- β,γ-diamino acids as building blocks for new analogues of Gramicidin S: Synthesis and biological activity
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We describe here the synthesis and biological activity study of a pair of diastereomeric analogues of Gramicidin S using β,γ-diamino acids as β-turn mimic. The synthesis of the orthogonally protected β,γ-diamino acids was achieved in 6 steps starting from D-alanine. The analogues were then synthesized in solution phase and on solid phase. Biological activity tests showed that, compared with Gramicidin S, both analogues exerted diminished hemolytic activity while they retained interesting antibacterial activity.
- Wan, Yang,Stanovych, Andrii,Gori, Didier,Zirah, Séverine,Kouklovsky, Cyrille,Alezra, Valérie
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supporting information
p. 122 - 128
(2018/03/06)
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- Benzimidazole analogs of l-tryptophan are substrates and inhibitors of tryptophan indole lyase from Escherichia coli
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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
- Harris, Austin P.,Phillips, Robert S.
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p. 1807 - 1817
(2013/06/05)
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- Macrocyclic hexaoxazoles: Influence of aminoalkyl substituents on RNA and DNA G-quadruplex stabilization and cytotoxicity
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A series of 24-membered macrocyclic hexaoxazoles containing one or two aminoalkyl substituents was synthesized and evaluated for cytotoxicity and for their ability to selectively stabilize G-quadruplex DNA and RNA. The most cytotoxic analog 4a, with IC50 values of 25 and 130 nM using KB3-1 and RPMI 8402 cells, is efficacious in vivo in athymic nude mice with a human tumor xenograft from the breast cancer cell line MDA-MB-435.
- Satyanarayana, Mavurapu,Kim, Young-Ah,Rzuczek, Suzanne G.,Pilch, Daniel S.,Liu, Angela A.,Liu, Leroy F.,Rice, Joseph E.,LaVoie, Edmond J.
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scheme or table
p. 3150 - 3154
(2010/09/10)
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- NG-aminoguanidines from primary amines and the preparation of nitric oxide synthase inhibitors
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A concise, general, and high-yielding method for the preparation of N G-aminoguanidines from primary amines is reported. Using available and readily prepared materials, primary amines are converted to protected N G-aminoguanidines in a one-pot procedure. The method has been successfully applied to a number of examples including the syntheses of four nitric oxide synthase (NOS) inhibitors. The inhibitors prepared were investigated as competitive inhibitors and as mechanistic inactivators of the inducible isoform of NOS (iNOS). In addition, one of the four inhibitors prepared, NG-amino-NG-2,2,2-trifluoroethyl-L-arginine 19, displays the unique ability to both inhibit NO formation and prevent NADPH consumption by iNOS without irreversible inactivation of the enzyme.
- Martin, Nathaniel I.,Beeson, William T.,Woodward, Joshua J.,Marletta, Michael A.
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p. 924 - 931
(2008/09/20)
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- Synthesis and evaluation of peptidic maleimides as transglutaminase inhibitors
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A series of novel transglutaminase inhibitors was prepared, based on the scaffold of a commonly used peptide substrate and bearing an electrophilic maleimide group. These compounds were evaluated in vitro and shown to lead to irreversible inactivation of tissue transglutaminase. Comparison with inhibitors studied previously provides insight into the steric environment of the enzyme active site.
- Halim, Dany,Caron, Karine,Keillor, Jeffrey W.
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p. 305 - 308
(2007/10/03)
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- SUBSTITUTED CHIRAL FUSED [1,2]IMIDAZO[4,5-C] RING COMPOUNDS
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Substituted fused [1,2]imidazo[4,5-c] ring compounds (e.g., imidazo[4,5-c]quinolines, 6,7,8,9-tetrahydroimidazo[4,5-c]quinolines, imidazo[4,5-c]naphthyridines, and 6,7,8,9-tetrahydroimidazo[4,5-c]naphthyridines) with a -CH(-R1)- group in the fused ring at the 1-position of the imidazo ring, wherein Rl includes a functional group, for example, an amide, sulfonamide, urea, carbamate, ester, ketone, ether, a thio analog of the forgoing, sulfone, oxime, or hydroxylamine, pharmaceutical compositions containing the compounds, intermediates, methods of making the compounds, and methods of use of these compounds as immunomodulators, for inducing cytokine biosynthesis in animals and in the treatment of diseases including viral and neoplastic diseases, are disclosed.
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Page/Page column 113
(2008/06/13)
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- Sulfonylaminovalerolactams and derivatives thereof as factor Xa inhibitors
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The present application describes sulfonylaminovalerolactams and derivatives thereof of Formula I: or pharmaceutically acceptable salt forms thereof, wherein ring G is a mono- or bicyclic carbocycle or heterocycle. Compounds of the present invention are useful as inhibitors of trypsin-like serine proteases, specifically factor Xa.
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Page/Page column 42
(2008/06/13)
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- Improved scalable syntheses of mono- and bis-urethane derivatives of ornithine
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In the search for a practical route to ornithine bisurethane derivatives useful for peptide synthesis, we elaborated the simple and efficient (86% yield) synthesis of Nε-tert-butoxycarbonyl-L-ornithine copper(II) complex(1). This served as substrate for obtaining Nε-tert-butoxycarbonyl-L-ornithine (2), Nα-benzyloxycarbonyl-Nε-tert- butoxycarbonyl-L-ornithine (3) and Nα-(9-fluorenyl)methoxycarbonyl-Nε-tert- butoxycarbonyl-L-ornithine (4). These were synthesized in 94-95% yields and with a purity above 99%.
- Wiejak,Masiukiewicz,Rzeszotarska
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p. 1189 - 1191
(2007/10/03)
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