1
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Lu J, Jerschow A, Korenchan DE. Selective filtration of NMR signals arising from weakly- and strongly-coupled spin systems. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 354:107529. [PMID: 37572586 DOI: 10.1016/j.jmr.2023.107529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/14/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for analyzing chemical and biological systems. However, in complex solutions with similar molecular components, NMR signals can overlap, making it challenging to distinguish and quantify individual species. In this paper, we introduce new spectral editing sequences that exploit the differences in nuclear spin interactions (J-couplings) between weakly- and strongly-coupled two-spin systems. These sequences selectively attenuate or nullify undesired spin magnetization while they preserve the desired signals, resulting in simplified NMR spectra and potentially facilitating single-species imaging applications. We demonstrate the effectiveness of our approach using a 31P spectral filtration method on a model system of nicotinamide dinucleotide (NAD), which exists in oxidized (NAD+) and reduced (NADH) forms. The presented sequences are robust to field inhomogeneity, do not require additional sub-spectra, and retain a significant portion of the original signal.
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Affiliation(s)
- Jiaqi Lu
- Department of Chemistry, New York University, 100 Washington Square East, Room 710, New York, 10003, NY, USA
| | - Alexej Jerschow
- Department of Chemistry, New York University, 100 Washington Square East, Room 710, New York, 10003, NY, USA
| | - David E Korenchan
- Department of Chemistry, New York University, 100 Washington Square East, Room 710, New York, 10003, NY, USA; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 75 3rd Ave., Room 1400A, Charlestown, 02129, MA, USA.
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2
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Hoyt EM, Smith LO, Crittenden DL. Simple, accurate, adjustable-parameter-free prediction of NMR shifts for molecules in solution. Phys Chem Chem Phys 2023; 25:9952-9957. [PMID: 36951928 DOI: 10.1039/d3cp00721a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Accurate prediction of NMR shifts is invaluable for interpreting and assigning NMR spectra, especially for complex applications such as determining the identity of unknown substances or resolving stereochemical assignments. Statistical linear regression models have proven effective for accurately correlating density functional theory predictions of chemical shieldings with experimentally-measured shifts, but lack transferability - they must be reparameterised using a reasonably extensive training set at each level of theory and for each choice of NMR solvent. We have previously introduced a novel two-point "shift-and-scale" correction procedure for gas phase shieldings that overcomes these limitations without significant loss of accuracy. In this work, we demonstrate that this approach is equally applicable for predicting solution-phase shifts from computed gas phase shieldings, using acetaldehyde as an experimentally and computationally convenient reference system. We also present all of the required experimental reference data to enable this approach to be used for any target analyte in a range of commonly used NMR solvents (chloroform, dichloromethane, acetonitrile, methanol, acetone, DMSO, D2O, benzene, pyridine).
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Affiliation(s)
- Emlyn M Hoyt
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch 8140, New Zealand.
| | - Lachlan O Smith
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch 8140, New Zealand.
| | - Deborah L Crittenden
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch 8140, New Zealand.
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3
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Chen K, Smith CJ. Best Practices for Submission of NMR Data to Support Higher Order Structure Assessment of Generic Peptide Drugs. AAPS J 2023; 25:17. [PMID: 36670271 DOI: 10.1208/s12248-023-00782-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/05/2023] [Indexed: 01/22/2023] Open
Affiliation(s)
- Kang Chen
- Division of Complex Drug Analysis, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, 20993, USA.
| | - Cameron J Smith
- Division of Liquid-Based Products I, Office of Lifecycle Drug Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, 20993, USA
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4
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Huang X, Ai C, Yao H, Zhao C, Xiang C, Hong T, Xiao J. Guideline for the extraction, isolation, purification, and structural characterization of polysaccharides from natural resources. EFOOD 2022. [DOI: 10.1002/efd2.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Xiaojun Huang
- State Key Laboratory of Food Science and Technology, China‐Canada Joint Lab of Food Science and Technology (Nanchang) Nanchang University Nanchang China
| | - Chao Ai
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Province Engineering Laboratory for Marine Biological Products, Guangdong Provincial Engineering Technology Research Center of Seafood, Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution, College of Food Science and Technology Guangdong Ocean University Zhanjiang China
| | - Haoyingye Yao
- State Key Laboratory of Food Science and Technology, China‐Canada Joint Lab of Food Science and Technology (Nanchang) Nanchang University Nanchang China
| | - Chengang Zhao
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Province Engineering Laboratory for Marine Biological Products, Guangdong Provincial Engineering Technology Research Center of Seafood, Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution, College of Food Science and Technology Guangdong Ocean University Zhanjiang China
| | - Chunhong Xiang
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Province Engineering Laboratory for Marine Biological Products, Guangdong Provincial Engineering Technology Research Center of Seafood, Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution, College of Food Science and Technology Guangdong Ocean University Zhanjiang China
| | - Tao Hong
- State Key Laboratory of Food Science and Technology, China‐Canada Joint Lab of Food Science and Technology (Nanchang) Nanchang University Nanchang China
| | - Jianbo Xiao
- Department of Analytical Chemistry and Food Science, Faculty of Food Science and Technology University of Vigo—Ourense Campus Ourense Spain
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5
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Matysik J, Song C, Bielytskyi P, Alia A. Teaching product operators using the Vega diagram. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2022; 122:101830. [PMID: 36223696 DOI: 10.1016/j.ssnmr.2022.101830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 08/31/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
We all will remember Shimon Vega (1942-2021) as wonderful human and scientist. Paramount examples of his scientific work are quoted in this special issue dedicated to his memory. This article is dedicated to remember Shimon Vega as a fantastic teacher. To introduce to the world of product operators, Shimon created a simple scheme that we now call the Vega diagram. It allows for fast analysis of pulse sequences for AX spin systems. Here, we want to document this scheme for future generations.
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Affiliation(s)
- Jörg Matysik
- Universität Leipzig, Institut für Analytische Chemie, Linnéstr. 3, 04103, Leipzig, Germany.
| | - Chen Song
- Universität Leipzig, Institut für Analytische Chemie, Linnéstr. 3, 04103, Leipzig, Germany
| | - Pavlo Bielytskyi
- Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Charles Tanford Protein Centre, Kurt-Mothes-Str. 3a, 06120, Halle an der Saale, Germany
| | - A Alia
- Universität Leipzig, Institut für Medizinische Physik und Biophysik, Härtelstr. 16-18, 04107, Leipzig, Germany; Leiden University, Leiden Institute of Chemistry, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
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6
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Thu ZM, Oo SM, Nwe TM, Aung HT, Armijos C, Hussain FHS, Vidari G. Structures and Bioactivities of Steroidal Saponins Isolated from the Genera Dracaena and Sansevieria. Molecules 2021; 26:1916. [PMID: 33805482 PMCID: PMC8037284 DOI: 10.3390/molecules26071916] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/13/2021] [Accepted: 03/23/2021] [Indexed: 11/23/2022] Open
Abstract
The species Dracaena and Sansevieria, that are well-known for different uses in traditional medicines and as indoor ornamental plants with air purifying property, are rich sources of bioactive secondary metabolites. In fact, a wide variety of phytochemical constituents have been isolated so far from about seventeen species. This paper has reviewed the literature of about 180 steroidal saponins, isolated from Dracaena and Sansevieria species, as a basis for further studies. Saponins are among the most characteristic metabolites isolated from the two genera. They show a great variety in structural motifs and a wide range of biological activities, including anti-inflammatory, anti-microbial, anti-proliferative effects and, in most case, remarkable cytotoxic properties.
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Affiliation(s)
- Zaw Min Thu
- Department of Chemistry, Kalay University, Kalay 03044, Myanmar; (S.M.O.); (T.M.N.)
| | - Sann Myint Oo
- Department of Chemistry, Kalay University, Kalay 03044, Myanmar; (S.M.O.); (T.M.N.)
| | - Thinn Myat Nwe
- Department of Chemistry, Kalay University, Kalay 03044, Myanmar; (S.M.O.); (T.M.N.)
| | - Hnin Thanda Aung
- Department of Chemistry, University of Mandalay, Mandalay 100103, Myanmar;
| | - Chabaco Armijos
- Departamento de Química y Ciencias Exactas, Universidad Técnica Particular de Loja, San Cayetano Alto s/n, Loja 1101608, Ecuador
| | - Faiq H. S. Hussain
- Medical Analysis Department, Faculty of Science, Tishk International University, Erbil 44001, Iraq;
| | - Giovanni Vidari
- Medical Analysis Department, Faculty of Science, Tishk International University, Erbil 44001, Iraq;
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7
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Yao HYY, Wang JQ, Yin JY, Nie SP, Xie MY. A review of NMR analysis in polysaccharide structure and conformation: Progress, challenge and perspective. Food Res Int 2021; 143:110290. [PMID: 33992390 DOI: 10.1016/j.foodres.2021.110290] [Citation(s) in RCA: 152] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 02/28/2021] [Accepted: 02/28/2021] [Indexed: 12/31/2022]
Abstract
Nuclear magnetic resonance (NMR) has been widely used as an analytical chemistry technique to investigate the molecular structure and conformation of polysaccharides. Combined with 1D spectra, chemical shifts and coupling constants in both homo- and heteronuclear 2D NMR spectra are able to infer the linkage and sequence of sugar residues. Besides, NMR has also been applied in conformation, quantitative analysis, cell wall in situ, degradation, polysaccharide mixture interaction analysis, as well as carbohydrates impurities profiling. This review summarizes the principle and development of NMR in polysaccharides analysis, and provides NMR spectra data collections of some common polysaccharides. It will help to promote the application of NMR in complex polysaccharides of biochemical interest, and provide valuable information on commercial polysaccharide products.
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Affiliation(s)
- Hao-Ying-Ye Yao
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang 330047, China.
| | - Jun-Qiao Wang
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang 330047, China.
| | - Jun-Yi Yin
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang 330047, China.
| | - Shao-Ping Nie
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang 330047, China.
| | - Ming-Yong Xie
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang 330047, China; National R&D Center for Freshwater Fish Processing, Jiangxi Normal University, Nanchang, Jiangxi 330022, China.
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8
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Buevich AV, Elyashberg ME. Enhancing computer-assisted structure elucidation with DFT analysis of J-couplings. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:594-606. [PMID: 31916609 DOI: 10.1002/mrc.4996] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
Computer-assisted structure elucidation (CASE) is the class of expert systems that derives molecular structures primarily from one-dimensional and two-dimensional nuclear magnetic resonance data. Contemporary CASE systems, including Advanced Chemistry Development/Structure Elucidator (ACD/SE), consider cross-peaks in heteronuclear multiple bond coherence (HMBC) and correlation spectroscopy (COSY) spectra as two- or three-bond correlations by default. However, four and more bond correlations (nonstandard correlations [NSCs]) could be present in these spectra too. The indiscriminate addition of NSCs to the CASE computations is prohibitively expensive. To address this problem, the ACD/SE program performs a logical analysis of observed correlations and determines the minimum number of NSCs. Guided by this information, a more efficient fuzzy structure generation (FSG) algorithm is subsequently applied. Until now, the FSG algorithm was utilized without any verification of the reliability of found NSCs. Here, we report a verification method for NSCs based on the relationship between NSCs and J-couplings computed with high accuracy density functional theory (DFT) methods. We used the example of strychnine to show that 41 (32%) of 8-Hz HMBC cross-peaks were NSCs and were consistent with 4-6 JCH couplings greater than 0.3 Hz. This cutoff value was largely confirmed by the analysis of NSCs in 11 real-world natural products elucidated by ACD/SE. Additionally, utilizing the example of the CASE study of cleospinol A, we showed that the DFT-computed J-couplings of NSCs can distinctively differentiate the correct structure among six proposed isomers. The proposed approach of NSC verification should further improve the robustness of CASE analysis and can help reveal potential problems with reported experimental data.
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Affiliation(s)
- Alexei V Buevich
- Department of Discovery and Preclinical Sciences, Process Research and Development, NMR Structure Elucidation, Merck & Co., Inc, Kenilworth, NJ
| | - Mikhail E Elyashberg
- Moscow Department, Advanced Chemistry Development (ACD/Laboratories), Moscow, Russia
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9
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Jia L, Qiao Y, Pedersen CM, Jia S, Ma H, Zhang Z, Wang Y, Hou X. Mechanistic study on the conversion of d-fructose into deoxyfructosazine: Insights from NMR and DFT study. Chem Eng Sci 2020. [DOI: 10.1016/j.ces.2019.115444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Aggregate morphology transition of an adamantane-containing surfactant via the host-guest interaction with β-cyclodextrin. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.09.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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11
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Todisco M, Fraccia TP, Smith GP, Corno A, Bethge L, Klussmann S, Paraboschi EM, Asselta R, Colombo D, Zanchetta G, Clark NA, Bellini T. Nonenzymatic Polymerization into Long Linear RNA Templated by Liquid Crystal Self-Assembly. ACS NANO 2018; 12:9750-9762. [PMID: 30280566 DOI: 10.1021/acsnano.8b05821] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Self-synthesizing materials, in which supramolecular structuring enhances the formation of new molecules that participate to the process, represent an intriguing notion to account for the first appearance of biomolecules in an abiotic Earth. We present here a study of the abiotic formation of interchain phosphodiester bonds in solutions of short RNA oligomers in various states of supramolecular arrangement and their reaction kinetics. We found a spectrum of conditions in which RNA oligomers self-assemble and phase separate into highly concentrated ordered fluid liquid crystal (LC) microdomains. We show that such supramolecular state provides a template guiding their ligation into hundred-bases long chains. The quantitative analysis presented here demonstrates that nucleic acid LC boosts the rate of end-to-end ligation and suppresses the formation of the otherwise dominant cyclic oligomers. These results strengthen the concept of supramolecular ordering as an efficient pathway toward the emergence of the RNA World in the primordial Earth.
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Affiliation(s)
- Marco Todisco
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale , Università di Milano , via Vanvitelli 32 , 20129 Milano , Italy
| | - Tommaso P Fraccia
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale , Università di Milano , via Vanvitelli 32 , 20129 Milano , Italy
- Dipartimento di Scienze Umane e Promozione della Qualità della Vita , Università San Raffaele di Roma , via di Val Cannuta, 247 , I-00166 Roma , Italy
| | - Greg P Smith
- Department of Physics and Soft Materials Research Center , University of Colorado , Boulder , Colorado 80309-0390 , United States
| | - Andrea Corno
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale , Università di Milano , via Vanvitelli 32 , 20129 Milano , Italy
| | | | | | - Elvezia M Paraboschi
- Department of Biomedical Sciences , Humanitas University , via Rita Levi Montalcini 4 , Pieve Emanuele, Milano I-20090 , Italy
| | - Rosanna Asselta
- Department of Biomedical Sciences , Humanitas University , via Rita Levi Montalcini 4 , Pieve Emanuele, Milano I-20090 , Italy
- Humanitas Clinical and Research Center , via Alessandro Manzoni 56 , Rozzano, Milano I-20089 , Italy
| | - Diego Colombo
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale , Università di Milano , via Vanvitelli 32 , 20129 Milano , Italy
| | - Giuliano Zanchetta
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale , Università di Milano , via Vanvitelli 32 , 20129 Milano , Italy
| | - Noel A Clark
- Department of Physics and Soft Materials Research Center , University of Colorado , Boulder , Colorado 80309-0390 , United States
| | - Tommaso Bellini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale , Università di Milano , via Vanvitelli 32 , 20129 Milano , Italy
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12
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Luber T, Niemietz M, Karagiannis T, Mönnich M, Ott D, Perkams L, Walcher J, Berger L, Pischl M, Weishaupt M, Eller S, Hoffman J, Unverzagt C. A Single Route to Mammalian N-Glycans Substituted with Core Fucose and Bisecting GlcNAc. Angew Chem Int Ed Engl 2018; 57:14543-14549. [PMID: 30144245 DOI: 10.1002/anie.201807742] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Indexed: 12/15/2022]
Abstract
The occurrence of α1,6-linked core fucose on the N-glycans of mammalian glycoproteins is involved in tumor progression and reduces the bioactivity of antibodies in antibody-dependent cell-mediated cytotoxicity (ADCC). Since core-fucosylated N-glycans are difficult to isolate from natural sources, only chemical or enzymatic synthesis can provide the desired compounds for biological studies. A general drawback of chemical α-fucosylation is that the chemical assembly of α1,6-linked fucosides is not stereospecific. A robust and general method for the α-selective fucosylation of acceptors with primary hydroxy groups in α/β ratios exceeding 99:1 was developed. The high selectivities result from the interplay of an optimized protecting group pattern of the fucosyl donors in combination with the activation principle and the reaction conditions. Selective deprotection yielded versatile azides of all mammalian complex-type core-fucosylated N-glycans with 2-4 antennae and optional bisecting GlcNAc.
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Affiliation(s)
- Thomas Luber
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Mathäus Niemietz
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | | | - Manuel Mönnich
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Dimitri Ott
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Lukas Perkams
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Janika Walcher
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Lukas Berger
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Matthias Pischl
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Markus Weishaupt
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Steffen Eller
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Joanna Hoffman
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Carlo Unverzagt
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
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13
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Luber T, Niemietz M, Karagiannis T, Mönnich M, Ott D, Perkams L, Walcher J, Berger L, Pischl M, Weishaupt M, Eller S, Hoffman J, Unverzagt C. A Single Route to Mammalian N-Glycans Substituted with Core Fucose and Bisecting GlcNAc. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201807742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Thomas Luber
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Mathäus Niemietz
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | | | - Manuel Mönnich
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Dimitri Ott
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Lukas Perkams
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Janika Walcher
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Lukas Berger
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Matthias Pischl
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Markus Weishaupt
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Steffen Eller
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Joanna Hoffman
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
| | - Carlo Unverzagt
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Germany
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14
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Zhai Z, Yan X, Song Z, Shang S, Rao X. Annular and threadlike wormlike micelles formed by a bio-based surfactant containing an extremely large hydrophobic group. SOFT MATTER 2018; 14:499-507. [PMID: 29303202 DOI: 10.1039/c7sm02163a] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A novel bio-based anionic surfactant containing a large rigid group and a flexible alkyl chain, namely, sodium N-dodecyl-maleimidepimaric carboxylate (C12-MPA-Na), was synthesized from rosin. The molecular structure of C12-MPA-Na was identified using 1H NMR, FT-IR spectroscopy and MS. Despite containing 36 carbon atoms, C12-MPA-Na showed good water solubility at room temperature. Large spherical aggregates with diameters of 100-200 nm were formed by C12-MPA-Na when its concentration was above 0.1 mM, which was slightly higher than the critical micelle concentration (0.078 mM). Annular wormlike micelles were discovered with increasing C12-MPA-Na concentration, and began to change into extremely long threadlike wormlike micelles when the C12-MPA-Na concentration reached approximately 58 mM. The viscoelastic properties of the wormlike micelle solutions were investigated using steady state and oscillatory shear sweep rheological measurements. The zero-shear viscosity (η0) strongly depended on the concentration of C12-MPA-Na, and the scaling exponent was 34.1. Cryo-TEM confirmed the formation of large spherical aggregates and wormlike micelles. 1H-1H 2D nuclear Overhauser effect spectroscopy (NOESY) was used to detect the molecular interactions of C12-MPA-Na. The results indicated that the alkyl chain of C12-MPA-Na was partially overlapped with its non-planar rigid structure in aqueous solution, and the possible aggregation process for C12-MPA-Na was proposed.
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Affiliation(s)
- Zhaolan Zhai
- Institute of Chemical Industry of Forest Products, CAF, Jiangsu Province, Nanjing 210042, China.
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15
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Qajar J, Arns CH. Characterization of reactive flow-induced evolution of carbonate rocks using digital core analysis - part 2: Calculation of the evolution of percolation and transport properties. JOURNAL OF CONTAMINANT HYDROLOGY 2017; 204:11-27. [PMID: 28822588 DOI: 10.1016/j.jconhyd.2017.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 07/29/2017] [Accepted: 08/05/2017] [Indexed: 06/07/2023]
Abstract
Percolation of reactive fluids in carbonate rocks affects the rock microstructure and hence changes the rock macroscopic properties. In Part 1 paper, we examined the voxel-wise evolution of microstructure of the rock in terms of mineral dissolution/detachment, mineral deposition, and unchanged regions. In the present work, we investigate the relationships between changes in two characteristic transport properties, i.e. permeability and electrical conductivity and two critical parameters of the pore phase, i.e. the fraction of the pore space connecting the inlet and outlet faces of the core sample and the critical pore-throat diameter. We calculate the aforementioned properties on the images of the sample, wherein a homogeneous modification of pore structure occurred in order to ensure the representativeness of the calculated transport properties at the core scale. From images, the evolution of pore connectivity and the potential role of micropores on the connectivity are quantified. It is found that the changing permeability and electrical conductivity distributions along the core length are generally in good agreement with the longitudinal evolution of macro-connected macroporosity and the critical pore-throat diameter. We incorporate microporosity into critical length and permeability calculations and show how microporosity locally plays a role in permeability. It is shown that the Katz-Thompson model reasonably predicts the post-alteration permeability in terms of pre-alteration simulated parameters. This suggests that the evolution of permeability and electrical conductivity of the studied complex carbonate core are controlled by the changes in the macro-connected macroporosity as well as the smallest pore-throats between the connected macropores.
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Affiliation(s)
- Jafar Qajar
- School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran; School of Petroleum Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
| | - Christoph H Arns
- School of Petroleum Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
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17
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Xie D, You D, Ying S, Song B, Tian J. Viscoelastic properties of supramolecular gemini-like surfactant solutions in the absence of inorganic salts. RSC Adv 2017. [DOI: 10.1039/c7ra08435h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A bola-type cation and a newly synthesized anionic surfactant together generate a supramolecular gemini-like structureviaelectrostatic interactions, which facilitates the formation of wormlike micelles.
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Affiliation(s)
- Danhua Xie
- Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry
- College of Chemistry and Materials
- Ningde Normal University
- Ningde
- P. R. China
| | - Donghong You
- Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry
- College of Chemistry and Materials
- Ningde Normal University
- Ningde
- P. R. China
| | - Shaoming Ying
- Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry
- College of Chemistry and Materials
- Ningde Normal University
- Ningde
- P. R. China
| | - Binglei Song
- Key Laboratory of Synthetic and Biological Colloids
- Ministry of Education
- School of Chemical & Materials Engineering
- Jiangnan University
- Wuxi
| | - Jinnian Tian
- Key Laboratory of Synthetic and Biological Colloids
- Ministry of Education
- School of Chemical & Materials Engineering
- Jiangnan University
- Wuxi
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18
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Kumar C, Kjærgaard T, Helgaker T, Fliegl H. Nuclei-selected atomic-orbital response-theory formulation for the calculation of NMR shielding tensors using density-fitting. J Chem Phys 2016; 145:234108. [DOI: 10.1063/1.4972212] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Chandan Kumar
- Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
| | - Thomas Kjærgaard
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Trygve Helgaker
- Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
| | - Heike Fliegl
- Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
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Mönnich M, Eller S, Karagiannis T, Perkams L, Luber T, Ott D, Niemietz M, Hoffman J, Walcher J, Berger L, Pischl M, Weishaupt M, Wirkner C, Lichtenstein RG, Unverzagt C. Hocheffiziente Synthese von multiantennären “bisected” N-Glycanen über Imidate. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604190] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Manuel Mönnich
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Steffen Eller
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | | | - Lukas Perkams
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Thomas Luber
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Dimitri Ott
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Mathäus Niemietz
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Joanna Hoffman
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Janika Walcher
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Lukas Berger
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Matthias Pischl
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Markus Weishaupt
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Cathrin Wirkner
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
| | - Rachel G. Lichtenstein
- Department of Biotechnology Engineering; Ben-Gurion University of the Negev; Beer-Sheva 84105 Israel
| | - Carlo Unverzagt
- Bioorganische Chemie, Gebäude NW1; Universität Bayreuth; 95440 Bayreuth Deutschland
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20
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Mönnich M, Eller S, Karagiannis T, Perkams L, Luber T, Ott D, Niemietz M, Hoffman J, Walcher J, Berger L, Pischl M, Weishaupt M, Wirkner C, Lichtenstein RG, Unverzagt C. Highly Efficient Synthesis of Multiantennary Bisected N-glycans Based on Imidates. Angew Chem Int Ed Engl 2016; 55:10487-92. [PMID: 27443163 DOI: 10.1002/anie.201604190] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Indexed: 12/11/2022]
Abstract
The occurrence of N-glycans with a bisecting GlcNAc modification on glycoproteins has many implications in developmental and immune biology. However, these particular N-glycans are difficult to obtain either from nature or through synthesis. We have developed a flexible and general method for synthesizing bisected N-glycans of the complex type by employing modular TFAc-protected donors for all antennae. The TFAc-protected N-glycans are suitable for the late introduction of a bisecting GlcNAc. This integrated strategy permits for the first time the use of a single approach for multiantennary N-glycans as well as their bisected derivatives via imidates, with unprecedented yields even in a one-pot double glycosylation. With this new method, rare N-glycans of the bisected type can be obtained readily, thereby providing defined tools to decipher the biological roles of bisecting GlcNAc modifications.
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Affiliation(s)
- Manuel Mönnich
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Steffen Eller
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | | | - Lukas Perkams
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Thomas Luber
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Dimitri Ott
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Mathäus Niemietz
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Joanna Hoffman
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Janika Walcher
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Lukas Berger
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Matthias Pischl
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Markus Weishaupt
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Cathrin Wirkner
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Rachel G Lichtenstein
- Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Carlo Unverzagt
- Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440, Bayreuth, Germany.
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Scherl M, Müller T, Kreutz CR, Huber RG, Zass E, Liedl KR, Kräutler B. Chlorophyll Catabolites in Fall Leaves of the Wych Elm Tree Present a Novel Glycosylation Motif. Chemistry 2016; 22:9498-503. [PMID: 27128523 PMCID: PMC5089558 DOI: 10.1002/chem.201601739] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Indexed: 12/23/2022]
Abstract
Fall leaves of the common wych elm tree (Ulmus glabra) were studied with respect to chlorophyll catabolites. Over a dozen colorless, non‐fluorescent chlorophyll catabolites (NCCs) and several yellow chlorophyll catabolites (YCCs) were identified tentatively. Three NCC fractions were isolated and their structures were characterized by spectroscopic means. Two of these, Ug‐NCC‐27 and Ug‐NCC‐43, carried a glucopyranosyl appendage. Ug‐NCC‐53, the least polar of these NCCs, was identified as the formal product of an intramolecular esterification of the propionate and primary glucopyranosyl hydroxyl groups of Ug‐NCC‐43. Thus, the glucopyranose moiety and three of the pyrrole units of Ug‐NCC‐53 span a 20‐membered ring, installing a bicyclo[17.3.1]glycoside moiety. This structural motif is unprecedented in heterocyclic natural products, according to a thorough literature search. The remarkable, three‐dimensional bicyclo[17.3.1]glycoside architecture reduces the flexibility of the linear tetrapyrrole. This feature of Ug‐NCC‐53 is intriguing, considering the diverse biological effects of known bicyclo[n.3.1]glycosidic natural products.
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Affiliation(s)
- Mathias Scherl
- Institute of Organic Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Thomas Müller
- Institute of Organic Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Christoph R Kreutz
- Institute of Organic Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Roland G Huber
- Institute of General, Inorganic & Theoretical Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria.,Bioinformatics Institute, Agency for Science, Technology & Research, 30 Biopolis Street, 138671, Singapore, Singapore
| | - Engelbert Zass
- Laboratory of Organic Chemistry, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland.
| | - Klaus R Liedl
- Institute of General, Inorganic & Theoretical Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria.
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria.
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22
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Kräutler B. Breakdown of Chlorophyll in Higher Plants--Phyllobilins as Abundant, Yet Hardly Visible Signs of Ripening, Senescence, and Cell Death. Angew Chem Int Ed Engl 2016; 55:4882-907. [PMID: 26919572 PMCID: PMC4950323 DOI: 10.1002/anie.201508928] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 01/06/2023]
Abstract
Fall colors have always been fascinating and are still a remarkably puzzling phenomenon associated with the breakdown of chlorophyll (Chl) in leaves. As discovered in recent years, nongreen bilin-type Chl catabolites are generated, which are known as the phyllobilins. Collaborative chemical-biological efforts have led to the elucidation of the key Chl-breakdown processes in senescent leaves and in ripening fruit. Colorless and largely photoinactive phyllobilins are rapidly produced from Chl, apparently primarily as part of a detoxification program. However, fluorescent Chl catabolites accumulate in some senescent leaves and in peels of ripe bananas and induce a striking blue glow. The structural features, chemical properties, and abundance of the phyllobilins in the biosphere suggest biological roles, which still remain to be elucidated.
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Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry & Center of Molecular Biosciences (CMBI), University of Innsbruck, 6020, Innsbruck, Austria.
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23
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Zhai Z, Lei L, Song J, Song B, Pei X, Cui Z. Mechanically-sensitive hydrogels formed from β-cyclodextrin and an anionic surfactant containing a biphenyl group. SOFT MATTER 2016; 12:2715-2720. [PMID: 26797228 DOI: 10.1039/c5sm02858b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hydrogels are important soft materials with intriguing properties. By taking advantage of the host-guest interactions and multiple molecular interactions, it is expected that novel hydrogel systems can be formed. This strategy has been implemented here, transparent hydrogels were formed by using a newly-synthesized anionic surfactant, sodium 2-(4-phenylphenoxy)dodecanoate (C12biphNa), and β-cyclodextrin (β-CD) in different proportions and their properties were investigated. Gelation of water occurs at extremely low surfactant concentrations (5 mM for a 1:3 C12biphNa: β-CD system), and a single C12biphNa with its associated β-CDs can trap about 11,000 water molecules on average. In addition, the systems are fragile to mechanical stimulus and thus show mechanical sensitivity. Cryo-TEM reveals that the hydrogels have a microstructure consisting of rigid nanowire-like aggregates (with cross-sectional diameters of about 7-8 nm) locally distributed in a parallel manner in solution. These microstructural features are responsible for the peculiar properties of the hydrogel systems presented. The inclusion complexes formed by C12biphNa and β-CD were investigated using (1)H NMR and 2D nuclear overhauser effect spectroscopy and their aggregation state was proposed. This work enriches the connotation of nonamphiphilic self-assembly and provides inspiration for constructing new functional soft materials.
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Affiliation(s)
- Zhaolan Zhai
- Key Laboratory of Food Colloids and Biotechnology Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University, 214122 Wuxi, People's Republic of China.
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Kräutler B. Der Chlorophyllabbau in höheren Pflanzen - Phyllobiline als weitverbreitete, aber kaum sichtbare Zeichen von Reifung, Seneszenz und Zelltod. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201508928] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Bernhard Kräutler
- Institut für Organische Chemie & Centrum für MolekulareBiowissenschaften (CMBI); Universität Innsbruck; 6020 Innsbruck Österreich
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25
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Liu Z, Wang D, Cao M, Han Y, Xu H, Wang Y. Enhanced Molecular Recognition between Nucleobases and Guanine-5'-monophosphate-disodium (GMP) by Surfactant Aggregates in Aqueous Solution. ACS APPLIED MATERIALS & INTERFACES 2015; 7:15078-15087. [PMID: 26106937 DOI: 10.1021/acsami.5b04441] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Only specific base pairs on DNA can bind with each other through hydrogen bonds, which is called the Watson-Crick (W/C) pairing rule. However, without the constraint of DNA chains, the nucleobases in bulk aqueous solution usually do not follow the W/C pairing rule anymore because of the strong competitive effect of water and the multi-interaction edges of nucleobases. The present work applied surfactant aggregates noncovalently functionalized by nucleotide to enhance the recognition between nucleobases without DNA chains in aqueous solution, and it revealed the effects of their self-assembling ability and morphologies on the recognition. The cationic ammonium monomeric, dimeric, and trimeric surfactants DTAB, 12-3-12, and 12-3-12-3-12 were chosen. The surfactants with guanine-5'-monophosphate-disodium (GMP) form micelles, vesicles, and fingerprint-like and plate-like aggregates bearing the hydrogen-bonding sites of GMP, respectively. The binding parameters of these aggregates with adenine (A), uracil (U), guanine (G), and cytosine(C) indicate that the surfactants can promote W/C recognitions in aqueous solution when they form vesicles (GMP/DTAB) or plate-like aggregates (GMP/12-3-12) with proper molecular packing compactness, which not only provide hydrophobic environments but also shield non-W/C recognition edges. However, the GMP/12-3-12 micelles with loose molecular packing, the GMP/12-3-12 fingerprint-like aggregates where the hydrogen bond sites of GMP are occupied by itself, and the GMP/12-3-12-3-12 vesicles with too strong self-assembling ability cannot promote W/C recognition. This work provides insight into how to design self-assemblies with the performance of enhanced molecule recognition.
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Affiliation(s)
- Zhang Liu
- †Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Dong Wang
- ‡Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China
| | - Meiwen Cao
- ‡Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China
| | - Yuchun Han
- †Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Hai Xu
- ‡Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, P. R. China
| | - Yilin Wang
- †Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
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Vergeiner C, Ulrich M, Li C, Liu X, Müller T, Kräutler B. Stereo- and regioselective phyllobilane oxidation in leaf homogenates of the peace lily (Spathiphyllum wallisii): hypothetical endogenous path to yellow chlorophyll catabolites. Chemistry 2014; 21:136-49. [PMID: 25382809 PMCID: PMC4517098 DOI: 10.1002/chem.201404783] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Indexed: 01/04/2023]
Abstract
In senescent leaves, chlorophyll typically is broken down to colorless and essentially photo-inactive phyllobilanes, which are linear tetrapyrroles classified as “nonfluorescent” chlorophyll catabolites (NCCs) and dioxobilane-type NCCs (DNCCs). In homogenates of senescent leaves of the tropical evergreen Spathiphyllum wallisii, when left at room temperature and extracted with methanol, the major endogenous, naturally formed NCC was regio- and stereoselectively oxidized (in part) to a mixture of its 15-hydroxy and 15-methoxy derivative. In the absence of methanol in the extract, only the 15-OH-NCC was observed. The endogenous oxidation process depended upon molecular oxygen. It was inhibited by carbon monoxide, as well as by keeping the leaf homogenate and extract at low temperatures. The remarkable “oxidative activity” was inactivated by heating the homogenate for 10 min at 70 °C. Upon addition of a natural epimeric NCC (epiNCC) to the homogenate of senescent or green Sp. wallisii leaves at room temperature, the exogenous epiNCC was oxidized regio- and stereoselectively to 15-OH-epiNCC and 15-OMe-epiNCC. The identical two oxidized epiNCCs were also obtained as products of the oxidation of epiNCC with dicyanodichlorobenzoquinone (DDQ). Water elimination from 15-OH-epiNCC occurred readily and gave a known “yellow” chlorophyll catabolite (YCC). The endogenous oxidation process, described here, may represent the elusive natural path from the colorless NCCs to yellow and pink coloured phyllobilins, which were found in (extracts of) some senescent leaves.
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Affiliation(s)
- Clemens Vergeiner
- Institute of Organic Chemistry, University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
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Perras FA, Bryce DL. Theoretical study of homonuclear J coupling between quadrupolar spins: single-crystal, DOR, and J-resolved NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 242:23-32. [PMID: 24594753 DOI: 10.1016/j.jmr.2014.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/12/2014] [Accepted: 01/20/2014] [Indexed: 06/03/2023]
Abstract
The theory describing homonuclear indirect nuclear spin-spin coupling (J) interactions between pairs of quadrupolar nuclei is outlined and supported by numerical calculations. The expected first-order multiplets for pairs of magnetically equivalent (A2), chemically equivalent (AA'), and non-equivalent (AX) quadrupolar nuclei are given. The various spectral changeovers from one first-order multiplet to another are investigated with numerical simulations using the SIMPSON program and the various thresholds defining each situation are given. The effects of chemical equivalence, as well as quadrupolar coupling, chemical shift differences, and dipolar coupling on double-rotation (DOR) and J-resolved NMR experiments for measuring homonuclear J coupling constants are investigated. The simulated J coupling multiplets under DOR conditions largely resemble the ideal multiplets predicted for single crystals, and a characteristic multiplet is expected for each of the A2, AA', and AX cases. The simulations demonstrate that it should be straightforward to distinguish between magnetic inequivalence and equivalence using J-resolved NMR, as was speculated previously. Additionally, it is shown that the second-order quadrupolar-dipolar cross-term does not affect the splittings in J-resolved experiments. Overall, the homonuclear J-resolved experiment for half-integer quadrupolar nuclei is demonstrated to be robust with respect to the effects of first- and second-order quadrupolar coupling, dipolar coupling, and chemical shift differences.
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Affiliation(s)
- Frédéric A Perras
- Department of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada
| | - David L Bryce
- Department of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada.
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Policianova O, Brus J, Hruby M, Urbanova M, Zhigunov A, Kredatusova J, Kobera L. Structural diversity of solid dispersions of acetylsalicylic acid as seen by solid-state NMR. Mol Pharm 2014; 11:516-30. [PMID: 24417442 DOI: 10.1021/mp400495h] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Solid dispersions of active pharmaceutical ingredients are of increasing interest due to their versatile use. In the present study polyvinylpyrrolidone (PVP), poly[N-(2-hydroxypropyl)-metacrylamide] (pHPMA), poly(2-ethyl-2-oxazoline) (PEOx), and polyethylene glycol (PEG), each in three Mw, were used to demonstrate structural diversity of solid dispersions. Acetylsalicylic acid (ASA) was used as a model drug. Four distinct types of the solid dispersions of ASA were created using a freeze-drying method: (i) crystalline solid dispersions containing nanocrystalline ASA in a crystalline PEG matrix; (ii) amorphous glass suspensions with large ASA crystallites embedded in amorphous pHPMA; (iii) solid solutions with molecularly dispersed ASA in rigid amorphous PVP; and (iv) nanoheterogeneous solid solutions/suspensions containing nanosized ASA clusters dispersed in a semiflexible matrix of PEOx. The obtained structural data confirmed that the type of solid dispersion can be primarily controlled by the chemical constitutions of the applied polymers, while the molecular weight of the polymers had no detectable impact. The molecular structure of the prepared dispersions was characterized using solid-state NMR, wide-angle X-ray scattering (WAXS), and differential scanning calorimetry (DSC). By applying various (1)H-(13)C and (1)H-(1)H correlation experiments combined with T1((1)H) and T1ρ((1)H) relaxation data, the extent of the molecular mixing was determined over a wide range of distances, from intimate intermolecular contacts (0.1-0.5 nm) up to the phase-separated nanodomains reaching ca. 500 nm. Hydrogen-bond interactions between ASA and polymers were probed by the analysis of (13)C and (15)N CP/MAS NMR spectra combined with the measurements of (1)H-(15)N dipolar profiles. Overall potentialities and limitations of individual experimental techniques were thoroughly evaluated.
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Affiliation(s)
- Olivia Policianova
- Institute of Macromolecular Chemistry , Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6, Czech Republic
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30
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Arrieta A, Jiao H, Spannenberg A, Michalik D. NMR investigation and theoretical studies on the tautomerism of β,β′-tricarbonyl compounds. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wu TY, Wang HC, Su SG, Gung ST, Lin MW, Lin CB. Aggregation Influence of Polyethyleneglycol Organic Solvents with Ionic Liquids BMIBF4and BMIPF6. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201000008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Vergeiner C, Banala S, Kräutler B. Chlorophyll breakdown in senescent banana leaves: catabolism reprogrammed for biosynthesis of persistent blue fluorescent tetrapyrroles. Chemistry 2013; 19:12294-305. [PMID: 23946204 PMCID: PMC3814416 DOI: 10.1002/chem.201301907] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Indexed: 11/23/2022]
Abstract
Chlorophyll breakdown is a visual phenomenon of leaf senescence and fruit ripening. It leads to the formation of colorless chlorophyll catabolites, a group of (chlorophyll-derived bilin-type) linear tetrapyrroles. Here, analysis and structure elucidation of the chlorophyll breakdown products in leaves of banana (Musa acuminata) is reported. In senescent leaves of this monocot all chlorophyll catabolites identified were hypermodified fluorescent chlorophyll catabolites (hmFCCs). Surprisingly, nonfluorescent chlorophyll catabolites (NCCs) were not found, the often abundant and apparently typical final chlorophyll breakdown products in senescent leaves. As a rule, FCCs exist only fleetingly, and they isomerize rapidly to NCCs in the senescent plant cell. Amazingly, in the leaves of banana plants, persistent hmFCCs were identified that accounted for about 80 % of the chlorophyll broken down, and yellow leaves of M. acuminata display a strong blue luminescence. The structures of eight hmFCCs from banana leaves were analyzed by spectroscopic means. The massive accumulation of the hmFCCs in banana leaves, and their functional group characteristics, indicate a chlorophyll breakdown path, the downstream transformations of which are entirely reprogrammed towards the generation of persistent and blue fluorescent FCCs. As expressed earlier in related studies, the present findings call for attention, as to still elusive biological roles of these linear tetrapyrroles.
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Affiliation(s)
- Clemens Vergeiner
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck6020 Innsbruck (Austria) E-mail:
| | - Srinivas Banala
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck6020 Innsbruck (Austria) E-mail:
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck6020 Innsbruck (Austria) E-mail:
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Nasibulov EA, Pravdivtsev AN, Yurkovskaya AV, Lukzen NN, Vieth HM, Ivanov KL. Analysis of Nutation Patterns in Fourier-Transform NMR of Non-Thermally Polarized Multispin Systems. Z PHYS CHEM 2013. [DOI: 10.1524/zpch.2013.0397] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The complex spin order of hyperpolarized multispin systems giving rise to anomalous NMR spectral patterns that vary with the RF excitation angle is analyzed by decomposing its nutation behavior in a superposition of Fourier harmonics. The product operator formalism is applied to calculating the spectral contributions of the various mutual alignments of scalar coupled spins. Two cases are treated, namely systems exhibiting only differences in population of their spin states and systems showing in addition zero-quantum coherences between states, a situation often seen at hyperpolarization. After deriving the general solution a number of representative examples are discussed in detail. The theoretical treatment is applied to analyzing the spin order observed in a hyperpolarized two-spin system that is prepared in the singlet state by para-hydrogen induced polarization.
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Affiliation(s)
- Egor A. Nasibulov
- International Tomography Center SB RAS, Novosibirsk, 630090, Russische Föderation
| | | | | | - Nikita N. Lukzen
- International Tomography Center SB RAS, Novosibirsk, 630090, Russische Föderation
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Scherl M, Müller T, Kräutler B. Chlorophyll catabolites in senescent leaves of the lime tree (Tilia cordata). Chem Biodivers 2012; 9:2605-17. [PMID: 23161638 PMCID: PMC3586658 DOI: 10.1002/cbdv.201200203] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Indexed: 11/10/2022]
Abstract
In cold extracts of senescent leaves of the Lime tree (Tilia cordata), two colorless nonfluorescent chlorophyll catabolites (NCCs) were identified, named Tc-NCC-1 and Tc-NCC-2, as well as a polar yellow chlorophyll catabolite (YCC), named Tc-YCC. The constitution of the two NCCs was determined by spectroscopic means. In addition, a tentative structure was derived for Tc-YCC. The three chlorophyll degradation products exhibited tetrapyrrolic structures, as are typical of NCCs or YCCs, and turned out to be rather polar, due to a glucopyranosyl group at their 8(2)-position. At their 3-positions, the more polar Tc-NCC-1 carried a 1,2-dihydroxyethyl group and the less polar Tc-NCC-2 a vinyl group. Tc-YCC was identified as the product of an oxidation of Tc-NCC-1.
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Affiliation(s)
- Mathias Scherl
- Institute of Organic Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
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35
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Moser S, Müller T, Holzinger A, Lütz C, Kräutler B. Structures of chlorophyll catabolites in bananas (Musa acuminata) reveal a split path of chlorophyll breakdown in a ripening fruit. Chemistry 2012; 18:10873-85. [PMID: 22807397 PMCID: PMC3499688 DOI: 10.1002/chem.201201023] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Indexed: 11/29/2022]
Abstract
The disappearance of chlorophyll is a visual sign of fruit ripening. Yet, chlorophyll breakdown in fruit has hardly been explored; its non-green degradation products are largely unknown. Here we report the analysis and structure elucidation of colorless tetrapyrrolic chlorophyll breakdown products in commercially available, ripening bananas (Musa acuminata, Cavendish cultivar). In banana peels, chlorophyll catabolites were found in an unprecedented structural richness: a variety of new fluorescent chlorophyll catabolites (FCCs) and nonfluorescent chlorophyll catabolites (NCCs) were detected. As a rule, FCCs exist only "fleetingly" and are hard to observe. However, in bananas several of the FCCs (named Mc-FCCs) were persistent and carried an ester function at the propionate side-chain. NCCs were less abundant, and exhibited a free propionic acid group, but functional modifications elsewhere. The modifications of NCCs in banana peels were similar to those found in NCCs from senescent leaves. They are presumed to be introduced by enzymatic transformations at the stage of the mostly unobserved, direct FCC-precursors. The observed divergent functional group characteristics of the Mc-FCCs versus those of the Mc-NCCs indicated two major "late" processing lines of chlorophyll breakdown in ripening bananas. The "last common precursor" at the branching point to either the persistent FCCs, or towards the NCCs, was identified as a temporarily abundant "secondary" FCC. The existence of two "downstream" branches of chlorophyll breakdown in banana peels, and the striking accumulation of persistent Mc-FCCs call for attention as to the still-elusive biological roles of the resulting colorless linear tetrapyrroles.
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Affiliation(s)
- Simone Moser
- Institute of Organic Chemistry, University of Innsbruck6020 Innsbruck (Austria)
- Center for Molecular Biosciences (CMBI), University of Innsbruck6020 Innsbruck (Austria)
- Present address: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne1015 Lausanne (Switzerland)
| | - Thomas Müller
- Institute of Organic Chemistry, University of Innsbruck6020 Innsbruck (Austria)
- Center for Molecular Biosciences (CMBI), University of Innsbruck6020 Innsbruck (Austria)
| | - Andreas Holzinger
- Institute of Botany, University of Innsbruck6020 Innsbruck (Austria)
| | - Cornelius Lütz
- Institute of Botany, University of Innsbruck6020 Innsbruck (Austria)
| | - Bernhard Kräutler
- Institute of Organic Chemistry, University of Innsbruck6020 Innsbruck (Austria)
- Center for Molecular Biosciences (CMBI), University of Innsbruck6020 Innsbruck (Austria)
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36
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Schwardt O, Rabbani S, Hartmann M, Abgottspon D, Wittwer M, Kleeb S, Zalewski A, Smieško M, Cutting B, Ernst B. Design, synthesis and biological evaluation of mannosyl triazoles as FimH antagonists. Bioorg Med Chem 2011; 19:6454-73. [DOI: 10.1016/j.bmc.2011.08.057] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 08/24/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022]
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Fan Y, Hou Y, Xiang J, Yu D, Wu C, Tian M, Han Y, Wang Y. Synthesis and aggregation behavior of a hexameric quaternary ammonium surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10570-10579. [PMID: 21797217 DOI: 10.1021/la202453c] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A star-shaped hexameric quaternary ammonium surfactant (PAHB), bearing six hydrophobic chains and six charged hydrophilic headgroups connected by an amide-type spacer group, was synthesized. The self-assembly behavior of the surfactant in aqueous solution was studied by surface tension, electrical conductivity, isothermal titration microcalorimetry, dynamic light scattering, cryogenic transmission electron microscopy, and NMR techniques. The results reveal that there are two critical aggregate concentrations during the process of aggregation, namely C(1) and C(2). The aggregate transitions are proved to be caused by the changes of the surfactant configuration through hydrophobic interaction among the hydrocarbon chains. Below C(1), PAHB may present a star-shaped molecular configuration due to intramolecular electrostatic repulsion among the charged headgroups, and large aggregates with network-like structure are observed. Between C(1) and C(2), the hydrophobic interaction among the hydrophobic chains may become stronger to make the hydrophobic chains of the PAHB molecules curve back and pack more closely, and then the network-like aggregates transfer to large spherical aggregates of ∼100 nm. Beyond C(2), the hydrophobic interaction may become strong enough to cause the PAHB molecular configuration to turn into a pyramid-like shape, resulting in the transition of the spherical large aggregates to spherical micelles of ∼10 nm. Interestingly, the PAHB displays high emulsification ability to linear fatty alkyls even at very low concentration.
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Affiliation(s)
- Yaxun Fan
- Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
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38
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Fedosov SN, Ruetz M, Gruber K, Fedosova NU, Kräutler B. A Blue Corrinoid from Partial Degradation of Vitamin B12 in Aqueous Bicarbonate: Spectra, Structure, and Interaction with Proteins of B12 Transport. Biochemistry 2011; 50:8090-101. [DOI: 10.1021/bi200724s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergey N. Fedosov
- Department of Molecular Biology
and Genetics, Aarhus University, Science
Park, Gustav Wieds Vej 10, DK 8000 Aarhus C, Denmark
| | - Markus Ruetz
- Institute of Organic Chemistry
and Center of Molecular Biosciences, University of Innsbruck, Innrain 52A, Innsbruck A-6020, Austria
| | - Karl Gruber
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/3, Graz A-8010,
Austria
| | - Natalya U. Fedosova
- Department of Biomedicine, Aarhus University, Ole Worms Alle 1185, DK 8000 Aarhus
C, Denmark
| | - Bernhard Kräutler
- Institute of Organic Chemistry
and Center of Molecular Biosciences, University of Innsbruck, Innrain 52A, Innsbruck A-6020, Austria
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Chandrashekar S, Shrot Y, Frydman L. A double-Fourier approach to enhance the efficiency of the indirect domain sampling in 2D NMR. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2011; 49:477-482. [PMID: 21761450 DOI: 10.1002/mrc.2769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 04/24/2011] [Accepted: 04/28/2011] [Indexed: 05/31/2023]
Abstract
The relatively long times that may be involved in high-resolution two-dimensional nuclear magnetic resonance (2D NMR) have stimulated the search for alternative schemes to collect these data. Particularly onerous situations arise when both high-resolution and large spectral widths are sought along the indirect domain. Strategies proposed for dealing with such cases include folding-over procedures, Hadamard encoding, and nonlinear data sampling. This communication discusses an alternative strategy, which exploits a partial prior knowledge regarding the position of the NMR resonances along the indirect domain together with customized excitations for every particular t1 increment, to achieve an optimal sampling in terms of resolution and bandwidth. On the basis of such optimized encoding of the indirect-domain evolution, which can easily be coped with by modern spectrometers, it becomes possible to maximize the resolution of fine structures without compromising on the spectral bandwidths. The processing of the resulting data along the indirect domain is based on the use of two serially applied discrete Fourier transforms; one to distinguish the main bands in the spectrum and the other to resolve the latter's fine features. A number of simple heteronuclear correlation experiments illustrating the significant acquisition time savings and simultaneous improvements in resolution that can be achieved with the resulting double-Fourier encoding procedure are illustrated.
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40
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41
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Ulrich M, Moser S, Müller T, Kräutler B. How the colourless 'nonfluorescent' chlorophyll catabolites rust. Chemistry 2011; 17:2330-4. [PMID: 21308817 PMCID: PMC3072522 DOI: 10.1002/chem.201003313] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Indexed: 12/01/2022]
Affiliation(s)
- Markus Ulrich
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 52a, 6020 Innsbruck, Austria
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42
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Banala S, Moser S, Müller T, Kreutz C, Holzinger A, Lütz C, Kräutler B. Hypermodified fluorescent chlorophyll catabolites: source of blue luminescence in senescent leaves. Angew Chem Int Ed Engl 2010; 49:5174-7. [PMID: 20533476 DOI: 10.1002/anie.201000294] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Srinivas Banala
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
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43
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Hajjar R, Millot Y, Man PP. Phase cycling in MQMAS sequences for half-integer quadrupole spins. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 57:306-342. [PMID: 20667403 DOI: 10.1016/j.pnmrs.2010.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 05/11/2010] [Indexed: 05/29/2023]
Affiliation(s)
- Redouane Hajjar
- UPMC Univ Paris 06, FRE 3230, Laboratoire RMN des Matériaux Nanoporeux, 4 Place Jussieu, F-75005 Paris, France
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A novel blue fluorescent chlorophyll catabolite accumulates in senescent leaves of the peace lily and indicates a split path of chlorophyll breakdown. FEBS Lett 2010; 584:4215-21. [DOI: 10.1016/j.febslet.2010.09.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 09/04/2010] [Accepted: 09/06/2010] [Indexed: 12/20/2022]
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45
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46
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Mezzato S, Unverzagt C. Synthesis of an Fmoc-Asn-heptasaccharide building block and its application to chemoenzymatic glycopeptide synthesis. Carbohydr Res 2010; 345:1306-15. [DOI: 10.1016/j.carres.2010.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 02/22/2010] [Accepted: 02/24/2010] [Indexed: 02/06/2023]
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47
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Banala S, Moser S, Müller T, Kreutz C, Holzinger A, Lütz C, Kräutler B. Hypermodifizierte fluoreszierende Chlorophyllkataboliten als Quelle blauer Lumineszenz in seneszenten Blättern. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201000294] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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48
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Charisiadis P, Exarchou V, Troganis AN, Gerothanassis IP. Exploring the "forgotten"-OH NMR spectral region in natural products. Chem Commun (Camb) 2010; 46:3589-91. [PMID: 20376399 DOI: 10.1039/b927256a] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Significantly enhanced resolution in the -OH NMR spectral region was observed which, in combination with 2D (1)H-(13)C HMBC techniques, will open new avenues in structure analysis of natural products with phenol type -OH groups in complex natural extracts without the need of laborious isolation of the individual compounds.
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Affiliation(s)
- Pantelis Charisiadis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece
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49
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Laufer B, Frank A, Chatterjee J, Neubauer T, Mas-Moruno C, Kummerlöwe G, Kessler H. The Impact of Amino Acid Side Chain Mutations in Conformational Design of Peptides and Proteins. Chemistry 2010; 16:5385-90. [DOI: 10.1002/chem.201000545] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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50
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Shrot Y, Frydman L. Spatial/spectral encoding of the spin interactions in ultrafast multidimensional NMR. J Chem Phys 2009; 131:224516. [DOI: 10.1063/1.3266422] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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