- Tripeptide based super-organogelators: Structure and function
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A novel series of tripeptide-based low molecular weight super-organogelators were synthesized and characterized. Four tripeptides with diverse steric crowding at the central amino acid residue were studied. From this series, only sterically less hindered
- Podder, Debasish,Chowdhury, Srayoshi Roy,Nandi, Sujay Kumar,Haldar, Debasish
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supporting information
p. 3743 - 3749
(2019/03/05)
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- Α-BORYL ISOCYANIDES, BOROPEPTIDES AND BORON HETEROCYCLES
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This application pertains to α-boryl isocyanates, wherein the boronate moiety is in the form of an N-methyliminodiacetic acid (MIDA) boronate of the Formula (2) and the utility of said compounds in the synthesis of the borylamide motif (Β-C-Namide) in the scaffold of biologically-active boropeptides, such as bortezomib, in the enablement of heterocycle synthesis, and in multi-component reactions (MCRs), such as the Ugi and Passerini processes.
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Page/Page column 23
(2014/10/18)
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- α-boryl isocyanides enable facile preparation of bioactive boropeptides
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Entry to bioactive boropeptides: MIDA-containing α-boryl isocyanides are isolable molecules which allow one-step access to boroalkyl-functionalized heterocycles as well as biologically active boropeptides through a multicomponent approach. Among these derivatives are 6-boromorpholinones, novel borocycles with nanomolar IC50 values for 20S proteasome inhibition. MIDA=N-methyliminodiacetyl. Copyright
- Zajdlik, Adam,Wang, Zezhou,Hickey, Jennifer L.,Aman, Ahmed,Schimmer, Aaron D.,Yudin, Andrei K.
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supporting information
p. 8411 - 8415
(2013/09/02)
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- α-N-Protected dipeptide acids: A simple and efficient synthesis via the easily accessible mixed anhydride method using free amino acids in DMSO and tetrabutylammonium hydroxide
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The importance of dipeptides both in medicinal and pharmacological fields is well documented and many efforts have been made to find simple and efficient methods for their synthesis. For this reason, we have investigated the synthesis of α-N-protected dipeptide acids by reacting the easily accessible mixed anhydride of α-N-protected amino acids with free amino acids under different reaction conditions. The combination of TBA-OH and DMSO has been found to be the best to overcome the low solubility of amino acids in organic solvents. Under these experimental conditions, the homogeneous phase condensation reaction occurs rapidly and without detectable epimerization. The present method is also applicable to side-chain unprotected Tyr, Trp, Glu, and Asp but not Lys. This latter residue is able to engage two molecules of mixed anhydride giving the corresponding isotripeptide. Moreover, the applicability of this protocol for the synthesis of tri- and tetrapeptides has been tested. This approach reduces the need for protecting groups, is cost effective, scalable, and yields dipeptide acids that can be used as building blocks in the synthesis of larger peptides.
- Verardo,Gorassini
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p. 315 - 324
(2013/06/05)
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- Epimerization-free C-terminal peptide activation
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Smooth operation: C-terminal peptide activation with full stereointegrity was accomplished using a copper(II)-mediated coupling reaction of carboxylic acids with arylboroxines (see scheme, NCL = native chemical ligation, Boc = tert-butoxycarbonyl). This method allows epimerization-free activation and ligation of peptides with racemization-prone phenylglycine at the C terminus.
- Popovic, Stanimir,Bieraeugel, Hans,Detz, Remko J.,Kluwer, Alexander M.,Koole, Jelmer A. A.,Streefkerk, Dieuwertje E.,Hiemstra, Henk,Van Maarseveen, Jan H.
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supporting information
p. 16934 - 16937
(2014/01/06)
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- Evaluation of α,β-unsaturated ketone-based probes for papain-family cysteine proteases
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The field of activity-based proteomics makes use of small molecule active site probes to monitor distinct subsets of enzymatic proteins. While a number of reactive functional groups have been applied to activity-based probes (ABPs) that target diverse families of proteases, there remains a continual need for further evaluation of new probe scaffolds and reactive functional groups for use in ABPs. In this study we evaluate the utility of the, α,β-unsaturated ketone reactive group for use in ABPs targeting the papain-family of cysteine proteases. We find that this reactive group shows highly selective labeling of cysteine cathepsins in both intact cells and total cell extracts. We observed a variable degree of background labeling that depended on the type of tag and linker used in the probe synthesis. The relative ease of synthesis of this class of compounds provides the potential for further derivatization to generate new families of cysteine protease ABPs with unique specificity and labeling properties.
- Yang, Zhimou,Fonovic, Marko,Verhelst, Steven H.L.,Blum, Galia,Bogyo, Matthew
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scheme or table
p. 1071 - 1078
(2009/09/25)
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- Synthesis and pharmacological investigation of segetalin C as a novel antifungal and cytotoxic agent
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In present study, a natural phenylalanine-rich cycloheptapeptide segetalin C (compound VIII) was synthesized by coupling and cyclization of peptide units Boc-gly-L-leu-L-his-OH and L-Phe-L-ala-L-phe-L-pro-OMe and examined for different bioactivities. The
- Dahiya, Rajiv,Kaur, Komalpreet
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- Fluorous (trimethylsilyl)ethanol: A new reagent for carboxylic acid tagging and protection in peptide synthesis
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Starting with a fluorous analogue of 2-(trimethylsilyl)ethanol, we have designed an easy method for preparing a new fluorous tag (FTMSE) for the protection of carboxylic acids. Because mild conditions are employed in the tag cleavage (TBAF in the presence of 4 A molecular sieves, which prevent racemization), this tag can be advantageously used in the synthesis of peptides and modified peptides, as we have demonstrated with several examples, including the fluorous synthesis of short α- and β-peptides as well as of modified fluorinated retropeptides.
- Fustero, Santos,Sancho, Amador Garcia,Chiva, Gema,Sanz-Cervera, Juan F.,Del Pozo, Carlos,Acena, Jose Luis
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p. 3299 - 3302
(2007/10/03)
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- Highly diastereoselective peptide chain extensions of unprotected amino acids with N-(Z-α-aminoacyl)benzotriazoles
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Coupling an unprotected amino acid or dipeptide in partially aqueous solution with a readily available N-(Z-α-amino-acyl)benzotriazole or N-(Z-α-aminopetidoyl)benzotriazole affords N-terminal-protected di-, tri-, and tetrapeptides in yields of 85-98% (average 95% for 2a-i, 93% for 4a-f and 4a′, 86% for 5a-b) with minimal epimerization.
- Katritzky, Alan R.,Suzuki, Kazuyuki,Singh, Sandeep K.
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p. 2645 - 2652
(2007/10/03)
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- Comparative lipase-catalyzed hydrolysis of ethylene glycol derived esters. The 2-methoxyethyl ester as a protective group in peptide and glycopeptide synthesis
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Comparison of the lipase-catalyzed cleavage of polar esters derived from ethylene glycol proved 2-methoxyethyl (ME) esters most favorable protecting groups for the carboxylic function of peptides and glycopeptides. They combine high substrate acceptance and iligh yields of hydrolysis with favorable physicochemical properties and advantageous solubility. The application of this polar ester as protecting group was extended to N-glycosylated amino acids and N-glycopeptides. The selective removal of ME esters by lipases was achieved under mild conditions (pH 7.0 and 37°C), leaving all other linkages including peptide bonds and other ester protecting groups unaffected.
- Gewehr, Markus,Kunz, Horst
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p. 1499 - 1510
(2007/10/03)
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- Facile Synthesis of N-Protected Peptide Fragments using Polymer-Bound 1-Hydroxybenzotriazole as an Active Ester
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Using polystyrene-bound 1-hydroxybenzotriazole as an active ester and an amino acid or peptide, temporarily C-terminal-protected by a phase-transfer reagent, as a nucleophile, C-terminal-free peptide fragments can be synthesized with very high yield and p
- Chen, Shui-Tein,Chang, Chung-Ho,Wang, Kung-Tsung
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p. 1967 - 1975
(2007/10/02)
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- ON THE USE OF CARBOXAMIDOMETHYL ESTERS ( CAM ESTERS ) IN THE SYNTHESIS OF MODEL PEPTIDES. SCOPE AND LIMITATIONS
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The usefulness of carboxamidomethyl esters ( CAM esters ) as a carboxyl protecting group for peptide synthesis was demonstrated.The synthesis of the chemotactic peptide For-Met-Leu-Phe-OH as well as the synthesis of Met-enkephalin using CAM ester as carbo
- Martinez, Jean,Laur, Janine,Castro, Bertrand
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p. 739 - 744
(2007/10/02)
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