Journal ArticleDOI
Eine neue Methode zur Synthese von Peptiden: Aktivierung der Carboxylgruppe mit Dicyclohexylcarbodiimid unter Zusatz von 1‐Hydroxy‐benzotriazolen
Wolfgang König,Rolf Geiger +1 more
TLDR
In this article, the authors show that 1-Hydroxy-benzotriazol and 1-hydroxy-acetyl carbodiimid-methode eignen sich als Zusatze bei der Dicyclohexylcarbodiimids-Methode zur Synthese von Peptiden, verhindern die N-Acyl-harnstoffbildung and fuhren in hoher Ausbeute.Abstract:
1-Hydroxy-benzotriazol sowie verschiedene kernsubstituierte 1-Hydroxy-benzotriazole eignen sich als Zusatze bei der Dicyclohexylcarbodiimid-Methode zur Synthese von Peptiden. Ihr Einflus auf die Racemisierung bei Peptidsynthesen wurde unter Anwendung des gaschromatographischen Racemisierungstests von Weygand u. Mitarbb.2) untersucht. Die neuen Zusatze senken die Racemisierung, verhindern die N-Acyl-harnstoffbildung und fuhren in hoher Ausbeute zu sehr reinen Peptiden.read more
Citations
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Journal ArticleDOI
Mechanistic Insights into the Cytochrome P450-Mediated Oxidation and Rearrangement of Littorine in Tropane Alkaloid Biosynthesis
Pitak Nasomjai,Darwin W. Reed,David J. Tozer,Michael J. G. Peach,Alexandra M. Z. Slawin,Patrick S. Covello,David O'Hagan +6 more
TL;DR: Measurement of the primary kinetic isotope effects indicates that C3′ hydrogen abstraction is the rate‐limiting step for the oxidation/rearrangement of natural littorine, and for the 3′‐hydroxylation reaction of the unnatural S enantiomer of littarine, whereas the product profile arising from rearrangement is more consistent with a benzylic radical intermediate.
Journal ArticleDOI
The synthesis of O-(2-acetamido-2-deoxy-β-d-glucopyranosyl)-(1→4)-N-acetylnormuramoyl-l-α-aminobutanoyl-d-isoglutamine☆
TL;DR: In this paper, the title compound was obtained in high yield on using the silver triflate method in the absence of base, and it was converted in six steps into benzyl 2-acetamido-4- O -(2-acetamide-3,4,6-tri-O -benzyl-2-deoxy-β-d -glucopyranosyl)-6- O-benzinyl-3-O-allyl-6-O(carboxymethyl)-2-Deoxy-α-d-
Journal ArticleDOI
K-Oxyma: a Strong Acylation-Promoting, 2-CTC Resin-Friendly Coupling Additive
Prabhakar Cherkupally,Gerardo A. Acosta,Lidia Nieto-Rodriguez,Jan Spengler,Hortensia Rodríguez,Sherine N. Khattab,Ayman El-Faham,Ayman El-Faham,Marina Shamis,Yoav Luxembourg,Rafel Prohens,Ramon Subiros-Funosas,Ramon Subiros-Funosas,Fernando Albericio +13 more
TL;DR: A new formulation of the recently introduced OxymaPure additive for peptide bond formation is presented, in which the N-hydroxylamine group is replaced by a potassium salt, converting KOxyma into the most suitable coupling choice when peptides are assembled on highly acid-labile solid-supports.
Journal ArticleDOI
Synthesis of steroidal 17 β-carboxamide derivatives
TL;DR: Several 17 β-carboxamide derivatives of natural and fluorinated glucocorticoids have been synthesized by periodic acid oxidation of their side chains as discussed by the authors, and they were then activated by N-hydroxybenzotriazole (HOBT) and coupled to several primary amines.
Journal ArticleDOI
Synthesis of 0-(2-0-α-d-glucopyranosyl)-β-d-galactopyranoside of optically pure δ-hydroxy-l-lysylglycine and -gd-hydroxy-l-lysylglycyl-l-glutamyl-l- aspartylglycine
TL;DR: The application of the levulinyl group as a temporary blocking group for the 2-OH function of galactose proved to be very efficient not only for the introduction of a β-linkage between Galactose and the optically pure δ-hydroxy- l -lysylglycine, but also to link galactoses, via an α-interglycosidic bond, with glucose.
References
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Journal ArticleDOI
The Use of Esters of N-Hydroxysuccinimide in Peptide Synthesis
Journal ArticleDOI
t-Butyl Esters of Amino Acids and Peptides and their Use in Peptide Synthesis1
Journal ArticleDOI
Zur Synthese des Glucagons, X. Darstellung der Sequenz 22–29
Erich Wünsch,Fritz Drees +1 more
TL;DR: In this paper, the geschutzte Teilsequenz 22-29 des Glucagons, wird auf zwei verschiedenen Wegen synthetisiert.