scholarly journals Artificial bioconjugates with naturally occurring linkages: the use of phosphodiester

2018 ◽  
Vol 14 ◽  
pp. 1946-1955 ◽  
Author(s):  
Takao Shoji ◽  
Hiroki Fukutomi ◽  
Yohei Okada ◽  
Kazuhiro Chiba
Keyword(s):  
Functional Groups ◽  
Phosphodiester Bond ◽  
Mild Conditions ◽  
Naturally Occurring

Artificial orthogonal bond formations such as the alkyne–azide cycloaddition have enabled selective bioconjugations under mild conditions, yet naturally occurring linkages between native functional groups would be more straightforward to elaborate bioconjugates. Herein, we describe the use of a phosphodiester bond as a versatile option to access various bioconjugates. An opposite activation strategy, involving 5’-phosphitylation of the supported oligonucleotides, has allowed several biomolecules that possess an unactivated alcohol to be directly conjugated. It should be noted that there is no need to pre-install artificial functional groups and undesired and unpredictable perturbations possibly caused by bioconjugation can be minimized.

Borates as a Traceless Activation Group for Intermolecular Alkylarylation of Ethylene through Photoredox/Nickel Dual Catalysis

Synlett ◽  
2020 ◽  
Author(s):  
Shengqing Zhu ◽  
Lingling Chu ◽  
Xiaoliang Feng ◽  
Lei Guo
Keyword(s):  
Functional Groups ◽  
Aryl Halides ◽  
Nickel Catalysis ◽  
Mild Conditions ◽  
Dual Catalysis

AbstractA formal ethylene alkylarylation reaction with aryl halides and alkyl oxalates enabled by synergistic photoredox/nickel catalysis is reported. This protocol takes advantage of borates as a traceless activation group, achieving the formal ethylene difunctionalized products via a catalytic three-component 1,2-alkylarylation of vinyl borate followed by a base-assisted deborylation process. The mild conditions allow for excellent functional groups compatibility and broad substrate scope.

Consecutive Multicomponent Reactions: Synthesis of 3-Acyl-4-alkynyl-Substituted 1,3-Thiazolidines

Synthesis ◽  
2018 ◽  
Vol 50 (05) ◽  
pp. 1123-1132 ◽  
Author(s):  
Jürgen Martens ◽  
Torben Schlüter ◽  
Nils Frerichs ◽  
Marc Schmidtmann
Keyword(s):  
Functional Groups ◽  
Multicomponent Reactions ◽  
Terminal Alkynes ◽  
Synthetic Route ◽  
Acyl Chlorides ◽  
Mild Conditions ◽  
Three Component Reaction

This work describes the synthesis of compounds containing thiazolidine and propargylamidic motifs. Their preparation follows a synthetic route containing two multicomponent reactions. First, the Asinger four-component reaction is used to prepare 3-thiazolines and 3-oxazolines. Secondly, these heterocyclic imines are converted into propargylamides by a copper-catalyzed three-component reaction using acyl chlorides and terminal alkynes. The synthetic route is characterized by mild conditions and many functional groups are tolerated. The formation of an unexpected α-alkynoxyamide is also presented.

Efficient Synthesis of 3,4-Disubstituted 7-Azaindoles Employing SEM as a Dual Protecting–Activating Group

Synlett ◽  
2019 ◽  
Vol 30 (20) ◽  
pp. 2273-2278 ◽  
Author(s):  
Piroska Gyárfás ◽  
János Gerencsér ◽  
Warren S. Wade ◽  
László Ürögdi ◽  
Zoltán Novák ◽  
...  
Keyword(s):  
Functional Groups ◽  
Efficient Method ◽  
Reaction Times ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Efficient Synthesis ◽  
Mild Conditions

An efficient method for nucleophilic aromatic substitution on 7-azaindoles has been developed. The reaction is facilitated by the unique dual influence of SEM as both protecting and activating group, permitting mild conditions and short reaction times that are compatible with sensitive functional groups. The method is suitable for the synthesis of a broad range of products, most notably ethers.

scholarly journals FireProtDB: database of manually curated protein stability data

2020 ◽  
Vol 49 (D1) ◽  
pp. D319-D324
Author(s):  
Jan Stourac ◽  
Juraj Dubrava ◽  
Milos Musil ◽  
Jana Horackova ◽  
Jiri Damborsky ◽  
...  
Keyword(s):  
Machine Learning ◽  
Elevated Temperatures ◽  
Recent Literature ◽  
Single Point ◽  
Biotechnological Applications ◽  
Computational Tools ◽  
Mild Conditions ◽  
Naturally Occurring ◽  
Stability Data ◽  
Living Organisms

Abstract The majority of naturally occurring proteins have evolved to function under mild conditions inside the living organisms. One of the critical obstacles for the use of proteins in biotechnological applications is their insufficient stability at elevated temperatures or in the presence of salts. Since experimental screening for stabilizing mutations is typically laborious and expensive, in silico predictors are often used for narrowing down the mutational landscape. The recent advances in machine learning and artificial intelligence further facilitate the development of such computational tools. However, the accuracy of these predictors strongly depends on the quality and amount of data used for training and testing, which have often been reported as the current bottleneck of the approach. To address this problem, we present a novel database of experimental thermostability data for single-point mutants FireProtDB. The database combines the published datasets, data extracted manually from the recent literature, and the data collected in our laboratory. Its user interface is designed to facilitate both types of the expected use: (i) the interactive explorations of individual entries on the level of a protein or mutation and (ii) the construction of highly customized and machine learning-friendly datasets using advanced searching and filtering. The database is freely available at https://loschmidt.chemi.muni.cz/fireprotdb.

Gold-catalyzed cyclization of 1-(2′-azidoaryl) propynols: synthesis of polysubstituted 4-quinolones

2019 ◽  
Vol 55 (98) ◽  
pp. 14769-14772 ◽  
Author(s):  
Xiang Wu ◽  
Lang-Lang Zheng ◽  
Li-Ping Zhao ◽  
Cheng-Feng Zhu ◽  
You-Gui Li
Keyword(s):  
Functional Groups ◽  
Mild Conditions ◽  
Carbon Migration ◽  
Reaction Works

α-Imino gold carbene intermediate is produced from 1-(2′-azidoaryl) propynols, which triggers a 1,2-carbon migration and is converted to 2,3-disubstituted 4-quinolones. The reaction works under mild conditions and tolerates various functional groups.

Green synthesis of Opuntia-derived carbon nanodots for the catalytic decolourization of cationic dyes

2020 ◽  
Vol 44 (46) ◽  
pp. 20001-20012
Author(s):  
Sabrina A. Beker ◽  
Adam Truskewycz ◽  
Ivan Cole ◽  
Andrew S. Ball
Keyword(s):  
Green Synthesis ◽  
Functional Groups ◽  
Cationic Dyes ◽  
Carbon Nanodots ◽  
Mild Conditions

Carbon nanodots, rich in functional groups and synthesised using green precursors, catalyse the decolourization of dyes under mild conditions.

scholarly journals The 1α-hydroxy-A-rings of norditerpenoid alkaloids are twisted-boat conformers

RSC Advances ◽  
2020 ◽  
Vol 10 (32) ◽  
pp. 18797-18805 ◽  
Author(s):  
Ziyu Zeng ◽  
Ashraf M. A. Qasem ◽  
Gabriele Kociok-Köhn ◽  
Michael G. Rowan ◽  
Ian S. Blagbrough
Keyword(s):  
Functional Groups ◽  
Norditerpenoid Alkaloids ◽  
Naturally Occurring ◽  
Twisted Boat

The skeletal conformations of naturally occurring norditerpenoid alkaloids fix their substituent functional groups in space, thereby directing their bioactivities.

Cerium(IV) Tetrabutylammonium Nitrate (CTAN): A Mild and Efficient N-dearylation Agent for Synthesis of N-unsubstituted 2-azetidinones

2017 ◽  
Vol 41 (4) ◽  
pp. 246-249 ◽  
Author(s):  
Maaroof Zarei
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Mild Conditions ◽  
Tetrabutylammonium Nitrate

A simple and efficient protocol for the conversion of N-p-methoxyphenyl, N-p-ethoxyphenyl, N-p-methoxynaphthyl, N-3,4-dimethoxybenzyl and N-p-methoxybenzyl-2-azetidinones to N-unsubstituted 2-azetidinones using cerium(IV) tetrabutylammonium nitrate (CTAN) in dichloromethane is described. The method is compatible with a number of functional groups, and N-unsubstituted 2-azetidinones can be prepared under mild conditions at room temperature. The reaction is rapid, and pure products are obtained in good yields.

Biologically active acyclonucleoside analogues. II. The synthesis of 9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine (BIOLF-62)

1982 ◽  
Vol 60 (24) ◽  
pp. 3005-3010 ◽  
Author(s):  
Kelvin K. Ogilvie ◽  
Ukken O. Cheriyan ◽  
Bruno K. Radatus ◽  
Kendall O. Smith ◽  
Karen S. Galloway ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Functional Groups ◽  
Biologically Active ◽  
Nucleoside Analogues ◽  
Naturally Occurring

The chemical synthesis of 9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine is described. This compound, known as BIOLF-62, is active against herpesviruses. This compound is a member of a novel class of nucleoside analogues which lack a rigid carbohydrate ring, but which possess all of the functional groups of naturally occurring deoxynucleosides.

scholarly journals Biobased Hyperbranched Poly(ester)s of Precise Structure for the Release of Therapeutics

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Bob Howell ◽  
Tracy Zhang ◽  
Patrick Smith
Keyword(s):  
Sustained Release ◽  
Functional Groups ◽  
Active Agent ◽  
Monomer Conversion ◽  
Single Type ◽  
Hydroxyl Groups ◽  
Naturally Occurring ◽  
Hyperbranched Poly ◽  
The Difference ◽  
Smith Model

Hyperbrached poly(ester)s derived from naturally-occurring biomonomers may serve as excellent platforms for the sustained-release of therapeutics. Those generated from glycerol are particularly attractive. Traditionally, the difference in reactivity of the hydroxyl groups of glycerol has precluded the formation of well-defined polymers at high monomer conversion without gelation. Using the Martin-Smith model to select appropriate monomer ratios (ratios of functional groups), polymerization may be carried out to high conversion while avoiding gelation and with the assurance of a single type of endgroup. Various agents may be attached via esterification, amide formation or other process. Sustained release of the active agent may be readily achieved by enzyme-catalyzed hydrolysis.

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