PubMed İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/4466

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Browsing PubMed İndeksli Yayınlar Koleksiyonu by Publisher "American Chemical Society"

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    Citation - WoS: 119
    Citation - Scopus: 124
    Post-Synthetically Elaborated Bodipy-Based Porous Organic Polymers (pops) for the Photochemical Detoxification of a Sulfur Mustard Simulant
    (American Chemical Society, 2020) Çetin, M. Mustafa; Atılgan, Ahmet; Beldjoudi, Yassine; Liu, Jian; Stern, Charlotte L.; Çetin, Furkan M.; İslamoğlu, Timur; Farha, Omar K.; Deria, Pravas; Stoddart, Frasser J.; Hupp, Joseph T.
    Designing new materials for the effective detoxification of chemical warfare agents (CWAs) is of current interest given the recent use of CWAs. Although halogenated borondipyrromethene derivatives (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene or BDP or BODIPY) at the 2 and 6 positions have been extensively explored as efficient photosensitizers for generating singlet oxygen (1 O2) in homogeneous media, their utilization in the design of porous organic polymers (POPs) has remained elusive due to the difficulty of controlling polymerization processes through cross-coupling synthesis pathways. Our approach to overcome these difficulties and prepare halogenated BODIPYbased porous organic polymers (X-BDP-POP where X = Br or I) represents an attractive alternative through post-synthesis modification (PSM) of the parent hydrogenated polymer. Upon synthesis of both the parent polymer, H-BDP-POP, and its post-synthetically modified derivatives, Br-BDP-POP and I-BDP-POP, the BET surface areas of all POPs have been measured and found to be 640, 430, and 400 m2 g-1, respectively. In addition, the insertion of heavy halogen atoms at the 2 and 6 positions of the BODIPY unit leads to the quenching of fluorescence (both polymer and solution-phase monomer forms) and the enhancement of phosphorescence (particularly for the iodo versions of the polymers and monomers), as a result of efficient intersystem crossing. The heterogeneous photocatalytic activities of both the parent POP and its derivatives for the detoxification of the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), have been examined; the results show a significant enhancement in the generation of singlet oxygen (1 O2). Both the bromination and iodination of H-BDP-POP served to shorten by 5-fold of the time needed for the selective and catalytic photo-oxidation of CEES to 2-chloroethyl ethyl sulfoxide (CEESO).
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    Structural Descriptors for Subunit Interface Regions in Homodimers: Effect of Lipid Membrane and Secondary Structure Type
    (American Chemical Society, 2025) Yüksek, A.; Yıkınç, B.; Nayır, I.; Alnıgeniş, D.; Fidan, V.G.; Topuz, T.; Akten, E.D.
    A total of 1311 homodimers were collected and analyzed in three different categories to highlight the impact of lipid environment and secondary structure type: 422 cytoplasmic α-helix, 411 cytoplasmic β-strand, and 478 membrane complexes. Structural features of the interface connecting two monomers were investigated and compared to those of the non-interface surface. Every residue on the surface of each monomer was explored based on four attributes: solvent-accessible surface area (SASA), protrusion index (Cx), surface planarity, and surface roughness. SASA and Cx distribution profiles clearly distinguished the interface from the surface in all categories, where the rim of the interface displayed higher SASA and Cx values than the rest of the surface. Surface residues in membrane complexes protruded less than cytoplasmic ones due to the hydrophobic environment, and consequently, the difference between surface and interface residues became less noticeable in that category. Cytoplasmic β-strand complexes displayed markedly lower SASA at the interface core than at the surface. The major distinction between the surface and interface was achieved through surface roughness, which displayed significantly higher values for the interface than the surface, especially in cytoplasmic complexes. Clearly, a surface which is relatively rugged favors the association of two monomers through multiple van der Waals interactions and hydrogen-bond formations. Another structural descriptor with strong distinguishing ability was surface planarity, which was higher at the interface than at the non-interface surface. Surface flatness would eventually facilitate the interconnectedness of an interface with a network of residue pairs bridging two complementary surfaces. Analysis of contact pairs revealed that hydrophobic pairs have the highest frequency of occurrence in the lipid environment of membrane complexes. However, despite the scarcity of polar residues at the interface, the likelihood of observing a contact between polar residues was markedly higher than that of hydrophobic ones. © 2025 The Authors. Published by American Chemical Society.