Results 51 to 60 of about 18,349 (284)

Chemoenzymatic Synthesis of Heparan Sulfate Oligosaccharides by a Covalent Catch‐and‐Release Approach

Angewandte Chemie, EarlyView.
A glycan having a hydrazide tag enables chemoenzymatic synthesis of HS oligosaccharides. The hydrazide can, under mild acidic conditions, react with an aldehyde‐containing resin to give an immobilized hydrazone that is stable under neutral conditions, allowing washing. The product can be released by transiminolysis using aqueous hydroxylamine to give a
Francesco Palmieri, Chin Huang, Digantkumar Chapla, Kelley W. Moremen, Geert‐Jan Boons   +4 more
wiley   +2 more sources

Light Switchable Ionic Conductivity of Arylazopyrazole Modified Polysiloxanes

Advanced Materials Technologies, EarlyView.
We present a polysiloxane functionalized with a novel arylazopyrazole dye that undergoes reversible photoisomerization. Upon lithium bis(trifluoromethanesulfonyl)imide addition and UV irradiation, the polymer exhibits a shift in tan(d) toward higher frequencies and enhanced ionic conductivity.
Malte S. Beccard, Thulasinath Raman Venkatesan, Michael Bauer, Valentin Razvan Lupu, Philipp Scheidegger, Francesco Taddei, Frank A. Nüesch, Dorina M. Opris   +7 more
wiley   +1 more source

Electronic Nose and Gas Chromatograph Devices for the Evaluation of the Sensory Quality of Green Coffee Beans

Foods, 2023
The aim of this work is to discriminate between the volatile org9anic compound (VOC) characteristics of different qualities of green coffee beans (Coffea arabica) using two analysis approaches to classify the fresh product.
Gema Cascos, Jesús Lozano, Ismael Montero-Fernández, Jhunior Abrahan Marcía-Fuentes, Ricardo S. Aleman, Antonio Ruiz-Canales, Daniel Martín-Vertedor   +6 more
doaj   +1 more source

Pd/C‐Catalyzed Hydrogenation of CF3‐, CF2H‐, and CF2CO2Et‐containing Pyridines: A Robust Method for Highly Functionalized containing Piperidines

Angewandte Chemie, EarlyView.
A robust and efficient method to access diversely functionalized fluorinated piperidines was developed. The approach features the hydrogenation of polysubstituted pyridines bearing CF3, CF2H, and CF2CO2Et substituents using an inexpensive, readily available heterogeneous Pd/C catalyst under air‐ and moisture‐tolerant conditions, offering an appealing ...
Thibaud Charvillat, Patrick Bernardelli, Marc Daumas, Xavier Pannecoucke, Vincent Ferey, Hassan Oulyadi, Muriel Sebban, Tatiana Besset   +7 more
wiley   +2 more sources

Chemical Characterization of Polar Species in Colombian Vacuum Residue and Its Supercritical Fluid Extraction Subfractions Using Electrospray Ionization FT-ICR Mass Spectrometry

Chemical Engineering Transactions, 2017
Compositional changes of Colombian vacuum residue and its supercritical fluid extraction fractionation (SFEF) subfractions were analysed by positive- and negative mode electrospray (ESI) coupled with Fourier-transform ion cyclotron resonance mass ...
J.P. Arenas-Diaz, D.C. Palacio Lozano, X. Ramirez, R. Cabanzo, A. Guzman, E. Mejia-Ospino   +5 more
doaj   +1 more source

Pyridine Carboxamides Based on Sulfobetaines: Design, Reactivity, and Biological Activity

Molecules, 2022
The synthesis of the products of the 1,3-propanesultone ring opening during its interaction with amides of pyridinecarboxylic acids has been carried out.
Eugene P. Kramarova, Sophia S. Borisevich, Edward M. Khamitov, Alexander A. Korlyukov, Pavel V. Dorovatovskii, Anastasia D. Shagina, Konstantin S. Mineev, Dmitri V. Tarasenko, Roman A. Novikov, Alexey A. Lagunin, Ivan Boldyrev, Aiarpi A. Ezdoglian, Natalia Yu. Karpechenko, Tatiana A. Shmigol, Yuri I. Baukov, Vadim V. Negrebetsky   +15 more
doaj   +1 more source

Lead‐Free Chiral Hybrid Metal Halides for Circularly Polarized Light‐Emitting Diodes

Advanced Optical Materials, EarlyView.
Lead‐free chiral hybrid metal halides provide a versatile platform for realizing chiroptical responses through chiral modulation of metal–halide frameworks with diverse dimensionalities, induces inversion‐symmetry breaking and enables dissymmetric excited‐state transitions toward efficient circularly polarized luminescence and electroluminescence. This
Kun Zhu, Li Wan
wiley   +1 more source

Synthesis of 3-(Cyclohexylamino)-2-arylimidazo[1,2-a]pyridine-8- carboxylic Acids Via an Efficient Three-component Condensation Reaction between Cyclohexylisocyanide and 2-Aminopyridine-3-carboxylic Acid in the Presence of Aromatic Aldehyde [PDF]

, 2018
Aim and Objective: The reaction of cyclohexylisocyanide and 2-aminopyridine-3- carboxylic acid in the presence of benzaldehyde derivatives in ethanol led to 3-(cyclohexylamino)-2- arylimidazo[1,2-a]pyridine-8-carboxylic acids in high yields. In a three
Ghasem Marandi
core   +1 more source

Flavin Catalysts in Organic Synthesis

Angewandte Chemie, EarlyView.
Flavins and their congeners are potent catalysts for organic synthesis inspired by enzymatic transformations. In addition to catalysis in the flavin ground state via covalent intermediates, the excited singlet and triplet states unlock applications including photooxidation, photoreduction, and energy transfer via sensitization.
Jan Freudenberg, Golo Storch
wiley   +2 more sources

Evaluation of the Olfactory Quality of Roasted Coffee Beans Using a Digital Nose

Sensors, 2022
The roasting process is one of the critical points to obtain a product of the highest quality with certain sensorial properties including the aroma of coffee. Samples of coffee beans were roasted at different thermal treatment intensities with the aim of
Juan Diego Barea-Ramos, Gema Cascos, Marta Mesías, Jesús Lozano, Daniel Martín-Vertedor   +4 more
doaj   +1 more source