measurements of 25, 75 and 150ngL(-1) Se(IV) and Sb(III), respectively. The method was validated by analysis of two certified reference materials (CRMs), and was successfully applied to the accurate and reliable speciation and determination of the contents of total Sb/Sb(III), and total Se/Se(IV) after UA-CPE of the pretreated sample matrices with and without pre-reduction with a mixture of l-cysteine and tartaric acid. Their Sb(V) and Se(VI) contents were calculated from the differences between total Sb and Sb(III) and/or total Se and Se(IV) levels.

  9. Fisetin Protects DNA Against Oxidative Damage and Its Possible Mechanism

    Science.gov (United States)

    Wang, Tingting; Lin, Huajuan; Tu, Qian; Liu, Jingjing; Li, Xican

    2016-01-01

    Purpose: The paper tries to assess the protective effect of fisetin against •OH-induced DNA damage, then to investigate the possible mechanism. Methods: The protective effect was evaluated based on the content of malondialdehyde (MDA). The possible mechanism was analyzed using various antioxidant methods in vitro, including •OH scavenging (deoxyribose degradation), •O2- scavenging (pyrogallol autoxidation), DPPH• scavenging, ABTS•+ scavenging, and Cu2+-reducing power assays. Results: Fisetin increased dose-dependently its protective percentages against •OH-induced DNA damage (IC50 value =1535.00±29.60 µM). It also increased its radical-scavenging percentages in a dose-dependent manner in various antioxidants assays. Its IC50 values in •OH scavenging, •O2- scavenging, DPPH• scavenging, ABTS•+ scavenging, and Cu2+-reducing power assays, were 47.41±4.50 µM, 34.05±0.87 µM, 9.69±0.53 µM, 2.43±0.14 µM, and 1.49±0.16 µM, respectively. Conclusion: Fisetin can effectively protect DNA against •OH-induced oxidative damage possibly via reactive oxygen species (ROS) scavenging approach, which is assumed to be hydrogen atom (H•) and/or single electron (e) donation (HAT/SET) pathways. In the HAT pathway, the 3’,4’-dihydroxyl moiety in B ring of fisetin is thought to play an important role, because it can be ultimately oxidized to a stable ortho-benzoquinone form. PMID:27478791

  10. Roles of reactive oxygen species and heme oxygenase-1 in modulation of alveolar macrophage-mediated pulmonary immune responses to Listeria monocytogenes by diesel exhaust particles.

    Science.gov (United States)

    Yin, Xuejun J; Ma, Jane Y C; Antonini, James M; Castranova, Vincent; Ma, Joseph K H

    2004-11-01

    Diesel exhaust particles (DEP) have been shown to suppress alveolar macrophage (AM)-mediated pulmonary immune responses to Listeria monocytogenes in vivo. In this study, effects of DEP-derived reactive oxygen species (ROS) and heme oxygenase (HO)-1 on AM-mediated immune responses to L. monocytogenes were investigated. Brown Norway rats were intratracheally inoculated with 100,000 L. monocytogenes, and AM were isolated at 7 days post-infection. Exposure to DEP or their organic extract (eDEP), but not the washed DEP (wDEP) or carbon black, increased intracellular ROS and HO-1 expression in AM. Induction of ROS and HO-1 by eDEP was partially reversed by alpha-naphthoflavone, a cytochrome P450 1A1 inhibitor, and totally blocked by N-acetylcysteine. In addition, exposure to eDEP, but not wDEP, inhibited lipopolysacchride-stimulated secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-12 (IL-12), but augmented production of IL-10 by AM. Kinetic studies showed that modulation of cytokines by eDEP was preceded by ROS and HO-1 induction. Furthermore, pretreatment of AM with superoxide dismutase (SOD) or zinc protoporphrin IX (Znpp), which attenuated eDEP-induced HO-1 expression/activity, substantially inhibited eDEP effect on IL-10. Finally, direct stimulation with pyrogallol (PYR), a superoxide donor, upregulated HO-1 and IL-10 but decreased secretion of IL-12 in L. monocytogenes-infected AM. These results show that DEP, through eDEP-mediated ROS, induce HO-1 expression and IL-10 production and at the same time inhibit AM production of TNF-alpha and IL-12 to dampen the host immune responses. The results also suggest that HO-1 may play an important role in regulating production of IL-10 by DEP-exposed and L. monocytogenes-infected AM.

  11. Purification and kinetic characterization of the liverwort Pallavicinia lyelli (Hook.) S. Gray. cytosolic ascorbate peroxidase.

    Science.gov (United States)

    Sajitha Rajan, S; Murugan, K

    2010-09-01

    Ascorbate peroxidase (APX) of the liverwort Pallavicinia lyelli was extracted and purified through ammonium sulfate precipitation, Butyl-Toyopearl, DEAE-Cellulofine and Sephadex G-75 chromatography. The purification factor for APX was 285 with 7.9% yield. The enzyme was characterized for thermal stability, pH and kinetic parameters. The molecular mass of APX was approximately 28 kDa estimated by SDS-PAGE. The purity was checked by native PAGE, showing a single prominent band. The optimum pH was 6.0. The enzyme had a temperature optimum at 40 degrees C and was relatively stable at 60 degrees C, with 54% loss of activity. When the enzyme was diluted with the ascorbate-deleted medium, the half inactivation time was approximately 15 min. The absorption spectra of the purified enzyme and the inhibition by cyanide and azide showed that it is a hemoprotein. Spectral analysis and inhibitor studies were consistent with the presence of a heme moiety. When compared with ascorbate peroxidase activity derived from ruptured intact chloroplasts, the purified enzyme was found to have a higher stability, a broader pH optimum for activity and the capacity to utilize alternate electron donors. p-Chloromercuribenzoate (pCMB), hydroxyurea and salicylic acid (SA) significantly inhibited APX activity. Ascorbate (AsA) and pyrogallol were found to be efficient substrates for Pallavicinia APX, considering the Vmax/Km ratio. We detected the activity of monodehydroascorbate reductase (MDHAR) involved in the regeneration of ascorbate, but failed to detect the dehydroascorbate reductase (DHAR) activity. The data obtained in this study may help to understand desiccation tolerance mechanism in the liverwort.

  12. 野生仙人掌多糖体外抗氧化作用研究%In Vitro Antioxidation Effect of Polysaccharides from Wild Opuntia dillenii Haw.

    Institute of Scientific and Technical Information of China (English)

    程杰; 袁清霞; 朱苗; 杨绮平; 杨海兰; 曾富华

    2013-01-01

    采用水提-醇沉法提取野生仙人掌中的多糖,用邻二氮菲-金属铁离子-H2O2体系法、DPPH法、邻苯三酚自氧化法分别研究了仙人掌多糖对羟自由基、DPPH自由基、超氧阴离子的清除作用.结果表明:仙人掌多糖能够有效地清除羟基自由基、DPPH自由基、超氧阴离子,最佳清除率分别为66.91%、67.17%、68.59%,并且其浓度与抗氧化活性呈现正比量效关系.试验证明了野生仙人掌中的多糖具有较好的抗氧化活性.%The polysaccharides in Opuntia dillenii Haw.were extracted by hot water and were precipitated with ethanol.The eliminating effects of Opuntia dillenii Haw.polysaccharides (ODPs) on hydroxy radical,DPPH and superoxide anion were researched by the system of orthophenanthroline-Fe2+-H2O2,the DPPH method and the Pyrogallol autoxidation method,respectively.The results showed that ODPs can eliminate hydroxy radical,DPPH and superoxide anion effectively with the best eliminating rate of 66.91%,67.17% and 68.59%,respectively,and the concentration and the antioxidant activity of ODPs showed a positive dose-effect relationship.Therefore,the polysaccharides from wild Opuntia dillenii Haw.have great antioxidant activity.

  13. The extent of fermentative transformation of phenolic compounds in the bioanode controls exoelectrogenic activity in a microbial electrolysis cell.

    Science.gov (United States)

    Zeng, Xiaofei; Collins, Maya A; Borole, Abhijeet P; Pavlostathis, Spyros G

    2017-02-01

    Phenolic compounds in hydrolysate/pyrolysate and wastewater streams produced during the pretreatment of lignocellulosic biomass for biofuel production present a significant challenge in downstream processes. Bioelectrochemical systems are increasingly recognized as an alternative technology to handle biomass-derived streams and to promote water reuse in biofuel production. Thus, a thorough understanding of the fate of phenolic compounds in bioanodes is urgently needed. The present study investigated the biotransformation of three structurally similar phenolic compounds (syringic acid, SA; vanillic acid, VA; 4-hydroxybenzoic acid, HBA), and their individual contribution to exoelectrogenesis in a microbial electrolysis cell (MEC) bioanode. Fermentation of SA resulted in the highest exoelectrogenic activity among the three compounds tested, with 50% of the electron equivalents converted to current, compared to 12 and 9% for VA and HBA, respectively. The biotransformation of SA, VA and HBA was initiated by demethylation and decarboxylation reactions common to all three compounds, resulting in their corresponding hydroxylated analogs. SA was transformed to pyrogallol (1,2,3-trihydroxybenzene), whose aromatic ring was then cleaved via a phloroglucinol pathway, resulting in acetate production, which was then used in exoelectrogenesis. In contrast, more than 80% of VA and HBA was converted to catechol (1,2-dihydroxybenzene) and phenol (hydroxybenzene) as their respective dead-end products. The persistence of catechol and phenol is explained by the fact that the phloroglucinol pathway does not apply to di- or mono-hydroxylated benzenes. Previously reported, alternative ring-cleaving pathways were either absent in the bioanode microbial community or unfavorable due to high energy-demand reactions. With the exception of acetate oxidation, all biotransformation steps in the bioanode occurred via fermentation, independently of exoelectrogenesis. Therefore, the observed

  14. Comparative DNA profiling, phytochemical investigation, and biological evaluation of two Ficus species growing in Egypt

    Directory of Open Access Journals (Sweden)

    El-Sayeda A El-Kashoury

    2013-01-01

    Full Text Available Aim and Background: A comparison between two Ficus species, cultivated in Egypt, was carried out in this study. Their DNA analysis revealed that they are not closely related. Materials and Methods: The pharmacopoeial constants of the leaves showed higher total ash and acid insoluble ash in F. lyrata than in F. platypoda. The other parameters were close in both species. Preliminary phytochemical screening revealed the presence of carbohydrate and/or glycosides, tannins, flavonoids, sterols, and triterpenes in their leaves and was detected in traces in their stems. Results: Saponification of n-hexane extract of the leaves yielded 46% and 74.8% for the unsaponifiable matters and 20% and 15% for the fatty acids for F. platypoda and F. lyrata, respectively. n-Docosane (21.69% and n-heptacosane (33.77% were the major hydrocarbons in F. platypoda and F. lyrata, respectively. b-Sitosterol was the main sterol, palmitic (22.07% and carboceric (35.72% acids were the major identified saturated fatty acids in both species, while linoleic acid was the main unsaturated fatty acid (18.66% and 16.7% in both species, respectively. The acute toxicity study revealed that the two species were safe up to 2 g/kg. The antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH assay and pyrogallol as the standard was more significant for F. platypoda (232.6 μg/ml than for F. lyrata, (790.9 μg/ml. The oral antihyperglycemic activity in diabetic rats using alloxan revealed that the 80% ethanolic extract of the leaves of F. platypoda was more active than that of the leaves of F. lyrata in decreasing the blood glucose level at 200 mg/kg/day (107.9 ± 5.817, 127.2 ± 4.359 and 400 mg/kg/day (64.11 ± 4.358, 127.7 ± 6.889, respectively, when compared with the diabetic control gliclazide (172.3 ± 2.089. Conclusion: The results of this study provide evidence that the two Ficus species have antioxidant and antihyperglycemic activity, in the order F. platypoda and then F

  15. 香水梨果实多酚氧化酶动力学研究及其底物对组织褐变的影响%Effect of Pgrus ussuriensismaxim Polyphenol Oxidase Kinetics and Substrate on Fruit Browning

    Institute of Scientific and Technical Information of China (English)

    贝盏临; 张欣; 雷茜; 张安东

    2015-01-01

    以宁夏海原香水梨为试材,采用分光光度法对香水梨多酚氧化酶(PPO)及不同抑制剂的动力学特征及其底物对组织褐变的影响进行了研究。实验表明:香水梨PPO活性是随时间变化逐渐增加,正好与香水梨出现褐变的时间吻合;将邻苯二酚和焦性没食子酸两种底物与香水梨PPO作用后进行全波段(200 nm~650 nm)扫描,274、275 nm处有吸收峰,可推断香水梨PPO作用邻位二元酚和三元酚能力很强;以邻苯二酚为底物,测定不同抑制剂对香水梨PPO活力的影响,抑制效果依次为抗坏血酸>间苯二酚>L-半胱氨酸>EDTA。%In this experiment,Ningxia Haiyuan Pgrus ussuriensismaxim as material,using spectrophotometry to Pgrus ussuriensismaxim polyphenol oxidase (PPO) and different inhibitors and substrates on the dynamic characteristics of Tissue Browning were studied.Experiments showed that Pgrus ussuriensismaxim PPO activity was gradually increased with time change,just browning time consistent with Pgrus ussuriensismaxim appear;the catechol and pyrogallol two substrates and Pgrus ussuriensismaxim after PPO of full band (200 nm-650 nm) scanning,274 nm,275 nm of a peak, Can be inferred Pgrus ussuriensismaxim PPO ortho phenol and three yuan two yuan strong ability to phenol;Catechol as substrate,to determine the effects of different inhibitors on the activity of PPO inhibitory effect of Pgrus ussuriensismaxim,followed by VC>L-cysteine>resorcinol>EDTA.

  16. Rubia cordifolia, Fagonia cretica linn and Tinospora cordifolia exert neuroprotection by modulating the antioxidant system in rat hippocampal slices subjected to oxygen glucose deprivation

    Directory of Open Access Journals (Sweden)

    Biswas Saibal K

    2004-08-01

    Full Text Available Abstract Background The major damaging factor during and after the ischemic/hypoxic insult is the generation of free radicals, which leads to apoptosis, necrosis and ultimately cell death. Rubia cordifolia (RC, Fagonia cretica linn (FC and Tinospora cordifolia (TC have been reported to contain a wide variety of antioxidants and have been in use in the eastern system of medicine for various disorders. However, their mechanism of action was largely unknown. We therefore selected these herbs for the present study to test their neuroprotective ability and the associated mechanism in rat hippocampal slices subjected to oxygen-glucose deprivation (OGD. Methods Hippocampal Slices were subjected to OGD (oxygen glucose deprivation and divided into 3 groups: control, OGD and OGD + drug treated. Cytosolic Cu-Zn superoxide dismutase (Cu-Zn SOD, reduced glutathione (GSH, glutathione peroxidase (GPx, nitric oxide (NO was measured as nitrite (NO2 in the supernatant and protein assays were performed in the respective groups at various time intervals. EPR was used to establish the antioxidant effect of RC, FC and TC with respect to superoxide anion (O2.-, hydroxyl radicals (. OH, nitric oxide (NO radical and peroxynitrite anion (ONOO generated from pyrogallol, menadione, DETA-NO and Sin-1 respectively. RT-PCR was performed for the three groups for GCLC, iNOS, Cu-Zn SOD and GAPDH gene expression. Results All the three herbs were effective in elevating the GSH levels, expression of the gamma-glutamylcysteine ligase and Cu-Zn SOD genes. The herbs also exhibited strong free radical scavenging properties against reactive oxygen and nitrogen species as studied by electron paramagnetic resonance spectroscopy. In addition all the three herbs significantly diminished the expression of iNOS gene after 48 hours which plays a major role in neuronal injury during hypoxia/ischemia. Conclusions RC, FC and TC therefore attenuate oxidative stress mediated cell injury during OGD

  17. Phenolic Compounds Characterization and Biological Activities of Citrus aurantium Bloom

    Directory of Open Access Journals (Sweden)

    Armin Oskoueian

    2012-01-01

    Full Text Available Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and flavonoids compared to ethanolic and boiling water extracts. The obtained total phenolics value for methanolic Citrus aurantium bloom extract was 4.55 ± 0.05 mg gallic acid equivalent (GAE/g dry weight (DW, and for total flavonoids it was 3.83 ± 0.05 mg rutin equivalent/g DW. In addition, the RP-HPLC analyses of phenolics and flavonoids indicated the presence of gallic acid, pyrogallol, syringic acid, caffeic acid, rutin, quercetin and naringin as bioactive compounds. The antioxidant activity of Citrus aurantium bloom were examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH assay and the ferric reducing/antioxidant potential (FRAP. The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of Citrus aurantium bloom at a concentration of 300 μg/mL, with values of 55.3% and 51.7%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. Furthermore, the anti-inflammatory result of methanolic extract showed appreciable reduction in nitric oxide production of stimulated RAW 264.7 cells at the presence of plant extract. Apart from that, the anticancer activity of the methanolic extract was investigated in vitro against human cancer cell lines (MCF-7; MDA-MB-231, human colon adenocarcinoma (HT-29 and Chang cell as a normal human hepatocyte. The obtained result demonstrated the moderate to

  18. 铜(II)离子对橙皮素清除自由基作用的影响%Study on effect of copper (II) ion on radical scavenging of hesperetin

    Institute of Scientific and Technical Information of China (English)

    邹淑君; 许树军; 张蕾; 徐暘

    2015-01-01

    为探讨Cu2+存在对橙皮素( Hsp)清除自由基作用的影响.将Hsp与Cu2+混合即生成不稳定配合物(Hsp-Cu),利用UV-Vis光谱测定Hsp及Hsp-Cu对1,1-二苯基-2-三硝基苯肼自由基( DPPH·)、羟基自由基(· OH)、超氧阴离子自由基( O2-·)的清除作用.在实验条件下Hsp-Cu对DPPH·及· OH有一定的清除作用,但清除能力不如Hsp.Hsp-Cu不能有效清除O2-·,且在邻苯三酚自氧化过程中表现出促氧化作用.表明Hsp作为抗氧化剂使用时,应避免与Cu2+接触,以免影响其抗氧化能力.%To study the affection of Copper ( II ) ions on radical scavenging of hesperetin . Unstable hesperetin -copper ( II ) complex was generated when hesperetin was mixed with copper ( II ) chloride dihydrate .By the contrast tests on the scavenging reaction to DPPH radical, hydroxyl radical (· OH), and superoxide free radical (O2 -· ) of hesperetin -copper ( II) complex and hesperetin , proves that the scavenging activity of DPPH · and · OH of hesperetin-copper ( II) complex was weaker than that of hesperetin .The hesperetin-copper (II) complex can’t scavenge O2 -· showing accelerated oxidation in the process of pyrogallol autoxidation .Hesperetin was used as an antioxidant , cannot coexist with Cu 2+, so as not to affect the antioxidant capacity of hesperetin .

  19. Direct and mediated electrochemistry of peroxidase and its electrocatalysis on a variety of screen-printed carbon electrodes: amperometric hydrogen peroxide and phenols biosensor.

    Science.gov (United States)

    Chekin, Fereshteh; Gorton, Lo; Tapsobea, Issa

    2015-01-01

    This study compares the behaviour of direct and mediated electrochemistry of horseradish peroxidase (HRP) immobilised on screen-printed carbon electrodes (SPCEs), screen-printed carbon electrodes modified with carboxyl-functionalised multi-wall carbon nanotubes (MWCNT-SPCEs) and screen-printed carbon electrodes modified with carboxyl-functionalised single-wall carbon nanotubes (SWCNT-SPCEs). The techniques of cyclic voltammetry and amperometry in the flow mode were used to characterise the properties of the HRP immobilised on screen-printed electrodes. From measurements of the mediated and mediatorless currents of hydrogen peroxide reduction at the HRP-modified electrodes, it was concluded that the fraction of enzyme molecules in direct electron transfer (DET) contact with the electrode varies substantially for the different electrodes. It was observed that the screen-printed carbon electrodes modified with carbon nanotubes (MWCNT-SPCEs and SWCNT-SPCEs) demonstrated a substantially higher percentage (≈100 %) of HRP molecules in DET contact than the screen-printed carbon electrodes (≈60 %). The HRP-modified electrodes were used for determination of hydrogen peroxide in mediatorless mode. The SWCNT-SPCE gave the lowest detection limit (0.40 ± 0.09 μM) followed by MWCNT-SPCE (0.48 ± 0.07 μM) and SPCE (0.98 ± 0.2 μM). These modified electrodes were additionally developed for amperometric determination of phenolic compounds. It was found that the SWCNT-SPCE gave a detection limit for catechol of 110.2 ± 3.6 nM, dopamine of 640.2 ± 9.2 nM, octopamine of 3341 ± 15 nM, pyrogallol of 50.10 ± 2.9 nM and 3,4-dihydroxy-L-phenylalanine of 980.7 ± 8.7 nM using 50 μM H2O2 in the flow carrier.

  20. “黑美人”土豆色素体外抗氧化性研究%Antioxidant Activity of the Pigment from "Black Beauty" Potato

    Institute of Scientific and Technical Information of China (English)

    高海宁; 李彩霞; 张勇; 王丽

    2012-01-01

    采用普鲁士蓝法、DPPH清除体系、H2O2/Fe2+/水杨酸检测体系、亚硝基清除体系、卵黄脂蛋白不饱和脂肪酸(PUFA)过氧化体系、邻苯三酚自氧化法研究了黑美人土豆色素的体外抗氧化活性,并同VC进行了比较.结果表明,黑美人土豆色素对几种自由基均有不同的清除作用,其中黑美人土豆色素的还原力、抗脂质过氧化能力、清除羟基自由基、亚硝基、超氧阴离子自由基(O2-·)和DPPH自由基的能力均高于VC.该结果显示,黑美人土豆色素是一种较好的天然自由基清除剂,可以作为绿色食品用于人们的日常饮食,有较大的开发利用潜能.%The antioxidant activity of pigment from black beauty potato was studied in vitro by prussian blue method, DP-PH scavenging system,H2O2/Fe2+ salicylic acid detection system,nitroso removal system,the yolk lipoprotein polyunsat-uiated fatty acids (PUFA) peroxidation system, pyrogallol autoxidation system,and compared with that of vitamin C. The results showed that the pigment of black beauty potatoes had different ability of scavenging on different free radicals, of which the reducing capacity, anti-lipid peroxidation, ability of scavenging hydroxyl radical, nitroso, superoxide anion (O2--' ) ,and DPPH radical were higher than VC. The results indicate that the pigment of black beauty potato is a good natural free radical scavenger. Therefore the black beauty potato can be used as Green food in daily diet,and it has great potential of development and utilization.

  1. 砷胁迫对药用植物黄芪中抗氧化酶活性的影响%Effects of Arsenic Stress on the Activities of Antioxidant Enzymes in Medicinal Plant Astragalus membranaceus ( Fisch. ) Bge. var.mongholicus (Bge.) Hsiao

    Institute of Scientific and Technical Information of China (English)

    姜志艳; 王建英; 徐彩荣

    2011-01-01

    [目的]探讨砷胁迫对药用植物黄芪中抗氧化酶活性的影响,以期为揭示砷毒害植物机理提供理论依据.[方法]以内蒙药用植物黄芪为材料,分别采用高锰酸钾滴定法、愈创木酚法、邻苯三酚自氧化法以及硫代巴比妥酸法研究不同浓度砷胁迫下对药用植物黄芪中过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)的活性影响以和丙二醛(MDA)的浓度变化.[结果]随着砷浓度升高,黄芪叶片中这3种酶的活性能够维持,特别是POD活性显著增加.从时间动态看,随处理时间的延长,黄芪叶片中的CAT活性先升高再降低,POD活性增加,SOD活性变化不显著;MDA含量先升后降,第8天达到最大值.[结论]该研究可为中药材重金属含量控制和药理活性鉴定提供理论依据.%[ Objective ] To discuss the effects of arsenic stress on the activities of antioxidant enzymes in medicinal plant Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao, so as to provide a theoretical basis for revealing the arsenic toxicity mechanism on plants.[ Method] Using Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao as tested materials, potassium permanganate titration,guaiacol method, pyrogallol autooxidation methods and thiobarbituric acid method were adopted to study effects of arsenic stress on catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) activities and malondialdehyde (MDA) concentrations. [Results] With the increase in concentration of arsenic, the activities of CAT, PCD and SOD in Astragalus membranaceus ( Fisch. ) Bge. var. mongholicus ( Bge. ) Hsiao could be maintained, especially POD. From the view point of dynamic time, CAT activity increased firstly then declined, POD activity increased and SOD activity changed little along with the increasing treatment time. Besides, MDA content increased firstly and then decreased, and reached the maximum on the 8th day. [ Conclusions] The

  2. Correlation of the aquarium goldfish toxicities of some phenols, quinones, and other benzene derivatives with their inhibition of autooxidative reactions.

    Science.gov (United States)

    SOLLMANN, T

    1949-07-01

    Hydroquinone when added to the aquarium water was found to be about a hundred times more toxic than phenol, to goldfish (and to Daphnia magna), but is only about twice as toxic when injected into fish or mammals. Tertiarybutyl catechol shows a similar high toxicity in the aquarium, while the toxicity of catechol, resorcinol, and pyrogallol approaches more closely that of phenol. As the substances of high aquarium toxicity are known to inhibit many oxidative and polymerizing autocatalytic "chain reactions," rank correlations were tabulated between the recorded inhibitory potency of various substances in these processes, and their aquarium toxicity for goldfish. The correlation between aquarium fish toxicity and electric oxidation potential (P 0.09) is more than suggestive, and becomes still more so if explainable discrepancies are excluded. Antioxidant fat stabilizers show suggestive correlation with fish toxicity (0.20), and better with electric oxidation potential (0.10). The photographic reduction potential gives suggestive correlation with fish toxicity (0.20) and somewhat better with the oxidation potential (0.15). The gasoline induction period correlation is more than suggestive with the oxidation potential (0.099), but rather poor for fish toxicity (0.265). The rubber anti-aging potency gives only poor correlation (0.39) with fish toxicity. The reasons for these divergencies are not clear; they may perhaps be connected with the solvent properties of the substrate. As an example, Lea (p. 175) cites that 0.01 per cent of maleic acid prevents rancidity of fats, but is rendered ineffective by the presence of water. Taken by themselves, no one of the P values is entirely convincing of the relationships stressed in this paper. However, the consistent finding of relatively small values of P lends considerable weight to the hypothesis that these chemicals act in a related manner; and that the chemical activity of a substance may furnish useful suggestions of its

  3. Processed coffee alleviates DSS-induced colitis in mice

    Directory of Open Access Journals (Sweden)

    Bernd L. Fiebich

    2013-05-01

    Full Text Available ABSTRACTBackground: Coffee is one of the most widely consumed beverages in the world and it has been demonstrated that it has important therapeutic activities not only because of its caffeine content but also owing to the presence of other biologically active small molecules such as chlorogenic acid, trigonelline and cyclopentadiones. However, chlorogenic acid is degraded into catechol, pyrogallol and hydroxyhydroquinone, which are thought to induce irritation of the gastric mucosa. To reduce the content of irritant compounds processing methods have been developed prior to roasting the coffee beans.Objectives: The aim of this study was to study the anti-inflammatory and gastro-protective effects of processed coffee (Idee-Kaffee on in LPS-treated human primary monocytes and in a murine model of colon inflammation (IBD model.Results: In this study we have analyzed the effects on inflammatory events in cultured cells and in mice drinking a commercially available processed coffee. The processed coffee inhibited lipopolysaccharide (LPS-induced proinflammatory cytokines such as interleukin (IL-1, tumor necrosis factor (TNF, IL-6 and IL-8, and other inflammatory mediators such as prostaglandin (PGE2 and 8-isoprostane in cultured human primary monocytes. Oral administration of dissolved processed coffee, i.e., in its usual beverage form, improved greatly the adverse macroscopic and histological features of dextran sodium sulfate (DSS-induced colitis in mice in a dose-dependent manner. Processed coffee not only largely prevented DSS-induced colitis but also dramatically suppressed in vivo NF-B and STAT3 activities through inhibition of IB and STAT3 phosphorylation. Furthermore, this solubleFunctional Foods in Health and Disease 2013; 3(5:133-145coffee bean extract reduced the expression of proinflammatory cytokines TNF, IL-11, and IL-6 and the expression of cyclooxygenase (COX-2 in colonic tissues.Conclusions: This work identified

  4. Antimicrobial, antioxidant and anti-tyrosinase properties of extracts of the Mediterranean parasitic plant Cytinus hypocistis.

    Science.gov (United States)

    Zucca, Paolo; Pintus, Manuela; Manzo, Giorgia; Nieddu, Mariella; Steri, Daniela; Rinaldi, Andrea C

    2015-10-13

    Cytinus is an endophytic parasitic plant occurring in South Africa, Madagascar, and in the Mediterranean region. We have extracted the inflorescences (the only visible part of the plant, emerging from the host roots at the time of blossom) of Cytinus hypocistis collected in Sardinia, Italy, and explored the antimicrobial, antioxidant, anti-tyrosinase, and cytotoxic activities of the extracts. Extracts from C. hypocistis were prepared using increasing polarity solvents: cyclohexane, ethanol, and water. Phenolic composition were determined through spectrophotometric assays, and antioxidant activity with both electron-transfer and hydrogen-atom assays. Nine different bacterial strains, including clinical isolate methicillin-resistant Staphylococcus aureus, were used in agar diffusion method. Cytotoxicity was tested using against the B16F10 melanoma cell line. While cyclohexane extracts where biologically inactive, ethanolic and aqueous extracts displayed an intriguing activity against several Gram-positive bacterial strains, including methicillin-resistant S. aureus, and against the Gram-negative Acinetobacter baumanii. Compared to the conventional antibiotics like cloxacillin, ampicillin, and oxytetracycline, C. hypocistis extracts were less active in absolute terms, but displayed a wider spectrum (notably, cloxacillin and ampicillin were inactive against methicillin-resistant S. aureus). The ethanolic extract of C. hypocistis was found to be particularly rich in polyphenols, in most part hydrolysable tannins. The antioxidant activity of extracts, tested with several methodologies, resulted to be particularly high in the case of ethanolic extracts, in accordance with the composition in phenolics. In detail, ethanol extracts presented about a twofold higher activity than the water sample when tested through the oxygen radical absorbance capacity-pyrogallol red (ORAC-PYR) assay. Cytotoxicity analysis against the B16F10 melanoma cell line showed that both extracts have

  5. Partial characterization of superoxide dismutase activity in the Barber pole worm-Haemonchus contortus infecting Capra hircus and abomasal tissue extracts

    Institute of Scientific and Technical Information of China (English)

    Sadia; Rashid; Malik; Irshadullah

    2014-01-01

    Objective:To determine the activity of superoxide dismutase(SOD) in the male and female haematophagous caprine worms,Haemonchus contortus infecting Capra hircus,and their E/S products and also to analyse the effect of Haemonchus infection on the level of host SOD.Methods:The SOD activity was analysed by using the pyrogallol autoxidation assay and non-denaturing polyacrylamide gel electrophoresis followed by specific enzyme staining by riboflavin-nitroblue tetrazolium method.Results:The adult females were found to have higher enzyme activity than the male worms.Appreciable amount of SOD activity was also detected in the worm culture medium and female worms secreted more SOD in comparison to the male parasites.The SOD activity was negatively correlated to the worm burden.Statistically significant decrease in SOD activity(P<0.05) was observed in the heavily infected host tissue in comparison to the control non-infected host tissue.SOD profile of the crude extracts of both the sexes revealed polymorphism and a fast migrating activity band being characteristic of E/S products.The SOD activities were found highly sensitive to potassium cyanide indicating the Cu/Zn form of SOD.Conclusions:Haemonchus contortus is a key model parasite for drug and vaccine discovery.The presences of SOD activity in appreciable amount in the parasite as well as its E/S products indicate that it has a well-developed active antioxidant system to protect itself from the host immune attack.SOD could be the target for vaccine development which is the need of the hour as mass drug administration for parasite control has resulted in anthelmintic resistance across the globe and threatens the viability of sheep and goat industry in many regions of the world.The infection with Haemonchus causes a drastic reduction in SOD activity of the host tissue thus effecting its protective potential.One characteristic SOD band was found in the females which was not present in any other preparations and thus could

  6. Study on Free Radical Scavenging in vitro and Antioxidative Activity of Extracts from Cook Noni (Morinda citrifolia ) Juice%库克诺你果汁提取物体外清除自由基及抗氧化活性研究

    Institute of Scientific and Technical Information of China (English)

    李昌; 谢明勇; 聂少平; 陈军辉; Barbara Zimmermann

    2006-01-01

    This study was conducted to investigate the antioxidant and radical scavenging activity of different extracts from Cook noni juice, including noni polysaccharide (noni-ppt), ethanol solute and ethyl acetate extract. Superoxide anion radicals and hydroxyl radicals were generated from autoxidation of pyrogallol (PR) and Fenton reaction (Fe2 +/H2O2). Furthermore 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) method was applied to evaluate the scavenging activity of the extracts. Malondialdehyde (MDA) ,the product of lipid peroxidation (LPO) was induced by adding Fe2+ into yolk homogenate. The ability of preventing LPO was measured by thibarbituric acid (TBA) method. All measurements were performed by spectrophotometric methods. The results suggested that the fraction of ethanol solute and ethyl acetate extract showed significant scavenging and antioxidant ability; L-ascorbic acid served as the standard. Noni-ppt had weaker activity on hydroxyl radical, DPPH radical, and LPO, and could accelerate the procedure of PR autoxidation. The abilities of the extracts may be related to their polarity.%本文对诺你果汁多糖、乙醇溶出物和乙酸乙酯萃取物体外对超氧阴离子(O2-·)、羟自由基(·OH)、DPPH和脂质过氧化(LPO)的抑制作用进行了研究.超氧阴离子(O2-·)由邻苯三酚自氧化产生;羟自由基(·OH)由Fenton反应产生;利用Fe2+诱发卵黄脂蛋白产生丙二醛(NDA),TBA法测定.所有测定均为分光光度法.结果表明,与已知抗氧化剂L-抗坏血酸相比,乙醇溶出物和乙酸乙酯萃取物均有明显的捕捉自由基和抗氧化能力,而多糖捕捉自由基和抗氧化能力很低,且对O2-·没有抑制作用,反而会增加其生成速度.

  7. Influence of hot water blanching process on nutritional content, microstructure, antioxidant activity and phenolic profile of Cinnamomum porrectum herbal tea

    Directory of Open Access Journals (Sweden)

    Phornthip Saetan

    2016-10-01

    was found that both control and treated extracts consisted of similar main phenolic and flavonoid compounds however, only kaempferol was found in un-treated. Moreover, hydrolyzed blanched extract showed a higher intensity of 2 unknown compounds than un-treated. Though un-treated provided a higher intensity of pyrogallol, gallic acid, and cinnamic acid, the blanched exhibited a higher intensity of caffeic acid, protocatechuic acid, p-coumaric acid, and rutin. Conclusion: Blanching before drying expanded pore size of dried leaves, increased yield extractability, maintained color value, chlorophylls and increased TPC and TFC which related to antioxidant activities. Blanched extract provided higher intensity of some phenolic compounds than un-treated.

  8. Study on Optimization of Ultrasonic Extraction of Procyanidins from Grape Seeds and Its Antioxidant Activity%超声提取葡萄籽原花青素工艺的优化及其抗氧化活性研究

    Institute of Scientific and Technical Information of China (English)

    金华; 刘志刚; 曾晓丹; 高艳; 马明硕

    2014-01-01

    Response surface methodology (RSM)is used to optimize the ultrasonic extraction technology of procyanidins from grape seeds. On the basis of single factor test, a central composite design experiment is conducted and the response surface analysis is employed to investigate the influences of four main factors including ultrasonic extraction temperature,ratio of solvent to raw material,ethanol concentration and ultrasonic time on the yield of procyanidins.Then a regression model is established. The optimum condition is temperature of 55 ℃,ratio of solvent to raw material of 20(mL/g),ethanol concentration of 65% and extraction time of 10 min.Under such conditions,the yield of procyanidins is 2.482%,which is extremely consistent with the experimental value with a relative error of 0.36%. Pyrogallol oxidation method is applied for determination of antioxidant activities of procyanidins in grape seeds.The results show that the extraction has capacity to scavenge radical and the scavenging activity increases with the procyanidins concentration.%研究利用响应曲面法优化超声提取葡萄籽原花青素的工艺。在单因素实验基础上,采用中心组合设计响应面实验,考察了提取温度、液料比、乙醇浓度以及超声时间对原花青素提取率的影响,并建立回归模型。优化后的工艺:提取温度55℃,液料比20(mL/g),乙醇浓度65%,超声时间10 min;在此条件下葡萄籽原花青素的提取率为2.482%,与回归模型预测值的相对偏差为0.36%。同时进行了提取物的抗氧化性检验,结果表明葡萄籽原花青素对超氧阴离子自由基具有较好的清除能力,且呈剂量相关性。

  9. Cloning, sequence analysis, expression of Cyathus bulleri laccase in Pichia pastoris and characterization of recombinant laccase

    Directory of Open Access Journals (Sweden)

    Garg Neha

    2012-10-01

    successfully produced extra-cellularly to a high level of 7200 U L-1 in P. pastoris under the control of the AOX1 promoter and purified by a simple three-step procedure to homogeneity. The kinetic parameters against ABTS, Guaiacol and Pyrogallol were similar with the nLac and the rLac. Tryptic finger print analysis of the nLac and the rLac indicated altered glycosylation patterns. Increased thermo-stability and salt tolerance of the rLac was attributed to this changed pattern of glycosylation.

  10. Study on the toxicity and antioxidant activity of mucus powder from salamander skin%大鲵皮肤黏液的抗氧化性及安全性评价研究

    Institute of Scientific and Technical Information of China (English)

    徐伟良; 陈德经; 魏泓; 刘宇

    2015-01-01

    The study focuses on antioxidant performance and safety evaluation of acute toxicity of sala-mander skin mucus.The study first uses pyrogallol autoxidation and DPPH method to determine salamander mucus to superoxide anion radical( O-·2 ) scavenging and DPPH radical scavenging.Then it experiments with giant salamander breeding mice fed to test acute toxicity of Andrias davidianus skin mucus and analyses toxic constituents of mucus temperament by using GC-MS chromatography.The results show that the clearance rate of Salamander mucus flour to superoxide anion radical and to DPPH radical scavenging is 6.77%and 90.25%respectively, and that LD50 value of Andrias mucus powder is 4.64 g/kg and toxic ingredient is imethyl disul-fide ( C2 H6 S2 ) .It concludes that Andrias mucus is antioxidant and low in toxicity, and that it can be devel-oped for health care products after detoxification.%为研究大鲵皮肤黏液的抗氧化性及急毒性安全性评价,利用邻苯三酚自氧化法和DPPH法,测定了大鲵黏液对超氧阴离子自由基( O-·2)及DPPH自由基的清除率;通过对小鼠灌胃饲养实验检测大鲵皮肤黏液的急毒性,并采用气质联用色谱分析黏液中的毒性成分。结果显示:大鲵黏液对超氧阴离子自由基的清除率为6.77%,对 DPPH 自由基的清除率为90.25%;大鲵黏液全粉的LD50值为4.64 g/kg,毒性成分为二甲基二硫醚( C2 H6 S2)。表明大鲵黏液具有抗氧化性和低毒性,经脱毒后可开发为保健产品。

  11. Study on Extraction and Antioxidant Activity of Water-soluble Polysaccharides from Moringa Oleifera%辣木茎叶中水溶性多糖的提取及抗氧化活性的研究

    Institute of Scientific and Technical Information of China (English)

    梁鹏; 甄润英

    2013-01-01

    In order to explore the extraction conditions of water-soluble polysaccharide from the Moringa oleifera leaves and antioxidant activity of it,dry powder was used as raw materials and using water as extracting solvent to extract polysaccharide from Moringa oleifera. The extraction temperature, time and solid-liquid ratio were optimized by orthogonal experiments. Then,use methods of Salicylic acid and Pyrogallol to test antioxidant activity on polysaccharide from Moringa oleifera in different concentrations respectively. The results showed that the extraction rate was up to 5.66%,the optimal extraction conditions was extract 120 min ,using 80℃hot water at a solid-liquid ratio of 1∶20 (g/mL). The polysaccharides from Moringa oleifera leaf had a certain degree of antioxidant activities in vitro:scavenge OH·oand O2-in a dose-dependant manner with the IC50 of 7.252 8 mg/ml and 2.501 1 mg/ml respectively.%  主要探讨辣木茎叶中水溶性多糖的提取工艺条件以及抗氧化活性。以辣木茎叶干粉为原料,采用水为提取剂,通过单因素和正交试验对浸提温度、浸提时间及料液比进行研究;采用水杨酸法和邻苯三酚法分别测定辣木多糖对羟自由基以及超氧阴离子的清除率,以确定提取物的抗氧化活性。实验条件下辣木茎叶多糖最佳提取工艺条件为料液比1∶20(g/mL)、浸提温度80℃、浸提时间120 min,在此条件下,辣木粗多糖的提取率可达5.66%;多糖提取物对羟自由基及超氧阴离子均有清除作用,且随着提取物浓度的提高对二者的清除作用逐渐增强,存在剂量效应关系。清除作用的半数抑制率(IC50)分别是7.2528 mg/mL和2.5011 mg/mL。

  12. 山竹壳总黄酮抗氧化及抑制亚硝化作用研究%The Flavonoids Antioxidant and Inhibition Effect of Nitrosation from Mangosteen Shell

    Institute of Scientific and Technical Information of China (English)

    王晓波; 李金芳; 王梅; 邹志辉; 刘冬英; 陈海珍

    2013-01-01

      对山竹壳总黄酮的抗氧化作用及对亚硝化反应的抑制作用进行研究.采用超声辅助热水浸提的方法提取山竹壳中的黄酮类化合物,以芦丁为标准物质来测定提取物的总黄酮含量,通过水杨酸法测定山竹壳总黄酮对羟自由基的清除作用、邻苯三酚自氧化法测定山竹壳总黄酮对超氧阴离子自由基的清除作用,以评价山竹壳总黄酮的抗氧化能力;并通过用分光光度法测定山竹壳总黄酮对亚硝酸盐的清除率和对亚硝胺合成的阻断率,以评价山竹壳总黄酮对亚硝化反应的抑制能力.采用超声辅助热水浸提方法提取的山竹壳提取物中总黄酮的含量为42.36%,该类化合物对羟自由基和超氧阴离子自由基具有一定的清除作用,随反应浓度增加清除率增大;在模拟人体胃液的条件下(pH 3.0、温度37℃),山竹壳总黄酮能有效地清除亚硝酸盐和阻断亚硝胺合成,随反应浓度增加清除率和阻断率增大.山竹壳总黄酮具有一定的抗氧化作用及抑制亚硝化反应的作用.%The flavonoids from mangosteen shell antioxidant and the inhibitory effect of Nitrosation was studied. The ultrasound-assisted extraction of hot water extraction method in the mangosteen hull flavonoids, rutin as the standard material to determine the total flavonoid content of extract, through the salicylic acid method of total flavonoidsofmangosteenshellonhydroxylradicalscavenging,pyrogallol autoxidation method for the determination of total flavonoids of mangosteen shell scavenging superoxide anion radical to evaluate the mangosteen shell flavonoids antioxidant and determined by spectrophotometry of total flavonoids nitrate removal rate and blocking rate of nitrosamine to evaluate the mangosteen shell flavonoids on the ability to inhibit nitrosation reactions. The hot water extraction method of ultrasonic assisted extraction of the mangosteen shell extract the

  13. 蛋清蛋白肽体外抗氧化作用模式的研究%Study on antioxidantive action mode of egg white-derived peptides in vitro

    Institute of Scientific and Technical Information of China (English)

    迟玉杰; 李冰; 程缘

    2013-01-01

    Objective To investigate antioxidantive action mode of egg white-derived peptides in vitro. Methods The egg white-derived peptides were separated by ultrafiltration from egg white protein hydroly-sates (EWPHs) produced by papain into three fractions. The hydroxyl radical, superoxide anion scavenging ac-tivities and lipid peroxidation inhibition of three fractions were detected by the methods related to Fenton sys-tem, pyrogallol autoxidation, and linoleic acid emulsion system. The reducing power, DPPH radical scavenging activities and alleviation of H2O2-induced oxidative stress on porcine embryonic fibroblast (PEF) cell were also determined. Results EWPH-Ⅲ (MW<3 kDa) accounted for 50.06% of the total amount of EWPHs. The values of hydroxyl radical, superoxide anion and DPPH radical scavenging activities were 52.86%, 35.05%and 78.74% at the concentration of 5 mg/mL, respectively. The percentage of inhibition of lipid peroxidation was 74.57% at the same concentration. The cell survival rate reached 70.06% at the concentration of 2.5mg/mL. EWPH exhibited significant increase (P<0.05) in antioxidant activity with a decrease in molecular weight of fraction values. Conclusion EWPH could act as a metal ion chelator, a hydrogen donor, as well as a radical stabilizer to inhibit lipid oxidation because of its antioxidant activity.%目的:研究蛋清蛋白肽抗氧化作用模式。方法利用超滤技术分离蛋清蛋白木瓜蛋白酶酶解产物;采用 Fenton 体系、邻苯三酚自氧化体系和亚油酸自氧化体系分别测定超滤各组分清除羟自由基、超氧阴离子及抑制脂质过氧化的能力,同时测定各组分对二苯代苦味肼基自由基清除能力(DPPH 自由基)、还原能力及对猪胎儿成纤维细胞(porcine embryonic fibroblast, PEF)过氧化损伤的保护作用。结果超滤各组分中分子量小于3 kDa组分(蛋清蛋白酶解产物-Ⅲ, egg white protein hydrolysate, EWPH-Ⅲ)占蛋清

  14. In vitro Antioxidant and Photostability Testing for Extracts of Enphorbia lunulata Bgel from Northwestern Hubei%鄂西北产猫眼草提取物体外抗氧化性及光稳定性测试

    Institute of Scientific and Technical Information of China (English)

    余海忠; 阮士龙; 刘统; 孙永林

    2012-01-01

    Euphorbia lunulata Bgel, a common toxic plant species distributed in Northwestern Hubei, was detected to have good insecticidal and fungicidal activities. To exploit this resource, it's neccessa-ry to evaluate in vitro antioxidant and photostability of its extract. The following methods was used to measure the antioxidantion of E. Lunulata extracts including a-deoxyribose method, adjacent pyrogal-lol auto-oxidation method, DPPH radical scavenging method and iron potassium ferricyanide reduction method and its photostability was tested by HPLC method as well. The results showed as followed: (I) With the concentration increase of the E. Lunulata extracts, the clearance rate of the hydroxyl radicals, the oxygen free radicals, and DPPH free radicals rises up, reaching up to 87. 73%, 87. 99%, and 82.04%, respectively. Within a certain range, along with the concentrations of E. Lunulata extracts, the iron potassium cyanide reductive ability is also on the rise, (ii) The testing revealed that E. Lunulata extracts had bad photostability and the Tween-20 (surfactant) and phenyl salicylate (light stabilizer) were found to have a certain degree of light atability on E. Lunulata extracts.%猫眼草为鄂西北地区常见的野生有毒植物种,经测定具有较强的杀虫、抑菌活性.为了深入开发此植物资源,室内测定其提取物的体外抗氧化性及光稳定性.采用α-脱氧核糖法、邻苯三酚自氧化法、DPPH自由基清除法和铁氰化钾还原法等方法体外评价猫眼草提取物的抗氧化性.同时,采用高效液相色谱法测定其光稳定性.结果表明:①随着猫眼草提取物质量浓度的升高,羟自由基、氧自由基、DPPH自由基的清除率上升,分别高达82.04%、87.99%、87.73%.在一定范围内,随着猫眼草提取物质量浓度的升高,对铁氰化钾的还原能力也在升高.②猫眼草提取物的光稳定性较差,Tween-20(表面活性剂)和水杨酸苯酯(光稳定剂)对其具有一定的光稳定增效作用.

  15. The developmental changes of antioxidant enzymes in rat liver from the fetus%发育晚期胎鼠肝脏抗氧化酶活性的变化

    Institute of Scientific and Technical Information of China (English)

    杨琨; 赵勇; 周影; 秦书剑; 赵艳敏; 张月

    2012-01-01

    目的:探讨发育晚期胎鼠肝脏中超氧化物岐化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性的变化.方法:成年雌性Wistar大鼠交配后并在妊娠母鼠第17、19、20和22天取出10只胎鼠肝脏.采用pyrogallol氧化法,Aebi法和间接法分别检查超氧化物岐化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性的变化.结果:发育晚期过氧化氢酶和谷胱甘肽过氧化物酶活性明显升高,CAT活性从第17天的1.8单位/mg蛋白升高到第22天的12单位/mg蛋白(P< 0.05).同时,GPx活性也从第17天的0.035单位/mg蛋白升高到第22天的0.13单位/mg蛋白(P<0.05).此时总SOD活性则从52单位/mg蛋白下降到32单位/mg蛋白(P<0.05),CuZnSOD活性从35单位/mg蛋白下降到16单位/mg蛋白,MnSOD活性未见变化.结论:胎儿过氧化氢酶和谷胱甘肽过氧化物酶活性的增加可能有助于胎儿适应出生后体外的高氧环境,但是,没有超氧化物岐化酶活性的增加,过氧化氢酶和谷胱甘肽过氧化物酶是很难完成抗氧化功能.%Objective:The developmental changes of antioxidant enzymes (superoxide dismntase, catalase and glutathione peroxidase)in rats liver were examined. Methods: Timed-pregnancy rats underwent rapid hysteroto-my on days 15 , 17, 19, 20 and 22 with subsequent removal of liver from the fetus. The enzymatic activities of antioxidant enzymes were analyzed using the pyrogallol autoxidation method, method of Beers and Sizer and the indirect coupled assay of Paglia and Valentine respectively. Results: CAT and GPx activities increased from 15 day of gestation to 22 day of gestation (per mg protein). CAT activity increased from 2. 5 U to 12 U/mg protein. GPx activity increased from 0. 035 U to 0. 13 U/mg protein whereas both total SOD and Cu/ZnSOD activity decreased significantly. Conclusion:Both CAT and GPx increase during the last stage of development and total SOD activity decreased before birth. CAT and GPx may play an important

  16. 蛋清的蛋白酶解物清除自由基能力的研究%STUDY ON FREE RADICAL SCAVENGING ACTIVITY OF PROTEINASE HYDROLYSATES FROM EGG WHITE

    Institute of Scientific and Technical Information of China (English)

    陈晨; 迟玉杰; 刘丽

    2009-01-01

    目的 研究胃蛋白酶、胰蛋白酶、木瓜蛋白酶、中性蛋白酶及Alcalase碱性蛋白酶对蛋清蛋白的水解效果以及其酶解物对自由基的清除能力.方法 采用茚三酮法分析五种蛋白酶对蛋清蛋白的水解效果;通过Fenton体系和邻苯三酚自氧化体系测定五种蛋白酶水解产物对羟自由基及超氧阴离子的清除能力.结果 五种蛋白酶在其最适反应条件下,水解度大小依次为:alcalase碱性蛋白酶>胰蛋白酶>木瓜蛋白酶>中性蛋白酶>胃蛋白酶;羟自由基清除能力强弱依次为:木瓜蛋白酶>alcalase碱性蛋白酶>胰蛋白酶>中性蛋白酶>胃蛋白酶;超氧阴离子清除能力强弱依次为:木瓜蛋白酶>alcalase碱性蛋白酶>中性蛋白酶>胃蛋白酶>胰蛋白酶.木瓜蛋白酶水解3h的产物对两种自由基清除能力最强,对羟自由基的清除率为65.63%,对超氧阴离子的清除率为38.40%.结论 蛋清的蛋白酶解物具有清除羟自由基及超氧阴离子的能力,且对羟自由基的清除能力大于超氧阴离子.%Objective To determine the degree of hydrolysis (DH) and free radical scavenging activity of the hydrolysates of egg white protein (EWPHs) with pepsin, trypsin, papain, neutrase and Alcalase. Method The degree of hydrolysis of EWPH was measured by ninhydrin colorimetric method. The hydroxyl radical and superoxide anion scavenging activity was detected by the methods related to pyrogallol autoxidation and Fenton system. Results Under the optimal conditions the sequence of enzyme hydrolysis capacity was: alcalase>typsin>papain>neutrase>pepsin. The order of hydroxyl radical scavenging activity was: papain>alcalase>trypsin>neutrase>pepsin and the order of superoxide radical scavenging activity was: papain>alcalase>neutrase>pepsin>trypsin. The EWPHs with papain for 3h displayed the strongest radical scavenging activity. The values of hydroxyl radical and superoxide free radical scavenging activity were 65.63% and 38

  17. Efecto antioxidante y contenido polifenólico de Syringodium filiforme (Cymodoceaceae

    Directory of Open Access Journals (Sweden)

    Kethia L González García

    2011-03-01

    Full Text Available Antioxidant effect and polyphenol content of Syringodium filiforme (Cymodoceaceae. The marine phanerogam Syringodium filiforme, known as "manatee grass", is a common species that grows in coastal areas associated to Thalassia testudinum. With the aim to describe some of its possible chemical characteristics, this study was performed with a sample of 1.2kg, collected in March 2009, in Guanabo beach, Havana, Cuba. The sample was dried (less than 12% humidity and a total extract prepared; other three extracts were prepared with the use of solvents of increasing polarity. The phytochemical screening and analytical determinations of each fraction were undertaken Total polyphenol content was determined using pyrogallol as reference´s standard; chlorophyll a and b and anthocyanin content were also quantified. Total extract and fractions antioxidant activity were evaluated by using the free radical scavenging activity assay with 1,1- Diphenyl-2-Picrylhydrazyl reactive (knowing as DPPH´s method. The phytochemical screening of the different extracts detected the presence of high concentrations of flavonoids, phenols, terpenes, antocyaninns, reducing sugars and alkaloids. The total extract and methanol fraction showed significant free radical scavenging properties, while the petroleum ether fraction showed moderate activity, and the chloroform fraction and the aqueous soluble precipitate (residual salt obtained didn’t show antioxidant properties against free radicals. The results of this work confirmed the potentialities of this species for biological purposes. Rev. Biol. Trop. 59 (1: 465-472. Epub 2011 March 01.La fanerógama marina Syringodium filiforme, conocida comúnmente como "Hierba Manatí", crece en los fondos marinos tropicales asociada con la especie Thalassia testudinum. Este estudio fue realizado con una muestra de S. filiforme (1.2kg peso húmedo recolectada en la playa de Guanabo en La Habana, Cuba en Marzo 2009. La muestra fue secada

  18. Comparative Study of Anti-oxidation Activities of Fruiting Body and Mycelial Polysaccharides of Edible Mushroom%食用菌子实体和菌丝体多糖抗氧化性的比较研究

    Institute of Scientific and Technical Information of China (English)

    冮洁; 王赛男; 季旭颖

    2015-01-01

    Antioxidant activities of the mycelial and fruiting body polysaccharides from Pleurotus ostreatus, Flammulina velutipe, Hypsizygus marmoreus and Agrocybe cylindracea were measured by several experiments, including the Fenton method, the pyrogallol self-oxidation system and DPPH(1,1-Diphenyl-2-picrylhydrazyl ) free radical reduction system. The polysaccharide content of Pleurotus ostreatus, Flammulina velutiper, Hypsizygus marmoreus and Agrocybe cylin-dracea fruiting bodies were 7. 12%, 9. 24%, 8. 96% and 7. 68%, respectively, the mycelial polysaccharide content were 8. 32%, 11. 33%, 10. 54% and 9. 75%, respectively. The scav-enging ·OH abilities of fruiting body and mycelial polysaccharides were in the order:Agrocybe cylindracea>Flammulina velutiper>Hypsizygus marmoreus>Pleurotus ostreatus. The scavenging O2-· abilities were in the order:Agrocybe cylindracea>Hypsizygus marmoreus>Flammulina ve-lutiper>Pleurotus ostreatus. The scavenging DPPH· abilities were in the order:Agrocybe cylin-dracea>Hypsizygus marmoreus >Flammulina velutiper>Pleurotus ostreatus. The results showed that the fruiting body and mycelial polysaccharides from the experimental four kinds of edible mushrooms had strong antioxidant properties in vitro. With the concentration of polysaccharides increasing, its antioxidant activity gradually grew stronger, and Agrocybe cylindracea polysaccha-rides showed the strongest, and the mycelial polysaccharide antioxidant activity was superior to fruiting body polysaccharides.%采用Fenton 法、邻苯三酚自氧化法和DPPH(1,1-二苯基-2-苦基肼)还原法对平菇、金针菇、真姬菇和茶树菇的子实体和菌丝体多糖的抗氧化性进行了比较研究。平菇、金针菇、真姬菇和茶树菇子实体多糖质量分数分别为7.12%,9.24%,8.96%和7.68%,菌丝体多糖质量分数分别为8.32%,11.33%,10.54%和9.75%。平菇、真姬菇、金针菇、茶树菇子实体多糖和菌丝体多糖清除羟自由基(·OH)的能力大小

  19. 黄秋葵粗多糖体外抗氧化活性测定%Determination of antioxidant activity of okra raw polysaccharides in vitro

    Institute of Scientific and Technical Information of China (English)

    赵焕焕; 贾陆; 裴迎新

    2012-01-01

    目的:测定黄秋葵粗多糖(RPS)的体外抗氧化活性.方法:采用水提醇沉淀法提取黄秋葵RPS,并用蒽酮-硫酸法测定RPS的含量,应用1,1-二苯基苦味酰基苯肼(DPPH)氧化法检测0.086、0.171、0.342、0.684、1.367和2.734 g/L RPS对 DPPH自由基(DPPH·)的清除率,水杨酸法检测0.157、0.313、0.625、1.250、2.500和5.000 g/L RPS对羟基自由基(·OH)的清除率,邻苯三酚自氧化法检测0.086、0.171、0.342、0.684、1.367和2.734 g/L RPS对超氧阴离子自由基(O2÷)的清除率,以维生素C作阳性对照.结果:黄秋葵中RPS含量为(11.23±0.04)%.RPS对DPDH·、·OH和O2÷的体外清除率呈现剂量依赖性.2.734 g/L RPS对DPPH·和O2÷的清除率分别达(44.48±0.64)%及(35.67±0.21)%,5.000 g/L RPS对·OH的清除率达(68.63±0.07)%.其清除能力较维生素C稍弱.结论:黄秋葵RPS具有较明显的体外抗氧化能力.%To study the antioxidant activity of okra raw polysaccharides( RPS ) in vitro. Methods: RPS was extracted from fresh okra by hot water, then precipitated by alcohol, and its total sugar content was determined by the an-throne-sulfuric acid method. 1, l-dipheny-2-picrylhy-drazyl ( DPPH ) oxidation method was adopted for measuring the DP-PH free radicals ( DPPH · ) clearance of 0.086,0. 171,0.342,0.684,1.367,2.734 g/L RPS, salicylic acid method was adopted for measuring hydroxyl radicals ( · OH) clearance of 0. 157,0.313,0.625,1.250,2.500,5.000 g/L RPS, pyro-gallol autoxidation method was adopted for determining superoxide anion free radicals ( 02 + ) clearance of 0. 086,0. 171, 0.342,0.684,1. 367,2. 734 g/L RPS. Vitamin C was selected as a positive control. Results: The content of RPS was ( 11. 23 ±0.04 )% . The scavenging effects of RPS had certain dosage-dependent trend and was lower than that of Vitamin C. When the concentration of RPS was 2. 734 g/L, the clearance rates of DPPH · and 02 + were ( 44. 48 ±0. 64 )% and ( 35. 67 ±0. 21 )% ,respectively. The clearance rate

  20. Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L

    Energy Technology Data Exchange (ETDEWEB)

    Tkalec, Mirta [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)], E-mail: mtkalec@zg.biol.pmf.hr; Malaric, Kresimir [Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb (Croatia); Pevalek-Kozlina, Branka [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)

    2007-12-15

    Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure to radiofrequency EMFs, and in particular, to clarify the possible role of oxidative stress in the observed effects. Duckweed was exposed for 2 h to EMFs of 400 and 900 MHz at field strengths of 10, 23, 41 and 120 V m{sup -1}. The effect of a longer exposure time (4 h) and modulation was also investigated. After exposure, parameters of oxidative stress, such as lipid peroxidation, H{sub 2}O{sub 2} content, activities and isoenzyme pattern of antioxidative enzymes as well as HSP70 expression were evaluated. At 400 MHz, lipid peroxidation and H{sub 2}O{sub 2} content were significantly enhanced in duckweed exposed to EMFs of 23 and 120 V m{sup -1} while other exposure treatments did not have an effect. Compared to the controls, the activities of antioxidative enzymes showed different behaviour: catalase (CAT) activity increased after most exposure treatments while pyrogallol (PPX) and ascorbate peroxidase (APX) activities were not changed. Exceptions were reduced PPX and APX activity after longer exposure at 23 V m{sup -1} and increased PPX activity after exposures at 10 and 120 V m{sup -1}. By contrast, at 900 MHz almost all exposure treatments significantly increased level of lipid peroxidation and H{sub 2}O{sub 2} content but mostly decreased PPX activity and did not affect CAT activity. Exceptions were exposures to a modulated field and to the field of 120 V m{sup -1} which increased PPX and CAT activity. At this frequency APX activity was significantly decreased after exposure at 10 V m{sup -1} and longer exposure at 23 V m{sup -1} but it increased after a shorter exposure at

  1. Preparation, Characterization and Activity Analysis of Selenium-Containing Pumpkin Polysaccharide%南瓜硒多糖的制备表征及活性分析

    Institute of Scientific and Technical Information of China (English)

    商龙臣; 吴少魏; 张驰; 廖红华; 刘信平

    2016-01-01

    对南瓜多糖进行硒化修饰,并对南瓜硒多糖的体外抗氧化和抑制人乳腺癌细胞MDA-MB-231生长等活性进行研究。以提取、分离、纯化的南瓜多糖为前体物,用Na2SeO3硒化修饰制备南瓜硒多糖,并用紫外光谱、红外光谱、原子荧光光谱、热重分析对产物结构进行表征,采用邻苯三酚自氧化法、水杨酸法、四甲基偶氮唑蓝比色法测定其清除超氧阴离子自由基(O2-•)、羟自由基(•OH)的能力以及对人乳腺癌细胞MDA-MB-231生长的抑制作用。结果表明:制备产物结构中含有Se=O键和Se—C键,即实现了南瓜多糖的硒化。南瓜硒多糖对O2-·、·OH的清除作用显著强于南瓜多糖,与样品量呈正相关;南瓜硒多糖对人乳腺癌细胞MDA-MB-231生长有抑制作用,比南瓜多糖具有更好的抑制效果。%Objective: To investigate selenium modification of pumpkin polysaccharide and to evaluate thein vitro antioxidant activity and antitumor effect against human breast cancer MDA-MB-231 cells of the modified polysaccharide. Methods: Pumpkin polysaccharide was prepared and purified and it was modified by reaction with Na2SeO3 to obtain selenium-containing polysaccharide. Furthermore, the structure of the modified polysaccharide was characterized through UV, IR, atomic fluorescence spectroscopies and thermogravimetric analysis. Finally, its scavenging effect on O2-· and ·OH as well as growth inhibitory effect on breast cancer cells were tested by using pyrogallol autoxidation, salicylic acid method and methyl thiazolyl tetrazolium colorimetric assay. Results: Se=O and Se–C bonds were observed in the structure of the target product, thus successfully achieving the selenium modification of pumpkin polysaccharide. The selenium-containing pumpkin polysaccharide had significantly stronger scavenging effects on O2-· and ·OH than ordinary pumpkin polysaccharide, which were concentration

  2. Study of microwave-assisted extraction and cosmetic effect of total flavonoids from Inonotus obliquus (Fr.) Pilat%桦褐孔菌总黄酮的微波提取及美容功效研究

    Institute of Scientific and Technical Information of China (English)

    蔡建秀; 龚丽芬; 许丽璇; 陈伟伟

    2012-01-01

    Extraction technology of total flovonoids from Inonotus obliquus ( Fr. ) Pilat were optimized via orthogonal designed experiment, and tyrosinase inhibition rate of the extract was measured. Varnishing cream was prepared using the extract as the active additive. Various performance tests of the varnishing cream were conducted, including determination of malonaldehyde (MDA) content, determination of SOD activity in mouse skin via pyrogallol auto - oxidation test and determination of hydroxy free radical scavenging capacity of skin tissue in vitro. Experimental results showed that the optimum conditions for extraction of flavinoids from Inonotus obliquus (Fr. ) Pilat are as follows: ethanol as solvent with volume fraction of 70% ; ratio of Inonotus obliquus (Fr. ) Pilat material to. solvent (g: mL) , 1: 40;microwave treatment time, 120 s;microwave power, 352 W. Under such conditions, the extraction yield of flavonoids from Inonotus obliquus (Fr. ) Pilat achieves 4. 96%. When vanishing cream base was treated by addition of 7. 5 mL of the extract with mass concentration of 0. 024 g · L-1 Inonotus obliquus ( Fr. ) Pilat flavonoids, the tyrosinase inhibition rate achieves the best condition of 25.0% and the finished product shows good appearance and stability. In addition,the antioxidation test results showed that the extract could reduce the formation of MDA, increase the enzymatic activity of SOD and hydroxyl free radical scavenging capacity in mouse skin tissue and displays good dosage -effect relationship. All results indicate that Inonotus obliquus ( Fr. ) Pilat flavonoids has certain antioxidation capacity and tyrosinase inhibition effect;it can be used as a cosmetic additive for skin decrepitude retarding and whitening.%通过正交试验优化了桦褐孔菌总黄酮的提取工艺,测定了总黄酮提取液的酪氨酸酶抑制率,并制备了桦褐孔菌总黄酮雪花膏.进行了该雪花膏的性能测试和大白鼠皮肤抗氧化试验:包括用丙二

  3. 三月竹开花前后几种重要代谢物差异研究%Difference of some important metabolites of flowering and non-flowering Chimonobambusa opienensis

    Institute of Scientific and Technical Information of China (English)

    王双燕; 李志宏; 易同培; 史军义; 甄铧

    2016-01-01

    (by Absorption Photometry), fat contents(by null method of measurement), soluble sugars,starch and cellulose contents (by phenol-sulfuric acid method), soluble protein contents (by Coomassie Brilliant Blue G-250 staining), peroxidase ( POD) liveness ( by guaiacol colorimetric method), super-oxide dismutase ( SOD) liveness ( by pyrogallol autoxidation method) were determined. The results showed that the chlorophyll contents in the leaf and secondary branch decline were respectively 14.42 and 71.39 ( P<0.05); the oil contents in the secondary branch and bough dropped 20.93 and 26.04 (P<0.05); the contents of soluble protein in the leaf and secondary branch fell 30.07 and 37.31 ( P<0.05);but the contents of soluble sugar in the leaf and secondary branch went up 21.04 and 17.81 , starch rose 8.33 and 8.21 and cellulose increased by 17.62 and 8.52 ( P<0.05);POD liveness in upper leaves went up 122.01 ( P<0.05) in the flowering and non-flowering C. opienensis. The result illustra-ted that the blossoming of C. opienensis was associated with the change of organotrophy and biochemical indexes. The management control of bamboo growth in March could be realized by monitoring the chlorophyll contents in the leaf and secondary branch, the oil contents in the secondary branch and bough, the contents of soluble sugar, starch and cellu-lose in the leaf and secondary branch, the contents of soluble protein in the leaf and secondary branch and POD liveness in upper leaves. These would provide the references for further studying the C. opienensis flowering mechanism and post-pone the flowering date.

  4. Therapeutic effects of flavonoids from Ceylon green tea on hypoxic human brain epithelial cells%锡兰绿茶中黄酮类成分对缺氧人脑上皮细胞的治疗作用

    Institute of Scientific and Technical Information of China (English)

    黄山红; Ranil De Silva

    2008-01-01

    为研究从锡兰绿茶(Dilmah)中提取纯化的黄酮类有效成分对缺氧人脑上皮细胞的治疗作用,体外培养人脑上皮细胞(HBEC),给与锡兰绿茶黄酮提取物治疗后造缺氧模型,检测锡兰绿茶中的黄酮类化合物的抗氧化活性及脑细胞的生存情况,探究其对缺氧脑细胞氧化应激的影响.生化检测显示锡兰绿茶提取物的自由基的清除抑制率(ABTS)为68%±2.8%,次氯酸漂白邻苯三酚红抑制率为79%±4.5%.缺氧后,空白对照组细胞生存率为29% ±2.3%,而锡兰绿茶黄酮提取物治疗组为41%±4.7%,氯沙坦治疗组为39% ±3.1%.同时,黄铜提取物与氯沙坦治疗组LDH释放分别减少75%±3.7%和79%±3.5%.锡兰绿茶的黄酮提取物治疗使细胞抗氧化酶活力显著增强,SOD:(1.5 ±0.6) μmol/min/mg蛋白,CAT:(0.61 ±0.06)μmol/min/mg蛋白,GPx:(2.6 ±0.41)μmol/min/mg蛋白,GST:(6.0 ±2.4)μmol/min/mg蛋白,显著高于缺氧对照组,其酶活力分别为:(0.5 ±0.52,51 ±0.04,1.2 ±0.35,3.1±1.6)μmol/min/mg蛋白.研究结果表明,锡兰绿茶有很大的临床应用价值.饮用锡兰绿茶可能成为预防中风的有效新方法,并能减少现代疾病对生命的威胁,提高人类生活质量.%We have extracted and purifiied flavonoids as active ingredients from Ceylon green tea (Dilmah).In this project,an in vitro hypoxic model using human brain epithelial cells (HBEC) was studied with treatment of the tea extract before inducing hypoxia.We have tested the hypothesis that flavonoids extracted from Ceylon green tea act as potential therapeutic ingredient (s) to reduce oxidative stress in hypoxic cells through its antioxidant properties and its ability to reduce cerebral cellular death.The biochemical antioxidant tests show that the Ceylon green tea has 68% ± 2.8% inhibition property of scavenging of ABTS.The inhibition of pyrogallol red bleaching by HOC1 from Ceylon tea was 79% ± 4.5%.After exposing to hypoxia,the cell viability was 29% ± 2.3% in

  5. Determination and Antioxidant Activity Investigation of Polysaccharides from Laggera pterodonta%翼齿六棱菊多糖的含量测定及抗氧化活性考察

    Institute of Scientific and Technical Information of China (English)

    杜清华; 黄元河; 潘乔丹; 王柳念; 唐海燕; 林庆云

    2013-01-01

    Objective:To determine the content of polysaccharides in Laggera pterodonta and investigate its in vitro antioxidative activity.Method:Polysaccharides in L.pterodonta was extracted by ultrasonic-microwave synergistic method,the content of polysaccharides was determined by phenol-sulfuric acid colorimetry,its antioxidant activity was measured by FRAP assay,salicylic acid assay,ABTS assay and adjacent benzene pyrogallol assay.Result:The content of polysaccharides in L.pterodonta was 200 mg ·g-1 Compared with the positive control of ascorbic acid and tea polyphenols,reducing Fe3+ antioxidant capacity of polysaccharides in L.Pterodonta (829.75 μmol · g-1) was weaker than ascorbic acid (1 536.5 pmol · g-1),but higher than tea polyphenols (739.75 μmol ·g-1).Scavenging ABTS+ radical capacity (IC50 0.197 g·L-1) and superoxide anion radical capacity (IC50 0.289 g ·L-1) was lower than ascorbic acid (IC50 were 0.032,0.259 g ·L-1,respectively),but higher than tea polyphenols (IC50 were 0.233,0.335 g · L-1,respectively).Scavenging OH · (IC50 0.245 g ·L-1) was lower than ascorbic acid (IC50 0.199 g ·L-1) and tea polyphenols (IC50 0.233 g · L-1).Conclusion:Phenol-sulfuric acid colorimetry to determine the content of polysaccharides from L.pterodonta was simple,rapid and accurate with good sensitivity,antioxidant activity of polysaccharides from L.pterodonta was strong.%目的:测定翼齿六棱菊多糖的含量并探讨其体外抗氧化活性.方法:运用微波-超声波协同提取翼齿六棱菊多糖,采用苯酚-硫酸法测定多糖含量,通过FRAP法、水杨酸法、ABTS法和邻苯三酚法检测翼齿六棱菊多糖的抗氧化能力.结果:翼齿六棱菊多糖提取量200 mg·g-1;与对照品抗坏血酸和茶多酚相比,翼齿六棱菊多糖的Fe3+还原抗氧化能力(829.75μmol·g-1)弱于抗坏血酸(1 536.5 μmol·g-1),强于茶多酚(739.75 μmol·g-1);清除ABTS+自由基能力(IC50 0.197 g·L-1)及清除超

  6. 氨基葡萄糖硫酸盐对兔膝关节骨关节炎的保护作用研究%Protection of glucosamine sulphate against knee osteoarthritis in rabbit

    Institute of Scientific and Technical Information of China (English)

    韦健; 周建飞; 洪定钢

    2016-01-01

    Objective To study protective effects of glucosamine sulphate against knee osteoarthritis in rabbit and explore its mechanism. Methods Rabbits were randomly divided into control group, model group, and glucosamine sulphate (63, 125, and 250 mg/kg) groups, and each group had eight rabbits. Right knee Hulth procedure was used to establish osteoarthritis models. The volume was 5 mL/kg, the treatment were carried out once daily, and lasted for 40 d. Body weight changes were observed, and joint mobility in rabbits were calculated. Gross tissue of rabbits with osteoarthritis was observed under naked eye and microscope. Cartilage tissue structure, cell number, toluidine blue staining, and the tidal line integrity were observed after He and toluidine blue staining, and Mankin's scores were compared. Pathological changes of synovial tissue and scores were compared. SOD activity in red blood cells of rabbits was determined by pyrogallol method.Results Compare with treatment before giving medicine, body weight changes in glucosamine sulphate group were increased, but the difference was not statistically significant. Compare with model group, joint mobility of rabbits in the glucosamine sulphate groups were significantly increased, especially glucosamine sulphate 250 mg/kg group (P < 0.05); The gross score of arthritis cartilage were significantly decreased with a certain dose-effect relationship (P < 0.01); Cartilage tissue structure, cell number, toluidine blue staining, and the tidal line integrity in Mankin's scores had a certain degree of improvement (P < 0.05, 0.01); Synovial tissue scores were significantly decreased, especially glucosamine sulphate 125 and 250 mg/kg group (P < 0.05, 0.01); And SOD activity in red blood cells were significantly increased, especially glucosamine sulphate 250 mg/kg group (P < 0.05).Conclusion Glucosamine sulphate has protection against knee osteoarthritis in rabbit in dose-dependent manner,which may be related to reducing chronic