LIVIVO - Das Suchportal für Lebenswissenschaften

switch to English language
Zurück zur letzten Suche Suchhistorie
Erweiterte Suche

Ihre letzten Suchen

  1. AU="Creech, Gardner S"
  2. AU="José P. Oliveira-Filho"
  3. AU="Munt, Jennifer E"
  4. AU="Whiley, Phillip J"
  5. AU="V.Sudhir, "
  6. AU="Chatow, Lior"
  7. AU=Xue Zhe
  8. AU="Peter D. Yurchenco"
  9. AU="Várbíró, Gábor"
  10. AU="Sheleg, Dmitriy"
  11. AU="Panzirer, David"

Suchergebnis

Treffer 1 - 7 von insgesamt 7

Suchoptionen

  1. Artikel ; Online: Tandem 6pi-electrocyclization and cycloaddition of nitrodienes to yield multicyclic nitroso acetals.

    Creech, Gardner S / Kwon, Ohyun

    Journal of the American Chemical Society

    2010  Band 132, Heft 26, Seite(n) 8876–8877

    Abstract: Upon heating, nitrodienes rearrange through 6pi-electrocyclization to form nitronate intermediates, which can be captured through tandem [3 + 2] dipolar cycloadditions to form highly functionalized nitroso acetals. The one-pot, two-step domino process is ...

    Abstract Upon heating, nitrodienes rearrange through 6pi-electrocyclization to form nitronate intermediates, which can be captured through tandem [3 + 2] dipolar cycloadditions to form highly functionalized nitroso acetals. The one-pot, two-step domino process is highly efficient, proceeding with good facial selectivity and exoselectivity. Dipolarophiles featuring electron-rich, -neutral, and -deficient carbon-carbon double bonds are viable substrates for [3 + 2] cycloadditions with the in situ generated nitronates. In addition, the highly functionalized nitroso acetal products can be hydrogenolyzed selectively to form densely functionalized spirocyclic hydroxy amides or hydroxy gamma-amino acids.
    Mesh-Begriff(e) Acetals/chemistry ; Cyclization ; Nitroso Compounds/chemistry ; Stereoisomerism
    Chemische Substanzen Acetals ; Nitroso Compounds
    Sprache Englisch
    Erscheinungsdatum 2010-06-15
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/ja1038819
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Bonn

    Z 4' 55/32: Hefte anzeigen
    Z 7.3: Hefte anzeigen

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  2. Artikel: Alcohol-assisted phosphine catalysis: one-step syntheses of dihydropyrones from aldehydes and allenoates.

    Creech, Gardner S / Kwon, Ohyun

    Organic letters

    2008  Band 10, Heft 3, Seite(n) 429–432

    Abstract: This paper describes the phosphine-catalyzed annulation of methyl allenoate with various aromatic aldehydes to form 6-aryl-4-methoxy-5,6-dihydro-2-pyrones. In this reaction, the addition of an alcohol was necessary to induce dihydropyrone formation, with ...

    Abstract This paper describes the phosphine-catalyzed annulation of methyl allenoate with various aromatic aldehydes to form 6-aryl-4-methoxy-5,6-dihydro-2-pyrones. In this reaction, the addition of an alcohol was necessary to induce dihydropyrone formation, with the optimal agent being methanol. Moreover, the addition of n-butyllithium suppressed the formation of the noncyclized product, leading to the exclusive isolation of the dihydropyrone. This method provides an efficient, one-step route toward disubstituted dihydropyrones from simple, stable starting materials.
    Mesh-Begriff(e) Alcohols/chemistry ; Aldehydes/chemistry ; Alkadienes/chemistry ; Catalysis ; Molecular Structure ; Phosphines/chemistry ; Pyrones/chemical synthesis ; Pyrones/chemistry ; Stereoisomerism
    Chemische Substanzen Alcohols ; Aldehydes ; Alkadienes ; Phosphines ; Pyrones ; propadiene (4AV0LZ8QKB) ; phosphine (FW6947296I)
    Sprache Englisch
    Erscheinungsdatum 2008-01-04
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural
    ISSN 1523-7060
    ISSN 1523-7060
    DOI 10.1021/ol702462w
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  3. Artikel ; Online: Chemical synthesis of the ATAD2 bromodomain.

    Creech, Gardner S / Paresi, Chelsea / Li, Yue-Ming / Danishefsky, Samuel J

    Proceedings of the National Academy of Sciences of the United States of America

    2014  Band 111, Heft 8, Seite(n) 2891–2896

    Abstract: Due to the emerging importance of the bromodomain binding region in the study of epigenetic effectors and the vast implications for a wide variety of human disease, the bromodomain region of human ATPase family AAA+ (ATPases associated with diverse ... ...

    Abstract Due to the emerging importance of the bromodomain binding region in the study of epigenetic effectors and the vast implications for a wide variety of human disease, the bromodomain region of human ATPase family AAA+ (ATPases associated with diverse cellular activities) domain-containing protein 2 (ATAD2) was targeted for chemical synthesis. The ATAD2 bromodomain (130 aa) was divided into five strategic fragments to be assembled using native chemical ligation with a focus on maximal convergency and efficiency. The fragments were assembled with one cysteine and three thioleucine ligations, unveiling the native alanine and leucine amino acids at the ligation points following metal-free dethiylation. Synthetic highlights of the study are a photolabile dimethoxynitrobenzyl-protected glutamic acid side chain used to impede hydrolysis of the C-terminal Glu-thioester, a thiazolidine-protected thioleucine, and an efficient assembly of three fragments in a single reaction vessel with dual-mode kinetic-standard chemical ligation. With a focus on material throughput and convergency, the five peptide fragments were assembled into the native ATAD2 bromodomain region with a total of three HPLC events in 8% overall yield from the fragments.
    Mesh-Begriff(e) ATPases Associated with Diverse Cellular Activities ; Adenosine Triphosphatases/chemical synthesis ; Chromatography, High Pressure Liquid ; DNA-Binding Proteins/chemical synthesis ; Humans ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Peptide Fragments/chemistry ; Protein Structure, Tertiary ; Solid-Phase Synthesis Techniques/methods
    Chemische Substanzen DNA-Binding Proteins ; Peptide Fragments ; Adenosine Triphosphatases (EC 3.6.1.-) ; ATAD2 protein, human (EC 3.6.1.3) ; ATPases Associated with Diverse Cellular Activities (EC 3.6.4.-)
    Sprache Englisch
    Erscheinungsdatum 2014-02-10
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.1400556111
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Köln/Königswinter

    Zs.A 1148: Hefte anzeigen Standort:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

  4. Artikel ; Online: Leveraging a "Catch-Release" Logic Gate Process for the Synthesis and Nonchromatographic Purification of Thioether- or Amine-Bridged Macrocyclic Peptides.

    Kheirabadi, Mahboubeh / Creech, Gardner S / Qiao, Jennifer X / Nirschl, David S / Leahy, David K / Boy, Kenneth M / Carter, Percy H / Eastgate, Martin D

    The Journal of organic chemistry

    2018  Band 83, Heft 8, Seite(n) 4323–4335

    Abstract: Macrocyclic peptides containing N-alkylated amino acids have emerged as a promising therapeutic modality, capable of modulating protein-protein interactions and an intracellular delivery of hydrophilic payloads. While multichannel automated solid-phase ... ...

    Abstract Macrocyclic peptides containing N-alkylated amino acids have emerged as a promising therapeutic modality, capable of modulating protein-protein interactions and an intracellular delivery of hydrophilic payloads. While multichannel automated solid-phase peptide synthesis (SPPS) is a practical approach for peptide synthesis, the requirement for slow and inefficient chromatographic purification of the product peptides is a significant limitation to exploring these novel compounds. Herein, we invent a "catch-release" strategy for the nonchromatographic purification of macrocyclic peptides. A traceless catch process is enabled by the invention of a dual-functionalized N-terminal acetate analogue, which serves as a handle for capture onto a purification resin and as a leaving group for macrocyclization. Displacement by a C-terminal nucleophilic side chain thus releases the desired macrocycle from the purification resin. By design, this catch/release process is a logic test for the presence of the key components required for cyclization, thus removing impurities which lack the required functionality, such as common classes of peptide impurities, including hydrolysis fragments and truncated sequences. The method was shown to be highly effective with three libraries of macrocyclic peptides, containing macrocycles of 5-20 amino acids, with either thioether- or amine-based macrocyclic linkages; in this latter class, the reported method represents an enabling technology. In all cases, the catch-release protocol afforded significant enrichment of the target peptides purity, in many cases completely obviating the need for chromatography. Importantly, we have adapted this process for automation on a standard multichannel peptide synthesizer, achieving an efficient and completely integrated synthesis and purification platform for the preparation of these important molecules.
    Sprache Englisch
    Erscheinungsdatum 2018--20
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.7b03124
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Köln/Königswinter

    Zs.A 4473: Hefte anzeigen Standort:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

  5. Artikel: Total Chemical Synthesis and Folding of All-l and All-d Variants of Oncogenic KRas(G12V)

    Levinson, Adam M / Creech Gardner S / Danishefsky Samuel J / Hendrickson Ronald C / McGee John H / Peterson Michael T / Roberts Andrew G / Verdine Gregory L / Wang Ting

    Journal of the American Chemical Society. 2017 June 07, v. 139, no. 22

    2017  

    Abstract: The Ras proteins are essential GTPases involved in the regulation of cell proliferation and survival. Mutated oncogenic forms of Ras alter effector binding and innate GTPase activity, leading to deregulation of downstream signal transduction. Mutated ... ...

    Abstract The Ras proteins are essential GTPases involved in the regulation of cell proliferation and survival. Mutated oncogenic forms of Ras alter effector binding and innate GTPase activity, leading to deregulation of downstream signal transduction. Mutated forms of Ras are involved in approximately 30% of human cancers. Despite decades of effort to develop direct Ras inhibitors, Ras has long been considered “undruggable” due to its high affinity for GTP and its lack of hydrophobic binding pockets. Herein, we report a total chemical synthesis of all-l- and all-d-amino acid biotinylated variants of oncogenic mutant KRas(G12V). The protein is synthesized using Fmoc-based solid-phase peptide synthesis and assembled using combined native chemical ligation and isonitrile-mediated activation strategies. We demonstrate that both KRas(G12V) enantiomers can successfully fold and bind nucleotide substrates and binding partners with observable enantiodiscrimination. By demonstrating the functional competency of a mirror-image form of KRas bound to its corresponding enantiomeric nucleotide triphosphate, this study sets the stage for further biochemical studies with this material. In particular, this protein will enable mirror-image yeast surface display experiments to identify all-d peptide ligands for oncogenic KRas, providing a useful tool in the search for new therapeutics against this challenging disease target.
    Schlagwörter cell proliferation ; enantiomers ; guanosine triphosphate ; guanosinetriphosphatase ; humans ; hydrophobicity ; ligands ; mutants ; neoplasms ; proteins ; signal transduction ; synthesis ; therapeutics ; yeasts
    Sprache Englisch
    Erscheinungsverlauf 2017-0607
    Umfang p. 7632-7639.
    Erscheinungsort American Chemical Society
    Dokumenttyp Artikel
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021%2Fjacs.7b02988
    Datenquelle NAL Katalog (AGRICOLA)

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Bonn

    Z 4' 55/32: Hefte anzeigen
    Z 7.3: Hefte anzeigen

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  6. Artikel ; Online: Total Chemical Synthesis and Folding of All-l and All-d Variants of Oncogenic KRas(G12V).

    Levinson, Adam M / McGee, John H / Roberts, Andrew G / Creech, Gardner S / Wang, Ting / Peterson, Michael T / Hendrickson, Ronald C / Verdine, Gregory L / Danishefsky, Samuel J

    Journal of the American Chemical Society

    2017  Band 139, Heft 22, Seite(n) 7632–7639

    Abstract: The Ras proteins are essential GTPases involved in the regulation of cell proliferation and survival. Mutated oncogenic forms of Ras alter effector binding and innate GTPase activity, leading to deregulation of downstream signal transduction. Mutated ... ...

    Abstract The Ras proteins are essential GTPases involved in the regulation of cell proliferation and survival. Mutated oncogenic forms of Ras alter effector binding and innate GTPase activity, leading to deregulation of downstream signal transduction. Mutated forms of Ras are involved in approximately 30% of human cancers. Despite decades of effort to develop direct Ras inhibitors, Ras has long been considered "undruggable" due to its high affinity for GTP and its lack of hydrophobic binding pockets. Herein, we report a total chemical synthesis of all-l- and all-d-amino acid biotinylated variants of oncogenic mutant KRas(G12V). The protein is synthesized using Fmoc-based solid-phase peptide synthesis and assembled using combined native chemical ligation and isonitrile-mediated activation strategies. We demonstrate that both KRas(G12V) enantiomers can successfully fold and bind nucleotide substrates and binding partners with observable enantiodiscrimination. By demonstrating the functional competency of a mirror-image form of KRas bound to its corresponding enantiomeric nucleotide triphosphate, this study sets the stage for further biochemical studies with this material. In particular, this protein will enable mirror-image yeast surface display experiments to identify all-d peptide ligands for oncogenic KRas, providing a useful tool in the search for new therapeutics against this challenging disease target.
    Mesh-Begriff(e) Amino Acid Sequence ; Genetic Variation ; Humans ; Protein Folding ; Proto-Oncogene Proteins p21(ras)/chemical synthesis ; Proto-Oncogene Proteins p21(ras)/genetics
    Chemische Substanzen KRAS protein, human ; Proto-Oncogene Proteins p21(ras) (EC 3.6.5.2)
    Sprache Englisch
    Erscheinungsdatum 2017-05-22
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.7b02988
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Bonn

    Z 4' 55/32: Hefte anzeigen
    Z 7.3: Hefte anzeigen

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  7. Artikel: Theory-Guided Design of Brønsted Acid-Assisted Phosphine Catalysis: Synthesis of Dihydropyrones from Aldehydes and Allenoates.

    Creech, Gardner S / Zhu, Xue-Feng / Fonovic, Branden / Dudding, Travis / Kwon, Ohyun

    Tetrahedron

    2009  Band 64, Heft 29, Seite(n) 6935–6942

    Abstract: The phosphine-catalyzed addition of 2,3-butadienoates to aldehydes has been extended to the formation of disubstituted dihydro-2-pyrones. The requisite shift in equilibrium of the intermediate zwitterionic beta-phosphonium dienolates toward the s-cis ... ...

    Abstract The phosphine-catalyzed addition of 2,3-butadienoates to aldehydes has been extended to the formation of disubstituted dihydro-2-pyrones. The requisite shift in equilibrium of the intermediate zwitterionic beta-phosphonium dienolates toward the s-cis intermediate was accomplished through the use of a Brønsted acid additive, which disrupts the favorable Coulombic interaction present in the s-trans intermediate. The detailed nature of the synergistic interactions involving the Brønsted acid additives and phosphine involved in the formation of s-cis beta-phosphonium dienolates was analyzed through a series of DFT calculations. Unlike previously reported annulations of aldehydes with allenoates, where trialkylphosphines are optimal catalysts, in this study triphenylphosphine was also found for the first time to be a suitable catalyst for the synthesis of dihydropyrones. This method provides a one-step route toward functionalized dihydropyrones from simple, stable starting materials. In addition, new reaction pathways of phosphine-catalyzed allene annulations are unveiled, with the formation of dihydropyrones being the first example of dual activation in this sphere.
    Sprache Englisch
    Erscheinungsdatum 2009-07-08
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 204285-x
    ISSN 1464-5416 ; 0040-4020 ; 0563-2064
    ISSN (online) 1464-5416
    ISSN 0040-4020 ; 0563-2064
    DOI 10.1016/j.tet.2008.04.075
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Volltext online

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Köln/Königswinter

    Zs.B 1076: Hefte anzeigen Standort:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
    ab Jg. 2022: Lesesaal (EG)

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

Zum Seitenanfang