184576-63-4Relevant articles and documents
Optimized syntheses of Fmoc azido amino acids for the preparation of azidopeptides
Pícha, Jan,Budě?ínsky, Milo?,Machá?ková, Kate?ina,Collinsová, Michaela,Jirá?ek, Ji?í
, p. 202 - 214 (2017/04/06)
The rise of CuI-catalyzed click chemistry has initiated an increased demand for azido and alkyne derivatives of amino acid as precursors for the synthesis of clicked peptides. However, the use of azido and alkyne amino acids in peptide chemistry is complicated by their high cost. For this reason, we investigated the possibility of the in-house preparation of a set of five Fmoc azido amino acids: β-azido l-alanine and d-alanine, γ-azido l-homoalanine, δ-azido l-ornithine and ω-azido l-lysine. We investigated several reaction pathways described in the literature, suggested several improvements and proposed several alternative routes for the synthesis of these compounds in high purity. Here, we demonstrate that multigram quantities of these Fmoc azido amino acids can be prepared within a week or two and at user-friendly costs. We also incorporated these azido amino acids into several model tripeptides, and we observed the formation of a new elimination product of the azido moiety upon conditions of prolonged couplings with 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate/DIPEA. We hope that our detailed synthetic protocols will inspire some peptide chemists to prepare these Fmoc azido acids in their laboratories and will assist them in avoiding the too extensive costs of azidopeptide syntheses. Experimental procedures and/or analytical data for compounds 3–5, 20, 25, 26, 30 and 43–47 are provided in the supporting information.
Benzimidazole analogs of l-tryptophan are substrates and inhibitors of tryptophan indole lyase from Escherichia coli
Harris, Austin P.,Phillips, Robert S.
, p. 1807 - 1817 (2013/06/05)
Tryptophan indole lyase (TIL), an enzyme found in Escherichia coli and related enterobacteria, produces indole from l-tryptophan (l-Trp). Indole is a signaling molecule in bacteria, affecting biofilm formation, pathogenicity and antibiotic resistance. β-(Benzimidazol-1-yl)-l-alanine (BZI-Ala), 2-amino-4-(benzimidazol-1-yl)butyric acid (homo-BZI-Ala) and 2-amino-5-(benzimidazol-1-yl)pentanoic acid (bishomo-BZI-Ala) were synthesized and tested as substrates and inhibitors of TIL. BZI-Ala is a good substrate of TIL, with Km = 300 μm, kcat = 5.6 s-1 and kcat/Km = 1.9 × 104, similar to l-Trp. BZI-Ala is also a good substrate for H463F mutant TIL, which has very low activity with l-Trp. In contrast, homo-BZI-Ala was found to be a potent competitive inhibitor of TIL, with a Ki of 13.4 μm. However, the higher homolog, bishomo-BZI-Ala, was inactive as an inhibitor of TIL at a concentration of 600 μm, and is thus a much weaker inhibitor. The reaction of TIL with BZI-Ala was too fast to be observed in the stopped-flow spectrophotometer, and shows an aldimine intermediate in the steady state. However, H463F TIL shows equilibrating mixtures of aldimine and quinonoid complexes in the steady state. The spectra of the reaction of TIL with homo-BZI-Ala show a rapidly formed intermediate absorbing at 340 nm, probably a gem-diamine, that decays slowly to form a quinonoid complex absorbing at 494 nm. The potent binding of homo-BZI-Ala may be due to it being a 'bi-product' analog of the indole-α-aminoacrylate complex. These results demonstrate that an amino acid substrate may be converted to a potent inhibitor of TIL simply by homologation, which may be useful in the design of other potent TIL inhibitors. β-(Benzimidazol-1-yl)-l-alanine (BZI-Ala), 2-amino-4-(benzimidazol-1-yl) butyric acid (homo-BZI-Ala), and 2-amino-5-(benzimidazol-1-yl)pentanoic acid (bishomo-BZI-Ala) were synthesized and tested as substrates and inhibitors of tryptophan indole-lyase (TIL), an enzyme found in Escherichia coli and related enterobacteria. BZI-Ala is a good substrate of TIL, homo-BZI-Ala is a potent competitive inhibitor of TIL, with Ki of 13.4 μM, but bishomo-BZI-Ala, was inactive as an inhibitor of TIL. 2013 The Authors Journal compilation
The two pathways for effective orthogonal protection of L-ornithine, for amino acylation of 5'-O-Pivaloyl nucleosides, describe the general and important role for the successful imitation, during the synthesis of the model substrates for the ribosomal mimic reaction
Bayryamov, Stanislav G.,Vassilev, Nikolay G.,Petkov, Dimiter D.
experimental part, p. 889 - 898 (2011/12/14)
Bz(NO2)-Orn(Boc)-OCH2CN was synthesized as an amino acid component with effective and successful orthogonal protection for amino acylation of 5'-O-Pivaloyl nucleosides and preparation of substrates for model ribosome reactions. The synthesis was carried out using suitable combinations of the methods of peptide synthesis and modification of amino acids.
