scholarly journals Leloir Glycosyltransferases in Applied Biocatalysis: A Multidisciplinary Approach

2019 ◽  
Vol 20 (21) ◽  
pp. 5263 ◽  
Author(s):  
Mestrom ◽  
Przypis ◽  
Kowalczykiewicz ◽  
Pollender ◽  
Kumpf ◽  
...  
Keyword(s):  
Multidisciplinary Approach ◽  
Efficient Production ◽  
Nucleotide Sugar ◽  
One Pot ◽  
Recent Advances ◽  
Excellent Control ◽  
Efficient Coupling ◽  
Synthetic Routes ◽  
The Way

Enzymes are nature’s catalyst of choice for the highly selective and efficient coupling of carbohydrates. Enzymatic sugar coupling is a competitive technology for industrial glycosylation reactions, since chemical synthetic routes require extensive use of laborious protection group manipulations and often lack regio- and stereoselectivity. The application of Leloir glycosyltransferases has received considerable attention in recent years and offers excellent control over the reactivity and selectivity of glycosylation reactions with unprotected carbohydrates, paving the way for previously inaccessible synthetic routes. The development of nucleotide recycling cascades has allowed for the efficient production and reuse of nucleotide sugar donors in robust one-pot multi-enzyme glycosylation cascades. In this way, large glycans and glycoconjugates with complex stereochemistry can be constructed. With recent advances, LeLoir glycosyltransferases are close to being applied industrially in multi-enzyme, programmable cascade glycosylations.

scholarly journals 1,3-Diketone Calix[4]arene Derivatives—A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1214
Author(s):  
Sergey N. Podyachev ◽  
Rustem R. Zairov ◽  
Asiya R. Mustafina
Keyword(s):  
Structural Diversity ◽  
Building Blocks ◽  
Structural Features ◽  
Structure Property ◽  
One Pot ◽  
Arene Ligands ◽  
Structure Property Relationships ◽  
New Type ◽  
Synthetic Routes ◽  
Magnetic Resonance Imaging Mri

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.

Empty Shelves on the Palatine

1993 ◽  
Vol 40 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Nicholas Horsfall
Keyword(s):  
Multidisciplinary Approach ◽  
Art Historians ◽  
Cross Fertilization ◽  
The Way

The way we study Augustus’ Rome has been changing dramatically: I do not mean so much new discoveries of monuments or inscriptions, exciting though they have been, as the new-found disposition of archaeologists, art-historians, epigraphists, and Latinists to talk to each other and to admit cross-fertilization into their work; this spirit of co-operation has engendered a large bibliography, and one only regrets that the sort of multidisciplinary approach that was self-evident to the best Hellenists in Germany 150 years ago has been so painfully slow in reaching Latin studies!

Recent advances and new concepts for the synthesis of axially stereoenriched biaryls

2015 ◽  
Vol 44 (11) ◽  
pp. 3418-3430 ◽  
Author(s):  
J. Wencel-Delord ◽  
A. Panossian ◽  
F. R. Leroux ◽  
F. Colobert
Keyword(s):  
Chiral Compounds ◽  
The Past ◽  
Recent Advances ◽  
New Concepts ◽  
Axially Chiral ◽  
Recent Developments ◽  
Synthetic Routes

Over the past decade the field of the synthesis of axially chiral compounds has been rapidly expanding. Not only key advances have been achieved concerning the already established strategies but also new synthetic routes have been devised. This review showcases the recent developments in this domain.

The Structure and Synthesis of Cytokinin Metabolites. 1. The 7- and 9-β-D-Glucofuranosides and Pyranosides of Zeatin and 6-Benzylaminopurine

1978 ◽  
Vol 31 (5) ◽  
pp. 1095 ◽  
Author(s):  
DE Cowley ◽  
CC Duke ◽  
AJ Liepa ◽  
JK Macleod ◽  
DS Letham
Keyword(s):  
Pyrimidine Ring ◽  
Ring Closure ◽  
Imidazole Derivative ◽  
High Yield ◽  
Ring Size ◽  
Plant Metabolites ◽  
One Pot ◽  
Synthetic Routes

The structures of the major stable plant metabolites of the cytokinins zeatin and 6-benzylaminopurine have been confirmed by synthesis to be 7- and 9-β-D-glucopyranosides. The small quantities of metabolites initially isolated (< 100 μg) precluded assignment of the glucose ring size or configuration of the anomeric linkage so that synthesis of both the furanose and pyranose forms of 7-β-D- and 9-β-D-glucosylzeatin and 6-benzylaminopurine was undertaken which allowed direct u.v., m.s. and t.l.c. comparison with the metabolites. Numerous synthetic routes to the unusual 7-glucosides of the two cytokinins were explored, the most successful utilizing a one-pot pyrimidine ring closure of an imidazole derivative to afford directly in high yield the required 7-glucosides of zeatin and 6-benzylaminopurine.

Recent advances in cyclohydrocarbonylation reactions

2005 ◽  
Vol 83 (6-7) ◽  
pp. 681-692 ◽  
Author(s):  
Wen-Hua Chiou ◽  
Seung-Yub Lee ◽  
Iwao Ojima
Keyword(s):  
Transition Metal Complexes ◽  
Relevant Literature ◽  
Cascade Process ◽  
One Pot ◽  
Polycyclic Compounds ◽  
Carbon Nucleophiles ◽  
Recent Advances ◽  
Carbocyclic Compounds ◽  
Cascade Processes ◽  
One Step

This article describes recent advances in the cyclohydrocarbonylation reactions catalyzed by transition-metal complexes and their applications in organic synthesis as a review covering the relevant literature up to the middle of 2004. The reactions are categorized into four types, i.e., intramolecular amidocarbonylation reactions, intramolecular aminocarbonylation reactions, cyclohydrocarbonylation reactions involving carbon–nucleophiles, and other cyclohydrocarbonylation reactions. Cyclohydrocarbonylation reactions provide efficient routes to various monocyclic, bicyclic, and polycyclic compounds as a one-step cascade process or a one-pot process. Reaction mechanisms for these cascade processes are discussed as needed for clarification. The heterocyclic and carbocyclic compounds, thus obtained, can be further transformed to specific targets. Examples of such applications are also discussed.Key words: catalysis, cyclohydrocarbonylation, hydroformylation, amidocarbonylation, cyclization, regioselectivity, aldehydes, regioselective, cascade, heterocycles, rhodium.

One-pot synthesis of PMMA/montmorillonite nanocomposites

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Adam Kiersnowski ◽  
Maria Trelinska-Wlazlak ◽  
Justyna Dolega ◽  
Jacek Piglowski
Keyword(s):  
Single Step ◽  
Layered Silicates ◽  
Trimethylammonium Chloride ◽  
One Pot ◽  
Structural Investigations ◽  
Preparation Methods ◽  
Simple Preparation ◽  
Acrylic Copolymers ◽  
Synthetic Routes ◽  
Montmorillonite Nanocomposites

AbstractThis article describes simple preparation methods of poly(methyl methacrylate) (PMMA)/synthetic montmorillonite nanocomposites by single-step insitu polymerizations. Compatibility between PMMA and the silicate was ensured by an addition of (3-acrylamidepropyl) trimethylammonium chloride (AAPTMA). The work also compares how different synthetic routes, namely emulsion and solution polymerization, affect the structure as well as thermal and mechanical properties of obtained nanocomposites. The results of structural investigations clearly show, that both the techniques lead to intercalated nanocomposites, but emulsion polymerization allows more effective deflocculating and intercalating of the clay with acrylic copolymers. The addition of small amounts of layered silicates causes an increase in thermal stability and stiffness of the materials. It is demonstrated that at 5 wt. % of the filler, the temperature of 10 % weight loss was shifted up by nearly 50 K in comparison to the neat PMMA. In the same sample, the Young’s modulus of the material was found to be increased by 26 %.

scholarly journals Dating Early Christian Papyri: Old and New Methods – Introduction

2019 ◽  
Vol 42 (1) ◽  
pp. 46-57
Author(s):  
Roberta Mazza
Keyword(s):  
Raman Spectroscopy ◽  
Radiocarbon Dating ◽  
Multidisciplinary Approach ◽  
Ancient Text ◽  
Early Christian ◽  
New Methods ◽  
Scientific Analysis ◽  
Academic Publications ◽  
The Way

This article provides a methodological introduction to the issues and questions raised in the dossier: How can we attribute a date to ancient papyri when it is not indicated in the text? What methods have been employed so far for dating and how reliable are they? What kind of conscious and unconscious biases underpin the attribution of a date to Christian papyri in particular? Is scientific analysis a more reliable means than palaeography to establish the age of composition of an ancient text? After discussing some research performed on papyri from the Rylands collection, bearing early Christian texts, the author addresses some of the strengths and pitfalls of any of the methods currently available, ranging from palaeography to radiocarbon dating and Raman spectroscopy. In conclusion, it is argued that more clarity and transparency are needed in the way motivations for attributing a date to a fragment are provided in academic publications and that only a multidisciplinary approach can partially overcome the problems at stake.

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