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Maamoun I, Eljamal R, Eljamal O. Statistical optimization of nZVI chemical synthesis approach towards P and NO 3- removal from aqueous solutions: Cost-effectiveness & parametric effects. Chemosphere 2023; 312:137176. [PMID: 36400198 DOI: 10.1016/j.chemosphere.2022.137176] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 11/02/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
This study aims to conduct statistical optimization of nZVI synthesis parameters towards the removal efficiency of phosphorus (P) and nitrate (NO3-), considering for the first time the cost-effectiveness index. The detailed statistical analysis was implemented to evaluate the main effects and interactions of eight synthesis parameters, including reductant concentration (RC), reductant delivery rate (RDR), reductant liquid volume (RLV), pH, aging time (AGT), mixing speed (MS), temperature (T), and precursor concentration (PC). Results revealed that the experimental optimization of the synthesis factors improved the removal efficiency of NO3- and P by 27 and 9%, respectively, with respect to that before the optimization. ANOVA statistical results indicated the significance of RP (%) and [Formula: see text] (%) models with F-values of 4.480 × 108 and 23,755.08, respectively. Moreover, the p-values of all the eight main linear effects were less than 0.05 in both two models of RP (%) and [Formula: see text] (%). However, most of the interaction parameters were not statistically significant (higher than 0.05) in the case of [Formula: see text] (%), which is unlike RP (%) where all interaction parameters were statistically significant (less than 0.05). The normal probability plots of factors effects provided significant evidence of the significance of the investigated parameters RC had the highest positive statistically significant effect on RP (%) followed by RLV, RDR, MS and T. In case of [Formula: see text] (%), RLV had the highest positive significant effect, followed by AGT > RDR > pH > T > MS. The cost-effective optimal constraints in this study resulted in the best economically optimized values of the nZVI synthesis parameters in terms of higher reactivity and reduced synthesis cost.
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Affiliation(s)
- Ibrahim Maamoun
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Ramadan Eljamal
- Research Center for Negative Emission Technology, International Science Innovation Center, Kyushu University, 744 Motooka, Nishiku 819-0395, Japan
| | - Osama Eljamal
- Water and Environmental Engineering Laboratory, Department of Earth System Science and Technology, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen Kasuga, Fukuoka 816-8580, Japan.
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2
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Zhou D, Liang M, Xia Y, Li C, Huang M, Peng S, Huang Y. Reduction mechanisms of V 5+ by vanadium-reducing bacteria in aqueous environments: Role of different molecular weight fractionated extracellular polymeric substances. Sci Total Environ 2022; 852:158394. [PMID: 36058324 DOI: 10.1016/j.scitotenv.2022.158394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/18/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Extracellular polymeric substances (EPS) are high-molecular polymers secreted by microbes and play essential roles in metallic biogeochemical cycling. Previous studies demonstrated the reducing capacity of the functional groups on EPS for metal reduction. However, the roles of different EPS components in vanadium speciation and their responsible reducing substances for vanadium reduction are still unknown. In this study, the EPS of Bacillus sp. PFYN01 was fractionated via ultrafiltration into six components with different kDa (EPS>100, EPS100-50, EPS50-30, EPS30-10, EPS10-3, and EPS<3). Batch reduction experiments of the intact cells, EPS-free cells, the pristine and fractionated EPS with V5+ were conducted and characterized. The results demonstrated that the extracellular reduction of V5+ into V4+ by EPS was the major reduction process. Among the functional groups in EPS, C=O/C-N of amide in protein/polypeptide and CO of carboxyl in fulvic acid-like substances might act as the reductants for V5+, while CO in polysaccharide molecules and PO in phosphodiester played a key role in the adsorption process. The intracellular reduction was via translocating V5+ into the cells and releasing V4+ by the intracellular reductases. The reducing capacity of the fractionated EPS followed a sequence of EPS<3 > EPS10-3 > EPS50-30 > EPS100-50 > EPS30-10 > EPS>100. The small molecules of fulvic acid-like substances and amino acids were responsible for the high reducing capacity of EPS<3. EPS>100 had the lowest reducing capacity due to its macromolecular structure decreasing the exposure of the reactive sites. In addition to reduction, those intermediate EPS components may also have supporting functions, such as connecting protein skeletons and increasing the specific surface area of EPS. Therefore, the diverse effects of the EPS components cannot be neglected in vanadium biogeochemical cycling.
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Affiliation(s)
- Dan Zhou
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, China
| | - Mengmeng Liang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China
| | - Yonglian Xia
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China
| | - Chao Li
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China
| | - Mingzheng Huang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China
| | - Shuming Peng
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China
| | - Yi Huang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Ecology and Environment, Chengdu University of Technology, Sichuan 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, China.
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3
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Ding H, Hu J. The optimal method for peroxydisulfate quenching: A comparison of commonly used reductants. Chemosphere 2021; 262:128000. [PMID: 33182106 DOI: 10.1016/j.chemosphere.2020.128000] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/08/2020] [Accepted: 08/11/2020] [Indexed: 06/11/2023]
Abstract
Peroxydisulfate-based advanced oxidation process has drawn increasing interest recently. Quenching the residual peroxydisulfate is essential for the accurate measurement of the concentration of target pollutants. However, it was rarely discussed which reductant is best for peroxydisulfate quenching. In this study, how the quenching of peroxydisulfate by four commonly used quenchers (methanol, ascorbic acid, sodium thiosulfate and sodium sulfite) affected the concentration of carbamazepine was investigated. Sodium sulfite reacted with carbamazepine directly, with the highest removal rate up to 39%. Higher carbamazepine removal rate was achieved by peroxydisulfate/sodium sulfite than by sodium sulfite alone. SO3•- and SO5•- rather than SO4•- played the major role in carbamazepine removal by sodium sulfite or peroxydisulfate/sodium sulfite. Methanol was found unable to reduce peroxydisulfate. Ascorbic acid, when used with a concentration more than three times higher than that of peroxydisulfate, was the best quencher with the lowest carbamazepine removal rate observed at a pH range of 3.5-10.0. Sodium thiosulfate was unfit for peroxydisulfate quenching at pH 3.5 as it was decomposed and formed bisulfite under strong acidic condition. The results of this study provided valuable guidance to the selection of proper quenchers for peroxydisulfate-related advanced oxidation processes.
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Affiliation(s)
- Han Ding
- Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore
| | - Jiangyong Hu
- Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore.
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Starowicz M, Lelujka E, Ciska E, Lamparski G, Sawicki T, Wronkowska M. The Application of Lamiaceae Lindl. Promotes Aroma Compounds Formation, Sensory Properties, and Antioxidant Activity of Oat and Buckwheat-Based Cookies. Molecules 2020; 25:molecules25235626. [PMID: 33260430 PMCID: PMC7729772 DOI: 10.3390/molecules25235626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/26/2020] [Accepted: 11/28/2020] [Indexed: 11/28/2022] Open
Abstract
Aroma plays an important role in designing innovative functional foods. This study aimed to study the influence of incorporating herbs from the Lamiaceae family (sage, mint, rosemary, oregano, thyme) on aroma compound formation and sensory properties in oat-buckwheat products. DPPH, FRAP and PCL have been used to describe possible antioxidant activity changes and reduce power of cookies after Lamiaceae Lindl. addition. The volatiles analysis by HS-SPME-GC/MS, has shown that Lamiaceae addition significantly influences the volatiles composition (29 molecules) with a predominance of molecules with a positive sensorial impression. Cookies elaborated with herbs were characterized by a greater share of monoterpenes (e.g., limonene, eucalyptol), in the volatile profile than in control cookies. These compounds’ occurrence was closely correlated with the appearance of herbal odor and taste among sensory attributes in cookies with herbs addition. In contrast, a decrease of negative oil aroma and the bitter aftertaste was noted by a sensory panel. Moreover, in cookies of mint and rosemary, hexanal share decreased about 13 and 9.7-times, respectively. Considering all presented experiments, rosemary addition was the most effective in forming a positive aroma profile with high sensory acceptance and increased functional properties.
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Affiliation(s)
- Małgorzata Starowicz
- Department of Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, 10-784 Olsztyn, Poland; (E.C.); (M.W.)
- Correspondence: ; Tel.: +48-89523-46-39
| | - Ewa Lelujka
- Faculty of Biology and Biotechnology, University of Warmia and Mazury, 10-719 Olsztyn, Poland;
| | - Ewa Ciska
- Department of Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, 10-784 Olsztyn, Poland; (E.C.); (M.W.)
| | - Grzegorz Lamparski
- Sensory Laboratory, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, 10-748 Olsztyn, Poland;
| | - Tomasz Sawicki
- Department of Human Nutrition, Faculty of Food Sciences, University of Warmia and Mazury, 10-718 Olsztyn, Poland;
| | - Małgorzata Wronkowska
- Department of Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, 10-784 Olsztyn, Poland; (E.C.); (M.W.)
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Wang Z, Schenkeveld WDC, Kraemer SM, Giammar DE. Synergistic effect of reductive and ligand-promoted dissolution of goethite. Environ Sci Technol 2015; 49:7236-7244. [PMID: 25965980 DOI: 10.1021/acs.est.5b01191] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ligand-promoted dissolution and reductive dissolution of iron (hydr)oxide minerals control the bioavailability of iron in many environmental systems and have been recognized as biological iron acquisition strategies. This study investigated the potential synergism between ligands (desferrioxamine B (DFOB) or N,N'-Di(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED)) and a reductant (ascorbate) in goethite dissolution. Batch experiments were performed at pH 6 with ligand or reductant alone and in combination, and under both oxic and anoxic conditions. Goethite dissolution in the presence of reductant or ligand alone followed classic surface-controlled dissolution kinetics. Ascorbate alone does not promote goethite dissolution under oxic conditions due to rapid reoxidation of Fe(II). The rate coefficients for goethite dissolution by ligands are closely correlated with the stability constants of the aqueous Fe(III)-ligand complexes. A synergistic effect of DFOB and ascorbate on the rate of goethite dissolution was observed (total rates greater than the sum of the individual rates), and this effect was most pronounced under oxic conditions. For HBED, macroscopically the synergistic effect was hidden due to the inhibitory effect of ascorbate on HBED adsorption. After accounting for the concentrations of adsorbed ascorbate and HBED, a synergistic effect could still be identified. The potential synergism between ligand and reductant for iron (hydr)oxide dissolution may have important implications for iron bioavailability in soil environments.
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Affiliation(s)
- Zimeng Wang
- †Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | | | - Stephan M Kraemer
- ‡Department of Environmental Geosciences, University of Vienna, 1010 Vienna, Austria
| | - Daniel E Giammar
- §Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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Vinayak RC, Sudha SA, Chatterji A. Bio-screening of a few green seaweeds from India for their cytotoxic and antioxidant potential. J Sci Food Agric 2011; 91:2471-2476. [PMID: 21674507 DOI: 10.1002/jsfa.4490] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 02/05/2011] [Accepted: 04/18/2011] [Indexed: 05/30/2023]
Abstract
BACKGROUND It has been evidenced in several epidemiological studies that seaweeds when consumed as diet protect against several chronic oxidative stress-related diseases. Seaweeds, raw, cooked, or dried, are used as food in many cultures, although not very popularly in India. Globally, several studies have indicated that seaweeds are a rich source of phenolic compounds and have antioxidant properties. In the present study, we screened methanolic extracts (MEs) of five species of green seaweeds commonly found in India for their cytotoxic activity by brine shrimp lethality assay and antioxidant properties using various in vitro assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, reducing power and metal ion chelating assays. RESULTS A markedly variable, dose-dependent activity was observed in all the seaweed extracts relative to their total phenolic content. Statistical analysis indicated a significantly strong correlation between the DPPH radical scavenging activity and total phenolic content (R(2) = 0.88, P < 0.05) as well as reducing power and total phenolic content (R(2) = 0.99, P < 0.01) of the dry MEs. Also, a very poor correlation between total phenolic content and metal chelating activity (R(2) = 0.13, P > 0.05) was noted. None of the seaweed extracts were potently cytotoxic. CONCLUSION The underlying results endorse seaweeds as a rich, novel source of antioxidant compounds needing systemic exploration.
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Affiliation(s)
- Rashmi C Vinayak
- Aquaculture Laboratory, Biological Oceanography Division, National Institute of Oceanography, Panaji, Goa, India.
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7
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Liu JR, Chen GF, Shih HN, Kuo PC. Enhanced antioxidant bioactivity of Salvia miltiorrhiza (Danshen) products prepared using nanotechnology. Phytomedicine 2008; 15:23-30. [PMID: 18077145 DOI: 10.1016/j.phymed.2007.11.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The traditional Chinese medicine, Salvia miltiorrhiza (Danshen), promotes blood circulation and relieves blood stasis, also demonstrating good antioxidant activity. In the present study, therefore, the antioxidant activities of medicinal plant materials prepared using nanotechnology or traditional grinding methods were compared using three biological assays. It was found that the nanotechnology preparation had stronger antioxidant bioactivities. Complementary quantitative analysis of four active constituents, salvianolic acid B, cryptotanshinone, tanshinone I and tanshinone IIA, by HPLC revealed only marked differences for salvianolic acid B. The results indicate that the polar active constituent in the nanotechnology samples was released faster compared to the traditionally powdered samples.
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Affiliation(s)
- Je-Ruei Liu
- Department of Animal Science and Technology and Institute of Biotechnology, National Taiwan University, Taipei 102, Taiwan, ROC
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8
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Cheng X, Peterkin E. A new reliable method for dimethyl sulfoxide analysis in wastewater: dimethyl sulfoxide in Philadelphia's three water pollution control plants. Water Environ Res 2007; 79:571-5. [PMID: 17571849 DOI: 10.2175/106143006x123094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A simple but reliable procedure was developed to analyze dimethyl sulfoxide (DMSO) in wastewater. The isotope DMSO_d6 was used as the internal standard to ensure accuracy. The DMSO was reduced with stannous chloride and measured as dimethyl sulfide (DMS) with purge-and-trap gas chromatography/mass spectrometry. The method detection limit was at the sub-microgram-per-milliliter level; precision, as measured by standard deviation, was better than +/- 0.5%; and the recoveries were between 95 and 105% at the level of 2 microg/mL. The procedure could use standard analytical instrumentation used for volatile organic compound analysis. A field study was conducted to validate the method and quantify DMSO concentration range in the three water pollution control plants (WPCPs) in the city of Philadelphia, Pennsylvania. Results showed that, when a local chemical facility discharged, DMSO concentration could be as high as 12 mg/L in the influent to a WPCP. This would lead to the formation of a toxic "canned corn" DMS odor during the treatment processes.
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Affiliation(s)
- Xianhao Cheng
- Bureau of Laboratory Services, Philadelphia Water Department, 1500 E. Hunting Park Ave., Philadelphia, PA 19124, USA.
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9
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Lastovicková M, Chmelík J. Simple and fast method for recognition of reducing and nonreducing neutral carbohydrates by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. J Agric Food Chem 2006; 54:5092-7. [PMID: 16819921 DOI: 10.1021/jf052988s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Negative-ion mode matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF-MS) was used for the characterization of storage, neutral oligosaccharides extracted from Jerusalem artichoke, red onion, and wheat. The oligosaccharides from the real samples were analyzed with 2,4,6-trihydroxyacetophenone as the most convenient matrix that was selected in advance with the standard carbohydrate samples (inulin and maltooligosaccharides). The oligosaccharides from Jerusalem artichoke and red onion (similarly as inulin) produced [M - H](-) peaks as the main distribution, which reflects their nonreducing composition. On the contrary, the cross-ring fragmentations [M - H - 120](-) formed the main distribution in the mass spectra of hydrolyzed wheat starch similarly to reducing maltooligosaccharides and dextrans. The negative-ion mode MALDI-TOF MS is capable of recognizing reducing and nonreducing oligosaccharides. Such a simple differentiation of malto or inulin type of oligosaccharides is not possible in the positive-ion mode.
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Affiliation(s)
- Markéta Lastovicková
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veveri 97, 611 42 Brno, Czech Republic.
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Lee MH, Jiang CB, Juan SH, Lin RD, Hou WC. Antioxidant and heme oxygenase-1 (HO-1)-induced effects of selected Taiwanese plants. Fitoterapia 2006; 77:109-15. [PMID: 16403605 DOI: 10.1016/j.fitote.2005.11.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Accepted: 11/17/2005] [Indexed: 10/25/2022]
Abstract
Recent studies have shown biological effects of heme oxygenase-1 (HO-1) induction and antioxidation in cardiovascular disorders. The ethanol extracts of leaves of 12 selected indigenous Taiwanese plants were investigated for their antioxidant activities, evaluated using assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals scavenging and reducing power activities as well as the induction of heme oxygenase-1 (HO-1). Acer albopurpurascens, Cinnamomum kanehirai, Diospyros discolor, Excoecaria kawakamii, Koelreuteria henryi, and Syzygium formosanum showed better DPPH-scavenging activities than the other plants. IC(50) values ranged from 1.7 to 8.7 microg/mL. Excepting Millettia pulchra var. microphylla and Pittosporum moluccanum, the extracts displayed hydroxyl-scavenging activities (IC(50) of 0.16-0.67 microg/mL). A. albopurpurascens, D. discolor, K. henryi, and S. formosanum also showed good superoxide anion radical scavenging activities and IC(50) values ranged from 12.9 to 28.5 microg/mL. D. discolor, K. henryi, and S. formosanum showed potent reducing power and M. pulchra var. microphylla and S. formosanum exhibited potent HO-1 induced activity. These active plant extracts also contained abundant phenolic constituents. The present results provide candidates to isolate the active constituents and develop natural antioxidants.
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Affiliation(s)
- Mei-Hsien Lee
- Graduate Institute of Pharmacognosy, Taipei Medical University, Taiwan.
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11
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Naumova NN, Schappert J, Kaplan LA. Reducing substances in urine: a paradigm for changes in a standard test. Ann Clin Lab Sci 2006; 36:447-8. [PMID: 17127733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Detection of reducing substances in urine has been a standard laboratory procedure for about 50 yr. It is used as a screening test for inborn errors of carbohydrate metabolism. Although the test has poor specificity and most states perform mandatory newborn screening for the common genetic defects, most clinical laboratories still perform this as a reflex test on all pediatric urine samples. We suggest that laboratories should perform this test only at the specific order of a physician and that they should review their test menu frequently to delete tests that no longer have a clinical rationale.
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Affiliation(s)
- Nadia N Naumova
- Department of Pathology and Laboratory Medicine, Beth Israel Medical Center, New York, NY 10003, USA
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12
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Papadopoulou MV, Pouremad R, Rao MK, Ji M, Bloomer WD. In vitro evaluation of 4-[3-(2-nitro-1-imidazolyl)-propylamino]-7-trifluoromethylquinoline hydrochloride (NLTQ-1), a new bioreductive agent as a hypoxia marker by 19F-magnetic resonance spectroscopy (19F-MRS). In Vivo 2001; 15:365-71. [PMID: 11695231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
19F-labeled bioreductive drugs bound to hypoxic cells in tumors could be detected by nuclear magnetic resonance, provided that they do not lose 19F during their metabolism. NLTQ-1, a 2-nitroimidazole-linked 7-trifluoromethylquinoline, has been synthesized to furnish this aim. NLTQ-1 demonstrated hypoxic selectivities of 7-10 in various cell-lines, in vitro. Uptake studies in V79 cells showed a 5 to 6 fold greater intracellular than extracellular concentration at a range of 100-300 microM input concentrations. A strong sharp peak, which was identified as the parent compound, was observed in the 19F-NMR spectrum of 90% MeCN extracts of V79 cells aerobically exposed to NLTQ-1, indicating that NLTQ-1 was not metabolized under aerobic conditions. Similarly, 19F NMR efflux studies in intact cells showed that the NLTQ-1 was bound to the cells predominantly under hypoxic conditions. 19F-NMR spectra of intact cells, exposed under hypoxic conditions to NLTQ-1, and of their lysates, after precipitation of various cellular components, indicated that possible covalent binding of NLTQ-1 had occurred with macromolecules such as proteins and nucleic acids. Therefore, NLTQ-1 might be suitable as a 19F-MRS/MRI hypoxia probe, although further in vivo work is necessary to verify this matter.
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Affiliation(s)
- M V Papadopoulou
- Department of Radiation Medicine, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston, IL 60201, USA.
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13
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Espada J, Juarranz A, Villanueva A, Cañete M, Andrés I, Stockert JC. Recycling cultured cells for immunofluorescent labeling. Histochem Cell Biol 2001; 116:41-7. [PMID: 11479721 DOI: 10.1007/s004180100290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2001] [Indexed: 11/27/2022]
Abstract
A method to use sequential rounds of immunofluorescent labeling in cell cultures is presented. The method is based on the utilization of a non-liquid reducing agent, sodium dithionite, in conjunction with ionic or non-ionic detergents (SDS or TX100, respectively) at room temperature. This method preserves cell morphology and substrate antigenicity, and operates through the complete extraction of most primary and secondary antibodies. Using this protocol, the sequential immunolocalization of different proteins is possible, without signal interference with previous immunolabeling rounds. In addition, the method is also useful to recycle blotted membranes in immunoblots.
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Affiliation(s)
- J Espada
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas, CSIC, Facultad de Medicina, Universidad Autónoma de Madrid, Arturo Duperier 4, 28029 Madrid, Spain.
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Boschi-Muller S, Azza S, Sanglier-Cianferani S, Talfournier F, Van Dorsselear A, Branlant G. A sulfenic acid enzyme intermediate is involved in the catalytic mechanism of peptide methionine sulfoxide reductase from Escherichia coli. J Biol Chem 2000; 275:35908-13. [PMID: 10964927 DOI: 10.1074/jbc.m006137200] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Methionine oxidation into methionine sulfoxide is known to be involved in many pathologies and to exert regulatory effects on proteins. This oxidation can be reversed by a ubiquitous monomeric enzyme, the peptide methionine sulfoxide reductase (MsrA), whose activity in vivo requires the thioredoxin-regenerating system. The proposed chemical mechanism of Escherichia coli MsrA involves three Cys residues (positions 51, 198, and 206). A fourth Cys (position 86) is not important for catalysis. In the absence of a reducing system, 2 mol of methionine are formed per mole of enzyme for wild type and Cys-86 --> Ser mutant MsrA, whereas only 1 mol is formed for mutants in which either Cys-198 or Cys-206 is mutated. Reduction of methionine sulfoxide is shown to proceed through the formation of a sulfenic acid intermediate. This intermediate has been characterized by chemical probes and mass spectrometry analyses. Together, the results support a three-step chemical mechanism in vivo: 1) Cys-51 attacks the sulfur atom of the sulfoxide substrate leading, via a rearrangement, to the formation of a sulfenic acid intermediate on Cys-51 and release of 1 mol of methionine/mol of enzyme; 2) the sulfenic acid is then reduced via a double displacement mechanism involving formation of a disulfide bond between Cys-51 and Cys-198, followed by formation of a disulfide bond between Cys-198 and Cys-206, which liberates Cys-51, and 3) the disulfide bond between Cys-198 and Cys-206 is reduced by thioredoxin-dependent recycling system process.
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Affiliation(s)
- S Boschi-Muller
- UMR CNRS-UHP 7567, Maturation des ARN et Enzymologie Moléculaire, Faculté des Sciences, Bld des Aiguillettes, BP 239, 54506 Vandoeuvre-les-Nancy, France
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15
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Yang L, Liu L, Olsen BA, Nussbaum MA. The determination of oxalic acid, oxamic acid, and oxamide in a drug substance by ion-exclusion chromatography. J Pharm Biomed Anal 2000; 22:487-93. [PMID: 10766366 DOI: 10.1016/s0731-7085(00)00230-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Oxalic acid, oxamic acid and oxamide are potential impurities in some active pharmaceutical ingredients (API). The retention and separation of oxalic and oxamic acids are particularly challenging using conventional reversed-phase HPLC due to their high polarity. An ion-exclusion chromatography (IEC) method has been shown to provide good separation and sensitivity for the three oxalate-related impurities in a hydrophobic API matrix. The method uses a Dionex IonPac ICE-ASI column with 95/5 (v/v) 0.1% sulfuric acid/acetonitrile as the mobile phase and UV detection at 205 nm. Development and validation of this method are described.
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Affiliation(s)
- L Yang
- Lilly Research Laboratories, Eli Lilly and Company, Lafayette, IN 47902, USA.
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16
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Raju TS, Nayak N, Briggs J, O'Connor JV, Lerner L. A convenient microscale colorimetric method for terminal galactose on immunoglobulins. Biochem Biophys Res Commun 1999; 261:196-201. [PMID: 10405345 DOI: 10.1006/bbrc.1999.1009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new approach for quantitative determination of terminal galactose (Gal) residues of immunoglobulins was developed by combining exoglycosidase digestion with the classical colorimetric estimation of reducing sugars. The ferricyanide colorimetric method was modified to increase the stability of the chromophore (Prussian blue) and adapted to determine the amount of terminal Gal residues present in immunoglobulins. The method involves the release of covalently bound Gal from immunoglobulins by Diplococcus pneumoniae beta-D-galactosidase (specific for beta(1,4) linked galactose), removal of the glycoprotein and enzyme from the reaction mixture by heat denaturation or ethanol precipitation, followed by colorimetric measurement of the released sugar using the ferricyanide assay. The ferricyanide method was modified to enhance the solubility and stability of the chromophore by increasing the concentration of aqueous sulfuric acid and sodium dodecyl sulfate (SDS). The linear range of the modified method was from approximately 11 to 111 microM Gal. Typical variation in assay results was on the order of 5%. Using the modified method, the terminal Gal content of a recombinant chimeric monoclonal antibody (anti-CD20, rIgG) expressed in Chinese hamster ovary (CHO) cells was determined and evaluated for batch-to-batch consistency. The method was used to optimize pH, time, temperature, and enzyme concentration for beta-galactosidase digestion for maximal release of terminal Gal residues from rIgG.
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Affiliation(s)
- T S Raju
- Analytical Chemistry, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA.
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17
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Abstract
Male Wistar rats were given ethanediol (9.4 g/l), 2-ethoxyethylacetate (5.4 g/l), 2-butoxyethylacetate (2.9 g/l) and 1,2-propanediol (40 g/l) respectively in their drinking water for 2 weeks. Urine was collected during the last 24 h of the exposure. There was a marked increase in the oxalic acid excretion by the rats given ethanediol while rats given the alkoxyacetates excreted large amounts of ethoxyacetic and butoxyacetic acid, respectively. While not increased compared with controls, the excretion of oxalic acid by the latter group of rats was correlated to the excretion of the respective alkoxyacetic acids. The ammonia and glycosaminoglycan excretion was also smaller than that of controls. The urinary activity of succinate dehydrogenase was decreased in rats given the alkoxyacetates but not in animals exposed to ethanediol or propanediol. The data show that oxalic acid is actually a minor metabolite of the alkoxyacetates while the biochemical effects in kidney are associated more with the alkoxyacetic acid load. Alkoxyacetic acids seem to be inhibitors of renal succinate dehydrogenase, which may account for the decreased ammonia and glycosaminoglycan excretion.
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Affiliation(s)
- J Liesivuori
- University of Kuopio, Department of Pharmacology and Toxicology, Finland.
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18
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Kerger BD, Richter RO, Chute SM, Dodge DG, Overman SK, Liang J, Finley BL, Paustenbach DJ. Refined exposure assessment for ingestion of tapwater contaminated with hexavalent chromium: consideration of exogenous and endogenous reducing agents. JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 1996; 6:163-79. [PMID: 8792295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Laboratory studies were conducted to determine how rapidly and completely chromium (VI) [Cr(VI)] is reduced upon contact with common beverages mixed with tapwater. Studies were performed for five common beverages (coffee, tea, orange juice, Kool Aid, and powdered lemonade) spiked with either 10 or 50 mg Cr(VI)/l. The concentrations of Cr(VI) were measured at several time intervals for up to four hours. It was demonstrated that each of these beverages had the capacity to reduce a concentration of > or = 8 mg Cr(VI)/l within a 15-minute time frame, and that continued monitoring of the beverages revealed greater reduction of the Cr(VI). These findings are consistent with the observation that many foods and beverages, as well as endogenous body fluids such as saliva and gastric juices, are capable of reducing substantial quantities of Cr(VI) to Cr(III). Our exposure assessment shows that the estimated high-end ingested dose of Cr(VI) from tapwater at both 1 and 5 mg Cr(VI)/l is generally two to three orders of magnitude below doses shown to have no adverse health effect in animal studies. When considered in conjunction with studies demonstrating that the reductive capacity of gastric juices may exceed 50 mg Cr(VI) daily, these observations suggest that little or no Cr(VI) is likely to be absorbed orally at a reasonable water concentration of Cr(VI), since tapwater is bright yellow at 5 mg Cr(VI)/l.
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Affiliation(s)
- B D Kerger
- McLaren/Hart-ChemRisk, Irvine, CA 92714, USA
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19
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Abstract
Seven commercial visible-light-cured (VL) dental composite resins were analytically studied for identification of the photo-initiator consisting of photo-sensitizer and reducing agent. Gas-liquid chromatography (GC) was used for the determination of the dilute components extracted from the composite resin. Mass spectroscopy (GC-MS) was used for confirmation of the qualitative data obtained by GC. The results showed that all composite resins examined included camphorquinone (CQ) as a photo-sensitizer. The concentration of CQ in the resin phase, however, ranged from 0.17 to 1.03% w/w. The composite resin with hybrid-sized filler tended to have a higher concentration of CQ than did the micro-filled composite resin. As for the reducing agent, two out of seven brands contained dimethylaminoethyl methacrylate (DMAEMA), and one included dimethyl-p-toluidine (DMPTI). The mixing ratio between CQ and the amine in these three composite resins also varied. Another four brands did not contain either DMAEMA or DMPTI, and would utilize different reducing agents.
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Affiliation(s)
- M Taira
- Department of Dental Materials, School of Dentistry, Hiroshima University, Japan
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