In an endeavor directed towards the construction of the oxabicyclic[3.2.1]octane segment present in the bioactive natural products of cortistatins and icetexanes genre, the title compound, C(13)H(19)BrO(3), was synthesized from (4aR,9aS)-1,3,4,4a,5,6,9,9a-octa-hydro-spiro-[benzo[7]annulene-2,2'-[1,3]dioxolane]-4a-ol via a transannular bromo-etherification protocol. The six-membered ring adopts a twist-boat conformation, while the fused cycloheptane ring adopts a chair conformation. The crystal packing is effected through two distinct inter-molecular C-H⋯O hydrogen-bond patterns and mol-ecules are arranged to define an inter-esting motif along the b axis.
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http://dx.doi.org/10.1107/S1600536812029777 | DOI Listing |
Viruses
January 2025
Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
The tripartite-motif protein 56 (TRIM56) is a RING-type E3 ubiquitin ligase whose functions were recently beginning to be unveiled. While the physiological role(s) of TRIM56 remains unclear, emerging evidence suggests this protein participates in host innate defense mechanisms that guard against viral infections. Interestingly, TRIM56 has been shown to pose a barrier to viruses of distinct families by utilizing its different domains.
View Article and Find Full Text PDFNat Struct Mol Biol
January 2025
Department of Molecular Biology and Genetics, Aarhus, Denmark.
The C3 protein is the central molecule within the complement system and undergoes proteolytic activation to C3b in the presence of pathogens. Pattern-independent activation of C3 also occurs via hydrolysis, resulting in C3(HO), but the structural details of C3 hydrolysis remain elusive. Here we show that the conformation of the C3(HO) analog, C3MA, is indistinguishable from C3b.
View Article and Find Full Text PDFChemistry
January 2025
National Chi Nan University, Department of Applied Chemistry, TAIWAN.
Three fluorescent Zn coordaintion polymers (CPs) have been synthesized from the reactions of Zn(NO3)2∙6H2O, benzene-1,4-dicarboxylic acid (1,4-H2bdc), and angular carbazole-derived bispyridyl ligands (Cz-3,6-bpy or Cz-Pr-3,6-bpy). CPs 1-3 all adopt similar two-dimensional (2D) ring-and-rod layer structures, described as topologically 4-connected 2∙65 nets where the Zn(II) centers act as 4-connected nodes. CPs 1 and 2 are a pair of solvent-mediated supramolecular isomers where the former shows a two-fold interlocked 2D → 2D polyrotaxane-like entangled net and the latter reveals a four-fold interpenetrated 2D → 3D polyrotaxane entanglement.
View Article and Find Full Text PDFSci Bull (Beijing)
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, College of Chemistry and Chemical Engineering, Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China.
Despite the many advantages for industrial mass production, vacuum-deposited organic solar cells (OSCs) suffer from low efficiency, primarily due to the limited molecular library of small-molecule donor and acceptor materials, which remains a significant challenge. Herein, two donor-acceptor-acceptor (D-A-A)-configured small-molecule donors, named TTBTDC and TTBTDC-F were synthesized, using 8H-thieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]pyrrole (TTP) as a new fused-ring donor unit. Benefiting from the strong electron-donating ability of the TTP moiety and the adoption of the D-A-A molecular configuration, these molecules exhibited strong visible and near-infrared absorption as well as deep-lying highest occupied molecular orbital (HOMO) energy levels.
View Article and Find Full Text PDFIn this work, a five-mode erbium-doped waveguide amplifier with low differential modal gain (DMG) is first proposed. A novel, to the best of our knowledge, gain equalization scheme for synergistic reconfiguration of refractive index and concentration doping is adopted to equalize the modal gains based on the dual-layer ring core structure. NaYF:5%Gd,20%Yb,2%Er@NaYF nanoparticles are synthesized by annealing treatment to improve the emission spectral properties and the concentration doped in a host core material.
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