Amides terms Links

The conclusions drawn from the data are that in terms of structural or electrostatic interactions with this antagonist site on the receptor, the amide bond linking residues two and three may not be as critical as those linking residues three to four and four to five. 

Other only rarely do carboxyl groups form cyclic hydrogen-bonded dimers and amide groups link with one another. We may state, in general terms, that acid-base complementarity determines the overall hydrogen-bonding arrangements. 

Proteins are large biomolecules made up of a-amino acid residues linked together by amide, or peptide, bonds. Chains with fewer than 50 amino acids are often called peptides, while the term protein is reserved for larger chains. Twenty amino acids are commonly found in proteins all are a-amino acids, and all except glycine have stereochemistry similar to that of l sugars. In neutral solution, amino acids exist as dipolar zwitterions. 

TFA). Among various linkers studied in this work, the indole linker [21] was found to be the most suitable linker in terms of cleavage kinetics and actual cost. Rink linker was the second best in term of kinetics. The rate of cleavage of various functional groups linked to the above-mentioned resins was as follows sul-fonamide>carbamate urea>amide. Results from this study demonstrated that optimization of cleavage conditions often led to more suitable conditions and safer release of precious compounds synthesized on a solid support. 

A peptide is any compound produced by amide formation between a carboxyl group of one amino acid and an amino group of another. The amide bonds in peptides are called peptide bonds. The word peptide is usually applied to compounds whose amide bonds (sometimes called eupeptide bonds) are formed between C-1 of one amino acid and N-2 of another, but it includes compounds with residues linked by other amide bonds (sometimes called isopeptide bonds). Peptides with fewer than about 10-20 residues may also be called oligopeptides those with more residues are called polypeptides. Polypeptides of specific sequence of more than about 50 residues are usually known as proteins, but authors differ greatly on where they start to apply this term. 

In a protein the amino acids are joined together in a linear order by amide linkages, also known as peptide bonds. The sequence of the covalently linked amino acids is referred to as the primary level of structure for the protein. In writing the sequence of amino acids in a chain, it is conventional to orient the chain so that the amino acid on the left is the one with a free amino group on its a-carbon, while the last amino acid on the right is the one whose a-carbon carboxylate is free. In other words, the amino- or N-terminus of the peptide chain is written on the left, and the carboxyl-or C-terminus is written on the right. One more convention the term backbone for a protein refers to the series of covalent bonds joining one a-carbon in a chain to the next a-carbon. 

Bodor and Brewster (1983) first used the term CDS, in describing the use of dihydropyridine ester- (or amide)-linked prodrugs such as 27 (X-OH is the parent) which can partition readily into the CNS, there to be oxidized to pyridinium salts (28), which are effectively trapped in the biophase because of their extreme polarity, and which then undergo enzymic or chemical hydrolysis of the now very labile ester link to release active drug. 

After the synthesis of the first amide-linked [2]rotaxanes, Vogtle et al. set out to study the limits of molecular recognition, which in terms of Emil Fischer means to discover if the lock (macrocycle) is specific to a certain key, or if several keys (monoamide threads) fit. It turned out that - in contrast to catenane formation - rotaxane synthesis is very tolerant towards the variation of the building... 

We use sugar amino add as a fundional, sucdnct classification term, although a plethora of terms have been proposed in the literature for compounds derived from Saa. These include saccharide-peptide hybrids, glycosamino adds, peptidosaccharides, sac-charopeptides, amide-linked carbohydrates, and carbopeptoids, although the latter compounds most often do not have a peptoid functionality. In some cases Saa are linked to each other, in other cases to amino acids. 

Amides are the derivatives of the carboxylic acids. In amides the carboxylic acid is linked with ammonia or an amine. Like esters, the parent carboxylic acid is identified. This is then termed an alkanamide and includes the nitrogen atom. For example, linking ethanoic acid with ammonia gives ethanamide ... 

Any polymer of amino acids linked by amide bonds between the amino group of each amino acid and the carboxyl group of the neighboring amino acid. The terms dipeptide, tripeptide, etc. may specify the number of amino acids in the peptide, (p. 1174)... 

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