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Koopmann AK, Ehgartner CR, Euchler D, Claros M, Huesing N. Sustainable Tannin Gels for the Efficient Removal of Metal Ions and Organic Dyes. Gels 2023; 9:822. [PMID: 37888395 PMCID: PMC10606356 DOI: 10.3390/gels9100822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023] Open
Abstract
The usage of a highly efficient, low-cost, and sustainable adsorbent material as an industrial wastewater treatment technique is required. Herein, the usage of the novel, fully sustainable tannin-5-(hydroxymethyl)furfural (TH) aerogels, generated via a water-based sol-gel process, as compatible biosorbent materials is presented. In particular, this study focusses on the surface modification of the tannin biosorbent with carboxyl or amino functional groups, which, hence, alters the accessible adsorption sites, resulting in increased adsorption capacity, as well as investigating the optimal pH conditions for the adsorption process. Precisely, highest adsorption capacities are acquired for the metal cations and cationic dye in an alkaline aqueous environment using a carboxyl-functionalized tannin biosorbent, whereas the anionic dye requires an acidic environment using an amino-functionalized tannin biosorbent. Under these determined optimal conditions, the maximum monolayer adsorption capacity of the tannin biosorbent ensues in the following order: Cu2+ > RB > Zn2+ > MO, with 500, 244, 192, 131 mg g-1, respectively, indicating comparable or even superior adsorption capacities compared to conventional activated carbons or silica adsorbents. Thus, these functionalized, fully sustainable, inexpensive tannin biosorbent materials, that feature high porosity and high specific surface areas, are ideal industrial candidates for the versatile adsorption process from contaminated (heavy) metal or dye solutions.
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Affiliation(s)
- Ann-Kathrin Koopmann
- Department of Chemistry and Physics of Materials, Paris Lodron University of Salzburg, 5020 Salzburg, Austria; (A.-K.K.)
- Salzburg Center for Smart Materials, 5020 Salzburg, Austria
| | - Caroline Ramona Ehgartner
- Department of Chemistry and Physics of Materials, Paris Lodron University of Salzburg, 5020 Salzburg, Austria; (A.-K.K.)
- Salzburg Center for Smart Materials, 5020 Salzburg, Austria
| | - Daniel Euchler
- Department of Chemistry and Physics of Materials, Paris Lodron University of Salzburg, 5020 Salzburg, Austria; (A.-K.K.)
| | - Martha Claros
- Escuela de Ingeniería Química, Pontificia Universidad Católica de Valparaíso, Valparaíso 2362854, Chile
| | - Nicola Huesing
- Department of Chemistry and Physics of Materials, Paris Lodron University of Salzburg, 5020 Salzburg, Austria; (A.-K.K.)
- Salzburg Center for Smart Materials, 5020 Salzburg, Austria
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Thiabmak C, Chiewchan N, Devahastin S. Production and characterization of nanofibrillated cellulose gels simultaneously exhibiting thermally stable green color and oil-in-water emulsion stabilizing capability from Centella asiatica. J Food Sci 2023; 88:3036-3048. [PMID: 37248778 DOI: 10.1111/1750-3841.16621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/02/2023] [Accepted: 05/10/2023] [Indexed: 05/31/2023]
Abstract
Nanofibrillated cellulose (NFC) gels simultaneously exhibiting Pickering stabilizing capability and thermally stable green color were developed for use as food additive in thermally processed food emulsion requiring the expression of color. Chopped Centella asiatica plant was mixed with zinc amino acid chelate solution and subject to autoclaving at 130°C for 2 h to form zinc-chlorophylls complex and to remove noncellulosic components. Autoclaved sample was high-shear homogenized at 26,000 rpm for 15 min and microfluidized at either 80, 120, or 160 MPa for 5 passes. An increase in microfluidization pressure resulted in a decrease in NFC diameters; microfluidization at 160 MPa did not nevertheless yield any further reduction in the diameters when compared with that at 120 MPa. From energy consumption point of view, microfluidization at 120 MPa for 5 passes was then noted as optimal condition for preparation of NFC coloring gel; NFC with diameters of 8-42 nm and crystallinity index of 35% was obtained. Freshly prepared gel exhibited gel-like behavior and dark green color. Heating at 121°C for 1 h did not affect diameters, viscoelasticity, and color of the gel. Addition of the gel at 0.9% or 1.2% (w/w) into soybean oil-in-water emulsion, in combination with high-shear homogenization at 18,000 rpm for 5 min, resulted in adequate emulsion stability. The emulsion exhibited stable dark green color and no phase separation after heating at 121°C for 1 h and during storage for 8 weeks. PRACTICAL APPLICATIONS: Information presented here can serve as a guideline for further development of a multifunctional food ingredient exhibiting thermally stable green color and oil-in-water emulsion stabilizing capability. In other words, one simple ingredient can serve at the same time as both natural food colorant and emulsion stabilizer.
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Affiliation(s)
- Chompunutch Thiabmak
- Advanced Food Processing Research Laboratory, Department of Food Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Naphaporn Chiewchan
- Advanced Food Processing Research Laboratory, Department of Food Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Sakamon Devahastin
- Advanced Food Processing Research Laboratory, Department of Food Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
- The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
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Anderson AJ, Hortin JM, Jacobson AR, Britt DW, McLean JE. Changes in Metal-Chelating Metabolites Induced by Drought and a Root Microbiome in Wheat. Plants (Basel) 2023; 12:1209. [PMID: 36986899 PMCID: PMC10055107 DOI: 10.3390/plants12061209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
The essential metals Cu, Zn, and Fe are involved in many activities required for normal and stress responses in plants and their microbiomes. This paper focuses on how drought and microbial root colonization influence shoot and rhizosphere metabolites with metal-chelation properties. Wheat seedlings, with and without a pseudomonad microbiome, were grown with normal watering or under water-deficit conditions. At harvest, metal-chelating metabolites (amino acids, low molecular weight organic acids (LMWOAs), phenolic acids, and the wheat siderophore) were assessed in shoots and rhizosphere solutions. Shoots accumulated amino acids with drought, but metabolites changed little due to microbial colonization, whereas the active microbiome generally reduced the metabolites in the rhizosphere solutions, a possible factor in the biocontrol of pathogen growth. Geochemical modeling with the rhizosphere metabolites predicted Fe formed Fe-Ca-gluconates, Zn was mainly present as ions, and Cu was chelated with the siderophore 2'-deoxymugineic acid, LMWOAs, and amino acids. Thus, changes in shoot and rhizosphere metabolites caused by drought and microbial root colonization have potential impacts on plant vigor and metal bioavailability.
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Affiliation(s)
- Anne J. Anderson
- Department of Biological Engineering, Utah State University, Logan, UT 84322, USA
| | - Joshua M. Hortin
- Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, Logan, UT 84322, USA
| | - Astrid R. Jacobson
- Department of Plants, Soils, and Climate, Utah State University, Logan, UT 84322, USA
| | - David W. Britt
- Department of Biological Engineering, Utah State University, Logan, UT 84322, USA
| | - Joan E. McLean
- Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, Logan, UT 84322, USA
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Aranaz J, de Hita D, Olaetxea M, Urrutia O, Fuentes M, Baigorri R, Garnica M, Movila M, Zamarreño AM, Erro J, Baquero E, Gonzalez-Gaitano G, Alvarez JI, Garcia-Mina JM. The molecular conformation, but not disaggregation, of humic acid in water solution plays a crucial role in promoting plant development in the natural environment. Front Plant Sci 2023; 14:1180688. [PMID: 37206971 PMCID: PMC10190593 DOI: 10.3389/fpls.2023.1180688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/11/2023] [Indexed: 05/21/2023]
Abstract
Many studies have shown the capacity of soil humic substances (HS) to improve plant growth in natural ecosystems. This effect involves the activation of different processes within the plant at different coordinated molecular, biochemical, and physiological levels. However, the first event triggered by plant root-HS interaction remains unclear. Some studies suggest the hypothesis that the interaction of HS with root exudates involves relevant modification of the molecular conformation of humic self-assembled aggregates, including disaggregation, which might be directly involved in the activation of root responses. To investigate this hypothesis, we have prepared two humic acids. A natural humic acid (HA) and a transformed humic acid obtained from the treatment of HA with fungal laccase (HA enz). We have tested the capacity of the two humic acids to affect plant growth (cucumber and Arabidopsis) and complex Cu. Laccase-treatment did not change the molecular size but increased hydrophobicity, molecular compactness and stability, and rigidity of HA enz. Laccase-treatment avoided the ability of HA to promote shoot- and root-growth in cucumber and Arabidopsis. However, it does not modify Cu complexation features. There is no molecular disaggregation upon the interaction of HA and HA enz with plant roots. The results indicate that the interaction with plant roots induced in both HA and laccase-treated HA (HA enz), changes in their structural features that showed higher compactness and rigidity. These events might result from the interaction of HA and HA enz with specific root exudates that can promote intermolecular crosslinking. In summary, the results indicate that the weakly bond stabilized aggregated conformation (supramolecular-like) of HA plays a crucial role in its ability to promote root and shoot growth. The results also indicate the presence of two main types of HS in the rhizosphere corresponding to those non-interacting with plant roots (forming aggregated molecular assemblies) and those produced after interacting with plant root exudates (forming stable macromolecules).
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Affiliation(s)
- Javier Aranaz
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - David de Hita
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Maite Olaetxea
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Oscar Urrutia
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Marta Fuentes
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Roberto Baigorri
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Maria Garnica
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Maria Movila
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Angel M. Zamarreño
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Javier Erro
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | - Enrique Baquero
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
| | | | - Jose Ignacio Alvarez
- Department of Chemistry, Faculty of Sciences, University of Navarra, Pamplona, Spain
| | - Jose M. Garcia-Mina
- Institute for Biodiversity and Environment BIOMA, University of Navarra, Pamplona, Spain
- *Correspondence: Jose M. Garcia-Mina,
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Boiteau RM, Repeta DJ. Slow Kinetics of Iron Binding to Marine Ligands in Seawater Measured by Isotope Exchange Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry. Environ Sci Technol 2022; 56:3770-3779. [PMID: 35213147 DOI: 10.1021/acs.est.1c06922] [Citation(s) in RCA: 4] [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] [Indexed: 06/14/2023]
Abstract
Current understanding of dissolved iron (Fe) speciation in the ocean is based on two fundamentally different approaches: electrochemical methods that measure bulk properties of a heterogeneous ligand pool and liquid chromatography mass spectrometry methods that characterize ligands at a molecular level. Here, we describe a method for simultaneously determining Fe-ligand dissociation rate constants (kd) of suites of naturally occurring ligands in seawater by monitoring the exchange of ligand-bound 56Fe with 57Fe using liquid chromatography-inductively coupled mass spectrometry. Values of kd were determined for solutions of ferrichrome and ferrioxamine E. In seawater, the dissociation rate constant of ferrichrome (kd = 10 × 10-8 s-1) was greater than that of ferrioxamine E (kd = 3.6 × 10-8 s-1). The rates for both compounds were over twice as fast in seawater compared with pure water, suggesting that seawater salts accelerate dissociation. Isotope exchange experiments on organic extracts of natural seawater indicated that ligand-binding sites associated with chromatographically unresolved dissolved organic matter exchanged Fe more quickly (kd = 1.8 × 10-5 s-1) than amphibactin siderophores (kd = 2.15 × 10-6 s-1) and an unidentified siderophore with m/z 709 (kd = 9.6 × 10-6 s-1). These findings demonstrate that our approach can bridge molecular-level ligand identification with kinetic and thermodynamic metal-binding properties.
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Affiliation(s)
- Rene M Boiteau
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97330, United States
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Daniel J Repeta
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States
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Fenger JA, Sigurdson GT, Robbins RJ, Collins TM, Giusti MM, Dangles O. Acylated Anthocyanins from Red Cabbage and Purple Sweet Potato Can Bind Metal Ions and Produce Stable Blue Colors. Int J Mol Sci 2021; 22:4551. [PMID: 33925312 DOI: 10.3390/ijms22094551] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 01/02/2023] Open
Abstract
Red cabbage (RC) and purple sweet potato (PSP) are naturally rich in acylated cyanidin glycosides that can bind metal ions and develop intramolecular π-stacking interactions between the cyanidin chromophore and the phenolic acyl residues. In this work, a large set of RC and PSP anthocyanins was investigated for its coloring properties in the presence of iron and aluminum ions. Although relatively modest, the structural differences between RC and PSP anthocyanins, i.e., the acylation site at the external glucose of the sophorosyl moiety (C2-OH for RC vs. C6-OH for PSP) and the presence of coordinating acyl groups (caffeoyl) in PSP anthocyanins only, made a large difference in the color expressed by their metal complexes. For instance, the Al3+-induced bathochromic shifts for RC anthocyanins reached ca. 50 nm at pH 6 and pH 7, vs. at best ca. 20 nm for PSP anthocyanins. With Fe2+ (quickly oxidized to Fe3+ in the complexes), the bathochromic shifts for RC anthocyanins were higher, i.e., up to ca. 90 nm at pH 7 and 110 nm at pH 5.7. A kinetic analysis at different metal/ligand molar ratios combined with an investigation by high-resolution mass spectrometry suggested the formation of metal–anthocyanin complexes of 1:1, 1:2, and 1:3 stoichiometries. Contrary to predictions based on steric hindrance, acylation by noncoordinating acyl residues favored metal binding and resulted in complexes having much higher molar absorption coefficients. Moreover, the competition between metal binding and water addition to the free ligands (leading to colorless forms) was less severe, although very dependent on the acylation site(s). Overall, anthocyanins from purple sweet potato, and even more from red cabbage, have a strong potential for development as food colorants expressing red to blue hues depending on pH and metal ion.
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Azizov S, Sharipov M, Lim JM, Tawfik SM, Kattaev N, Lee YI. Solvent-resistant microfluidic paper-based analytical device/spray mass spectrometry for quantitative analysis of C 18 -ceramide biomarker. J Mass Spectrom 2021; 56:e4611. [PMID: 32789982 DOI: 10.1002/jms.4611] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/28/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
We developed a highly efficient and low-cost organic solvents-resistant microfluidic paper-based analytical device (μPAD) coupled with paper spray mass spectrometry (PS-MS) for quantitative determination of C18 -ceramide as a prognostic biomarker for several diseases. Several models of μPAD patterns have been examined to select the most resistant and efficient microchannel barriers, which can provide continuous spray at ionization zone and prevent "coffee ring" effect. Moreover, the developed μPAD has enabled the analysis of low concentration of C18 -ceramide because of the maximum supply of deposited analyte through microchannel. The MS results confirmed the formation of doubly and singly charged metal ion complexes between ceramide and different metal ions. Notably, the complexation that occurs between lithium ions and C18 -ceramide showed a high relative abundance compared with other formed complexes. Taking into account the relative abundance of complex [Cer + Li]+ at 572.8 m/z, it can be considered as a stable ion and therefore be used for the analysis of C18 -ceramide at low concentrations. Complexation of C18 -ceramide and lithium confirmed with quantum chemical calculations. The proposed method represents good linearity with a regression coefficient of 0.9956 for the analysis of C18 -ceramide and reaches a limit of detection to 0.84 nM. It has been adapted successfully for practical application in human serum samples with high recovery values in range of 92%-105%. The developed μPAD-MS technique provides clear advantages by reducing the experimental steps and simplifying the operation process and enables to identify subnanomolar concentration of C18 -ceramide in human serum samples.
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Affiliation(s)
- Shavkatjon Azizov
- Department of Chemistry, Changwon National University, Changwon, 51140, Republic of Korea
| | - Mirkomil Sharipov
- Department of Chemistry, Changwon National University, Changwon, 51140, Republic of Korea
| | - Jae-Min Lim
- Department of Chemistry, Changwon National University, Changwon, 51140, Republic of Korea
| | - Salah M Tawfik
- Department of Chemistry, Changwon National University, Changwon, 51140, Republic of Korea
| | - Nuritdin Kattaev
- Department of Chemistry, National University of Uzbekistan, Tashkent, 100174, Uzbekistan
| | - Yong-Ill Lee
- Department of Chemistry, Changwon National University, Changwon, 51140, Republic of Korea
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Bai Y, Liu X, Shi SQ, Li J. A Tough and Mildew-Proof Soybean-Based Adhesive Inspired by Mussel and Algae. Polymers (Basel) 2020; 12:E756. [PMID: 32244366 PMCID: PMC7240608 DOI: 10.3390/polym12040756] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/22/2020] [Accepted: 03/26/2020] [Indexed: 11/16/2022] Open
Abstract
Despite the recent advances in protein-based adhesives, achieving strong adhesion and mold resistance in wet environment is challenging. Herein, a facile fabrication technology of preparing tough bio-adhesive by incorporating soybean meal and blood meal is presented. Inspired by the marine mussel byssi and brown algae, metal coordination was introduced into a loosely bound protein system to construct multiple chemical cross-linking networks. Mixed alkali-modified blood meal (mBM) was mixed with soybean meal, then 1,6-hexane dioldiglycidyl ether (HDE) and zinc ion were introduced to fabricate soybean meal and blood meal-based adhesives. The attained adhesives exhibited good thermal stability, water resistance (the wet shear strength is 1.1 MPa), and mold resistance, with appropriate solid content (34.3%) and relatively low moisture uptake (11.9%). These outstanding performances would be attributed to the reaction of 1,6-hexane dioldiglycidyl ether with protein to form a preliminary cross-linking network; subsequently, the coordination of zinc ions with amino or carboxyl strengthened and toughened the adhesive. Finally, the calcium ions gelled the adhesives, providing cohesion force and making the network structure more compact. This study realized the value-added utilization of protein co-products and developed a new eco-friendly bio-based adhesive.
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Affiliation(s)
- Yue Bai
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China; (Y.B.); (X.L.)
- Key Laboratory of Wood Materials Science and Utilization, Beijing Forestry University, Beijing 100083, China;
- College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China
| | - Xiaorong Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China; (Y.B.); (X.L.)
- Key Laboratory of Wood Materials Science and Utilization, Beijing Forestry University, Beijing 100083, China;
- College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China
| | - Sheldon Q. Shi
- Key Laboratory of Wood Materials Science and Utilization, Beijing Forestry University, Beijing 100083, China;
- Department of Mechanical and Energy Engineering, University of North Texas, Denton, TX 76203, USA
| | - Jianzhang Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China; (Y.B.); (X.L.)
- Key Laboratory of Wood Materials Science and Utilization, Beijing Forestry University, Beijing 100083, China;
- College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China
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Ozsváth A, Bíró L, Nagy EM, Buglyó P, Sanna D, Farkas E. Trends and Exceptions in the Interaction of Hydroxamic Acid Derivatives of Common Di- and Tripeptides with Some 3d and 4d Metal Ions in Aqueous Solution. Molecules 2019; 24:E3941. [PMID: 31683673 DOI: 10.3390/molecules24213941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 12/12/2022] Open
Abstract
By using various techniques (pH-potentiometry, UV-Visible spectrophotometry, 1H and 17O-NMR, EPR, ESI-MS), first time in the literature, solution equilibrium study has been performed on complexes of dipeptide and tripeptide hydroxamic acids—AlaAlaNHOH, AlaAlaN(Me)OH, AlaGlyGlyNHOH, and AlaGlyGlyN(Me)OH—with 4d metals: the essential Mo(VI) and two half-sandwich type cations, [(η6-p-cym)Ru(H2O)3]2+ as well as [(η5-Cp*)Rh(H2O)3]2+, the latter two having potential importance in cancer therapy. The tripeptide derivatives have also been studied with some biologically important 3d metals, such as Fe(III), Ni(II), Cu(II), and Zn(II), in order to compare these new results with the corresponding previously obtained ones on dipeptide hydroxamic acids. Based on the outcomes, the effects of the type of metal ions, the coordination number, the number and types of donor atoms, and their relative positions to each other on the complexation have been evaluated in the present work. We hope that these collected results might be used when a new peptide-based hydroxamic acid molecule is planned with some purpose, e.g., to develop a potential metalloenzyme inhibitor.
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Radaelli M, Scalabrin E, Toscano G, Capodaglio G. High Performance Size Exclusion Chromatography-Inductively Coupled Plasma-Mass Spectrometry to Study the Copper and Cadmium Complexation with Humic Acids. Molecules 2019; 24:E3201. [PMID: 31484411 DOI: 10.3390/molecules24173201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/30/2019] [Accepted: 09/01/2019] [Indexed: 11/16/2022] Open
Abstract
Dissolved organic matter (DOM) plays an important role in the environment by influencing the transport and distribution of organic and inorganic components through different processes: the retention, mobilization, and bio-availability of potentially toxic elements (PTEs). The aim of the present study is to examine the dimensional characterization of humic acids (HA) extracted from soil matrix, as well as to analyze the metal distribution among different ligand classes. The molecular size distribution of the HA extract from soil showed three dimensional classes: 52 KDa, 4.5 KDa, and 900 Da. HPSEC-ICP-MS measurements demonstrated that the dimensional classes, relative to first two fractions, bind the largest part of metals. The complexing capacity of HA was evaluated to assess the pollutants mobility in the environmental system. In particular, cadmium (Cd) and copper (Cu) complexation was investigated due to the great concern regarding their bio-availability and toxicity in natural waters. The complexing capacity of HA solution (20 mg/L) was measured by titration using a high-performance size exclusion chromatography (HP-SEC) coupled to an inductively coupled mass spectrometry (ICP-MS). Results obtained by this technique are compared with those obtained by anodic stripping voltammetry (ASV) to investigate the effects of kinetic lability of complexes on measurements carried by HPSEC-ICP-MS. In this study, results of ligand concentrations and stability constants obtained via the two techniques are assessed considering the detection window associated to the applied analytical methodology. Results obtained using the two analytical techniques showed that Cd is complexed by two classes of ligands. However, the ligand concentration values obtained using the two techniques are different, because the detection window associated to the two methodologies; the complexing capacity, which was obtained as sum of the two classes of ligands, were 33 nmol/L and 9 nmol/L for ASV and HPSEC-ICP-MS, respectively. The copper complexing capacities determined by the two methodologies are comparable: 166 and 139 nmol/L for ASV and HPSEC-ICP-MS, respectively. However, the results of Cu titration differ for the two techniques, highlighting only one class of ligands when ASV was used, and two classes when HPSEC-ICP-MS was employed. Differences on results obtained by the two techniques are explained considering the kinetic lability of complexes; the results show that, differently from previous studies, also Cu complexes can be kinetically labile, if one technique with high reaction time is used, as well some cadmium complexes are sufficient stable to be determined by HPSEC-ICP-MS.
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Nakai A, Kim J, Kim D, Osuka A. 5,20-Bis(ethoxycarbonyl)-Substituted Antiaromatic [28]Hexaphyrin and Its Bis-Ni II and Bis-Cu II Complexes. Chem Asian J 2019; 14:968-971. [PMID: 30793503 DOI: 10.1002/asia.201900189] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Indexed: 11/11/2022]
Abstract
5,20-Bis(ethoxycarbonyl)-[28]hexaphyrin was synthesized by acid catalyzed cross-condensation of meso-diaryl-substituted tripyrrane and ethyl 2-oxoacetate followed by subsequent oxidation. This hexaphyrin was found to be a stable 28π-antiaromatic compound with a dumbbell-like conformation. Upon oxidization with PbO2 , this [28]hexaphyrin was converted into an aromatic [26]hexaphyrin with a rectangular shape bearing two ester groups at the edge side. The [28]hexaphyrin can incorporate two NiII or CuII metals by using the ester carbonyl groups and three pyrrolic nitrogen atoms to give bis-NiII and bis-CuII complexes with essentially the same dumbbell-like structure. The antiaromatic properties of the [28]hexaphyrin and its metal complexes have been well characterized.
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Affiliation(s)
- Akito Nakai
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Jinseok Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea
| | - Dongho Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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Ciotta E, Prosposito P, Tagliatesta P, Lorecchio C, Stella L, Kaciulis S, Soltani P, Placidi E, Pizzoferrato R. Discriminating between Different Heavy Metal Ions with Fullerene-Derived Nanoparticles. Sensors (Basel) 2018; 18:E1496. [PMID: 29747464 DOI: 10.3390/s18051496] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 01/04/2023]
Abstract
A novel type of graphene-like nanoparticle, synthesized by oxidation and unfolding of C60 buckminsterfullerene fullerene, showed multiple and reproducible sensitivity to Cu2+, Pb2+, Cd2+, and As(III) through different degrees of fluorescence quenching or, in the case of Cd2+, through a remarkable fluorescence enhancement. Most importantly, only for Cu2+ and Pb2+, the fluorescence intensity variations came with distinct modifications of the optical absorption spectrum. Time-resolved fluorescence study confirmed that the common origin of these diverse behaviors lies in complexation of the metal ions by fullerene-derived carbon layers, even though further studies are required for a complete explanation of the involved processes. Nonetheless, the different response of fluorescence and optical absorbance towards distinct cationic species makes it possible to discriminate between the presence of Cu2+, Pb2+, Cd2+, and As(III), through two simple optical measurements. To this end, the use of a three-dimensional calibration plot is discussed. This property makes fullerene-derived nanoparticles a promising material in view of the implementation of a selective, colorimetric/fluorescent detection system.
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Abstract
This study was focused on the description of interaction between Cu2+ ions and the 1:1 mono- and dirhamnolipid mixtures in the premicellar and aggregated state in water and 20 mM KCl solution at pH 5.5 and 6.0. The critical micelle concentration of biosurfactants was determined conductometrically and by the pH measurements. Hydrodynamic diameter and electrophoretic mobility were determined in micellar solutions using dynamic light scattering and laser Doppler electrophoresis, respectively. The copper immobilization by rhamnolipids, methylglycinediacetic acid (MGDA), and ethylenediaminetetraacetic acid (EDTA) was estimated potentiometrically for the Cu2+ to chelating agent molar ratio from 16:100 to 200:100. The degree of ion binding and the complex stability constant were calculated at a 1:1 metal to chelant molar ratio. The aggregates of rhamnolipids (diameter of 43-89 nm) were negatively charged. Biosurfactants revealed the best chelating activities in premicellar solutions. For all chelants studied the degree of metal binding decreased with the increasing concentration of the systems. The presence of K⁺ lowered Cu2+ binding by rhamnolipids, but did not modify the complex stability significantly. Immobilization of Cu2+ by biosurfactants did not cause such an increase of acidification as that observed in MGDA and EDTA solutions. Rhamnolipids, even in the aggregated form, can be an alternative for the classic chelating agents.
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Affiliation(s)
- Jolanta Cieśla
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Magdalena Koczańska
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Andrzej Bieganowski
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
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14
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Joo Y, Brady GJ, Kanimozhi C, Ko J, Shea MJ, Strand MT, Arnold MS, Gopalan P. Polymer-Free Electronic-Grade Aligned Semiconducting Carbon Nanotube Array. ACS Appl Mater Interfaces 2017; 9:28859-28867. [PMID: 28758721 DOI: 10.1021/acsami.7b06850] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Conjugated polymers are used commonly to selectively sort semiconducting carbon nanotubes (S-CNTs) from their metallic counterparts in organic solvents. The polymer-wrapped S-CNTs can be easily processed from organic solvents into arrays of CNTs for scalable device fabrication. Though the conjugated polymers are essential for sorting and device fabrication, it is highly desirable to remove them completely as they limit the electronic properties of the device. Here, we use a commercially available polymer, namely, poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(6,6'-(2,2'-bipyridine))] (PFO-BPy), to sort large-diameter S-CNTs with ultrahigh selectivity and fabricate CNT-array-based field effect transistors (FETs) via a floating evaporative self-assembly (FESA) process. We report quantitative removal of the polymer wrapper from the FESA aligned S-CNT arrays using a metal-chelation-assisted polymer removal (McAPR) process. The implementation of this process on FESA films requires the selective thermal degradation of the polymer into oligomers, combined with optimization of the solvent type and temperature of the metal complexation reaction. Resulting S-CNT array FET devices show that the electronic properties of pristine CNT are preserved through this process. Optical microscopy, UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) were used to characterize the quantitative polymer removal. We quantitatively describe the FET devices to analyze the fundamental characteristics of FETs (mobility (μ), on-conductance (Gon), and contact resistance (2Rc)) by comparing before and after polymer removal. The ability to completely remove the polymer wrapper in aligned CNT arrays without adversely affecting the device properties opens up applications beyond FETs into photovoltaics and biosensing.
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Affiliation(s)
- Yongho Joo
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Gerald J Brady
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Catherine Kanimozhi
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Jaehyoung Ko
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Matthew J Shea
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Michael T Strand
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Michael S Arnold
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Padma Gopalan
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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15
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Vallverdú-Queralt A, Biler M, Meudec E, Guernevé CL, Vernhet A, Mazauric JP, Legras JL, Loonis M, Trouillas P, Cheynier V, Dangles O. p-Hydroxyphenyl-pyranoanthocyanins: An Experimental and Theoretical Investigation of Their Acid-Base Properties and Molecular Interactions. Int J Mol Sci 2016; 17:ijms17111842. [PMID: 27827954 PMCID: PMC5133842 DOI: 10.3390/ijms17111842] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [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: 09/26/2016] [Revised: 10/27/2016] [Accepted: 10/31/2016] [Indexed: 11/26/2022] Open
Abstract
The physicochemical properties of the wine pigments catechyl-pyranomalvidin-3-O-glucoside (PA1) and guaiacyl-pyranomalvidin-3-O-glucoside (PA2) are extensively revisited using ultraviolet (UV)-visible spectroscopy, dynamic light scattering (DLS) and quantum chemistry density functional theory (DFT) calculations. In mildly acidic aqueous solution, each cationic pigment undergoes regioselective deprotonation to form a single neutral quinonoid base and water addition appears negligible. Above pH = 4, both PA1 and PA2 become prone to aggregation, which is manifested by the slow build-up of broad absorption bands at longer wavelengths (λ ≥ 600 nm), followed in the case of PA2 by precipitation. Some phenolic copigments are able to inhibit aggregation of pyranoanthocyanins (PAs), although at large copigment/PA molar ratios. Thus, chlorogenic acid can dissociate PA1 aggregates while catechin is inactive. With PA2, both chlorogenic acid and catechin are able to prevent precipitation but not self-association. Calculations confirmed that the noncovalent dimerization of PAs is stronger with the neutral base than with the cation and also stronger than π–π stacking of PAs to chlorogenic acid (copigmentation). For each type of complex, the most stable conformation could be obtained. Finally, PA1 can also bind hard metal ions such as Al3+ and Fe3+ and the corresponding chelates are less prone to self-association.
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Affiliation(s)
- Anna Vallverdú-Queralt
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
- CIBER Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28903 Madrid, Spain.
| | - Michal Biler
- INSERM UMR 850, University of Limoges, School of Pharmacy, 2 rue du Dr. Marcland, F-87025 Limoges, France.
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic.
| | - Emmanuelle Meudec
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
| | - Christine Le Guernevé
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
| | - Aude Vernhet
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
| | - Jean-Paul Mazauric
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
| | - Jean-Luc Legras
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
| | - Michèle Loonis
- INRA, UMR408 SQPOV, University of Avignon, 84000 Avignon, France.
| | - Patrick Trouillas
- INSERM UMR 850, University of Limoges, School of Pharmacy, 2 rue du Dr. Marcland, F-87025 Limoges, France.
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, tř. 17. listopadu 12, 77146 Olomouc, Czech Republic.
| | - Véronique Cheynier
- Institut National de la Recherche Agronomique (INRA), UMR1083 Sciences pour l'œnologie, 2 place Pierre Viala, 34060 Montpellier CEDEX, France.
| | - Olivier Dangles
- INRA, UMR408 SQPOV, University of Avignon, 84000 Avignon, France.
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Boguta P, Pieczywek PM, Sokołowska Z. A Comparative Study of the Application of Fluorescence Excitation-Emission Matrices Combined with Parallel Factor Analysis and Nonnegative Matrix Factorization in the Analysis of Zn Complexation by Humic Acids. Sensors (Basel) 2016; 16:E1760. [PMID: 27782078 DOI: 10.3390/s16101760] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/12/2016] [Accepted: 10/19/2016] [Indexed: 11/17/2022]
Abstract
The main aim of this study was the application of excitation-emission fluorescence matrices (EEMs) combined with two decomposition methods: parallel factor analysis (PARAFAC) and nonnegative matrix factorization (NMF) to study the interaction mechanisms between humic acids (HAs) and Zn(II) over a wide concentration range (0–50 mg·dm−3). The influence of HA properties on Zn(II) complexation was also investigated. Stability constants, quenching degree and complexation capacity were estimated for binding sites found in raw EEM, EEM-PARAFAC and EEM-NMF data using mathematical models. A combination of EEM fluorescence analysis with one of the proposed decomposition methods enabled separation of overlapping binding sites and yielded more accurate calculations of the binding parameters. PARAFAC and NMF processing allowed finding binding sites invisible in a few raw EEM datasets as well as finding totally new maxima attributed to structures of the lowest humification. Decomposed data showed an increase in Zn complexation with an increase in humification, aromaticity and molecular weight of HAs. EEM-PARAFAC analysis also revealed that the most stable compounds were formed by structures containing the highest amounts of nitrogen. The content of oxygen-functional groups did not influence the binding parameters, mainly due to fact of higher competition of metal cation with protons. EEM spectra coupled with NMF and especially PARAFAC processing gave more adequate assessments of interactions as compared to raw EEM data and should be especially recommended for modeling of complexation processes where the fluorescence intensities (FI) changes are weak or where the processes are interfered with by the presence of other fluorophores.
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17
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Sun C, Wang H, Wang Y, Xiao S. Rapid Isolation and Determination of Flavones in Biological Samples Using Zinc Complexation Coupled with High-Performance Liquid Chromatography. Molecules 2016; 21:molecules21081067. [PMID: 27537870 PMCID: PMC6274430 DOI: 10.3390/molecules21081067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 06/16/2016] [Revised: 08/02/2016] [Accepted: 08/09/2016] [Indexed: 01/31/2023] Open
Abstract
Chlorophyll-type contaminants are commonly encountered in the isolation and determination of flavones of plant aerial plant parts. Heme is also a difficult background substance in whole blood analysis. Both chlorophyll and heme are porphyrin type compounds. In this study, a rapid method for isolating flavones with 5-hydroxyl or ortho-hydroxyl groups from biological samples was developed based on the different solubilities of porphyrin-metal and flavone-metal complexes. It is important that other background substances, e.g., proteins and lipids, are also removed from flavones without an additional processing. The recoveries of scutellarin, baicalin, baicalein, wogonoside and wogonin, which are the primary constituents of Scutellaria baicalensis (skullcaps) were 99.65% ± 1.02%, 98.98% ± 0.73%, 99.65% ± 0.03%, 97.59% ± 0.09% and 95.19% ± 0.47%, respectively. As a sample pretreatment procedure, this method was coupled to high-performance liquid chromatography (HPLC) with good separation, sensitivity and linearity and was applied to determine the flavone content in different aerial parts of S. baicalensis and in dried blood spot samples.
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Affiliation(s)
- Chenghe Sun
- Institute of Special Wild Animals and Plants, Chinese Academy of Agricultural Science, Changchun 130122, China.
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China.
| | - Hecheng Wang
- Institute of Special Wild Animals and Plants, Chinese Academy of Agricultural Science, Changchun 130122, China.
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China.
| | - Yingping Wang
- Institute of Special Wild Animals and Plants, Chinese Academy of Agricultural Science, Changchun 130122, China.
| | - Shengyuan Xiao
- Institute of Special Wild Animals and Plants, Chinese Academy of Agricultural Science, Changchun 130122, China.
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China.
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18
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Butler M, Cabrera GM. A mass spectrometry-based method for differentiation of positional isomers of monosubstituted pyrazine N-oxides using metal ion complexes. J Mass Spectrom 2015; 50:136-144. [PMID: 25601685 DOI: 10.1002/jms.3506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 05/19/2014] [Revised: 09/05/2014] [Accepted: 09/10/2014] [Indexed: 06/04/2023]
Abstract
A series of 11 pairs of substituted pyrazine N-oxides, differing in the substituent position, were examined using electrospray ionization mass spectrometry (ESI-MS) in order to use spectra to assess the differentiation of positional isomers. For each compound, mass spectra were recorded with three different metal cations, namely calcium (II), copper (II) and aluminum (III), with characterization of the observed peaks. Differentiation between regioisomeric N-oxides has been achieved by comparison of the identity and relative intensities of the peaks originating from the adduct ions formed with the metal ions. Principal component analysis (PCA) has been employed to assist in the interpretation of the results obtained with each metal ion, exploring possible trends according to the nature and position of the substituent in the pyrazine N-oxide.
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Affiliation(s)
- Matías Butler
- Departamento de Química Orgánica, UMyMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
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Rossow T, Bayer S, Albrecht R, Tzschucke CC, Seiffert S. Supramolecular hydrogel capsules based on PEG: a step toward degradable biomaterials with rational design. Macromol Rapid Commun 2013; 34:1401-7. [PMID: 23929582 DOI: 10.1002/marc.201300353] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 07/04/2013] [Indexed: 01/23/2023]
Abstract
Supramolecular microgel capsules based on polyethylene glycol (PEG) are a promising class of soft particulate scaffolds with tailored properties. An approach to fabricate such particles with exquisite control by droplet-based microfluidics is presented. Linear PEG precursor polymers that carry bipyridine moieties on both chain termini are gelled by complexation to iron(II) ions. To investigate the biocompatibility of the microgels, living mammalian cells are encapsulated within them. The microgel elasticity is controlled by using PEG precursors of different molecular weights at different concentrations and the influence of these parameters on the cell viabilities, which can be optimized to exceed 90% is studied. Reversion of the supramolecular polymer cross-linking allows the microcapsules to be degraded at mild conditions with no effect on the viability of the encapsulated and released cells.
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Affiliation(s)
- Torsten Rossow
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, Berlin, D-14195, Germany
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Robotham SA, Brodbelt JS. Identification of flavone glucuronide isomers by metal complexation and tandem mass spectrometry: regioselectivity of uridine 5'-diphosphate-glucuronosyltransferase isozymes in the biotransformation of flavones. J Agric Food Chem 2013; 61:1457-63. [PMID: 23362992 PMCID: PMC3578006 DOI: 10.1021/jf304853j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Flavone glucuronide isomers of five flavones (chrysin, apigenin, luteolin, baicalein, and scutellarein) were differentiated by collision-induced dissociation of [Co(II) (flavone-H) (4,7-diphenyl-1,10-phenanthroline)(2)](+) complexes. The complexes were generated via postcolumn addition of a metal-ligand solution after separation of the glucuronide products generated upon incubation of each flavone with an array of uridine 5'-diphosphate (UDP)-glucuronosyltransferase (UGT) isozymes. Elucidation of the glucuronide isomers allowed a systematic investigation of the regioselectivity of 12 human UGT isozymes, including 8 UGT1A and 4 UGT2B isozymes. Glucuronidation of the 7-OH position was the preferred site for all the flavones except for luteolin, which possessed adjacent hydroxyl groups on the B ring. For all flavones and UGT isozymes, glucuronidation of the 5-OH position was never observed. As confirmed by the metal complexation/MS/MS strategy, glucuronidation of the 6-OH position only occurred for baicalein and scutellarein when incubated with three of the UGT isozymes.
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Carbonaro RF, Atalay YB, Di Toro DM. Linear Free Energy Relationships for Metal-Ligand Complexation: Bidentate Binding to Negatively-Charged Oxygen Donor Atoms. Geochim Cosmochim Acta 2011; 75:2499-2511. [PMID: 21833149 PMCID: PMC3151533 DOI: 10.1016/j.gca.2011.02.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Stability constants for metal complexation to bidentate ligands containing negatively-charged oxygen donor atoms can be estimated from the following linear free energy relationship (LFER): log K(ML) = χ(OO)(α(O) log K(HL,1) + α(O) log K(HL,2)) where K(ML) is the metal-ligand stability constant for a 1:1 complex, K(HL,1) and K(HL,2) are the proton-ligand stability constants (the ligand pK(a) values), and α(O) is the Irving-Rossotti slope. The parameter χ(OO) is metal specific and has slightly different values for 5 and 6 membered chelate rings. LFERs are presented for 21 different metal ions and are accurate to within approximately 0.30 log units in predictions of log K(ML) values. Ligands selected for use in LFER development include dicarboxylic acids, carboxyphenols, and ortho-diphenols. For ortho-hydroxybenzaldehydes, α-hydroxycarboxylic acids, and α-ketocarboxylic acids, a modification of the LFER where log K(HL,2) is set equal to zero is required. The chemical interpretation of χ(OO) is that it accounts for the extra stability afforded to metal complexes by the chelate effect. Cu-NOM binding constants calculated from the bidentate LFERs are similar in magnitude to those used in WHAM 6. This LFER can be used to make log K(ML) predictions for small organic molecules. Since natural organic matter (NOM) contains many of the same functional groups (i.e. carboxylic acids, phenols, alcohols), the LFER log K(ML) predictions shed light on the range of appropriate values for use in modeling metal partitioning in natural systems.
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Affiliation(s)
- Richard F. Carbonaro
- Department of Civil & Environmental Engineering, Manhattan College, Riverdale, NY 10471
- Corresponding author:
| | - Yasemin B. Atalay
- Department of Civil & Environmental Engineering, University of Delaware, Newark DE 19716
| | - Dominic M. Di Toro
- Department of Civil & Environmental Engineering, University of Delaware, Newark DE 19716
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Hauck M, Jürgens SR, Willenbruch K, Huneck S, Leuschner C. Dissociation and metal-binding characteristics of yellow lichen substances suggest a relationship with site preferences of lichens. Ann Bot 2009; 103:13-22. [PMID: 18977765 PMCID: PMC2707280 DOI: 10.1093/aob/mcn202] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Many species of lichen-forming fungi contain yellow or orange extracellular pigments belonging to the dibenzofurans (usnic acid), anthraquinones (e.g. parietin) or pulvinic acid group. These pigments are all equally efficient light screens, leading us to question the potential ecological and evolutionary significance of diversity in yellow and orange lichen substances. Here the hypothesis is tested that the different pigments differ in metal-binding characteristics, which suggest that they may contribute to adaptation to sites differing in pH and metal availability. METHODS UV spectroscopy was used to study the dissociation and the pH dependence of the metal-binding behaviour of seven isolated lichen substances in methanol. Metals applied were selected macro- and micro-nutrients (Cu(2+), Fe(2+), Fe(3+), Mg(2+), Mn(2+) and Zn(2+)). KEY RESULTS All the pigments studied are strong to moderate acids with pK(a1) values between 2.8 and 4.5. Metal complexation is common in the lichen substances studied. Complexation takes place under acidic conditions with usnic acid, but under alkaline conditions with parietin and most compounds of the pulvinic acid group. The pulvinic acid derivative rhizocarpic acid forms metal complexes both in the acidic and the alkaline range. CONCLUSIONS Metal complexation by lichen substances could be a prerequisite for lichen substance-mediated control of metal uptake. Assuming such an effect at pH values where the affinity of the metal for the lichen substance is intermediate would explain the strong preference of lichens with usnic or rhizocarpic acids to acidic substrata. Moreover, it would explain the preference of lichens with parietin and some lichens with compounds of the pulvinic acid group either for nutrient-rich substrata at low pH or for calcareous substrata.
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Affiliation(s)
- Markus Hauck
- Albrecht von Haller Institute of Plant Sciences, Department of Plant Ecology, University of Göttingen, Untere Karspüle 2, Göttingen, Germany.
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