ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Rationally Designed Bicyclic Lactams Control Different Turn Motifs and Folding Patterns in Hexapeptide Mimics (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 695-699 
    Details
    ISSN: 1434-193X
    Keywords: Reverse-turn mimics ; γ-Turns ; β-Turns ; β-Hairpins ; Peptides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Conformational analysis of N-acetylated hexapeptide mimics incorporating a bicyclic lactam (1-4) was carried out by a combination of 1H-NMR spectroscopy, IR spectroscopy, and computer modeling. The nature of the bicyclic lactam determines the turn motifs and the folding patterns of these constrained peptides. The (5,6)-bicyclic lactam derivatives 1 and 2, characterized by a type-II' β-turn (C=O3···H6-N), are very compact intramolecularly H-bonded structures. The (5,7)-bicyclic lactam derivative 3, characterized by an inverse γ-turn (C=O4···H6-N), is a quite flexible “tweezer-like” structure.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    Synthesis of Combinatorial Libraries of Vinylogous Sulfonamidopeptides (vs-Peptides) (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2437-2449 
    Details
    ISSN: 1434-193X
    Keywords: Vinylogous sulfonamidopeptides ; Solid-phase synthesis ; Combinatorial libraries ; N-Alkylation ; Michael addition ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chiral vinylogous sulfonamidopeptides (vs-peptides) were synthesized on TentaGel resin employing (S)- and (R)-N-Boc-vinylogous sulfonyl chlorides 2a-i as building blocks. Glycine and two different photocleavable molecules were used as linkers, and the corresponding cleavage conditions were optimized. According to preliminary studies in solution and on solid phase, three libraries were synthesized with the “split-mix synthesis” method. Taking advantage of the acidic character of the sulfonamides (RSO2-NHR: pKa = 10-11), mild conditions were developed to alkylate the sulfonamide nitrogen atom so as to reduce the acidity of the monomers and of the oligomers and increase their in vivo bioavailability. This synthetic methodology was employed to increase the diversity in a library of di-N-alkylated vs-dipeptides 26. The electron-withdrawing capability of the sulfonamido group pointed to the use of vinylogous sulfonamidopeptides as Michael acceptors. The sodium enolate of dimethyl malonate was used as nucleophile to obtain N-Boc-γ-lactams 35 in moderate yields and good diastereoselectivity.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...