St. Guttmann

Bio: St. Guttmann is an academic researcher from University of Geneva. The author has contributed to research in topics: Tripeptide & Lysine. The author has an hindex of 21, co-authored 31 publications receiving 1643 citations.

Une nouvelle synthèse de l'oxytocine

Abstract: A new synthesis of oxytocin is described. N-CBO-L-glutaminyl-L-asparaginyl-S-benzyl-L-cysteinyl-azide is reacted with L-prolyl-L-leucyl-glycinamide to give N-CBO-L- glutaminyl-L-asparaginyl-S-benzyl-L-cysteinyl-L-prolyl-L-leucyl-glycinamide. After removal of the CBO group by HBr in acetic acid this hexapeptide is condensed with N-CBO-S-benzyl-L-cysteinyl-L-tyrosyl-L-isoleucyl-azide to give the nonapeptide N-CBO-S-benzyl-L-cysteinyl-L-tyrosyl-L- isoleucyl-L-glutaminyl-L-asparaginyl-S-benzyl-L-cysteinyl-L-prolyl-L-leucyl-glycinamide already obtained by du Vigneaud and coworkers through another route. Reduction with sodium in liquid ammonia and reoxydation gives biologically active material.

Synthèse du N-acétyl-L-séryl-L-tyrosyl-L-séryl-L-méthionyl-γ-L-glutamate de benzyle et de peptides apparentés

Abstract: N-CBO-L-Seryl-L-tyrosyl-L-serine methyl ester and L-methionyl-γ-benzyl-L-glutamate are prepared by different methods. Condensation by the hydrazideazide procedure affords N-CBO-L-seryl-L-tyrosyl-L-seryl-L-methionyl-γ-benzyl-L-glutamate, which is shown to be optically pure by leucine-aminopeptidase digestion. Transformation of the above N-CBO-tripeptide ester to the N-acetyltripeptide ester and condensation by the hydrazide-azide procedure with the above dipeptide gives N-acetyl-L-seryl-L-tyrosyl-L-seryl-L-methionyl-γ-benzyl-L-glutamate. The effects produced in the course of fissure of CBO- and benzyl-groups from peptides containing serine and methionine residues, using HBr and acetic acid, are studied.

Synthèse de la L-arginyl-L-prolyl-L-prolyl-glycyl-L-phénylalanyl-L-Séryl-L-prolyl-L-phénylalanyl-L-arginine, un nonapeptide présentant les propriétés de la bradykinine

Abstract: The synthesis of a nonapeptide exhibiting bradykinin-like properties is described. Condensation of CBO-(nitro)Arg-Pro-OH with H-Pro-Gly-NHNH-CTO and selective splitting of the CTO-group yielded CBO-(nitro)Arg-Pro-Pro-Gly-NHNH2. CBO-Phe- Ser-N2 was condensed with H-Pro-Phe-(nitro)Arg-OBzN, the CBO-group was selectively split, and the resulting pentapeptide was made to react with the azide corresponding to the above-mentioned hydrazide. All the protective groups of the resulting nonapeptide were split off by catalytic hydrogenolysis, giving pure H-Arg- Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg-OH after counter-current distribution. On a molar basis, this nonapeptide was more active than histamine (ileum, bronchial muscle and capillary permeability of the guinea pig) and acetylcholine (duodenum of the rabbit, blood pressure of the rabbit and dog).

Synthèse de la L‐histidyl‐L‐phénylalanyl‐L‐arginyl‐L‐tryptophanyl‐glycyl‐ϵ‐CBO‐L‐lysyl‐L‐prolyl‐L‐valylamide

Abstract: Trityl-glycyl-ϵ-CBO-L-lysine is condensed with L-prolyl-L-valine methyl ester and, after amidification and splitting of the trityl group, glycyl-ϵ-CBO-L-lysyl-L-prolyl-L-valylamide is obtained This is condensed with ditrityl-L-histidyl-L-phenylalanyl-L-arginyl-L-tryptophane prepared by condensation of ditrityl-L-histidyl-L-phenylalanine with L-arginyl-L-tryptophane methyl ester and saponification Dicyclohexyl-carbodiimide is used as a condensing agent After splitting off the trityl groups, the final octapeptide, L-histidyl-L-phenylalanyl-L-arginyl-L-tryptophanyl-glycyl-ϵ-CBO-L-lysyl-L-prolyl-L-valylamide is shown to be optically pure by leucine-aminopeptidase digestion

Synthesis and biological activity of peptides related to bradykinin.

Abstract: Die Synthese von 6 Polypeptiden aus den im Bradykinin vorkommenden Aminosauren wird beschrieben. Das Nonapeptid H-l-Arg-l-Pro-l-Pro-Gly-l-Phe-l-Ser-l-Pro-l-Phe-l-Arg-OH zeigte hohe Bradykinin-ahnliche Wirksamkeit in verschiedenen biologischen Testen.

Solid phase peptide synthesis utilizing 9‐fluorenylmethoxycarbonyl amino acids

Abstract: 9-Fluorenylmethoxycarbonyl (Fmoc) amino acids were first used for solid phase peptide synthesis a little more than a decade ago. Since that time, Fmoc solid phase peptide synthesis methodology has been greatly enhanced by the introduction of a variety of solid supports, linkages, and side chain protecting groups, as well as by increased understanding of solvation conditions. These advances have led to many impressive syntheses, such as those of biologically active and isotopically labeled peptides and small proteins. The great variety of conditions under which Fmoc solid phase peptide synthesis may be carried out represents a truly "orthogonal" scheme, and thus offers many unique opportunities for bioorganic chemistry.

International Union of Pharmacology. XLV. Classification of the Kinin Receptor Family: from Molecular Mechanisms to Pathophysiological Consequences

Abstract: Kinins are proinflammatory peptides that mediate numerous vascular and pain responses to tissue injury. Two pharmacologically distinct kinin receptor subtypes have been identified and characterized for these peptides, which are named B1 and B2 and belong to the rhodopsin family of G protein-coupled receptors. The B2 receptor mediates the action of bradykinin (BK) and lysyl-bradykinin (Lys-BK), the first set of bioactive kinins formed in response to injury from kininogen precursors through the actions of plasma and tissue kallikreins, whereas the B(1) receptor mediates the action of des-Arg9-BK and Lys-des-Arg9-BK, the second set of bioactive kinins formed through the actions of carboxypeptidases on BK and Lys-BK, respectively. The B2 receptor is ubiquitous and constitutively expressed, whereas the B1 receptor is expressed at a very low level in healthy tissues but induced following injury by various proinflammatory cytokines such as interleukin-1beta. Both receptors act through G alpha(q) to stimulate phospholipase C beta followed by phosphoinositide hydrolysis and intracellular free Ca2+ mobilization and through G alpha(i) to inhibit adenylate cyclase and stimulate the mitogen-activated protein kinase pathways. The use of mice lacking each receptor gene and various specific peptidic and nonpeptidic antagonists have implicated both B1 and B2 receptors as potential therapeutic targets in several pathophysiological events related to inflammation such as pain, sepsis, allergic asthma, rhinitis, and edema, as well as diabetes and cancer. This review is a comprehensive presentation of our current understanding of these receptors in terms of molecular and cell biology, physiology, pharmacology, and involvement in human disease and drug development.

A cleavage method which minimizes side reactions following Fmoc solid phase peptide synthesis.

Abstract: The success of solid phase peptide synthesis utilizing 9-fluorenylmethoxycarbonyl (Fmoc) amino acids is often limited by deleterious side reactions which occur during TFA peptide-resin cleavage and side-chain deprotection. The majority of these side reactions modify susceptible residues, such as Trp, Tyr, Met, and Cys, with TFA-liberated side-chain protecting groups and linkers. The purpose of this study was to assess the relative effectiveness of various scavengers in suppressing these side reactions. We found that the cleavage mixture 82.5% TFA : 5% phenol : 5% H2O : 5% thioanisole : 2.5% EDT (Reagent K) was maximally efficient in inhibiting a great variety of side reactions. Synthesis and cleavage of 10 peptides, each containing 20-50 residues, demonstrated the complementarity of Fmoc chemistry with Reagent K for efficient synthesis of complex peptides.

Amino Acid-Protecting Groups

Abstract: Albert Isidro-Llobet, Mercedes Alvarez,* and Fernando Albericio* Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain; Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028 Barcelona, Spain; and Department of Organic Chemistry, University of Barcelona, Marti i Franques 1, 08028 Barcelona, Spain Received April 28, 2008