- MgI2-Mediated Chemoselective Cleavage of Protecting Groups: An Alternative to Conventional Deprotection Methodologies
-
The scope of MgI2 as a valuable tool for quantitative and mild chemoselective cleavage of protecting groups is described here. This novel synthetic approach expands the use of protecting groups, widens the concept of orthogonality in synthetic processes, and offers a facile opportunity to release compounds from solid supports. Amazing MgI2: Protecting groups have had a tremendous positive impact on the art of biomolecule synthesis. In a context in which the use of attractive protecting groups is often limited by harsh deprotection conditions and low chemoselective flexibility, MgI2 offers, by the execution of a very simple protocol, a fresh vision with extensive perspectives.
- Berthet, Mathéo,Davanier, Florian,Dujardin, Gilles,Martinez, Jean,Parrot, Isabelle
-
supporting information
p. 11014 - 11016
(2015/11/10)
-
- Ethyl substituted coumarin-4-yl derivatives as photoremovable protecting groups for amino acids with improved stability for SPPS
-
The synthesis, photochemical properties and chemical stability of 7-(N,N-diethylamino-coumarin-4-yl)-1-ethyl (DEACE) photoremovable protecting group for carboxylic acids are presented. We demonstrate that the ethyl substituent of DEACE improves the hydrolytic stability of the protected ester in basic conditions used in solid phase peptide synthesis (SPPS) and retains the good photochemical properties of the coumarin-4-yl methyl derivatives. DEACE allows the preparation of peptides with protected carboxylic side groups with high yield via SPPS.
- Weis, Simone,Shafiq, Zahid,Gropeanu, Radu A.,Del Campo, Aránzazu
-
scheme or table
p. 52 - 57
(2012/09/07)
-
- New TFA-free cleavage and final deprotection in Fmoc solid-phase peptide synthesis: Dilute HCl in fluoro alcohol
-
A novel method for cleaving from resin and removing acid-labile protecting groups for the Fmoc solid-phase peptide synthesis is described. 0.1 N HCl in hexafluoroisopropanol or trifluoroethanol cleanly and rapidly removes the tert-butyl ester and ether, Boc, trityl, and Pbf groups and cleaves the common resin linkers: Wang, HMPA, Rink amide, and PAL. Addition of just 5-10% of a hydrogen-bonding solvent considerably retards or even fully inhibits the reaction. However, a non-hydrogen-bonding solvent is tolerated.
- Palladino, Pasquale,Stetsenko, Dmitry A.
-
supporting information
p. 6346 - 6349
(2013/02/25)
-
- A microwave-assisted synthesis of (S)-N-protected homoserine γ-lactones from l-aspartic acid
-
A three-pot preparation of (S)-N-protected homoserine γ-lactones is presented. Conversion of N-protected l-aspartic acid to an oxazolidinone is followed by selective reduction/acid-catalyzed cyclization to deliver the lactones. Microwave irradiation proved valuable for improving the latter reaction steps in some cases.
- Singh, Suneel P.,Michaelides, Alex,Merrill, A. Rod,Schwan, Adrian L.
-
experimental part
p. 6825 - 6831
(2011/10/08)
-
- Liquid-chromatography quantitative analysis of 20 amino acids after derivatization with FMOC-CI and its application to different origin Radix isatidis
-
We developed a simple, rapid and reliable method for determination of 20 common amino acids based on derivatization with 9-fluorenylmethyl chloroformate (FMOC-CI) and RP-LC/UV, this method was first introduced into quantitative analysis of amino acids. The amino groups of amino acids were trapped with FMOC-CI to form amino acid-FMOC-Cl adducts which can be suitable for LC-UV. Chromatographic separation was performed on a C18 column with a mobile phase gradient consisting of acetonitrile and sodium acetate solution. This method was shown to be sensitive for 20 common amino acids. In the intra-day precisions assay, the range of RSDs was 3.21-7.67% with accuracies of 92.34-102.51%; for the inter-day precisions assay, the range of RSDs was 5.82-9.19% with accuracies of 90.25-100.63%. The results also indicated that solutions of amino acids-FMOC-Cl can be kept at room temperature for at least 24 h without showing significant losses in the quantified values. The validated method was successfully applied to the determination of major four kinds of amino acids in R. isatidis samples (Arg, Pro, Met and Val). The total content of amino acids in different origin R. isatidis was 13.32-19.16 mg/g. The differences between R. isatidis samples were large using HCA.
- Zhou, Wei,Zhang, Xiao-Yan,Duan, Geng-Li
-
experimental part
p. 509 - 515
(2012/01/04)
-
- Identification of small peptides mimicking the R2 C-terminus of Mycobacterium tuberculosis ribonucleotide reductase
-
Ribonucleotide reductase (RNR) is a viable target for new drugs against the causative agent of tuberculosis, Mycobacterium tuberculosis. Previous work has shown that an N-acetylated heptapeptide based on the C-terminal sequence of the smaller RNR subunit can disrupt the formation of the holoenzyme sufficiently to inhibit its function. Here the synthesis and binding affinity, evaluated by competitive fluorescence polarization, of several truncated and N-protected peptides are described. The protected single-amino acid Fmoc-Trp shows binding affinity comparable to the N-acetylated heptapeptide, making it an attractive candidate for further development of non-peptidic RNR inhibitors. Copyright
- Ericsson, Daniel J.,Nurbo, Johanna,Muthas, Daniel,Hertzberg, Kalle,Lindeberg, Gunnar,Karlen, Anders,Ungea, Torsten
-
experimental part
p. 159 - 164
(2011/02/24)
-
- Reaction of N-Fmoc aspartic anhydride with glycosylamines: a simple entry to N-glycosyl asparagines
-
The reaction of N-Fmoc-aspartic anhydride with glycosyl amines in DMSO selectively leads to the formation of β-substituted products, thus providing a simple and efficient route to N-glycosyl asparagine derivatives, the building blocks for glycopeptide synthesis.
- Ibatullin, Farid M.,Selivanov, Stanislav I.
-
experimental part
p. 6351 - 6354
(2010/02/27)
-
- Amphiphilic cyclodextrin derivatives, method for preparation thereof and uses thereof
-
The invention relates to cyclodextrin derivatives of formula (I): in which: R1═—NH-E-AA-(L1)p(L2)q where E=a linear or branched Cl-Cl5 hydrocarbon-based group with, optionally, one or more hetero atoms; AA=the residue of an amino acid; L1 and L2=a C6-C24 hydrocarbon-based group with, optionally, one or more hetero atoms; p and q=0 or 1, at least one being ≠0; R2═H, —CH3, isopropyl, hydroxypropyl, sulphobutyl ether; R3═H or R2, except when R2=hydroxypropyl; all the R4═—OH or R2, except when R2=hydroxypropyl, or at least one of the R4═R1; n=5, 6 or 7. The invention also relates to a process for preparing them, and to inclusion complexes and organized surfactant systems comprising them.
- -
-
Page/Page column 8
(2010/11/27)
-
- Aqueous phosphoric acid as a mild reagent for deprotection of tert-butyl carbamates, esters, and ethers
-
(Chemical Equation Presented) Aqueous phosphoric acid (85 wt %) is an effective, environmentally benign reagent for the deprotection of tert-butyl carbamates, tert-butyl esters, and tert-butyl ethers. The reaction conditions are mild and offer good selectivity in the presence of other acid-sensitive groups, including CBZ carbamates, azetidine, benzyl and methyl esters, TBDMS, and methyl phenyl ethers. The mildness of the reaction is further demonstrated in the synthesis of clarithromycin derivative 4, in which a tert-butyl ester is removed in the presence of cyclic carbamate, lactone, ketal, acetate ester, and epimerizable methyl ketone functionalities. The reaction preserves the stereochemical integrity of the substrates. The reactions are high yielding, and the workup is convenient.
- Li, Bryan,Berliner, Martin,Buzon, Richard,Chiu, Charles K.-F.,Colgan, Stephen T.,Kaneko, Takushi,Keene, Nandell,Kissel, William,Le, Tung,Leeman, Kyle R.,Marquez, Brian,Morris, Ronald,Newell, Lisa,Wunderwald, Silke,Witt, Michael,Weaver, John,Zhang, Zhijun,Zhang, Zhongli
-
p. 9045 - 9050
(2007/10/03)
-
- Enzyme-cleavable linkers for peptide and glycopeptide synthesis
-
Hydroxymethylphenoxy linkers that are commonly used in solid phase peptide synthesis are surprisingly susceptible to efficient cleavage by the protease chymotrypsin with a broad range of amino acid residues being tolerated at the scissile bond; this enzyme-cleavable linker system has been applied to peptide and glycopeptide synthesis. The Royal Society of Chemistry 2005.
- Maltman, Beatrice A.,Bejugam, Mallesham,Flitsch, Sabine L.
-
p. 2505 - 2507
(2007/10/03)
-
- Profiling primary protease specificity by peptide synthesis on a solid support
-
Reverse screening: A greatly simplified primary screening of protease specificity has been achieved by monitoring the fluorescence during the protease-catalyzed coupling of amino acids instead of peptide hydrolysis on a solid support (see picture, AA = amino acid). This approach paves the way for flexible, rapid, high-throughput identification and characterization of proteases without the need for expensively labeled peptide arrays.
- Doeze, Ron H. P.,Maltman, Beatrice A.,Egan, Claire L.,Ulijn, Rein V.,Flitsch, Sabine L.
-
p. 3138 - 3141
(2007/10/03)
-
- A new polymer-supported reagent for the Fmoc-protection of amino acids
-
A new polymer-supported Fmoc-OSu (Fmoc-P-OSu) has been prepared from polymer-bound N-hydroxysuccinimide (P-HOSu), and used as a solid-supported reagent for the Fmoc-protection of amino groups. The residual P-HOSu generated after the protection reaction can be separated by simple filtration and reused.
- Chinchilla, Rafael,Dodsworth, David,Nájera, Carmen,Soriano, José
-
p. 7579 - 7581
(2007/10/03)
-
- Target-selective protocols based on mimics
-
A method to potentiate the effect of a chemotherapeutic agent in a tumor cell, which method comprises administering to said tumor cell, along with said chemotherapeutic agent, a potentiating amount of a compound of the formula: STR1 or an amide, ester or hybrid amide/ester thereof, wherein X is a hydrocarbon radical optionally substituted on any aromatic moiety contained therein; Y--CO is γ-Glu or β-Asp and AAC is an amino acid, preferably glycine, phenylglycine, β-alanine, alanine or phenylalanine is disclosed. Similar compounds can also be used to selectively exert cytotoxicity versus target cells as compared to nontarget cells and also to elevate the production of GM progenitors in bone marrow of mammalian subjects.
- -
-
-
- Glutathione analogs and paralog panels comprising glutathione mimics
-
Compounds of the formula STR1 or the alkyl (1-6 C), alkenyl (1-6 C), or arylalkyl (7-12 C) amides or salts including the cycloamido forms thereof; wherein n is 1 or 2; wherein when n is 1, X is a mono- or disubstituted or unsubstituted hydrocarbyl (1-20 C) moiety optionally containing 1 or 2 nonadjacent heteroatoms (O, S or N), and wherein said substitution is selected from the group consisting of halo, OR, and SR, wherein R is H or lower alkyl (1-4 C); when n is 2, one X is as above defined and the other X is lower alkyl (1-4 C); Y is selected from the group consisting of STR2 wherein m is 1 or 2; and AAC is an amino acid coupled through a peptide bond to the remainder of the compound of formula 1, are useful as affinity ligands, elution reagents, solution inhibitors, diagnostic reagents and therapeutics. These compounds and analogous tripeptide glutathione analogs can be used as members of panels to obtain specific characteristic profiles for various glutathione-S-transferases.
- -
-
-
- Glutathione analogs and paralog panels comprising glutathione mimics
-
Compounds of the formula or the alkyl (1-6C) or arylalkyl (7-12C) amides or salts including the cycloamido forms thereof;, wherein n is 1 or 2;, wherein when n is 1, X is a mono- or disubstituted or unsubstituted hydrocarbyl (1-20C) moiety optionally containing 1 or 2 nonadjacent heteroatoms (O, S or N), and wherein said substitution is selected from the group consisting of halo, OR, and SR, wherein R is H or lower alkyl (1-4C); when n is 2, one X is as above defined and the other X is lower alkyl (1-4C);, Y is selected from the group consisting of wherein m is 1 or 2; and, AACis an amino acid coupled through a peptide bond to the remainder of the compound of formula 1, are useful as affinity ligands, elution reagents, solution inhibitors, diagnostic reagents and therapeutics. These compounds and analogous tripeptide glutathione analogs can be used as members of panels to obtain specific characteristic profiles for various glutathione-S-transferases.
- -
-
-
- Improved efficiency and selectivity in peptide synthesis: Use of triethylsilane as a carbocation scavenger in deprotection of t-butyl esters and t-butoxycarbonyl-protected sites
-
The use of triethylsilane as a carbocation scavenger in the presence of trifluoroacetic acid in dichloromethane leads to increased yields, decreased reaction times, simple work-up and improved selectivity for the deprotection of t-butyl ester and t-butoxycarbonyl sites in protected amino-acids and peptides in the presence of other acid-sensitive protecting groups such as the benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, O- and S-benzyl and t-butylthio groups.
- Mehta, Anita,Jaouhari, Rabih,Benson, Timothy J.,Douglas, Kenneth T.
-
p. 5441 - 5444
(2007/10/02)
-
