Results 41 to 50 of about 64,971 (268)

Selenium halide-induced bridge formation in [2.2]paracyclophanes

Beilstein Journal of Organic Chemistry, 2014
An addition/elimination sequence of selenium halides to pseudo-geminally bis(acetylene) substituted [2.2]paracyclophanes leads to new bridges with an endo-exo-diene substructure.
Laura G. Sarbu, Henning Hopf, Peter G. Jones, Lucian M. Birsa   +3 more
doaj   +1 more source

Oxygen evolution electrocatalytic properties of perovskite-type oxides obtained by PVP sol-gel route: Part II. The effect of partial substitution of Sm for Sr in La0.4Sr0.6CoO3

International Journal of Electrochemical Science, 2020
This paper deals the findings of quaternary perovskite-type oxides, La0.4SmxSr0.6-xCoO3 (0 ≤ x ≤ 0.4), which is the extended research work obtained by further substitution Sm (0.2 to 0.4 mol) for Sr in the ternary perovskite oxide of La0.4Sr0.6CoO3 ...
Narendra Kumar Singh, Priya Sharma, Manish Kumar Yadav, Reena Parihar   +3 more
doaj   +1 more source

Tau acetylation at K331 has limited impact on tau pathology in vivo

FEBS Letters, EarlyView.
We mapped tau post‐translational modifications in humanized MAPT knock‐in mice and in amyloid‐bearing double knock‐in mice. Acetylation within the repeat domain, particularly around K331, showed modest increases under amyloid pathology. To test functional relevance, we generated MAPTK331Q knock‐in mice.
Shoko Hashimoto, Yukio Matsuba, Mika Takahashi, Takaomi C. Saido   +3 more
wiley   +1 more source

Nucleophilic Substitution at Tetracoordinate Phosphorus. Stereochemical Course and Mechanisms of Nucleophilic Displacement Reactions at Phosphorus in Diastereomeric cis- and trans-2-Halogeno-4-methyl-1,3,2-dioxaphosphorinan-2-thiones: Experimental and DFT Studies

Molecules, 2021
Geometrical cis- and trans- isomers of 2-chloro-, 2-bromo- and 2-fluoro-4-methyl-1,3,2-dioxaphosphorinan-2-thiones were obtained in a diastereoselective way by (a) sulfurization of corresponding cyclic PIII-halogenides, (b) reaction of cyclic ...
Marian Mikołajczyk, Barbara Ziemnicka, Jan Krzywański, Marek Cypryk, Bartłomiej Gostyński   +4 more
doaj   +1 more source

Calpain small subunit homodimerization is robust and calcium‐independent

FEBS Letters, EarlyView.
Calpains dimerize via penta‐EF‐hand (PEF) domains. Using single‐molecule force spectroscopy, we measured the strength and kinetics of PEF–PEF homodimer binding. The interaction is robust, shows a transient conformational step before dissociation, and remains largely insensitive to Ca2+.
Nesha May O. Andoy, Trina Dykstra‐MacPherson, Mathias A. Bell, Peter L. Davies, Ruby May A. Sullan   +4 more
wiley   +1 more source

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

Beilstein Journal of Organic Chemistry, 2023
A highly α-regioselective N-nucleophilic allylic substitution of cyclic MBH alcohols and acetates with imidazole or benzimidazole, in toluene at reflux with an azeotropic distillation, was successfully carried out with no catalysts or additives ...
Olfa Mhasni, Jalloul Bouajila, Farhat Rezgui   +2 more
doaj   +1 more source

Gut microbiome and aging—A dynamic interplay of microbes, metabolites, and the immune system

FEBS Letters, EarlyView.
Age‐dependent shifts in microbial communities engender shifts in microbial metabolite profiles. These in turn drive shifts in barrier surface permeability of the gut and brain and induce immune activation. When paired with preexisting age‐related chronic inflammation this increases the risk of neuroinflammation and neurodegenerative diseases.
Aaron Mehl, Eran Blacher
wiley   +1 more source

Nucleoside cyclic 3′,5′-phosphorothioates with purine and pyrimidine scaffolds. A chemical minireview

European Journal of Medicinal Chemistry Reports, 2022
The common nucleobases purine (adenine and guanine) and pyrimidine (cytosine, uracil and thymine) in naturally occurring nucleosides and their 3′,5′-cyclic phosphates are β-bonded to the anomeric carbon (C1′) of d-ribose or its 2′-deoxy congener.
Kjell Undheim
doaj   +1 more source

Continuum of Mechanisms for Nucleophilic Substitutions of Cyclic Acetals [PDF]

Organic Letters, 2008
The effect of nucleophile strength on diastereoselectivity in the nucleophilic substitution of cyclic acetals was explored. Stereoselectivity remained constant and high as nucleophilicity increased until a threshold value was reached. Beyond this point, however, selection of Lewis acid determined whether stereochemical inversion or erosion was observed.
Jennifer R, Krumper, Walter A, Salamant, K A, Woerpel   +2 more
openaire   +2 more sources

A methionine‐lined active site governs carbocation stabilization and product specificity in a bacterial terpene synthase

FEBS Letters, EarlyView.
This study reveals a unique active site enriched in methionine residues and demonstrates that these residues play a critical role by stabilizing carbocation intermediates through novel sulfur–cation interactions. Structure‐guided mutagenesis further revealed variants with significantly altered product profiles, enhancing pseudopterosin formation. These
Marion Ringel, Carl P. O. Helmer, Shani Zev, Ronja Driller, Emily Buhr, Markus Reinbold, Renana Schwartz, Gabriel Foley, Mikael Boden, Daniel Garbe, Gerhard Schenk, Dan Thomas Major, Bernhard Loll, Thomas Brück   +13 more
wiley   +1 more source