Peptides amides

Toxic Proteins, Peptides, Amides, and Amino Acids... 

D-alanine (peptides) DL-alanine (peptide) amide(s) D-amino acid arninopeptidase Ochrobactrum anthropi, Bhodococcus erythropolis 174... 

The chloroisocyanurates can be used in the bleaching of cotton, synthetics, and their blends they do, however, attack proteinaceous fibers, such as silk or wool, presumably via active chlorine reaction with the peptide (amide) linkage. However, the chloroisocyanurates can be used as shrink-proofing agents in wool finishing (131), (see Textiles Wool). The same action of chlorine upon proteins contributes to the effectiveness of chloroisocyanurates in automatic dishwashers. 

Digestion (Section 29.1) The first stage of catabolism, in which food is broken down by hydrolysis of ester, glycoside (acetal), and peptide (amide) bonds to yield fatty acids, simple sugars, and amino acids. 

Polymer supported xanthene derivatives have been used in the solid phase synthesis of 1-aminophosphinic acids, RCH(NH2)PH(0)0H, <%TL1647> and of C-terminal peptide amides <96JOC6326>. Xanthene units also feature in crown ethers <96JCS(P2)2091>, calixarenes <96JOC5670> and in a flexible template for a P-sheet nucleator <96JOC7408>. 

In an extension to the xanthenyl theme, the benzyl hydrogen was replaced with a substituted / -methoxyphenyl ring to give linker 35 (Scheme 10) [41]. Peptide amides were cleaved rapidly and in high purity with TFA-DCM (1 9) for 15 min or as a protected fragment with TFA-DCM (1 99) for 3-10 min. 

Matsueda GR, Stewart JM. A p-methylbenzhydrylamine resin for improved solid-phase synthesis of peptides amides. Peptides 1981 2 45-50. 

Henkel B, Zeng W, Bayer E. 9-Hydroxy-9-(4-carboxyphenyl)xanthene- a new linker for the synthesis of peptide amides. Tetrahedron Lett 1997 38 3511-3512. 

Albericio F, Kneib-Cordonier N, Biancalana S, Gera L, Masada RI, Hudson D, Barany G. Preparation and application of the 5-(4-(9-fluorenylmethoxycarbonyl)aminomethyl-3, 5-dimethoxyphenoxy)-valeric acid (PAL) handle for the solid-phase synthesis of C-terminal peptide amides under mild conditions. J Org Chem 1990 55 3730-3743. 

Breipohl G, Knolle J, Stuber W. Synthesis and application of acid labile anchor groups for the synthesis of peptide amides by Fmoc-solid-phase peptide synthesis. Int J Peptide Protein Res 1989 34 262-267. 

Seiber P. A new acid-labile anchor groups for the solid phase synthesis of C-terminal peptide amides by the Fmoc method. Tetrahedron Lett 1987 28 2107-2110. 

Meisenbach M, Echner H, Voelter W. New methoxy-substituted 9-phenyl-xanthen-9-ylamine linkers for the solid phase phase synthesis of protected peptide amides. Chem Commun (Cambridge) 1997 849-850. 

Peptides and proteins are composed of amino acids polymerized together through the formation of peptide (amide) bonds. The peptide bonded polymer that forms the backbone of polypeptide structure is called the a-chain. The peptide bonds of the a-chain are rigid planar units formed by the reaction of the oc-amino group of one amino acid with the a-carboxyl group of another (Figure 1.1). The peptide bond possesses no rotational freedom due to the partial double bond character of the carbonyl-amino amide bond. The bonds around the oc-carbon atom, however, are true single bonds with considerable freedom of movement. 

Figure 17.24 The traceless Staudinger reaction can be used to form larger peptides from smaller peptides, if one contains an azido group at the N-terminal and the other one contains a phosphine ester at its C-terminal. The reaction gives a native peptide (amide) bond with loss of the phosphine group.

Proteolytic degradation of a protein is characterized by hydrolysis of one or more peptide (amide) bonds in the protein backbone, generally resulting in loss of biological activity. Hydrolysis is usually promoted by the presence of trace quantities of proteolytic enzymes, but can also be caused by some chemical influences. 

Prigge, S. T., Mains, R. E., Eipper, B. A. and Amzel, L. M. New insights into copper monooxygenases and peptide amidation structure, mechanism and function. Cell Mol. Life Sci. 57 1236-1259, 2000. 

Based on the CAAX motif, peptide analogues were designed in which peptide amide bonds are replaced by amine and ether groups [18]. In particular /I-turn mimetic 1 (Fig. 1) inhibits the FTase in vitro with an IC50 value of 1.8 nmol/1 and shows highly specific activity in comparison to inhibition of GGTase I. 

The first example describes the synthesis of a pyrimidine derivative. Starting from a, 3-unsaturated ketones (see Schemes 1, 8), a library of different heterocycles was prepared in research (Felder and Marzinzik 1998). In preparation for any large-scale synthesis, the availability of starting materials is always considered (Lee and Robinson 1995). For this work, we had to replace Rink amide resin B (Rink 1987), which was used by our colleagues in research for the synthesis of pyrimidine 1 due to its unavailability in large quantities (see Fig. 1). It was replaced with the Rink amide acetamido resin 4, which is well established in peptide amide synthesis (Bernatowicz et al. 1989) and easily accessible. 

BENZHYDRYLAMINE RESIN FOR SYNTHESIS OF PEPTIDE AMIDES USING BOC/BZL CHEMISTRY... 

The first peptide amides prepared by solid-phase synthesis were obtained by ammonolysis of resin-bound benzyl esters of peptides in solvents containing methanol (Figure 5.16, A). The method was occasionally employed but was not popular because it was inefficient, producing some ester in addition to the amide. A new variant employing gaseous ammonia will likely rekindle this approach (see Section 8.3). During the early developments of solid-phase synthesis, it was known that the... 

FIGURE 5.16 Production of amides by cleavage of benzhydryl amides. Recognition that removal by acidolysis of benzhydryl protectors from carboxamides gave the amides (B) led to development of benzhydrylamine (BHA) resin (C).33 Treatment with HF of a peptide amide that has been assembled on a BHA resin using Boc/Bzl chemistry gives the peptide amide (D). Peptide amide is also obtainable by ammonolysis of the resin-bound benzyl ester (A), a reaction that is more efficient if gaseous NH3 is employed (see Section 8.3). 

GR Matsueda, J Stewart. A p-methylbenzhydrylarnine resin for improved solid-phase synthesis of peptide amides. Peptides 2, 45, 1981. 

FIGURE 5.18 Resins and linkers for synthesis of peptide amides using Fmoc/tBu chemistry. Chain assembly is effected after removal of the Fmoc group. Treatment with CF3C02H releases a peptide amide by cleavage at the NH-CH/CH2 bond. 

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