- Hydrogen bond surrogate stabilized water soluble 310-helix from a disordered pentapeptide containing coded α-amino acids
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Replacing a hypothetical i + 3 → i peptide H-bond in a disordered pentapeptide, that lacks any helicogenic Cα-tetrasubstituted residues, with a propyl linker and carbamylating the N-terminal nitrogen constrains it in the elusive 310-helical structure with high helicity and stability under varying conditions of temperature and pH, confirmed by NMR and CD analyses.
- Pal, Sunit,Prabhakaran, Erode N.
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p. 2515 - 2519
(2018/05/28)
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- Cyclizing pentapeptides: Mechanism and application of dehydrophenylalanine as a traceless turn-inducer
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Dehydrophenylalanine is used as a traceless turn-inducer in the total synthesis of dichotomin E. Macrocyclization of the monomer is achieved in high yields and selectivity over cyclodimerization under conditions 100 times more concentrated than previously achieved. The enamide facilitates ring closing, and Rh-catalyzed hydrogenation of the unsaturated cyclic peptide results in selective formation of the natural product or its epimer, depending on our choice of phosphine ligand. NMR analysis and molecular modeling revealed that the linear peptide adopts a left-handed α-turn that preorganizes the N- and C-termini toward macrocyclization.
- Le, Diane N.,Riedel, Jan,Kozlyuk, Natalia,Martin, Rachel W.,Dong, Vy M.
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p. 114 - 117
(2017/11/27)
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- Microwave-Assisted Synthesis of 2,2′-Azopyridine-Labeled Amines, Amino Acids, and Peptides
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A microwave-assisted procedure for labeling amines, amino acids, and peptides with 2,2′-azopyridines (2,2′-AzPy) is described using the corresponding 2,2′-azopyridine-diacylbenzotriazoles. The efficiency of the procedure is proven by the generation of thr
- Avan, Ilker
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p. 365 - 378
(2016/01/28)
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- Redox-triggered changes in the self-assembly of a ferrocene-peptide conjugate
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Ultrasonication of a ferrocene conjugate of a short amyloid peptide (Aβ18-20) in toluene causes formation of an organogel, which undergoes dramatic structural changes upon oxidation from a nanofibrillar network to spherical micelles. This morphological change is redox-controlled and reversible. the Partner Organisations 2014.
- Adhikari, Bimalendu,Kraatz, Heinz-Bernhard
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p. 5551 - 5553
(2014/05/20)
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- Gabapentin hybrid peptides and bioconjugates
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Synthetic approaches to gabapentin bioconjugates that overcome the tendency of gabapentin to cyclize into its γ-lactam are studied. Gabapentin was converted by N-acylation at its N-terminus into di-, tri-, and tetrapeptides (L-Ala-Gbp, L-Val-Gbp, L-Ala-L-Phe-Gbp, Gly-L-Ala-β-Ala-Gbp). Carboxyl-activated Boc-protected gabapentin was used to N-, O-, and S-acylate small peptides and hormones to give conjugates that could also provide prodrugs containing conformationally constrained gabapentin units.
- Lebedyeva, Iryna O.,Ostrov, David A.,Neubert, John,Steel, Peter J.,Patel, Kunal,Sileno, Sean M.,Goncalves, Kevin,Ibrahim, Mohamed A.,Alamry, Khalid A.,Katritzky, Alan R.
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p. 1479 - 1486
(2014/03/21)
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- COMPOUNDS FOR AMIDE-FORMING REACTIONS
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Provided herein is a compound of Formula I, that displays remarkable physicochemical properties as a peptide-coupling additive for peptide-forming reactions in water, wherein said coupling reactions proceed without measurable racemization. A method of pro
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Page/Page column 23; 24; 26; 27
(2014/01/07)
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- A new oxyma derivative for nonracemizable amide-forming reactions in water
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An Oxyma derivative, (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 2-cyano-2-(hydroxyimino)acetate (2), displayed remarkable physicochemical properties as a peptide-coupling additive for peptide-forming reactions in water. Short peptides to oligopeptides could b
- Wang, Qinghui,Wang, Yong,Kurosu, Michio
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supporting information; experimental part
p. 3372 - 3375
(2012/09/07)
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- An efficient synthetic method of N-protected dipeptide acids using amino acid calcium carboxylates in an organic solvent
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The syntheses of N-protected dipeptide acids using alkaline earth metal (Mg, Ca, and Ba) carboxylates of an amino acid in organic solvents were investigated. It was found that amino acid calcium carboxylates are the most effective among the carboxylates of the amino acids tested for coupling with active esters of Boc-Ala-OH in organic solvents. The coupling of Boc-Ala-ONp or Boc-Ala-ONSu with amino acid calcium carboxylates in DMF gave the desired N-protected dipeptide acids in high yields (92-100%). Georg Thieme Verlag Stuttgart - New York.
- Hashimoto, Chikao,Takeguchi, Kazunobu,Kodomari, Mitsuo
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experimental part
p. 1427 - 1430
(2011/08/03)
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- Smart oligopeptide gels: In situ formation and stabilization of gold and silver nanoparticles within supramolecular organogel networks
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Tripeptide with redox active chemical entities based smart organogels have been used for in situ formation and stabilization of gold and silver nanoparticles within the supramolecular gel networks and the gold nanoparticles are aligned in arrays along the gel nanofibers of peptide 1-toluene gels. The Royal Society of Chemistry 2006.
- Ray, Sudipta,Das, Apurba Kumar,Banerjee, Arindam
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p. 2816 - 2818
(2008/09/19)
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- A new approach to the synthesis of di- and tripeptides with unnatural amino acids using organozinc chemistry
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Di- and tripeptides which incorporate an iodoalanine unit at the C-terminus can be converted into the corresponding organozinc reagents upon treatment with activated zinc. These C-terminal di- and tripeptide organozinc reagents react with electrophiles either under palladium catalysis, or by prior transmetallation to a zinc/copper reagent, to give di- and tripeptides incorporating non-proteinogenic amino acids without loss of stereochemical purity.
- Dunn, Michael J.,Jackson, Richard F. W.
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p. 13905 - 13914
(2007/10/03)
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- An approach towards more selective anticancer agents
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A promising approach towards better targeted anticancer drug therapy takes advantage of enhanced expression of proteases associated with human malignancies. Especially plasminogen activator activity has been found to be substantially increased, leading to an enhanced activity of the serine protease plasmin. Bifunctional alkylating agents, such as N-(2-chloroethyl)-N-nitrosoureas, display broad spectrum anticancer activity, but also exhibit considerable systemic toxicity. We describe here the synthesis of new N-nitrosourea-based prodrugs designed to become activated by tumor-associated proteases, to provide for enhanced antitumor activity and reduced systemic toxicity. Tripeptides representing substrates for plasmin were linked by an amide bond to N'-(2-aminoethyl)-N-(2-chloroethyl)-N-nitrosourea and the corresponding N'-methyl derivative. Synthesis and plasmin-triggered decomposition of these new tripeptide conjugates is described. Cancer cells expressing high plasminogen activator activity are highly sensitive to the new prodrugs in the presence of plasminogen, but not in its absence.
- Eisenbrand,Lauck-Birkel,Tang
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p. 1246 - 1258
(2007/10/03)
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- Enzymatische Synthese von Peptiden und Ras-Lipopeptiden unter Verwendung des Cholinesters als loeslichkeitsvermittelnder Schutz- und Aktivierungsgruppe
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Keywords: Cholinesterase; Enzymkatalyse; Peptidsynthesen; Ras-Proteine
- Schelhaas, Michael,Glomsda, Simone,Haensler, Marion,Jakubke, Hans-Dieter,Waldmann, Herbert
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- Facile amide bond formation from esters of amino acids and peptides catalyzed by alkaline protease in anhydrous tert-butyl alcohol using ammonium chloride/triethylamine as a source of nucleophilic ammonia
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An industrial alkaline protease 'Alcalase', stable and active in tert-butyl alcohol, was used to catalyze the synthesis of N-protected amino acids or peptide amides in anhydrous tert-butyl alcohol using ammonium chloride/triethylamine as source of nucleophilic ammonia
- Chen,Jang,Wang
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p. 858 - 860
(2007/10/02)
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- Unique sequence in deltorphin C confers structural requirement for δ opioid receptor selectivity
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A series of deltorphin C (H-Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2) analogues were synthesized to assess the consequences of changing anionic and hydrophobic residues on δ receptor selectivity.Analogues with altered C-terminal groups, inverted sequences, or es
- Lazarus, LH,Salvadori, S,Grieco, P,Wilson, WE,Tomatis, R
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p. 791 - 797
(2007/10/02)
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- PROTECTION DES ACIDES PAR LES GROUPEMENTS ABz. UTILISATION EN SYNTHESE PEPTIDIQUE
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The novel azidomethoxybenzyl esters (ABz esters) of various acids are easily obtained and are cleanly cleaved in very mild reductive conditions.Such esters serve to protect the carboxyl group in peptide synthesis without any racemisation.
- Loubinoux, Bernard,Gerardin, Philippe
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p. 239 - 248
(2007/10/02)
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