We describe different modes of dimerization of various α',γ-dioxyenone derivatives with potential applications to the synthesis of high-order securinega alkaloids. We learned that the relative stereochemical relationship between α'- and γ-hydroxyl groups of the α',γ-dihydroxyenone derivative determines the mode of dimerization. While cis-α',γ-dioxyenone 26 provided the Rauhut-Currier-type (RC-type) dimer 31 upon reaction with TBAF, trans-α',γ-dihydroxyenone 34 afforded dimeric tetrahydrofuran derivative 41 under the same reaction conditions. We also noticed that the protection of the γ-hydroxyl group drastically changes the reaction outcomes. While cis-α'-oxy-γ-OPiv-enone 49 did not show any reactivity in the presence of TBAF, trans-α'-hydroxy-γ-OPiv-enone 45 produced the RC-type dimer 46 under the same reaction conditions. Computational analysis revealed the detailed mechanism of the latter transformation.
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http://dx.doi.org/10.1021/acs.joc.8b02852 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637.
Many proteins form paralogous multimers-molecular complexes in which evolutionarily related proteins are arranged into specific quaternary structures. Little is known about the mechanisms by which they acquired their stoichiometry (the number of total subunits in the complex) and heterospecificity (the preference of subunits for their paralogs rather than other copies of the same protein). Here, we use ancestral protein reconstruction and biochemical experiments to study historical increases in stoichiometry and specificity during the evolution of vertebrate hemoglobin (Hb), an αβ heterotetramer that evolved from a homodimeric ancestor after a gene duplication.
View Article and Find Full Text PDFCurr Opin Immunol
January 2025
Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences, RIKEN Yokohama Institute, Yokohama, Japan; Division of Integrated High-Order Regulatory Systems, Center for Cancer Immunotherapy and Immunobiology, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Energy metabolism of immune cells, such as glycolysis and mitochondrial activity, requires strict regulation. This is especially critical in the complex environment of the bone marrow (BM), where there is a need to both preserve the quiescence of hematopoietic stem cells (HSCs) and guarantee timed and effective lineage differentiation of the HSCs. Recent advances highlight the critical roles played by bioactive metabolites in regulating hematopoiesis.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
Alzheimer's Disease (AD) significantly aggravates human dignity and quality of life. While newly approved amyloid immunotherapy has been reported, effective AD drugs remain to be identified. Here, we propose a novel AI-driven drug-repurposing method, DeepDrug, to identify a lead combination of approved drugs to treat AD patients.
View Article and Find Full Text PDFmLife
December 2024
State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology Shanghai Jiao Tong University Shanghai China.
Inorg Chem
January 2025
Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, No.30, Shuangqing Avenue, Beijing, Haidian 100084, China.
Cyclic compounds are appealing owing to their intrinsic porous structures and facile accessibility as building blocks (BBs) for fabricating high-order assemblies. Nevertheless, the modular synthesis of such molecular entities and their subsequent controlled assembly are still very challenging. Herein, we report the synthesis of a gigantic molybdenum blue (MB) wheel {Mo} (), featuring a skirt-shaped structure dimerized from {Mo}.
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