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1. Basic understanding of the color distinction of lignin and the proper selection of lignin in color-depended utilizations.

Author

Zhang H, Fu S, and Chen Y

Subjects
Lignin classification, Lignin isolation & purification, Lignin ultrastructure, Microscopy, Electron, Scanning, Color, Lignin chemistry, Molecular Structure
Abstract

Lignin based materials and chemicals with outstanding sustainability have drawn increasingly attentions. However, the dark color of lignin limits the utilization in color-depended fields. In this work, the factors that influence the color of lignin were investigated and mechanisms were illustrated by GPC, NBO, 2D HSQC, XPS, SEM, and visible light spectrum. It is found that the condensed structures were mainly separated at higher pH due to its high molecular weight and low solubility. The condensation contributes to the conjugation and unsaturation, which resulted in the dark-color of the lignin precipitated at high pH value. The oxidation is not crucial for the color darkening of lignin in drying, it is the micro aggregation that dominantly determined the color degree. The concentration of chromophore was decreased owing to the decrease of bulk density (caused by the alleviation of aggregation), which endowed lignin with the bright seeing macroscopically. Notably, the selection of light-colored lignin needs to be individually considered regarding different use, since the dominating factors that influence the color at solid or solution are totally different. In summary, this work offers guidance for acquiring light-colored lignin and helps people select the light-colored lignin properly regarding utilizations., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Published
2020
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2. Revealing the structure and distribution changes of Eucalyptus lignin during the hydrothermal and alkaline pretreatments.

Author

Wang C, Li H, Li M, Bian J, and Sun R

Subjects
Carbohydrates chemistry, Lignin ultrastructure, Magnetic Resonance Spectroscopy, Molecular Weight, Nonlinear Optical Microscopy, Sugars chemistry, Alkalies chemistry, Eucalyptus chemistry, Lignin chemistry, Molecular Structure, Temperature
Abstract

An integrated pretreatment process based on hydrothermal pretreatment (HTP) followed by alkaline pretreatment has been applied to treat Eucalyptus. The chemical composition and structure changes of lignin during the pretreatment were comprehensively characterized. The surface morphology of the cell walls and lignin distribution of the pretreated Eucalyptus were detected by scanning electron and confocal Raman microscopies. It was found that the chemical bonds between lignin and hemicelluloses were cleaved during the pretreatment. The results also indicated that the contents of β-O-4', β-β', and β-5' linkages were decreased with the increase of hydrothermal pretreatment temperature and the cleavage of β-O-4' linkages in lignin was accompanied with repolymerization reactions. 31 P NMR analysis showed that the content of aliphatic OH was reduced as the temperature increased and the total phenolic OH was elevated and then declined with the increase of temperature. Raman spectra analysis revealed that the dissolution rate of lignin in the secondary wall regions was faster than that in cell corner middle lamella regions during the pretreatment. These results will enhance the understanding of the cell wall deconstruction during the pretreatment and the mechanism of the integrated pretreatment process acting on Eucalyptus.

Published
2017
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3. Can individual fatty acids be used as functional biomarkers of dairy fat consumption in relation to cardiometabolic health? A narrative review.

Author

Sellem, Laury, Jackson, Kim G., Paper, Laura, Givens, Ian D., and Lovegrove, Julie A.

Subjects
CARDIOVASCULAR disease related mortality, BIOMARKERS, CARDIOVASCULAR diseases risk factors, NUTRITIONAL assessment, SERUM, BLOOD plasma, GLYCEMIC control, GUT microbiome, HEALTH status indicators, DAIRY products, TYPE 2 diabetes, METABOLIC disorders, RISK assessment, METABOLIC syndrome, MOLECULAR structure, FATTY acids, DIETARY fats, SHORT-chain fatty acids
Abstract

In epidemiological studies, dairy food consumption has been associated with minimal effect or decreased risk of some cardiometabolic diseases (CMD). However, current methods of dietary assessment do not provide objective and accurate measures of food intakes. Thus, the identification of valid and reliable biomarkers of dairy product intake is an important challenge to best determine the relationship between dairy consumption and health status. This review investigated potential biomarkers of dairy fat consumption, such as odd-chain, trans- and branched-chain fatty acids (FA), which may improve the assessment of full-fat dairy product consumption. Overall, the current use of serum/plasma FA as biomarkers of dairy fat consumption is mostly based on observational evidence, with a lack of well-controlled, dose–response intervention studies to accurately assess the strength of the relationship. Circulating odd-chain SFA and trans-palmitoleic acid are increasingly studied in relation to CMD risk and seem to be consistently associated with a reduced risk of type 2 diabetes in prospective cohort studies. However, associations with CVD are less clear. Overall, adding less studied FA such as vaccenic and phytanic acids to the current available evidence may provide a more complete assessment of dairy fat intake and minimise potential confounding from endogenous synthesis. Finally, the current evidence base on the direct effect of dairy fatty acids on established biomarkers of CMD risk (e.g. fasting lipid profiles and markers of glycaemic control) mostly derives from cross-sectional, animal and in vitro studies and should be strengthened by well-controlled human intervention studies. [ABSTRACT FROM AUTHOR]

Published
2022
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4. Natural Products as Angiogenesis Inhibitors

Author

D. H. Paper

Subjects
Adult, Angiogenesis, Pharmaceutical Science, Inflammation, Endogeny, Biology, Analytical Chemistry, Neovascularization, Pathogenesis, Drug Discovery, medicine, Animals, Humans, Pharmacology, Molecular Structure, Neovascularization, Pathologic, Plant Extracts, Organic Chemistry, Cancer, medicine.disease, Angiogenesis inhibitor, Complementary and alternative medicine, Immunology, Cancer research, Molecular Medicine, medicine.symptom, Wound healing
Abstract

Angiogenesis is a strictly controlled process in the healthy, adult human body. It is regulated by a variety of endogenous angiogenic and angiostatic factors. It is only switched on, e.g., during wound healing. Pathological angiogenesis occurs, for example, in cancer, chronic inflammation, or atherosclerosis. Angiogenesis inhibitors are able to interfere with various steps of angiogenesis, like basement destruction of blood vessels, proliferation and migration of endothelial cells, or the lumen formation. Among the known angiogenesis inhibitors compounds derived from natural sources, like flavonoids, sulphated carbohydrates, or triterpenoids are playing a prominent role.

Published
1998

5. Sulfemodin 8-O-β-<scp>d</scp>-Glucoside, a New Sulfated Anthraquinone Glycoside, and Antioxidant Phenolic Compounds from Rheum emodi

Author

Riddhi Pradhan, B. Kopp, Beate Bahr, Klaus K. Mayer, Liselotte Krenn, D. H. Paper, and Armin Presser

Subjects
DPPH, Pharmaceutical Science, Anthraquinones, Plant Roots, Antioxidants, Analytical Chemistry, Inhibitory Concentration 50, chemistry.chemical_compound, Nepal, Picrates, Glucoside, Drug Discovery, Organic chemistry, Glycosides, Phenols, Rheum, Nuclear Magnetic Resonance, Biomolecular, Benzofurans, Pharmacology, chemistry.chemical_classification, Plants, Medicinal, Molecular Structure, biology, Rheum emodi, Biphenyl Compounds, Organic Chemistry, Glycoside, biology.organism_classification, Biphenyl compound, Complementary and alternative medicine, chemistry, Molecular Medicine, Emodin
Abstract

A sulfated emodin glucoside, emodin 8-O-beta-D-glucopyranosyl-6-O-sulfate (1), was isolated from the roots of Rheum emodi in an investigation of the active constituents of this Nepalese medicinal plant, and its structure was determined by spectroscopic and chemical methods. Additionally, two rare auronols, carpusin (2) and maesopsin (3), besides other anthraquinones and phenolics, were isolated and identified. Compounds 2 and 3 showed significant antioxidant activity in the DPPH assay, while chrysophanol, physcion, and emodin and their 8-O-glucosides were found to be inactive.

Published
2003

6. Antiangiogenic activity of synthetic dihydrobenzofuran lignans

Author

Slavka Baronikova, Jutta Bürgermeister, Luc Pieters, Stefaan Van Dyck, D. H. Paper, Sandra Apers, Guy L. F. Lemiere, and A. Vlietinck

Subjects
Magnetic Resonance Spectroscopy, Stereochemistry, Pharmaceutical Science, Stereoisomerism, Angiogenesis Inhibitors, Chemical synthesis, Catalysis, Lignans, Analytical Chemistry, Ferulic acid, chemistry.chemical_compound, Caffeic Acids, Drug Discovery, Organic chemistry, Derivatization, Chromatography, High Pressure Liquid, Benzofurans, Pharmacology, Lignan, Bicyclic molecule, Molecular Structure, Organic Chemistry, Biological activity, Chorion, Chorioallantoic membrane, Complementary and alternative medicine, chemistry, Molecular Medicine, Propionates
Abstract

A series of synthetic dihydrobenzofuran lignans, obtained by biomimetic oxidative dimerization of caffeic or ferulic acid methyl ester followed by derivatization reactions, was tested for its antiangiogenic activity in the CAM (chorioallantoic membrane) assay. The dimerization product of caffeic acid methyl ester (2a) (methyl (E)-3-[2-(3,4-dihydroxyphenyl)-7-hydroxy-3-methoxycarbonyl-2,3-dihydro-1-benzofuran-5-yl]prop-2-enoate) showed a pronounced antiangiogenic activity, especially the 2R,3R-enantiomer.

Published
2002

7. Cationic Biphotonic Lanthanide Luminescent Bioprobes Based on Functionalized Cross-Bridged Cyclam Macrocycles

Author

Amandine Roux, Damien Curton, Maryline Beyler, Raphaël Tripier, Véronique Patinec, Anh Thy Bui, Sophie Brasselet, Olivier Maury, Jean-Christophe Mulatier, Alexei Grichine, Jonathan Mendy, Chantal Andraud, François Riobé, Alain Duperray, Boris Le Guennic, Yannick Guyot, RENARD, NICOLAS, Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Université de Brest (UBO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO), Laboratoire de Chimie - UMR5182 (LC), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institute for Advanced Biosciences / Institut pour l'Avancée des Biosciences (Grenoble) (IAB), Centre Hospitalier Universitaire [Grenoble] (CHU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement français du sang - Auvergne-Rhône-Alpes (EFS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Luminescence (LUMINESCENCE), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), MOSAIC (MOSAIC), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), The authors are grateful to the referees for careful reading of the paper and valuable suggestions and comments. The authors also acknowledge support of the Ministère de l'Enseignement Supérieur et de la Recherche, the Centre National de la Recherche Scientifique, the Institut National de la Santé et de la Recherche Médicale and the Agence Nationale de la Recherche (SADAM ANR‐16‐CE07‐0015‐02). M.B. and R.T. thanks the ‘‘Service Commun de RMN’’ of the University of Brest. Confocal and 2P facility of the IAB platform was co‐funded thanks to grants of 'Association pour la Recherche sur le Cancer' (ARC, Villejuif, France), 'Ligue vs Cancer' (LCC Isère/Ardèche) and the CPER program. B.L.G. thanks the French GENCI‐CINES center for high‐performance computing resources., Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Université de Lyon-Université de Lyon, Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and ANR-16-CE07-0015,SADAM,Diagnostiquer et guérir par des agents azamacrocycliques multimodaux(2016)

Subjects
Lanthanide, Ytterbium, Macrocyclic Compounds, Luminescence, chemistry.chemical_element, 02 engineering and technology, Europium(III), 010402 general chemistry, Photochemistry, 01 natural sciences, Lanthanoid Series Elements, chemistry.chemical_compound, Coordination Complexes, Cations, Cell Line, Tumor, Cyclam, [CHIM] Chemical Sciences, Humans, [CHIM]Chemical Sciences, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Ytterbium(III), Two-photon microscopy, Density Functional Theory, Photons, Aqueous solution, Luminescent Agents, Spectroscopy, Near-Infrared, Molecular Structure, Chemistry, Optical Imaging, Cationic polymerization, Bioprobe, [CHIM.COOR] Chemical Sciences/Coordination chemistry, 021001 nanoscience & nanotechnology, Bioimaging, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Solvent, 0210 nano-technology, Europium
Abstract

Cationic lanthanide complexes are generally able to spontaneously internalize into living cells. Following our previous works based on diMe-cyclen framework, a second generation of cationic water-soluble lanthanide complexes based on a constrained cross-bridged cyclam macrocycle functionalized with donor-p-conjugated picolinate antennas has been prepared with europium(III) and ytterbium(III). Their spectroscopic properties were thoroughly investigated in various solvents and rationalized with the help of DFT calculations. A significant improvement is observed in the case of the Eu3+ complex, while the Yb3+ analogous conserve an excellent brightness in aqueous solvent. Two-photon (2P) microscopy imaging experiments on living T24 human cancer cells confirmed the spontaneous internalization of the probes and images with good signal-to-noise have been obtained in the classical NIR-to-visible configuration with Eu3+ luminescent bioprobe and in the NIR-to-NIR with the Yb3+ one.

Published
2020

8. Minimal NMR distance information for rigidity of protein graphs

Author

Leo Liberti, Benjamin Bardiaux, Michael Nilges, Thérèse E. Malliavin, Bradley Worley, Bruce R. Donald, Carlile Lavor, Instituto de Matemática, Estatística e Computação Científica [Brésil] (IMECC), Universidade Estadual de Campinas (UNICAMP), Laboratoire d'informatique de l'École polytechnique [Palaiseau] (LIX), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Duke University [Durham], Bioinformatique structurale, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), C.L. would like to thank the Brazilian research agencies CNPq, FAPESP and B.D. would like to thank the NIH grants R01 GM-118543 and R01 GM-078031 for their financial support., We are also thankful to Angela Gronenborn and Michael Souza, for discussions that clarify some ideas in the paper, and to anonymous referees that made very important comments to this work., Bioinformatique structurale - Structural Bioinformatics, Universidade Estadual de Campinas = University of Campinas (UNICAMP), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Computational complexity theory, Nuclear Magnetic Resonance, 0211 other engineering and technologies, Structure (category theory), Rigidity (psychology), 0102 computer and information sciences, 02 engineering and technology, [INFO.INFO-DM]Computer Science [cs]/Discrete Mathematics [cs.DM], Topology, 01 natural sciences, Article, Cardinality, Protein structure, Distance Geometry, Discrete Mathematics and Combinatorics, Molecule, Combinatorial search, Mathematics, Quantitative Biology::Biomolecules, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Applied Mathematics, Solution set, 021107 urban & regional planning, [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Vertex orders, 010201 computation theory & mathematics, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM], Molecular structure
Abstract

International audience; Nuclear Magnetic Resonance (NMR) experiments provide distances between nearby atoms of a protein molecule. The corresponding structure determination problem is to determine the 3D protein structure by exploiting such distances. We present a new order on the atoms of the protein, based on information from the chemistry of proteins and NMR experiments, which allows us to formulate the problem as a combinatorial search. Additionally, this order tells us what kind of NMR distance information is crucial to understand the cardinality of the solution set of the problem and its computational complexity.

Published
2019