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bio chemistry

Sacha Escamez, Madhavi Latha Gandla, Marta Derba-Maceluch, Sven-Olof Lundqvist, Ewa J Mellerowicz, Leif J Jönsson, Hannele Tuominen
Wood represents a promising source of sugars to produce bio-based renewables, including biofuels. However, breaking down lignocellulose requires costly pretreatments because lignocellulose is recalcitrant to enzymatic saccharification. Increasing saccharification potential would greatly contribute to make wood a competitive alternative to petroleum, but this requires improving wood properties. To identify wood biomass traits associated with saccharification, we analyzed a total of 65 traits related to wood chemistry, anatomy and structure, biomass production and saccharification in 40 genetically engineered Populus tree lines...
November 17, 2017: Scientific Reports
Sarah Lopez, Laurianne Rondot, Chloé Leprêtre, Caroline Marchi-Delapierre, Stéphane Ménage, Christine Cavazza
Designing systems that merge the advantages of heterogeneous catalysis, enzymology and molecular catalysis represents the next major goal for sustainable chemistry. Cross-linked enzyme crystals display most of these essential assets (well-designed mesoporous support, protein selectivity, molecular recognition of substrates). Nevertheless, a lack of reaction diversity, particularly in the field of oxidation, remains a constraint for their increased use in the field. Here, thanks to the design of cross-linked artificial non-heme iron oxygenase crystals, we filled this gap by developing bio-based heterogeneous catalysts capable of oxidizing carbon-carbon double bonds...
November 17, 2017: Journal of the American Chemical Society
Zhijun Li, Kim A Munro, Iraklii I Ebralidze, Mina R Narouz, J Daniel Padmos, Hongxia Hao, Cathleen M Crudden, J Hugh Horton
Surface plasmon resonance (SPR)-based biosensing is a powerful tool to study the recognition processes between biomole-cules in real-time without need for labels. The use of thiol chemistry is a critical component in surface functionalization of various SPR biosensor surfaces on gold. However, its use is hampered by the high propensity for oxidation of the gold-thiol linkage even in ambient atmosphere, resulting in a short lifetime of SPR sensor chips unless strict precautions are taken. Herein, we describe an approach to overcome this limitation by employing highly robust self-assembled monolayers (SAMs) of alkylated N-heterocyclic carbenes (NHCs) on gold...
November 15, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Williamson N Oloo, Rahul Banerjee, John D Lipscomb, Lawrence Que
Inspired by the remarkable chemistry of the family of Rieske oxygenase enzymes, nonheme iron complexes of tetradentate N4 ligands have been developed to catalyze hydrocarbon oxidation reactions using H2O2 in the presence of added carboxylic acids. The observation that the stereo- and enantioselectivity of the oxidation products can be modulated by the electronic and steric properties of the acid implicates an oxidizing species that incorporates the carboxylate moiety. Frozen solutions of these catalytic mixtures generally afford two S = ½ intermediates, a highly anisotropic g2...
November 14, 2017: Journal of the American Chemical Society
Meng Zhao, Fabio D Steffen, Richard Börner, Michelle F Schaffer, Roland K O Sigel, Eva Freisinger
Labeling of long RNA molecules in a site-specific yet generally applicable manner is integral to many spectroscopic applications. Here we present a novel covalent labeling approach that is site-specific and scalable to long intricately folded RNAs. In this approach, a custom-designed DNA strand that hybridizes to the RNA guides a reactive group to target a preselected adenine residue. The functionalized nucleotide along with the concomitantly oxidized 3'-terminus can subsequently be conjugated to two different fluorophores via bio-orthogonal chemistry...
November 9, 2017: Nucleic Acids Research
Min Zhang, Hao Song, Yannan Yang, Xiaodan Huang, Yang Liu, Chao Liu, Chengzhong Yu
Resoles are base-catalyzed phenol-formaldehyde resins with a 3-dimensional cross-linked framework. The chemistry of resoles is generally considered as highly chemical resistant, thus calcination is always used in the treatment of resole-type resin, which significantly limit the diversity of nanostructured materials derived from resole-type resins. Here we report that selected metal nitrate solutions can be applied to dissolve various types of nanostructured resoles through an oxidative dissolution mechanism...
November 13, 2017: Angewandte Chemie
Sandeep T Koshy, David K Y Zhang, Joshua M Grolman, Alexander G Stafford, David J Mooney
Sustained, localized protein delivery can enhance the safety and activity of protein drugs in diverse disease settings. While hydrogel systems are widely studied as vehicles for protein delivery, they often suffer from rapid release of encapsulated cargo, leading to a narrow duration of therapy, and protein cargo can be denatured by incompatibility with the hydrogel crosslinking chemistry. In this work, we describe injectable nanocomposite hydrogels that are capable of sustained, bioactive, release of a variety of encapsulated proteins...
November 8, 2017: Acta Biomaterialia
Sanju Gupta, Brendan Evans, Alex Henson, Sara B Carrizosa
Nanodiamond particles form agglomerates in the dry powder state and this poses limitation to the accessibility of their diamond-like core thus dramatically impacting their technological advancement. In this work, we report de-agglomeration of nanodiamond (ND) by using a facile technique namely, salt-assisted ultrasonic de-agglomeration (SAUD). Utilizing ultrasound energy and ionic salts (sodium chloride and sodium acetate), SAUD is expected to break apart thermally treated nanodiamond aggregates (~50-100 nm) and produce an aqueous slurry of de-aggregated stable colloidal nanodiamond dispersions by virtue of ionic interactions and electrostatic stabilization...
November 10, 2017: Materials
Domenico Iacopetta, Annaluisa Mariconda, Carmela Saturnino, Anna Caruso, Giuseppe Palma, Jessica Ceramella, Noemi Muià, Mariarita Perri, Maria Stefania Sinicropi, Maria Cristina Caroleo, Pasquale Longo
Cisplatin and other platinum-based drugs are well-known valid anticancer drugs. However, during the chemotherapy, the presence of numerous side effects and the onset of frequent phenomena of resistance pushes forward many research groups to devise new metal-based compounds holding improved anticancer properties and lower undesired effects. Amongst the variety of synthesized compounds, significant anti-proliferative effects were obtained employing organometallic compounds, particularly those based on silver or gold...
November 9, 2017: ChemMedChem
Avijit Das, Jumi Deka, Adil Majeed Rather, Bibhas K Bhunia, Partha Pratim Saikia, Biman B Mandal, Kalyan Raidongia, Uttam Manna
Artificial bio-inspired superhydrophobicity-that are generally developed through appropriate optimization of chemistry and hierarchical topography, is being recognized for its immense prospective applications related to environment and healthcare. Nevertheless, the week interfacial interaction that are associated in the fabrication of such special interfaces-makes the material often delicate, and embedded antifouling property collapses on exposures to harsh and complex aqueous phases, and also after regular physical deformations including bending, creasing etc...
November 9, 2017: ACS Applied Materials & Interfaces
Roderigh Rohling, Emiel Hensen, Evgeny Alexandrovich Pidko
The catalytic Diels-Alder cycloaddition/dehydration (DAC/D) reaction of furanics with ethylene is a promising route to bio-derived aromatics. The reaction can be catalyzed by alkali-exchanged faujasites. Herein, we present the results of periodic DFT calculations based on accurate structural models of alkali-exchanged zeolites, revealing the fundamental roles of confinement and the nature of the exchangeable cations in zeolite micropores for the performance of faujasite-based catalysts in the DAC/D-reaction...
November 3, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Erik Anderson, Min Addy, Paul Chen, Roger Ruan
A novel process was developed for the biorefining of floatable wastewater scum and other waste oils from water treatment facilities into biodiesel and other value-added bio-products. To test the scalability and commercial potential of the technology, a 7000 l/year pilot-scale system was designed and built. Scum from a wastewater treatment facility, located in St. Paul, Mn, was collected and converted into methyl esters (biodiesel) according to the process chemistry. All of the incoming and outgoing process streams were sampled, tested, weighed and recorded to calculate both the process efficiency and product quality...
November 1, 2017: Bioresource Technology
Timothy W Bumpus, Felice J Liang, Jeremy M Baskin
Imaging approaches that track biological molecules within cells are essential tools in modern biochemistry. Lipids are particularly challenging to visualize, as they are not directly genetically encoded. Phospholipids, the most abundant subgroup of lipids, are structurally diverse and accomplish many cellular functions, acting as major structural components of membranes and as signaling molecules that regulate cell growth, division, apoptosis, cytoskeletal dynamics, and numerous other physiological processes...
November 8, 2017: Biochemistry
Savita K Sharma, Andrew W Schaefer, Hyeongtaek Lim, Hirotoshi Matsumura, Pierre Moënne-Loccoz, Britt Hedman, Keith O Hodgson, Edward I Solomon, Kenneth D Karlin
Peroxynitrite (-OON=O, PN) is a reactive nitrogen species (RNS) which can effect deleterious nitrative or oxidative (bio)chemistry. It may derive from reaction of superoxide anion (O2•-) with nitric oxide (•NO) and has been suggested to form an as-yet unobserved bound heme-iron-PN intermediate in the catalytic cycle of Nitric Oxide Dioxygenase (NOD) enzymes, which facilitate a •NO homeostatic process, i.e., its oxidation to the nitrate anion. Here, a discrete six-coordinate low-spin porphyrinate-FeIII complex [(PIm)FeIII(-OON=O)] (3) (PIm; a porphyrin moiety with a covalently tethered imidazole axial 'base' donor ligand) has been identified and characterized by various spectroscopies (UV-Vis, NMR, EPR, XAS, resonance Raman) and DFT calculations, following its formation at -80 °C by addition of •NO(g) to the heme-superoxo species, [(PIm)FeIII(O2•-)] (2)...
November 1, 2017: Journal of the American Chemical Society
Yijing Wang, Ashton Partridge, Yinqiu Wu
Solution based protein conjugation of small molecules involves multiple steps of chemical syntheses, bio-conjugation and purifications which are labor intensive and time-consuming. Since many small molecules have limited water solubility, conjugation to a protein is also a relatively low efficiency process in aqueous solutions. In this study, a model in situ protein conjugation of small molecules was achieved onto SPR surfaces, using progesterone and ovalbumin as a model small-molecule-protein system. The in situ protein conjugation not only eliminated the requirement for wet chemistry, but also provided an easy way to optimize the assay performance and screen various molecular linkers...
October 21, 2017: Analytical Biochemistry
Ryo Sekine, Katie L Moore, Marianne Matzke, Pascal Vallotton, Haibo Jiang, Gareth M Hughes, Jason K Kirby, Erica Donner, Chris R M Grovenor, Claus Svendsen, Enzo Lombi
Increasing consumer use of engineered nanomaterials has led to significantly increased efforts to understand their potential impact on the environment and living organisms. Currently, no individual technique can provide all the necessary information such as their size, distribution, and chemistry in complex biological systems. Consequently, there is a need to develop complementary instrumental imaging approaches that provide enhanced understanding of these "bio-nano" interactions to overcome the limitations of individual techniques...
November 13, 2017: ACS Nano
SooHyun Park, Mohammad R Abidian, Sheereen Majd
Conducting polymers (CPs) are easy to process and have tunable physical and chemical properties including conductivity, volume, color, and hydrophobicity. Therefore, these organic polymers are attractive in a broad spectrum of bioelectronic applications ranging from implantable electrodes to biosensors and actuators. Patterned films of CPs, especially with various surface chemistries, provide versatile and sophisticated building-blocks for bioelectronics. In this context, we recently introduced a simple and efficient technique of hydrogel-mediated electropolymerization to directly pattern films of PPy (polypyrrole) with spatially-addressable chemistries...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Jixiang Fan, Dongyun Chen, Najun Li, Qingfeng Xu, Hua Li, Jinghui He, Jianmei Lu
Adsorption and improved biodegradation of dyes in wastewater was achieved with Fe3O4@MIL-100 core-shell bio-nanocomposites, which were prepared by a step-by-step strategy and attached to the surface of bacteria via zero-length carbodiimide chemistry. The Fe3O4@MIL-100 (Fe) nano-composite showed excellent dye adsorption properties and the overall dye removal process followed second-order kinetics. The dye AO10 was completely eliminated from solution by the combined effects of adsorption and biodegradation within 15 and 25 h from initial dye concentrations of 25 and 50 mg/L, respectively...
October 10, 2017: Chemosphere
Robin M Bär, Stefan Kirschner, Martin Nieger, Stefan Bräse
Herein we report the addition of different thiols to the strained carbon-carbon bond of [1.1.1]propellane (1). We investigated the reaction pathway, performed the addition with substituted thiols, hydrogen sulfide and protected cysteine and verified further modifications of the products. The clean reaction proceeds probably through a radical chain process as we confirmed with different deuterium labelling experiments. It shows great functional group tolerance as halogen-, hydroxy-, methoxy-, carboxy-, amino- and nitro-substituted thiols could be added to 1 with few by-products in 16-90% yield...
October 16, 2017: Chemistry: a European Journal
Tian Tian, Hui-Xin Zhang, Chun-Peng He, Song Fan, Yan-Liang Zhu, Cui Qi, Ning-Ping Huang, Zhong-Dang Xiao, Zu-Hong Lu, Bakhos A Tannous, Jun Gao
The safe and effective delivery of drugs is a major obstacle in the treatment of ischemic stroke. Exosomes hold great promise as an endogenous drug delivery nanosystem for the treatment of cerebral ischemia given their unique properties, including low immunogenicity, innate stability, high delivery efficiency, and ability to cross the blood-brain barrier (BBB). However, exosome insufficient targeting capability limits their clinical applications. In this study, the c(RGDyK) peptide has been conjugated to the exosome surface by an easy, rapid, and bio-orthogonal chemistry...
October 4, 2017: Biomaterials
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