jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Manuel Nieto‐Domínguez | Beatriz Fernández de Toro | Laura I. de Eugenio | Andrés G. Santana | Lara Bejarano-Muñoz | Zachary Armstrong | Juan A. Méndez-Líter | Juan Luis Asensio | Alicia Prieto | Stephen G. Withers | F. Javier Cañada | Marı́a Jesús Martı́nez
Source: Nature Communications (article, 2020-09-25)
Field: Chemistry — Organic Chemistry

Thioglycoligase derived from fungal GH3 β-xylosidase is a multi-glycoligase with broad acceptor tolerance The synthesis of customized glycoconjugates constitutes a major goal for biocatalysis. To this end, engineered glycosidases have received great attention and, among them, thioglycoligases have proved useful to connect carbohydrates to non-sugar acceptors. However, hitherto the scope of these biocatalysts was considered limited to strong nucleophilic acceptors. Based on the particularities of the GH3 glycosidase family active site, we hypothesized that converting a suitable member into a thioglycoligase could boost the acceptor range. Herein we show the engineering of an acidophilic fungal β-xylosidase into a thioglycoligase with broad acceptor promiscuity. The mutant enzyme displays the ability to form O-, N-, S- and Se- glycosides together with sugar esters and phosphoesters with conversion yields from moderate to high. Analyses also indicate that the pK<sub>a</sub> of the target compound was the main factor to determine its suitability as glycosylation acceptor. These results expand on the glycoconjugate portfolio attainable through biocatalysis. Biocatalysis ; Glycoconjugate ; Acceptor ; Chemistry ; Glycosylation ; Protein engineering ; Glycoside hydrolase ; Biochemistry ; Enzyme ; Mutant ; Stereochemistry ; Combinatorial chemistry ; Catalysis ; Gene Carbohydrate Chemistry and Synthesis ; Enzyme Production and Characterization ; Glycosylation and Glycoproteins Research
Authors: Özgün Can Önder | Petra Utroša | Simon Caserman | Marjetka Podobnik | Magda Tušek Žnidarič | Jože Grdadolnik | Sebastijan Kovačič | Ema Žagar | David Pahovnik
Source: Polymer Chemistry (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Emulsion-templated synthetic polypeptide scaffolds prepared by ring-opening polymerization of<i>N</i>-carboxyanhydrides Ring-opening polymerization of<italic>N</italic>-carboxyanhydrides was performed in oil-in-oil high internal phase emulsion to obtain well-defined macroporous synthetic polypeptides. Polymerization ; Chemistry ; Emulsion ; Ring-opening polymerization ; Polymer chemistry ; Emulsion polymerization ; Phase (matter) ; Ring (chemistry) ; Chemical engineering ; Organic chemistry ; Polymer Pickering emulsions and particle stabilization ; Advanced Polymer Synthesis and Characterization ; Supramolecular Self-Assembly in Materials
Authors: Anatolii Abalymov | Bogdan V. Parakhonskiy | André G. Skirtach
Source: Colloids and Surfaces A Physicochemical and Engineering Aspects (article, 2020-06-20)
Field: Materials Science — Surfaces, Coatings and Films

Colloids-at-surfaces: Physicochemical approaches for facilitating cell adhesion on hybrid hydrogels Self-healing hydrogels ; Nanotechnology ; Materials science ; Biomolecule ; Colloid ; Adhesion ; Surface modification ; Colloidal particle ; Nano- ; Chemical engineering ; Composite material ; Polymer chemistry Polymer Surface Interaction Studies ; 3D Printing in Biomedical Research ; Cellular Mechanics and Interactions
Authors: Jung-Seop Lee | In‐ho Song | Pramod B. Shinde | Satish Balasaheb Nimse
Source: Antioxidants (review, 2020-09-14)
Field: Chemistry — Spectroscopy

Macrocycles and Supramolecules as Antioxidants: Excellent Scaffolds for Development of Potential Therapeutic Agents Oxidative stress due to the high levels of reactive oxygen species (ROS) that damage biomolecules (lipids, proteins, DNA) results in acute inflammation. However, without proper intervention, acute inflammation progresses to chronic inflammation and then to several chronic diseases, including cancer, myocardial infarction, cardiovascular diseases, chronic inflammation, atherosclerosis, and more. There has been extensive research on the antioxidants of natural origin. However, there are myriad possibilities for the development of synthetic antioxidants for pharmacological applications. There is an increasing interest in the identification of novel synthetic antioxidants for the modulation of biochemical processes related to ROS. In this regard, derivatives of supramolecules, such as calix[n]arene, resorcinarene, calixtyrosol, calixpyrrole, cucurbit[n]uril, porphyrin etc. are gaining attention for their abilities to scavenge the free radicals. Supramolecular chemistry offers excellent scaffolds for the development of novel antioxidants that can be used to modulate free radical reactions and to improve the disorders related to oxidative stress. This review focuses on the interdisciplinary approach for the design and development of novel synthetic antioxidants based on supramolecular scaffolds, with potentially protective effects against oxidative stress. Oxidative stress ; Inflammation ; Chemistry ; Reactive oxygen species ; Supramolecular chemistry ; Pharmacology ; Biochemistry ; Medicine ; Immunology ; Organic chemistry ; Molecule Molecular Sensors and Ion Detection ; Porphyrin and Phthalocyanine Chemistry ; Supramolecular Chemistry and Complexes
Authors: Ghada Manai | Hend Houimel | Mathilde Rigoulet | Angélique Gillet | Pier‐Francesco Fazzini | Alfonso Ibarra | Stéphanie Balor | Pierre Roblin | Jérôme Esvan | Yannick Coppel | Bruno Chaudret | Colin Bonduelle | Simon Tricard
Source: Nature Communications (article, 2020-04-28)
Field: Materials Science — Biomaterials

Bidimensional lamellar assembly by coordination of peptidic homopolymers to platinum nanoparticles A key challenge for designing hybrid materials is the development of chemical tools to control the organization of inorganic nanoobjects at low scales, from mesoscopic (~µm) to nanometric (~nm). So far, the most efficient strategy to align assemblies of nanoparticles consists in a bottom-up approach by decorating block copolymer lamellae with nanoobjects. This well accomplished procedure is nonetheless limited by the thermodynamic constraints that govern copolymer assembly, the entropy of mixing as described by the Flory-Huggins solution theory supplemented by the critical influence of the volume fraction of the block components. Here we show that a completely different approach can lead to tunable 2D lamellar organization of nanoparticles with homopolymers only, on condition that few elementary rules are respected: 1) the polymer spontaneously allows a structural preorganization, 2) the polymer owns functional groups that interact with the nanoparticle surface, 3) the nanoparticles show a surface accessible for coordination. Lamellar structure ; Platinum ; Nanoparticle ; Platinum nanoparticles ; Materials science ; Nanotechnology ; Self-assembly ; Chemical engineering ; Chemistry ; Organic chemistry ; Catalysis ; Metallurgy Supramolecular Self-Assembly in Materials ; Surface Chemistry and Catalysis ; Polymer Surface Interaction Studies
Authors: Mihaela Badea | Valentina Uivaroşi | Rodica Olar
Source: Molecules (review, 2020-12-10)
Field: Materials Science — Biomaterials

Improvement in the Pharmacological Profile of Copper Biological Active Complexes by Their Incorporation into Organic or Inorganic Matrix Every year, more Cu(II) complexes are proven to be biologically active species, but very few are developed as drugs or entered in clinical trials. This is due to their poor water solubility and lipophilicity, low stability as well as in vivo inactivation. The possibility to improve their pharmacological and/or oral administration profile by incorporation into inorganic or organic matrix was studied. Most of them are either physically encapsulated or conjugated to the matrix via a moiety able to coordinate Cu(II). As a result, a large variety of species were developed as delivery carriers. The organic carriers include liposomes, synthetic or natural polymers or dendrimers, while the inorganic ones are based on carbon nanotubes, hydrotalcite and silica. Some hybrid organic-inorganic materials based on alginate-carbonate, gold-PEG and magnetic mesoporous silica-Schiff base were also developed for this purpose. Chemistry ; Lipophilicity ; Copper ; Hydrotalcite ; Conjugated system ; Combinatorial chemistry ; Solubility ; Polymer ; Organic chemistry ; Catalysis Nanoparticle-Based Drug Delivery ; Metal complexes synthesis and properties ; Lanthanide and Transition Metal Complexes
Authors: Julien Es Sayed | Cédric Lorthioir | Philippe Banet | Patrick Perrin | Nicolas Sanson
Source: Angewandte Chemie International Edition (article, 2020-02-07)
Field: Materials Science — Materials Chemistry

Reversible Assembly of Microgels by Metallo‐Supramolecular Chemistry The combination of supramolecular chemistry and soft colloids as microgels represents an ambitious way to develop multi-versatile colloidal assemblies. Hereafter, terpyridine-functionalized poly(N-isopropylacrylamide) (PNiPAM) microgel building blocks are shown to undergo an assemble-freeze-disassemble process. The microgel assemblies, which are controlled by monitoring the attractive and repulsive potentials between the soft colloidal particles, are then frozen by forming inter-particle metal-terpyridine bis-complexes upon addition of the metallic cation (such as Fe<sup>II</sup> , Co<sup>II</sup> ). By oxidation of the metal-terpyridine bis-complex links, the aggregates open up, which is due to the complex dissociation releasing the connected particles in the form of single microgels. We extended our work to the development of 1D filaments and 2D membranes materials made of soft particles connected via supramolecular chemistry. Terpyridine ; Supramolecular chemistry ; Colloid ; Nanotechnology ; Soft materials ; Chemistry ; Dissociation (chemistry) ; Metal ; Self-assembly ; Colloidal particle ; Polymer chemistry ; Membrane ; Chemical engineering ; Materials science ; Molecule ; Organic chemistry Pickering emulsions and particle stabilization ; Hydrogels: synthesis, properties, applications ; Micro and Nano Robotics
Authors: Goreti Ribeiro Morais | Robert A. Falconer
Source: Organic & Biomolecular Chemistry (review, 2020-11-10)
Field: Chemistry — Organic Chemistry

Glycosyl disulfides: importance, synthesis and application to chemical and biological systems The disulfide bond plays an important role in the formation and stabilisation of higher order structures of peptides and proteins, while in recent years interest in this functional group has been extended to carbohydrate chemistry. Rarely found in nature, glycosyl disulfides have attracted significant attention as glycomimetics, with wide biological applications including lectin binding, as key components of dynamic libraries to study carbohydrate structures, the study of metabolic and enzymatic studies, and even as potential drug molecules. This interest has been accompanied and fuelled by the continuous development of new methods to construct the disulfide bond at the anomeric centre. Glycosyl disulfides have also been exploited as versatile intermediates in carbohydrate synthesis, particularly as glycosyl donors. This review focuses on the importance of the disulfide bond in glycobiology and in chemistry, evaluating the different methods available to synthesise glycosyl disulfides. Furthermore, we review the role of glycosyl disulfides as intermediates and/or glycosyl donors for the synthesis of neoglycoproteins and oligosaccharides, before finally considering examples of how this important class of carbohydrates have made an impact in biological and therapeutic contexts. Glycosyl ; Chemistry ; Carbohydrate synthesis ; Combinatorial chemistry ; Biochemical engineering ; Biochemistry ; Carbohydrate ; Engineering Carbohydrate Chemistry and Synthesis ; Glycosylation and Glycoproteins Research ; Polyamine Metabolism and Applications
Authors: Samson Afewerki | Ana Franco | Alina M. Balu | Cheuk‐Wai Tai | Rafael Luque | Armando Córdova
Source: Scientific Reports (article, 2020-04-14)
Field: Chemistry — Organic Chemistry

Sustainable and recyclable heterogenous palladium catalysts from rice husk-derived biosilicates for Suzuki-Miyaura cross-couplings, aerobic oxidations and stereoselective cascade carbocyclizations A new eco-friendly approach for the preparation of sustainable heterogeneous palladium catalysts from rice husk-derived biogenic silica (RH<sub>P</sub>-Si and RH<sub>U</sub>-Si). The designed heterogeneously supported palladium species (RH<sub>P</sub>-Si-NH<sub>2</sub>-Pd and RH<sub>U</sub>-Si-NH<sub>2</sub>-Pd) were fully characterized and successfully employed as catalysts for various chemical transformations (C-C bond-forming reactions, aerobic oxidations and carbocyclizations). Suzuki-Miyaura transformations were highly efficient in a green solvent system (H<sub>2</sub>O:EtOH (1:1) with excellent recyclability, providing the cross-coupling products with a wide range of functionalities in high isolated yields (up to 99%). Palladium species (Pd(0)-nanoparticles or Pd(II)) were also efficient catalysts in the green aerobic oxidation of an allylic alcohol and a co-catalytic stereoselective cascade carbocyclization transformation. In the latter case, a quaternary stereocenter was formed with excellent stereoselectivity (up to 27:1 dr). Palladium ; Stereocenter ; Stereoselectivity ; Catalysis ; Allylic rearrangement ; Husk ; Chemistry ; Solvent ; Combinatorial chemistry ; Organic chemistry ; Enantioselective synthesis ; Botany ; Biology Catalytic Cross-Coupling Reactions ; Chemical synthesis and alkaloids ; Catalytic C–H Functionalization Methods
Authors: Yao Wan | Wenzhou Xu | Xuan Ren | Yu Wang | Biao Dong | Lin Wang
Source: Frontiers in Bioengineering and Biotechnology (review, 2020-06-12)
Field: Materials Science — Materials Chemistry

Microporous Frameworks as Promising Platforms for Antibacterial Strategies Against Oral Diseases Nowadays, the heavy burden of oral diseases such as dental caries, periodontitis, endodontic infections, etc., and their consequences on the patients' quality of life indicate a strong need for developing effective therapies. Bacterial infections played an important role in the field of oral diseases, in-depth insight of such oral diseases have given rise to the demand for antibacterial therapeutic strategies. Recently, microporous frameworks have attracted tremendous interest in antibacterial application due to their well-defined porous structures for drug delivery. In addition, intensive efforts have been made to enhance the antibacterial performance of microporous frameworks, such as ion doping, photosensitizer incorporation as building blocks, and surface modifications. This review article aims on the major recent developments of microporous frameworks for antibacterial applications against oral diseases. The first part of this paper puts concentration on the cutting-edge researches on the versatile antibacterial strategies of microporous materials via drug delivery, inherent activity, and structural modification. The second part discusses the antibacterial applications of microporous frameworks against oral diseases. The applications of microporous frameworks not only have promising therapeutic potential to inhibit bacterial plaque-initiated oral infectious diseases, but also have a wide applicability to other biomedical applications. Microporous material ; Nanotechnology ; Drug delivery ; Medicine ; Intensive care medicine ; Materials science Covalent Organic Framework Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Nanoplatforms for cancer theranostics
Authors: Anna Said Stålsmeden | Andrew J. Paterson | Imola Cs. Szigyártó | Linda Thunberg | Johan R. Johansson | Tamás Beke‐Somfai | Nina Kann
Source: Organic & Biomolecular Chemistry (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Chiral 1,5-disubstituted 1,2,3-triazoles – versatile tools for foldamers and peptidomimetic applications 1,4- and 1,5-Disubstituted triazole amino acid monomers have gained increasing interest among peptidic foldamers, as they are easily prepared via Cu- and Ru-catalyzed click reactions, with the potential for side chain variation. While the latter is key to their applicability, the synthesis and structural properties of the chiral mono- or disubstituted triazole amino acids have only been partially addressed. We here present the synthesis of all eight possible chiral derivatives of a triazole monomer prepared via a ruthenium-catalyzed azide alkyne cycloaddition (RuAAC). To evaluate the conformational properties of the individual building units, a systematic quantum chemical study was performed on all monomers, indicating their capacity to form several low energy conformers. This feature may be used to effect structural diversity when the monomers are inserted into various peptide sequences. We envisage that these results will facilitate new applications for these artificial oligomeric compounds in diverse areas, ranging from pharmaceutics to biotechnology. Peptidomimetic ; Chemistry ; Combinatorial chemistry ; Stereochemistry ; Peptide ; Biochemistry Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Synthesis and Catalytic Reactions
Authors: Sripati Jana | Claire Empel | Chao Pei | Thành Vinh Nguyễn | René M. Koenigs
Source: Advanced Synthesis & Catalysis (article, 2020-10-14)
Field: Chemistry — Organic Chemistry

Gold‐catalyzed C−H Functionalization of Phenothiazines with Aryldiazoacetates Abstract Phenothiazine is an important structural motif in pharmaceuticals and advanced functional organic materials. However, the C−H functionalization reaction of N ‐protected phenothiazine is rather unexplored and often shadowed by its chemical reactivity on the heteroatomic centers, which limits the diversity of its potential applications. This report demonstrates a straightforward approach towards the site‐selective C−H functionalization of phenothiazine at the para ‐position of N atom via gold‐catalyzed carbene transfer reactions (37 examples, up to 83% yield). The mechanism behind the regionselectivity of the C−H functionalization reaction was also elucidated by a combination of computational and experimental studies. magnified image Phenothiazine ; Chemistry ; Surface modification ; Carbene ; Catalysis ; Combinatorial chemistry ; Reactivity (psychology) ; Photochemistry ; Nanotechnology ; Organic chemistry ; Physical chemistry Cyclopropane Reaction Mechanisms ; Catalytic C–H Functionalization Methods ; Catalytic Alkyne Reactions
Authors: Mohsen Mirzaie Yegane | Fatemeh Hashemi | F.F. Vercauteren | Nicole Meulendijks | Ridha Gharbi | Pouyan E. Boukany | P. L. J. Zitha
Source: Soft Matter (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Rheological response of a modified polyacrylamide–silica nanoparticles hybrid at high salinity and temperature Water-soluble polyacrylamides have often been used to modify flow response in various water-based technologies and industrial processes, including paints, water treatment, paper manufacturing, and chemical enhanced oil recovery. Polymers are susceptible to degradation at combined high salinity and elevated temperature conditions which limits their overall performance. Hybrid mixtures of hydrophobically modified polyacrylamide (HMPAM) with hydrophobically modified silica nanoparticles (NPs) emerged as a promising strategy for achieving enhanced stability and high viscosity in brines having a high total dissolved solids (TDS) content and high hardness at elevated temperatures (>20 wt% TDS, including >1.5 wt% divalent cations at T > 70 °C). The rheological response of the hybrids at various concentrations of HMPAM and NPs was examined to investigate the synergic effects. Hybridization of HMPAM with NPs led to a higher viscosity at high salinity and elevated temperature. The viscosity improvement was more pronounced when the concentration of HMPAM was in the semi-dilute regime and concentration of NPs was higher than a critical threshold where the viscosity increased roughly by a factor of 1.5. Here we present the mechanisms of improved viscosity behaviour. The rheological data suggest the role of NPs in the bridging between HMPAM molecules, which in turn increases the hydrodynamic radius and consequently the viscosity of the hybrids. Polyacrylamide ; Rheology ; Viscosity ; Chemical engineering ; Nanoparticle ; Materials science ; Salinity ; Nanotechnology ; Polymer chemistry ; Composite material ; Geology Surfactants and Colloidal Systems ; Pickering emulsions and particle stabilization ; Enhanced Oil Recovery Techniques
Authors: Daniele Del Giudice | Emanuele Spatola | Roberta Cacciapaglia | Alessandro Casnati | Laura Baldini | Gianfranco Ercolani | Stefano Di Stefano
Source: Chemistry - A European Journal (article, 2020-08-05)
Field: Chemistry — Organic Chemistry

Time Programmable Locking/Unlocking of the Calix[4]arene Scaffold by Means of Chemical Fuels In this work, we report that 2-cyano-2-phenylpropanoic acid and its p-Cl, p-CH<sub>3</sub> and p-OCH<sub>3</sub> derivatives can be used as chemical fuels to control the geometry of the calix[4]arene scaffold in its cone conformation. It is shown that, under the action of the fuel, the cone calix[4]arene platform assumes a "locked" shape with two opposite aromatic rings strongly convergent and the other two strongly divergent ("pinched cone" conformation). Only when the fuel is exhausted, the cone calix[4]arene scaffold returns to its resting, "unlocked" shape. Remarkably, the duration of the "locked" state can be controlled at will by varying the fuel structure or amount. A kinetic study of the process shows that the consume of the fuel is catalyzed by the "unlocked" calixarene that behaves as an autocatalyst for its own production. A mechanism is proposed for the reaction of fuel consumption. Calixarene ; Chemistry ; Cone (formal languages) ; Catalysis ; Kinetic control ; Kinetic energy ; Work (physics) ; Combinatorial chemistry ; Stereochemistry ; Molecule ; Organic chemistry ; Computer science ; Physics ; Engineering ; Mechanical engineering Supramolecular Chemistry and Complexes ; Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis