Introduction of an asymmetric center to C-2 of one of the benzothiophene rings of bisbenzothienylperfluorocyclopentene results in a highly diastereoselective photochromic system. The stereogenic center bears a hydrogen atom, a methyl group, and a methoxymethoxy group. The steric as well as the electronic repulsions gave an 87-88% diastereomer excess in various solvents at room temperature with 80-85% conversion to the colored form. The enantioselective synthesis was also carried out. Upon photoirradiation in hexane, a change in optical rotation at 820 nm, where neither the open form nor the colored form absorbs light, was observed repeatedly.
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http://dx.doi.org/10.1021/ja029535d | DOI Listing |
Biochemistry
January 2025
Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru 560012, India.
Eukaryotic Initiation Factor 4 (eIF4) is a group of factors that activates mRNA for translation and recruit 43S preinitiation complex (PIC) to the mRNA 5' end, forming the 48S PIC. The eIF4 factors include mRNA 5' cap-binding protein eIF4E, ATP-dependent RNA helicase eIF4A, and scaffold protein eIF4G, which anchors eIF4A and eIF4E. Another eIF4 factor, eIF4B, stimulates the RNA helicase activity of eIF4A and facilitates mRNA recruitment.
View Article and Find Full Text PDFBioinform Adv
November 2024
Institute of Biochemistry and Molecular Medicine, University of Bern, Bern 3012, Switzerland.
Summary: Protein structure prediction aims to infer a protein's three-dimensional (3D) structure from its amino acid sequence. Protein structure is pivotal for elucidating protein functions, interactions, and driving biotechnological innovation. The deep learning model AlphaFold2, has revolutionized this field by leveraging phylogenetic information from multiple sequence alignments (MSAs) to achieve remarkable accuracy in protein structure prediction.
View Article and Find Full Text PDFACS Nano
January 2025
Conte Center for Polymer Research, Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
Bottlebrush block copolymers (BBCPs) are a unique class of materials that contain a backbone with densely grafted and chemically distinct polymeric side chains. The nonlinear architecture of BBCPs provides numerous degrees of freedom in their preparation, including control over key parameters such as grafting density, side chain length, block arrangement, and overall molecular weight. This uniquely branched structure provides BBCPs with several important distinctions from their linear counterparts, including sterically induced side chain and backbone conformations, rapid and large self-assembled nanostructures, and reduced or eliminated entanglement effects (assuming sufficient grafting density and that the molecular weight of the side chains is below their respective entanglement molecular weight).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
CAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Well-defined single-atom catalysts (SACs) serve as ideal model systems for directly comparing experimental results with theoretical calculations, offering profound insights into heterogeneous catalytic processes. However, precisely designing and controllably synthesizing SACs remain challenging due to the unpredictable structure evolution of active sites and generation of embedded active sites, which may bring about steric hindrance during chemical reactions. Herein, we present the precious nonpyrolysis synthesis of Re SACs with a well-defined phenanthroline coordination supported by NiO (Re-phen/NiO).
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Mathematics, National Institute of Technology Durgapur, Durgapur-713209, India.
The present article deals with the modulation of oscillatory electroosmotic flow (EOF) and solute dispersion across a nanochannel filled with an electrolyte solution surrounded by a layer of a dielectric liquid. The dielectric permittivity of the liquid layer adjacent to supporting rigid walls is taken to be lower than that of the electrolyte solution. Besides, the aforesaid liquid layer may bear additional mobile charges, , free lipid molecules, charged surfactant molecules , which in turn lead to a nonzero charge along the liquid-liquid interface.
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