Aminoethyl linkage

Figure 5-4 The basic structure of duplex 1 with the aminoethyl linkage in the TT central region as indicated with the box.

Malto-oligosaccharide aldonolactones react with ethylenediamine to give Ar-(2-aminoethyl)aldonamides (113-115), which have been successfully grafted onto carriers via amide linkages. The malto-oligosaccharides were produced by degradation of amylose with alpha amylase. After purification of the oligosaccharides, they were converted into the lactones by hypoiodite or electrolytic oxidation. 

Treatment of wool or hair with carbodiimides improves the wash fastness of applied dyes. The cosmetic qualities of bleached hair can be improved by treatment with N-cyclohexyl-N -(N-methylmorpholino)carbodiimide. N-ethyl-N -(3-trimethylammonio)propylcarbodiimide Axes the red dye 2-nitro-4[08-aminoethyl)amino]aniline to hair, most likely via an amide linkage. The coupling of a phosphorous dyestuff to cellulosic materials can also be accomplished using a carbodiimide. ... 

Bonds formed by cysteinyl residues can be made susceptible to tryptic action when the thiol group of the cysteine side chains is reacted with i8-bromoethylamine (Bindley, 1956). The resulting ( -( -aminoethyl)-cysteinyl side chains provide the specificity requirements necessary for tryptic action. One methylene carbon of the lysyl side chain is replaced by a sulfur atom in thioether linkage. Bonds formed by the carboxyl group of this derivative are susceptible to tryptic action. Reduction of... 

Cleavage of disulfide bonds occurs before hydrolysis of the protein into peptides. Disulfide bonds may be cleaved oxidatively, or they may be reduced and alkylated. Treatment of the native protein with performic acid, a powerful oxidizing agent, breaks disulfide bonds and converts cystine residues to cysteic acid (Figure 3-11). Reduction of the disulfide linkage by thiols, such as d-mercaptoethanol, yields reactive sulfhydryl groups. These groups may be stabilized by alkylation with iodoacetate or ethyleneimine to yield the carboxymethyl or aminoethyl derivative, respectively. 

Hep. The P NMR spectra and the linkage analysis data suggested the presence of a monoester phosphate (PO4) at the Q-1 position of the inmost LD-Hep of the strains described here, except in strain R-7A, where a 2-aminoethyl phosphate was shown to replace the monoester phosphate, as in //. pylori Sydney strain (Section IV). 

Figure 2.4 Comparison of PNA and DNA. PNA contains neither phosphodiester links nor the fi-D-2 -deoxyribofuranose rings. Instead the backbone consists of W-(2-aminoethyl)-glycine repeat units conjoined by peptide links. The main purine and pyrimidine bases of DNA are linked to the the PNA backbone by methylene carbonyl bridge linkages. Watson-Crick base-complementary PNA strands are capable of Watson-Crick base pairing and hence anti-parallel double helix formation.

The structure elucidation of BLM was not straightforward because of the noncrystalline nature of the molecule [36]. An extensive degradation study indicated that BLM contains novel amino acid constituents and an unusual disaccharide, i.e., pyrimidoblamic acid (1), rytfcro-P-hydroxy-L-histidine (2), (2S, 35,4/ )-4-amino-3-hydroxy-2-methylpentanoic acid (3), 2 -(2-aminoethyl)-2,4 -bithiazole-4-carboxylic acid (4), and 2-0-(3-0-carbamoyl-a-D-mannopyranosyl)-a-L- u/opyranose (5) (Fig. 9). The sequence of the peptide bonding and the glycoside linkage was established by selective partial hydrolysis and, in 1978, the total structure was eventually determined by Takita et al. on the basis of further direct and indirect evidence (Fig. 1) [2]. 

A number of alkylating agents yield derivatives which are stable under the conditions for acidic hydrolysis of proteins. The reaction with ethylene imine giving an S-aminoethyl derivative and, hence, an additional linkage position in the protein for hydrolysis by trypsin, was mentioned in Section 1.4.1.3. lodoacetic acid, depending on the pH, can react with cysteine, methionine, lysine and histidine residues ... 

A review has appeared on carbohydrate-containing amphlphiles with amide linkages, these compounds being prepared by reaction of aldonolactones of glucose or maltose with alkylamines or by interaction of N-(2-aminoethyl) aldonamides with C6-C20 alkanoic acids. ... 

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