Using density functional calculations with and without dispersion interaction, we studied the effects of linear octyl and branched 2-ethylhexyl side chains on the oligomer conformation of the conjugated copolymer poly(p-anthracene-ethynylene)-alt-poly(p-phenylene-vinylene). With dispersion included, the branched side chains can cause significant bending of the oligomer backbone, while without dispersion they induce mainly torsional disorder. The oligomers with mainly linear side chains keep good planarity when optimized with and without dispersion. Despite their dramatically different conformations, the calculated absorption spectra of the oligomers with various side chain combinations are very similar, indicating that the conformation of the copolymer is not the main reason for the experimentally observed different spectra of ordered and disordered phases.
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http://dx.doi.org/10.1021/acs.jpca.6b01386 | DOI Listing |
J Struct Biol
January 2025
State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China. Electronic address:
Cryptosporidium has gained much attention as a major cause of diarrhea worldwide. Here, we present the first structure of H-2K complexed with a decapeptide from Cryptosporidium parvum Gp40/15 protein (Gp40/15-VTF10). In contrast to all published structures, the aromatic residue P3-Phe of Gp40/15-VTF10 is anchored in pocket C rather than the canonical Y/F at P5 or P6 reported for octapeptides and nonapeptides.
View Article and Find Full Text PDFChem Biodivers
January 2025
Guizhou Medical University, School of Pharmaceutical Sciences, University Town, Gui'an New District, 550025, Guiyang, CHINA.
An unrevealed dihydroflavone-monoterpene conjugate (1), two unrevealed kavalactones (2-3, including one with an uncommon side chain), and thirteen previously identified compounds (4-16) were extracted from Alpinia katsumadai Hayata. seeds. The two-dimension structures of the new compounds were authenticated utilizing HRESIMS as well as NMR spectral analysis, while their absolute chiral configurations were ascertained either by correlating the experimental and simulated values of electronic circular dichroism (ECD) patterns or conducting X-ray diffraction experiments.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
School of the Chemical Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
The folding of the guanine repetitive region in the telomere unit into G-quadruplex (G4) by drugs has been suggested as an alternative approach for cancer therapy. Hydroxychloroquine (HCQ) and chloroquine (CQ) are two important drugs in the trial stage for cancer. Both drugs can induce the folding of telomere-guanine-rich sequences into G4 even in the absence of salt.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Fachgebiet Angewandte Nanophysik, Institut für Physik & IMN MacroNano, Technische Universität Ilmenau, Ilmenau 98693, Germany.
Organic materials, with abundant resources, low cost, high flexibility, tunable structures, lightweight nature, and wide operating temperature range, are regarded as promising candidates for sodium-ion batteries (SIBs). Unfortunately, their poor electronic and ionic conductivity remain significant challenges, hindering the achievement of high power density for sodium storage. Power density, a critical factor in battery performance evaluation, is essential for assessing fast charging capabilities.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Endocrinology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing 400014, China. Electronic address:
Polysaccharides are the major bioactive composition of Polygonatum sibiricum (P. sibiricum). However, the structural and functional identifications of these polysaccharides were still limited.
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