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Mischnick P, Schleicher S. Potential of ion mobility mass spectrometry in cellulose ether analysis: substitution pattern of hydroxyethyl celluloses. Anal Bioanal Chem 2024:10.1007/s00216-024-05224-w. [PMID: 38436692 DOI: 10.1007/s00216-024-05224-w] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/25/2024] [Accepted: 02/26/2024] [Indexed: 03/05/2024]
Abstract
Ion mobility mass spectrometry (ESI-tims-ToF-MS, syringe pump infusion) has been applied to glucose and oligosaccharide ethers derived from hydroxyethyl-methyl celluloses (HEMC) and hydroxyethyl celluloses (HEC) after permethylation and partial depolymerization: by hydrolysis without or with subsequent reductive amination with m-amino benzoic acid (mABA) or by reductive cleavage. As model compounds without tandem substitution methoxyethylated methylcellulose was used. Regioisomeric glucose ethers were separated according to their ion mobility, and positions of substitution could be assigned. Glucose ethers including isomers with tandem substitution showed additional signals with a smaller collision cross-section (CCS) than core-substituted isomers. Positional isomers of cellobiose ethers were only partly resolved due to too high complexity but showed a characteristic fingerprint that might allow classifying samples. Relative intensities of signals of glucose ether isomers could only be quantified in case of ABA derivatives with its fixed charge, while sodium adducts of methoxyethyl ethers showed an influence of the MeOEt position on ion yield. Results were in very good agreement with reference analysis. [M + Na]+ adducts of α- and β-anomers of glucose derivatives were separated in IM, complicating position assignment. This could be overcome by reductive cleavage of the permethylated HE(M)C yielding 1,5-anhydroglucitol-terminated oligosaccharides, showing the best resolved fingerprints of the cellobiose ethers of a particular cellulose ether. With this first application of ion mobility MS to the analysis of complex cellulose ethers, the promising potential of this additional separation dimension in mass spectrometry is demonstrated and discussed.
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Affiliation(s)
- Petra Mischnick
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
| | - Sarah Schleicher
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany
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Schleicher S, O'Connor G, Mischnick P. Comparing 13C methyl and deuterated methyl isotopic labeling for the quantification of methyl cellulose patterns using mass spectrometry. Anal Bioanal Chem 2023; 415:1817-1828. [PMID: 36867199 PMCID: PMC10050035 DOI: 10.1007/s00216-023-04622-w] [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: 12/22/2022] [Revised: 02/08/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023]
Abstract
The methyl substitution along and among the polymer chains of methyl cellulose (MC) is commonly analyzed by ESI-MS after perdeuteromethylation of the free-OH groups and partial hydrolysis to cello-oligosaccharides (COS). This method requires a correct quantification of the molar ratios of the constituents belonging to a particular degree of polymerization (DP). However, isotopic effects are most pronounced for H/D since their mass difference is 100%. Therefore, we investigated whether more precise and accurate results could be obtained for the methyl distribution of MC by MS of 13CH3 instead of CD3-etherified O-Me-COS. Internal isotope labeling with 13CH3 makes the COS of each DP chemically and physically much more similar, reducing mass fractionation effects, but at the same time requires more complex isotopic correction for evaluation. Results from syringe pump infusion ESI-TOF-MS with 13CH3 and CD3 as isotope label were equal. However, in the case of LC-MS with a gradient system, 13CH3 was superior to CD3. In the case of CD3, the occurrence of a partial separation of the isotopologs of a particular DP resulted in slight distortion of the methyl distribution since the signal response is significantly dependent on the solvent composition. Isocratic LC levels this problem, but one particular eluent-composition is not sufficient for a series of oligosaccharides with increasing DP due to peak broadening. In summary, 13CH3 is more robust to determine the methyl distribution of MCs. Both syringe pump and gradient-LC-MS measurements are possible, and the more complex isotope correction is not a disadvantage.
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Affiliation(s)
- Sarah Schleicher
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
| | - Gavin O'Connor
- Department of Biochemistry, Physikalisch-Technische-Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany
- Department of Biochemistry and Bioinformatics, Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Petra Mischnick
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
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Schleicher S, Horoba D, Krafzig P, Mischnick P. Impact of instrumental settings in electrospray ionization ion trap mass spectrometry on the analysis of O-methoxyethyl-O-methyl cellulose: a comprehensive quantitative evaluation. Anal Bioanal Chem 2022; 414:4727-4743. [PMID: 35501507 PMCID: PMC9174117 DOI: 10.1007/s00216-022-04095-3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 11/26/2022]
Abstract
The hydroxyethyl substitution along and among the polymer chains of respective cellulose ethers (HEC and HEMC) can be analyzed by ESI-IT-MS after permethylation of the free OH-groups, partial hydrolysis, and mABA labeling. This method requires the correct quantification of the molar ratios of the constituents belonging to a particular degree of polymerization (DP) with respect to their numbers of MeOEt and Me groups without any discrimination along the MS analysis pathway. The influence of the chemistry on the ionization and the impact of the voltages controlling the ion transport (Cap Exit, Octopoles) and the ion storage efficiency (Trap Drive, TD) on a relative quantification were studied using binary equimolar mixtures of cellobiose with increasing number of methoxyethyl and decreasing number of methyl groups (Δ m/z 88, 2× MeOEt). No suppression effects were observed in concentration-dependent measurements. Choice of Cap Exit is especially crucial for low m/z with less MeOEt residues. An equation describing the relationship between Oct 2 DC, m/z, and TDmax (TD at maximum intensity) was established from the experimental data and applied to calculate TDmax for higher DPs (larger COS). Optimized conditions allowed to determine the correct molar ratio of binary mixtures. Measurements of overlapping m/z segments and subsequent interrelation of the data gave complete substitution profiles for MeOEt/Me celluloses in accordance with reference data. The study generally makes aware of potential erroneous quantification in ESI-IT-MS analysis using internal standards of similar chemistry or in relative quantification of analytes, even for those with related structures.
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Affiliation(s)
- Sarah Schleicher
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr 20, 38106, Braunschweig, Germany
| | - Dominik Horoba
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr 20, 38106, Braunschweig, Germany
| | - Philip Krafzig
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr 20, 38106, Braunschweig, Germany
| | - Petra Mischnick
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr 20, 38106, Braunschweig, Germany.
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Wandee Y, Uttapap D, Mischnick P, Rungsardthong V. Production of pectic-oligosaccharides from pomelo peel pectin by oxidative degradation with hydrogen peroxide. Food Chem 2021; 348:129078. [PMID: 33515939 DOI: 10.1016/j.foodchem.2021.129078] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 10/02/2019] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 11/17/2022]
Abstract
Oxidative depolymerization of alkali- and acid-extracted pomelo pectins was performed using 1% hydrogen peroxide (H2O2) with a microwave power of 550 W for 10 min. Pectic-oligosaccharides (POS) produced from the acid-extracted methyl-esterified pectin contained higher amounts of DP1 and DP2 than that from the nearly ester-free alkali-extracted pectin, and the loss of these small-size products during recovery resulted in a lower POS yield (25.0%) compared to the alkali-extracted pectin (57.7%). Degradation of the alkali-extracted pectin with 3 and 5% H2O2 led to a decrease in precipitable POS yield. The relative amount of large-sized POS decreased as the H2O2 concentration increased. An increase in the microwave power to 1100 W had no significant effect on overall yield, but the average size shifted to be lower. The results of sugar composition and identification of the degraded products with ESI-MS confirmed the existence of several POS species with different sizes and structures.
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Affiliation(s)
- Yuree Wandee
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand.
| | - Dudsadee Uttapap
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand
| | - Petra Mischnick
- Faculty of Life Sciences, Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr, 20, D-38106 Braunschweig, Germany
| | - Vilai Rungsardthong
- Department of Agro-Industrial Technology, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand
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Nichols BLB, Chen J, Mischnick P, Edgar KJ. Selective Oxidation of 2-Hydroxypropyl Ethers of Cellulose and Dextran: Simple and Efficient Introduction of Versatile Ketone Groups to Polysaccharides. Biomacromolecules 2020; 21:4835-4849. [PMID: 33236636 DOI: 10.1021/acs.biomac.0c01045] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxidation of polysaccharides has been a useful approach to new materials. However, selectivity in oxidation of polysaccharide macromolecular polyols remains a significant challenge with few methods for the synthesis of ketone-substituted polysaccharides. We report here a selective, practical, and efficient process, beginning with 2-hydroxypropyl ethers of polysaccharides that are simple and economical to prepare. We demonstrate this approach herein using commercial 2-hydroxypropyl cellulose (HPC) and 2-hydroxypropyl dextran (HPD) that we prepared. We oxidize the terminal, secondary alcohols of the oligo(2-hydroxypropyl) substituents with sodium hypochlorite so that the product has an oligo(2-hydroxypropyl) side chains terminated by a ketone. We demonstrate the high chemo- and regioselectivity of this oxidation by analytical methods including hydrolysis to monosaccharides and mass spectrometry of the resulting mixture. We provide an initial demonstration of the potential utility of these keto-polysaccharides by reacting Ox-HPC with primary amines to form Schiff base imines, providing proactive polymers.
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Affiliation(s)
- Brittany L B Nichols
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Junyi Chen
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Petra Mischnick
- Institute of Food Chemistry, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Kevin J Edgar
- Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, Virginia 24061, United States.,Macromolecules Innovation Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
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Hashemi P, Mischnick P. 1,4-D-Glucan block copolymers: synthesis and comprehensive structural characterization. Anal Bioanal Chem 2020; 412:1597-1610. [PMID: 31960080 PMCID: PMC7026270 DOI: 10.1007/s00216-020-02388-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/17/2019] [Accepted: 01/03/2020] [Indexed: 11/28/2022]
Abstract
Multi-block glucans comprising permethylated and partially methylated blocks are compounds of interest. In order to monitor their formation by transglycosylation of corresponding starting glucans, a method has been developed and applied to model compounds. This method allows determining the average length of the blocks and the progress of incorporation of methyl blocks in partially methylated sequences with a random distribution. The method, comprising liquid chromatography mass spectrometry (LC-MS) and electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MSn) measurements of two types of peralkylated glucans representing derivatives of the target compounds, is comprehensively described and discussed. ESI-MSn allows looking into the sequences of oligomeric domains. In addition, transglycosylation is followed by attenuated total reflection FTIR and NMR spectroscopy. Graphical abstract ![]()
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Affiliation(s)
- Payam Hashemi
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany
| | - Petra Mischnick
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
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Wandee Y, Uttapap D, Mischnick P. Yield and structural composition of pomelo peel pectins extracted under acidic and alkaline conditions. Food Hydrocoll 2019. [DOI: 10.1016/j.foodhyd.2018.08.017] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Middendorf D, Bindrich U, Mischnick P, Franke K, Heinz V. AFM-based local thermal analysis is a suitable tool to characterize the impact of different grinding techniques on sucrose surface properties. J FOOD ENG 2018. [DOI: 10.1016/j.jfoodeng.2018.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Nagar S, Hensel A, Mischnick P, Kumar V. A unique polysaccharide containing 3- O -methylarabinose and 3- O -methylgalactose from Tinospora sinensis. Carbohydr Polym 2018; 193:326-335. [DOI: 10.1016/j.carbpol.2018.03.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/08/2018] [Accepted: 03/23/2018] [Indexed: 12/20/2022]
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Affiliation(s)
- Qimeng Zhang
- Institute of Food Chemistry; Technische Universität Braunschweig; Schleinitzstr. 20 D-38106 Braunschweig Germany
| | - Petra Mischnick
- Institute of Food Chemistry; Technische Universität Braunschweig; Schleinitzstr. 20 D-38106 Braunschweig Germany
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11
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Zhang Q, Mischnick P. Influence of Stereochemistry on Relative Reactivities of Glucosyl and Mannosyl Residues in Konjac Glucomannan (KGM). MACROMOL CHEM PHYS 2017. [DOI: 10.1002/macp.201700119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Qimeng Zhang
- Technische Universität Braunschweig; Institute of Food Chemistry; Schleinitzstr. 20 38106 Braunschweig Germany
| | - Petra Mischnick
- Technische Universität Braunschweig; Institute of Food Chemistry; Schleinitzstr. 20 38106 Braunschweig Germany
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12
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Hashemi P, Luckau L, Mischnick P, Schmidt S, Stosch R, Wünsch B. Biomacromolecules as tools and objects in nanometrology-current challenges and perspectives. Anal Bioanal Chem 2017; 409:5901-5909. [PMID: 28808731 PMCID: PMC5602082 DOI: 10.1007/s00216-017-0554-9] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/21/2017] [Accepted: 07/31/2017] [Indexed: 11/02/2022]
Abstract
Nucleic acids, proteins, and polysaccharides are the most important classes of biopolymers. The inherent properties of biomacromolecules are contrary to those of well-defined small molecules consequently raising a number of specific challenges which become particularly apparent if biomacromolecules are treated as objects in quantitative analysis. At the same time, their specific functional ability of molecular recognition and self-organization (e.g., enzymes, antibodies, DNA) enables us to make biomacromolecules serving as molecular tools in biochemistry and molecular biology, or as precisely controllable dimensional platforms for nanometrological applications. Given the complexity of biomacromolecules, quantitative analysis is not limited to the measurement of their concentration but also involves the determination of numerous descriptors related to structure, interaction, activity, and function. Among the biomacromolecules, glycans set examples that quantitative characterization is not necessarily directed to the measurement of amount-of-substance concentration but instead involves the determination of relative proportions (molar ratios) of structural features for comparison with theoretical models. This article addresses current activities to combine optical techniques such as Raman spectroscopy with isotope dilution approaches to realize reference measurement procedures for the quantification of protein biomarkers as an alternative to mass spectrometry-based techniques. Furthermore, it is explored how established ID-MS protocols are being modified to make them applicable for quantifying virus proteins to measure the HIV viral load in blood samples. As an example from the class of carbohydrates, the challenges in accurate determination of substitution patterns are outlined and discussed. Finally, it is presented that biomacromolecules can also serve as tools in quantitative measurements of dimensions with an example of DNA origami to generate defined dimensional standards to be used for calibration in super-resolution fluorescence microscopy. Graphical abstract Quantitative analysis of biomacromolecules is accompanied with special challenges different from low molecular weight compounds. In addition, they are not only objects but also tools applicable for quantitative measurements.
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Affiliation(s)
- Payam Hashemi
- Institute for Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany
| | - Luise Luckau
- Metrology in Chemistry, Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany
| | - Petra Mischnick
- Institute for Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
| | - Sarah Schmidt
- Metrology in Chemistry, Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany
| | - Rainer Stosch
- Metrology in Chemistry, Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany
| | - Bettina Wünsch
- Institute for Physical and Theoretical Chemistry, Braunschweig Integrated Centre of Systems Biology (BRICS), and Laboratory for Emerging Nanometrology (LENA), Technische Universität Braunschweig, 38106, Braunschweig, Germany
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Middendorf D, Bindrich U, Mischnick P, Juadjur A, Franke K, Heinz V. Atomic Force Microscopy study on the effect of different lecithins in cocoa-butter based suspensions. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.03.057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Affiliation(s)
- Marko Rother
- Technische Universität Braunschweig; Institute for Food Chemistry; Schleinitzstr. 20 D-38106 Braunschweig Germany
| | - Wolfgang Radke
- Deutsches Kunststoff-Institut; Schlossgartenstr. 6 64289 Darmstadt Germany
| | - Petra Mischnick
- Technische Universität Braunschweig; Institute for Food Chemistry; Schleinitzstr. 20 D-38106 Braunschweig Germany
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Middendorf D, Juadjur A, Bindrich U, Mischnick P. AFM approach to study the function of PGPR's emulsifying properties in cocoa butter based suspensions. Food Structure 2015. [DOI: 10.1016/j.foostr.2014.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Zhang Y, Li J, Lindström ME, Mischnick P. Relative reactivities in the O-methylation of glucomannans: the influence of stereochemistry at C-2 and the solvent effect. Carbohydr Res 2015; 402:172-9. [DOI: 10.1016/j.carres.2014.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/27/2014] [Accepted: 06/06/2014] [Indexed: 11/28/2022]
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Moriana R, Zhang Y, Mischnick P, Li J, Ek M. Thermal degradation behavior and kinetic analysis of spruce glucomannan and its methylated derivatives. Carbohydr Polym 2014; 106:60-70. [DOI: 10.1016/j.carbpol.2014.01.086] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/22/2014] [Accepted: 01/25/2014] [Indexed: 11/30/2022]
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Lak A, Dieckhoff J, Ludwig F, Scholtyssek JM, Goldmann O, Lünsdorf H, Eberbeck D, Kornowski A, Kraken M, Litterst FJ, Fiege K, Mischnick P, Schilling M. Highly stable monodisperse PEGylated iron oxide nanoparticle aqueous suspensions: a nontoxic tracer for homogeneous magnetic bioassays. Nanoscale 2013; 5:11447-11455. [PMID: 24056778 DOI: 10.1039/c3nr02197a] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Uniformly sized and shaped iron oxide nanoparticles with a mean size of 25 nm were synthesized via decomposition of iron-oleate. High resolution transmission electron microscopy and Mössbauer spectroscopy investigations revealed that the particles are spheres primarily composed of Fe3O4 with a small fraction of FeO. From Mössbauer and static magnetization measurements, it was deduced that the particles are superparamagnetic at room temperature. The hydrophobic particles were successfully transferred into water via PEGylation using nitrodopamine as an anchoring group. IR spectroscopy and thermogravimetric analysis showed the success and efficiency of the phase transfer reaction. After PEGylation, the particles retained monodispersity and their magnetic core remained intact as proven by photon cross-correlation spectroscopy, ac susceptibility, and transmission electron microscopy. The particle aqueous suspensions revealed excellent water stability over a month of monitoring and also against temperature up to 40 °C. The particles exhibited a moderate cytotoxic effect on in vitro cultured bone marrow-derived macrophages and no release of inflammatory or anti-inflammatory cytokines. The PEGylated particles were functionalized with Herceptin antibodies via a conjugation chemistry, their response to a rotating magnetic field was studied using a fluxgate-based setup and was compared with the one recorded for hydrophobic and PEGylated particles. The particle phase lag rose after labeling with Herceptin, indicating the successful conjugation of Herceptin antibodies to the particles.
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Affiliation(s)
- Aidin Lak
- TU Braunschweig, Institute of Electrical Measurement and Fundamental Electrical Engineering, Hans-Sommer-St. 66, 38106 Braunschweig, Germany.
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Tahir MN, Cho E, Mischnick P, Lee JY, Yu JH, Jung S. Pentynyl dextran as a support matrix for immobilization of serine protease subtilisin Carlsberg and its use for transesterification of N-acetyl-l-phenylalanine ethyl ester in organic media. Bioprocess Biosyst Eng 2013; 37:687-95. [PMID: 23978850 DOI: 10.1007/s00449-013-1038-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 08/13/2013] [Indexed: 10/26/2022]
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Lämmerhardt N, Merzsch S, Ledig J, Bora A, Waag A, Tornow M, Mischnick P. Toward three-dimensional microelectronic systems: directed self-assembly of silicon microcubes via DNA surface functionalization. Langmuir 2013; 29:8410-8416. [PMID: 23786592 DOI: 10.1021/la401558f] [Citation(s) in RCA: 1] [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: 06/02/2023]
Abstract
The huge and intelligent processing power of three-dimensional (3D) biological "processors" like the human brain with clock speeds of only 0.1 kHz is an extremely fascinating property, which is based on a massively parallel interconnect strategy. Artificial silicon microprocessors are 7 orders of magnitude faster. Nevertheless, they do not show any indication of intelligent processing power, mostly due to their very limited interconnectivity. Massively parallel interconnectivity can only be realized in three dimensions. Three-dimensional artificial processors would therefore be at the root of fabricating artificially intelligent systems. A first step in this direction would be the self-assembly of silicon based building blocks into 3D structures. We report on the self-assembly of such building blocks by molecular recognition, and on the electrical characterization of the formed assemblies. First, planar silicon substrates were functionalized with self-assembling monolayers of 3-aminopropyltrimethoxysilane for coupling of oligonucleotides (single stranded DNA) with glutaric aldehyde. The oligonucleotide immobilization was confirmed and quantified by hybridization with fluorescence-labeled complementary oligonucleotides. After the individual processing steps, the samples were analyzed by contact angle measurements, ellipsometry, atomic force microscopy, and fluorescence microscopy. Patterned DNA-functionalized layers were fabricated by microcontact printing (μCP) and photolithography. Silicon microcubes of 3 μm edge length as model objects for first 3D self-assembly experiments were fabricated out of silicon-on-insulator (SOI) wafers by a combination of reactive ion etching (RIE) and selective wet etching. The microcubes were then surface-functionalized using the same protocol as on planar substrates, and their self-assembly was demonstrated both on patterned silicon surfaces (88% correctly placed cubes), and to cube aggregates by complementary DNA functionalization and hybridization. The yield of formed aggregates was found to be about 44%, with a relative fraction of dimers of some 30%. Finally, the electrical properties of the formed dimers were characterized using probe tips inside a scanning electron microscope.
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Affiliation(s)
- Nico Lämmerhardt
- Institute of Semiconductor Technology, Technische Universität Braunschweig, Hans-Sommer-Straße 66, 38106 Braunschweig, Germany
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Fiege K, Lünsdorf H, Mischnick P. Aminoalkyl functionalization of dextran for coupling of bioactive molecules and nanostructure formation. Carbohydr Polym 2013; 95:569-77. [DOI: 10.1016/j.carbpol.2013.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 02/15/2013] [Accepted: 03/03/2013] [Indexed: 11/15/2022]
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Mischnick P, Unterieser I, Voiges K, Cuers J, Rinken M, Adden R. A New Method for the Analysis of the Substitution Pattern of Hydroxyethyl(methyl)-Celluloses Along the Polysaccharide Chain. MACROMOL CHEM PHYS 2013. [DOI: 10.1002/macp.201300070] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Rühmkorf C, Bork C, Mischnick P, Rübsam H, Becker T, Vogel RF. Identification of Lactobacillus curvatus TMW 1.624 dextransucrase and comparative characterization with Lactobacillus reuteri TMW 1.106 and Lactobacillus animalis TMW 1.971 dextransucrases. Food Microbiol 2013; 34:52-61. [DOI: 10.1016/j.fm.2012.11.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/17/2012] [Accepted: 11/10/2012] [Indexed: 10/27/2022]
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Nazir Tahir M, Riaz-ul Qamar, Mischnick P, Kim J, Jung S. A Rapid Click Chemistry Using Beta-Cyclodextrin Immobilized on Glass Micro-Particles. LETT ORG CHEM 2013. [DOI: 10.2174/1570178611310040008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | | | | | | | - Seunho Jung
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea
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Affiliation(s)
- Daiqiang Xu
- Department of Sustainable
Biomaterials, Macromolecules and Interfaces Institute and Institute for Critical Technologies and Applied
Science, Virginia Tech, 230
Cheatham Hall, Blacksburg, Virginia 24061, United States
| | - Kristin Voiges
- Institute of Food
Chemistry, Technische Universität of Braunschweig, Schleinitzstr 20, 38106 Braunschweig,
Germany
| | - Thomas Elder
- U.S. Forest Service, 2500 Shreveport Highway, Pineville, Louisiana 71360, United States
| | - Petra Mischnick
- Institute of Food
Chemistry, Technische Universität of Braunschweig, Schleinitzstr 20, 38106 Braunschweig,
Germany
| | - Kevin J. Edgar
- Department of Sustainable
Biomaterials, Macromolecules and Interfaces Institute and Institute for Critical Technologies and Applied
Science, Virginia Tech, 230
Cheatham Hall, Blacksburg, Virginia 24061, United States
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Rühmkorf C, Rübsam H, Becker T, Bork C, Voiges K, Mischnick P, Brandt MJ, Vogel RF. Effect of structurally different microbial homoexopolysaccharides on the quality of gluten-free bread. Eur Food Res Technol 2012. [DOI: 10.1007/s00217-012-1746-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pieper S, Unterieser I, Mann F, Mischnick P. A new arabinomannan from the cell wall of the chlorococcal algae Chlorella vulgaris. Carbohydr Res 2012; 352:166-76. [DOI: 10.1016/j.carres.2012.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 11/24/2022]
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Fiege K, Lünsdorf H, Atarijabarzadeh S, Mischnick P. Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles. Beilstein J Org Chem 2012; 8:551-66. [PMID: 22563354 PMCID: PMC3343282 DOI: 10.3762/bjoc.8.63] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 03/23/2012] [Indexed: 02/04/2023] Open
Abstract
Cyanoethylglucans with a degree of substitution in the range of 0.74 to 2.40 for dextran and 0.84 to 2.42 for pullulan were obtained by Michael addition of acrylonitrile to the glucans under various conditions. Products were thoroughly characterized, comprising elementary analysis, NMR and ATR-IR spectroscopy, and analysis of the substituent distribution in the glucosyl units by GC-FID and GC-MS of the constituting monosaccharide derivatives. Nanostructuring of the highly substituted cyanoethylpolysaccharides was performed by dialysis against a non-solvent. In the presence of ferromagnetic iron-oxide nanoparticles, multicore cyanoethylglucan-coated ferromagnetic nanoparticles were formed by selective entrapment. The specific interaction between cyano groups and iron could be proven. The size distribution and morphology of the nanoparticles were analyzed by dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-filtered transmission electron microscopy (EF-TEM) with parallel electron energy loss spectroscopy (PEELS).
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Affiliation(s)
- Kathrin Fiege
- Institute for Food Chemistry, Technische Universität Braunschweig, Schleinitzstraße 20, D-38106 Braunschweig, Germany
| | - Heinrich Lünsdorf
- Department of Vaccinology and Applied Microbiology, EM-Unit, Helmholtz Centre for Infection Research, Inhoffenstraße 7, D-38124 Braunschweig, Germany
| | - Sevil Atarijabarzadeh
- Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-10044 Stockholm, Sweden
| | - Petra Mischnick
- Institute for Food Chemistry, Technische Universität Braunschweig, Schleinitzstraße 20, D-38106 Braunschweig, Germany
- Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-10044 Stockholm, Sweden
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29
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Tahir MN, Lämmerhardt N, Mischnick P. Introduction of various functionalities into polysaccharides using alkynyl ethers as precursors: Pentynyl dextrans. Carbohydr Polym 2012. [DOI: 10.1016/j.carbpol.2011.11.082] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Unterieser I, Cuers J, Voiges K, Enebro J, Mischnick P. Quantitative aspects in electrospray ionization ion trap and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of malto-oligosaccharides. Rapid Commun Mass Spectrom 2011; 25:2201-2208. [PMID: 21710600 DOI: 10.1002/rcm.5105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mass spectrometry is widely applied in carbohydrate analysis, but still quantitative evaluation of data is critical due to different ionization efficiencies of the constituents in a mixture. Different size and chemical structure of the analytes cause their uneven distribution in droplets (electrospray ionization, ESI) or matrix spots (matrix-assisted laser desorption/ionization, MALDI). In addition, instrumental parameters affect final ion yields. In order to study and optimize the latter, an equimolar mixture of malto-oligosaccharides (DP1-6) was analyzed using varying target masses for ESI as well as different matrices and laser power for MALDI. The sodium adducts and derivatives for positive ion mode (hydrazones with Girard's T Reagent, GT) and negative ion mode (reductively aminated with o-aminobenzoic acid, oABA) were studied. Negatively charged oABA-labeled malto-oligosaccharides turned out to be unsuitable for quantification of the malto-oligomeric composition. Best agreement was achieved when applying target masses in the range of the highest homolog in the mixture in electrospray ionization ion trap (ESI-IT) (1-2% deviation with GT label or as Na(+) adducts). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) gave best results when the laser power was adjusted significantly over the desorption/ionization threshold (1% deviation with GT label). Both parameters show significant influence on the determined oligomeric composition. Consequently, estimation and even quantitative determination of amounts of oligosaccharides in a mixture can be achieved when the analytes are labeled and the proper instrumental parameters are used.
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Affiliation(s)
- Inga Unterieser
- Technische Universität Braunschweig, Institut für Lebensmittelchemie, Schleinitzstr. 20, D-38106 Braunschweig, Germany
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31
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Mischnick P. Learning chemistry—the Agnes-Pockels-Student-Laboratory at the Technical University of Braunschweig, Germany. Anal Bioanal Chem 2011; 400:1533-5. [DOI: 10.1007/s00216-011-4914-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Tahir MN, Bork C, Risberg A, Horst JC, Komoß C, Vollmer A, Mischnick P. Alkynyl Ethers of Glucans: Substituent Distribution in Propargyl-, Pentynyl- and Hexynyldextrans and -amyloses and Support for Silver Nanoparticle Formation. MACROMOL CHEM PHYS 2010. [DOI: 10.1002/macp.200900700] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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35
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Tahir MN, Adnan A, Mischnick P. Lipase immobilization on O-propargyl and O-pentynyl dextrans and its application for the synthesis of click beetle pheromones. Process Biochem 2009. [DOI: 10.1016/j.procbio.2009.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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Adden R, Melander C, Brinkmalm G, Knarr M, Engelhardt J, Mischnick P. The Applicability of Enzymes in Cellulose Ether Analysis. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/masy.200950605] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Patel TR, Morris GA, de la Torre JG, Ortega A, Mischnick P, Harding SE. Molecular flexibility of methylcelluloses of differing degree of substitution by combined sedimentation and viscosity analysis. Macromol Biosci 2009; 8:1108-15. [PMID: 18683163 DOI: 10.1002/mabi.200800064] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The flexibility/rigidity of methylcelluloses (MCs) plays an important part in their structure-function relationship and therefore on their commercial applications in the food and biomedical industries. In the present study, two MCs of low degree of substitution (DS) 1.09 and 1.32 and four of high DS (1.80, 1.86, 1.88 and 1.93) were characterised in distilled water in terms of intrinsic viscosity [h]; sedimentation coefficient (s020,w) and weight average molar mass (Mw). Solution conformation and flexibility were estimated qualitatively using conformation zoning and quantitatively (persistence length Lp) using the new combined global method. Sedimentation conformation zoning showed an extended coil (Type C) conformation and the global method applied to each MC sample yielded persistence lengths all within the range Lp(1/4)12-17 nm (for a fixed mass per unit length) with no evidence of any significant change in flexibility with DS.
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Affiliation(s)
- Trushar R Patel
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, UK
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38
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Patel TR, Morris GA, de la Torre JG, Ortega A, Mischnick P, Harding SE. Macromol. Biosci. 12/2008. Macromol Biosci 2008. [DOI: 10.1002/mabi.200890020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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39
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Mischnick P, Adden R. Fractionation of Polysaccharide Derivatives and Subsequent Analysis to Differentiate Heterogeneities on Various Hierarchical Levels. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/masy.200850201] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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41
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Tankam PF, Müller R, Mischnick P, Hopf H. Alkynyl polysaccharides: synthesis of propargyl potato starch followed by subsequent derivatizations. Carbohydr Res 2007; 342:2049-60. [PMID: 17573053 DOI: 10.1016/j.carres.2007.05.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [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: 03/18/2007] [Revised: 05/01/2007] [Accepted: 05/09/2007] [Indexed: 11/24/2022]
Abstract
Potato starch propargyl ethers (PgS) with degrees of substitution (DS) from 0.1 to 2.2 have been prepared by etherification of starch with sodium hydroxide or Li dimsyl in Me(2)SO and propargyl bromide. DS values and substituent distribution were determined after hydrolysis and acetylation by GC-MS. The order of reactivity was 2>6>>3, with O-3 substitution being preferably observed in the trisubstituted units. Repeated analysis of the starch derivatives revealed that propargyl residues were lost during storage, a phenomenon that was not fully understood until now. Selected PgS were further functionalized: (a) O- and C-methylated to O-(2-butynyl)-O-methyl starch (BMS), (b) in a Mannich type reaction with diethylamine and formaldehyde to yield O-(4-diethylamino)-2-butinyl starch (DEABiS), (c) in a 1,3-dipolar cycloaddition with benzyl azide ('click-chemistry') to a N-benzyltriazole derivatized starch (BTrS), and (d) with carbon dioxide to O-(3-carboxy)-2-butinyl starch (CBiS). While the yield of carboxylation was only poor, conversion was high or nearly quantitative for reactions a-c. Thus, it is demonstrated that starch propargyl ethers are valuable intermediates for the preparation of functional polysaccharides.
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Affiliation(s)
- Pascal F Tankam
- Technical University Braunschweig, Institute of Food Chemistry, Schleinitzstr 20, D-38106 Braunschweig, Germany
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Tankam PF, Mischnick P, Hopf H, Jones PG. Modification of methyl O-propargyl-d-glucosides: model studies for the synthesis of alkynyl based functional polysaccharides. Carbohydr Res 2007; 342:2031-48. [PMID: 17553472 DOI: 10.1016/j.carres.2007.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [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: 03/18/2007] [Revised: 05/01/2007] [Accepted: 05/09/2007] [Indexed: 11/22/2022]
Abstract
Methyl 4,6-O-benzylidene-2,3-di-O-propargyl-alpha-D-glucoside (2) has been prepared and its structure determined, including its X-ray structural analysis. For comparison the structure of the corresponding allyl derivative has also been determined by X-ray crystallography. Glucoside 2 is a versatile starting material for numerous novel derivatives such as diols, a diester, a diacid, and a dialdehyde. Subjecting 2 to a Mannich reaction leads to a (bis)amine in excellent yields. The click reaction between 2 and benzyl azide furnishes a (bis)triazole as the main product. Deprotection of 2 furnishes a (bis)propargyl ether, which can be converted by the methodology developed for 2 to the corresponding (bis)acetylenes; click reaction with benzyl azide converts 2 into a (bis)triazole.
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Affiliation(s)
- Pascal F Tankam
- Technical University Braunschweig, Institute of Organic Chemistry, Hagenring 30, D-38106 Braunschweig, Germany
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Abstract
During our studies on the preparation of blocklike substituted 1,4-glucans by cationic ring-opening polymerization,1,2 we found that TiCl4 behaves differently from common initiators like Et3O+X- (X = PF6, SbCl6), BF3.Et2O, or methyl triflate, causing only ring opening under formation of alpha-maltooligosyl chlorides bearing one free hydroxyl group (4-OH) at the nonreducing end. These compounds are valuable building blocks for the preparation of new glyco-architectures since they are easily accessible starting materials for direct glycosylations or the preparation of a variety of oligomeric glycosyl donors like alkyl glycosides, thioglycosides, or azides. We successfully carried out and optimized the TiCl4-promoted ring opening with per-O-methylated, per-O-ethylated, and temporarily protected per-O-allylated cyclodextrins of various ring size. 1H NMR spectroscopy and high-pressure liquid chromatography-evaporative light-scattering detection (HPLC-ELSD) were used to characterize the products.
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Affiliation(s)
- Andreas Bösch
- Technical University Braunschweig, Institute of Food Chemistry, Schleinitzstrasse 20, Braunschweig, Germany
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Schwartz-Albiez R, Adams Y, von der Lieth CW, Mischnick P, Andrews KT, Kirschfink M. Regioselectively modified sulfated cellulose as prospective drug for treatment of malaria tropica. Glycoconj J 2006; 24:57-65. [PMID: 17115275 DOI: 10.1007/s10719-006-9012-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [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: 10/23/2022]
Abstract
Adhesion of Plasmodium falciparum infected erythrocytes (IE) to placental chondroitin-4-sulfate (CSA) has been linked to the severe disease outcome of pregnancy-associated malaria. Consequently, sulfated polysaccharides with inhibitory capacity may be considered for therapeutic strategies as anti-adhesive drugs. During in vitro screening a regioselectively modified cellulose sulfate (CS10) was selected as prime candidate for further investigations because it was able to inhibit adhesion to CSA expressed on CHO cells and placental tissue, to de-adhere already bound infected erythrocytes, and to bind to infected erythrocytes. Similar to the undersulfated placental CSA preferred by placental-binding infected erythrocytes, CS10 is characterized by a clustered sulfate pattern along the polymer chain. In further evaluation of its effects on P. falciparum interactions with host erythrocytes, we now show that CS10 inhibits the in vitro asexual growth of parasites in erythrocytes. Furthermore, we show that CS10 interferes with C1 of the classical complement pathway but not with MBL of the lectin pathway. In order to gain insights into the possible interactions of CS10 with known parasite receptors at the molecular level, we designed 3D-structures of characteristic stretches of CS10. CS10 fragments with clustered sulfate groups showed complex patterns of hydrophobic and hydrophilic patches most likely suitable for interactions with protein binding partners. The significance of CS10 interactions with the complement system as well as its anti-malarial effect for prospective drug application are discussed.
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Affiliation(s)
- Reinhard Schwartz-Albiez
- German Cancer Research Center, Tumor Immunology, D010, Im Neuenheimer Feld 580, D-69120 Heidelberg, Germany.
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Adden R, Müller R, Brinkmalm G, Ehrler R, Mischnick P. Comprehensive Analysis of the Substituent Distribution in Hydroxyethyl Celluloses by Quantitative MALDI-ToF-MS. Macromol Biosci 2006; 6:435-44. [PMID: 16761275 DOI: 10.1002/mabi.200600028] [Citation(s) in RCA: 17] [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] [Indexed: 11/09/2022]
Abstract
Three HECs with a high MS (HEC 1: 1.89, HEC 2: 1.94, HEC 3: 3.03) were analyzed with respect to their substituent distribution and tandem reaction in the glucosyl unit by GLC of the corresponding glucitol acetates, and along the polymer chain by MALDI-ToF-MS after a multi-step sample preparation. For comparison of the experimental data with a random pattern an extended Bernoulli plot was applied to calculate a random distribution for the composition of un-, mono-, di-, tri-, and up to heptasubstituted glucosyl units (c0, c1, c2, ... c7).
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Affiliation(s)
- Roland Adden
- TU Braunschweig, Institut für Lebensmittelchemie, Schleinitzstr. 20, D-38106 Braunschweig, Germany
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Adden R, Müller R, Mischnick P. Fractionation of Methyl Cellulose According to Polarity – a Tool to Differentiate First and Second Order Heterogeneity of the Substituent Distribution. MACROMOL CHEM PHYS 2006. [DOI: 10.1002/macp.200600048] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Adden R, Melander C, Brinkmalm G, Gorton L, Mischnick P. New Approaches to the Analysis of Enzymatically Hydrolyzed Methyl Cellulose. Part 1. Investigation of the Influence of Structural Parameters on the Extent of Degradation. Biomacromolecules 2006; 7:1399-409. [PMID: 16677020 DOI: 10.1021/bm050941+] [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] [Indexed: 11/28/2022]
Abstract
Six methyl celluloses (MCs), one with a degree of substitution (DS) of 1.32 and five with DS between 1.83 and 1.88, were thoroughly investigated. Monomer composition and methyl distribution in the polymer chain were analyzed after total or partial random hydrolysis and appropriate derivatization with gas chromatography (GC) and mass spectrometry (MS), respectively, and used as reference data. The same MCs were then hydrolyzed with an enzyme preparation of Trichoderma longibrachiatum and further investigated with size-exclusion chromatography with multiangle light scattering and refractive index detection (SEC-MALS/RI) and MS. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) in combination with various MS analyzers were compared with respect to quantification of the degradation products directly and after perdeuteriomethylation. The methyl group distribution in the oligomeric fractions and the average DS as a function of chain length were calculated from ESI mass spectra. With help of the reference analysis, patterns could be corrected for the unspecific contribution of end groups. By labeling and ESI tandem MS, our knowledge about the tolerance of the enzymes' sub-sites with respect to the number of methyl groups could be improved.
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Affiliation(s)
- Roland Adden
- TU Braunschweig, Institut für Lebensmittelchemie, Schleinitzstr. 20, D-38106 Braunschweig, Germany
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Melander C, Tüting W, Bengtsson M, Laurell T, Mischnick P, Gorton L. Hydrolysis of Maltoheptaose in Flow through Silicon Wafer Microreactors Containing Immobilised α-Amylase and Glycoamylase. STARCH-STARKE 2006. [DOI: 10.1002/star.200500450] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Aminopropyl amyloses with various degrees of substitution (DS) were prepared and investigated with respect to their surface modification properties. Poly(acrylic acid) was grafted to plasma-activated PVDF films, and the functional amylose was bound via amide linkage formation. Layer formation was confirmed by X-ray photoelectron spectroscopy. Contact angle measurements and surface MALDI-TOF mass spectrometry indicated a hydrophilic surface and minimization of protein adsorption.
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Affiliation(s)
- Zahida Ademovic
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Pauwelsstrasse 8, D-52056 Aachen, Germany
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Melander C, Adden R, Brinkmalm G, Gorton L, Mischnick P. New Approaches to the Analysis of Enzymatically Hydrolyzed Methyl Cellulose. Part 2. Comparison of Various Enzyme Preparations. Biomacromolecules 2006; 7:1410-21. [PMID: 16677021 DOI: 10.1021/bm0509422] [Citation(s) in RCA: 17] [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] [Indexed: 11/28/2022]
Abstract
In this part of our studies, dealing with new approaches to the analysis of enzymatically hydrolyzed methyl cellulose, five different enzymes or enzyme preparations containing endoglucanases (from Bacillus agaradhaerens Cel 5A, Trichoderma reesei, Trichoderma viride, and two obtained from Trichoderma longibrachiatum) were used to hydrolyze six different methyl celluloses (MCs). The main goal was to investigate whether enzymes could be used for determination of the heterogeneity of the substituent distribution along the cellulose chain. To obtain information about the heterogeneity, it was necessary to gather information on how the enzymes affect hydrolysis. Size exclusion chromatography with multi-angle light scattering and refractive index detection (SEC-MALS/RI) was used to estimate the molar mass distribution of the MCs before and after hydrolysis. A novel internal standard addition method in combination with electrospray ionization ion trap mass spectrometry (ESI-ITMS) was used to determine the amount of formed oligomers. Two MCs, one with a degree of substitution (DS) of 1.8 and one with DS 1.3, were hydrolyzed with all of the five enzymes. The yield of summarized di- and trisaccharides was approximately 2% of the hydrolysis products for the MC with DS 1.8, whereas the product mixture, obtained from a MC with a DS of 1.3, contained 7-16% di- and trisaccharides. By a novel sample preparation method in combination with ESI-IT tandem MS, outlined in part 1 of this work, it was shown that the enzymes produced oligomers with the reducing end bearing no or only one substituent. Comparison of the methyl pattern at the nonreducing ends of the dimers and trimers indicated that the -2 subsite of the active complex is less tolerant than subsites -3 and +1. All enzymes had similar general selectivity toward the methyl substituents but also showed some differences. From both SEC-MALS/RI and ESI-ITMS, differences with respect to substituent distribution of MCs could be recognized but not for each enzyme used. Basic considerations for enzymatic hydrolysis and analysis of methyl cellulose were listed as a consequence of the results from the work.
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Affiliation(s)
- Claes Melander
- Department of Analytical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
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