Stereoselective β-mannosylations and β-rhamnosylations from glycosyl hemiacetals mediated by lithium iodide

Despite all achievements of the modern medicine, the problem of chronic obstructive pulmonary disease (COPD) does not lose its relevance. The current paradigm suggests a key role of macrophages in inflammation in COPD. Macrophages are known to be heterogeneous in their functions. This heterogeneity is determined by their immunometabolic profile and also by peculiarities of lipid homeostasis of cells. Aim. To analyze the role of the ABCA1 transporter, a member of the ABC A subfamily, in the pathogenesis of COPD. The expression of ABCA1 in lung tissues is on the second place after the liver, which shows the important role of the carrier and of lipid homeostasis in the function of lungs. Analysis of the literature shows that participation of the transporter in inflammation consists in regulation of the content of cholesterol in the lipid rafts of the membranes, in phagocytosis and apoptosis. Conclusion. Through regulation of the process of reverse transport of cholesterol in macrophages of lungs, ABCA1 can change their inflammatory response, which makes a significant contribution to the pathogenesis of COPD.

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RetroBioCat: Computer-Aided Synthesis Planning for Biocatalytic Reactions and Cascades

10.26434/chemrxiv.12571235.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

William Finnigan ◽

Lorna J. Hepworth ◽

Nicholas J. Turner ◽

Sabine Flitsch

Keyword(s):

Organic Chemistry ◽

Computer Aided Design ◽

Selective Synthesis ◽

Test Set ◽

Synthesis Design ◽

Computer Aided ◽

Synthesis Planning ◽

Enzymatic Cascades ◽

Target Molecules ◽

Aided Design

As the enzyme toolbox for biocatalysis has expanded, so has the potential for the construction of powerful enzymatic cascades for efficient and selective synthesis of target molecules. Additionally, recent advances in computer-aided synthesis planning (CASP) are revolutionizing synthesis design in both synthetic biology and organic chemistry. However, the potential for biocatalysis is not well captured by tools currently available in either field. Here we present RetroBioCat, an intuitive and accessible tool for computer-aided design of biocatalytic cascades, freely available at retrobiocat.com. Our approach uses a set of expertly encoded reaction rules encompassing the enzyme toolbox for biocatalysis, and a system for identifying literature precedent for enzymes with the correct substrate specificity where this is available. Applying these rules for automated biocatalytic retrosynthesis, we show our tool to be capable of identifying promising biocatalytic pathways to target molecules, validated using a test-set of recent cascades described in the literature.

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Enantioselective Synthesis of Azamerone

10.26434/chemrxiv.7369844.v1 ◽

2018 ◽

Author(s):

Matthew L. Landry ◽

Grace McKenna ◽

Noah Burns

Keyword(s):

Late Stage ◽

Cross Coupling ◽

Enantioselective Synthesis ◽

Selective Synthesis

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.

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Enantioselective Synthesis of Azamerone

10.26434/chemrxiv.7369844 ◽

2018 ◽

Author(s):

Matthew L. Landry ◽

Grace McKenna ◽

Noah Burns

Keyword(s):

Late Stage ◽

Cross Coupling ◽

Enantioselective Synthesis ◽

Selective Synthesis

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.

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Selective α,α-Dibromination of Arylethanones with Copper(II) Bromide

Letters in Organic Chemistry ◽

10.2174/1570178616666190118152325 ◽

2019 ◽

Vol 16 (9) ◽

pp. 700-704

Author(s):

Jitander K. Kapoor ◽

Loveena Arora ◽

Om Prakash

Keyword(s):

Ethyl Acetate ◽

Heterogeneous System ◽

Side Chain ◽

Selective Synthesis ◽

Aromatic Ketones

Various arylethanones including electron-rich aromatic ketones such as o-hydroxyacetophenone and its p-isomer underwent selective side-chain α,α-dibromination using a heterogeneous system consisting of four molar equivalents of copper(II) bromide in chloroform-ethyl acetate under reflux. This study provides the cleanest method for the selective synthesis of several synthetically useful α,α-dibromoketones which are otherwise difficult to prepare.

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