Umlagerungen peptidähnlicher Stoffe II. Derivate der<i>γ</i>-Amino-<i>β</i>-oxybuttersäure.

Bergmann, Max; Brand, Erwin; Weinmann, Fritz

doi:10.1515/bchm2.1923.131.1-3.1

Cited by 85 publications

(13 citation statements)

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“…treatment, involving a five-member oxazolidine-like ring The objectives of this work are relatively similar to the intermediate (24). We proposed a similar rearrangement elegant chemical scheme proposed by Kemp and coworkers involving a 3,3,0 fused ring intermediate (Fig.…”

Section: Methodsmentioning

confidence: 90%

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Peptide segment ligation strategy without use of protecting groups.

Liu

Tam

1994

Proc. Natl. Acad. Sci. U.S.A.

209

161

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We describe the concept and the verification of a chemical ligation approach to the synthesis of proteins using peptide se-ents with no protecting groups and no activation of the C-tenal a-carboxyl group. This approach of three steps: (i) aldehyde introduction, in which a masked glycolaldehyde ester Is linked to the carboxyl terminus of an unprotected peptide by reverse protedlysis; (ii) ring formation, in which the umaked aldehyde reacts with the N-teinal a-amino group of the second unprotected peptide containing either a cysteine or a threonine residue to form a t ne or olidine ring at an acidic pH; and (iii) rearrangement in which O-acyl ester linkage is transferred to N-acyl amide linkage to form a peptide bond with a pseudoproline stuture at higher pH. The (4), and the semi-synthesis of proteins consisting of components from synthetic peptides with unusual amino acids and proteins obtained through recombinant technology.The conventional segment-synthesis approaches (5) usually require a maximal protection strategy which has the limitations ofpoor solubility, low coupling efficiency, and the possible danger of racemization due to the overactivation of the carboxyl group. Considerable efforts have been made to overcome these limitations through the use of partial or minimal protecting-group strategies and improvements in the activation methods (6-11). However, these approaches do not overcome the problem of the poor coupling efficiency between large peptide segments, because of the intrinsic difficulty of obtaining effective molar concentrations for high molecular weight molecules. Alternative approaches to overcome the difficulty of forming amide bonds use hydrazone (12,13) or thioether and thioester (14) as surrogate bonds. The advantage of these peptide-bond replacement approaches resides in the high and specific reactivity between the two functional groups not found in amino acids to make the conjugation efficient. The disadvantage is that these linkages are substantially different from the peptide bond, which may lead to conformational distortion, and are usually not stable at either acidic (12) or basic (14) pH.We have now designed and developed a chemical ligation method by which two unprotected peptide segments can be ligated together through an amide bond. In our design, we make use of a highly regiospecific and efficient reaction to link covalently two unprotected peptides. The selectivity of this reaction would also obviate the need for any protecting groups. A peptide bond is then formed in a second step through an intramolecular rearrangement between the two closely neighboring carboxyl and amino groups. The efficiency of the first reaction would solve the slow kinetic problem for reactions between large molecules, and the second reaction, designed as a spontaneous process to form amide bonds without activating the carboxyl group, would overcome the racemization problem of the conventional segment condensation method. EXPERIMENTAL PROCEDURESGeneral. 1H NMR spectra were obtained at 300 ...

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Section: Methodsmentioning

confidence: 90%

“…The reaction of carbonyl compounds with Cys has been extensively studied (22,23 (24,25) and is a dominating side reaction formed through an intramolecular 0-to-N acyl transfer reamc (26) in the acidic deprotection step of peptide synthesis tion ( Fig. 1).…”

Section: Methodsmentioning

confidence: 99%

Peptide segment ligation strategy without use of protecting groups.

Liu

Tam

1994

Proc. Natl. Acad. Sci. U.S.A.

209

161

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“…The NO acyl migration of β‐amino alcohols, firstly described by Bergmann,1 is a well‐known side reaction in peptide synthesis 2. This reversible, pH‐dependent migration occurs in peptides or proteins at serine or threonine residues upon treatment with strong acid, but also in moderately acidic medium 3.…”

Section: Introductionmentioning

confidence: 99%

From Polyesters to Polyamides Via ON Acyl Migration: An Original Multi‐Transfer Reaction

Tailhades

Blanquer

Nottelet

et al. 2011

Macromol. Rapid Commun.

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A new strategy for the synthesis of polyamides from polyesters of hydroxyl-containing amino acids using a multi O-N acyl transfer reaction was developed. This original approach allowed the synthesis of three generations of polymers from the same starting monomer. The polymerization of N-benzyloxycarbonyl-serine and its γ-homologated derivative provided the Z-protected polyesters; then the water-soluble polycationic polyesters were obtained by removal of the Z-protecting group; and finally the polyamides were obtained by a base-induced multi O-N acyl transfer, both in aqueous or organic medium. The key step transfer reaction was monitored by the disappearance and appearance of characteristic NMR proton signals and IR bands of polyesters and polyamides.

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“…As in standard Fmoc‐strategy, the depsipeptide is deprotected and cleaved from the resin with TFA and purified. Only at the very end, the O ‐acyl isomer is converted into the target peptide through an O , N ‐acyl shift, a long known reaction which occurs smoothly in aqueous environment at mildly basic conditions17–20 (Figure 1). With respect to the all‐amide form, depsipeptide isomers are often more easily synthesized and handled: by extending the backbone through an ester bond via a side chain, the regular polyamide structure ‐ and thereby a possible regular hydrogen bond pattern ‐ is interrupted, and elements of flexibility are introduced (the C α C β bond and the CO bond).…”

Section: Depsipeptide Strategymentioning

confidence: 99%

The depsipeptide method for solid‐phase synthesis of difficult peptides

Coin

2010

Journal of Peptide Science

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After about one century of peptide chemistry, the main limitation to the accessibility of peptides and proteins via chemosynthesis is the arising of folding and aggregation phenomena. This is true not only for sequences above a critical length but also for several biologically relevant substrates that are relatively short yet form either highly folded structures (e.g. WW domains) or fibrils and aggregates after final deprotection (beta-amyloid peptide). Such so-called difficult sequences may be more easily obtained via their corresponding depsipeptides (O-acyl isopeptides), ester isomers that are often easier to assemble and purify, and are smoothly converted to the parent amides under mild conditions. The depsipeptide method is the most recent technique to improve the outcome of difficult syntheses, applicable to sequences containing residues of serine or threonine. A brief overview is presented about chemical aspects of the method, the steps that have been undertaken for its optimization, and the evaluation of its efficiency. Further applications of analogous principles to other critical topics in peptide synthesis such as condensation of peptide segments and solid-phase synthesis of naturally occurring cyclodepsipeptides are addressed as well.

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Umlagerungen peptidähnlicher Stoffe II. Derivate derγ-Amino-β-oxybuttersäure.

Abstract: Um zur /-Amino-/?-oxybuttersäure zu gelangen, haben wir das ^Chlor-/9-oxy-/-aminopropan zunächst mit Hilfe seiner cyclischen Benzaldehydverbindung (I) benzoyliert und den Aldehyd wieder abgespalten. 2 )

Cited by 85 publications

References 0 publications

Peptide segment ligation strategy without use of protecting groups.

Peptide segment ligation strategy without use of protecting groups.

From Polyesters to Polyamides Via ON Acyl Migration: An Original Multi‐Transfer Reaction

The depsipeptide method for solid‐phase synthesis of difficult peptides

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