Oligomers amide-linked

Amide-linked carbohydrate-based oligomers with defined secondary structures were first engineered by Szabo et al. [66]. )8-Methoxy neuraminic acid was used as the monomer unit, and solid phase techniques were employed in the construction of oligomers ranging from dimer to octamer. Caproamide was incorporated at the car-boxy terminus to prevent solvation of the terminal residue, a phenomenon commonly referred to as fraying (Fig. 37). The hydrophobic end group provided directionality... 

Workers at Novartis have prepared structures 234 (B = Thy, Cyt, Ade) from D-hydroxyproline, and have assembled them into amide-linked oligonucleotide analogues by conventional solid-state peptide synthesis. A homopyrimidine oligomer bound to complementary RNA with significant affinity, whilst no binding was observed with complementary DNA. ... 

Ando et al. 292,293 sported a series of chlorin dimers 341 and trimers 342 joined by amide bonds and found that among such oligomers, dimer 341 (Scheme 71) did show good tumor uptake and selectivity compared with the hematoporphyrin derivative (HpD). As part of their effort to improve the in vivo antitumor activity of chlorin-based photosensitizers, Pandey et extended this approach for the preparation of a series of amide-linked symmetrical and unsynunetrical chlorin dimers 345-347 (Scheme 72). For the preparation of unsymmeuical dimo 349, methyl pheophorfoide a was reacted with 1,3-propanediamine and the intermediate amide 345 was isolated in 80% yield. Reaction of 348 with H2(HPPH) afforded the unsymme-ttical dimer in 70% yield, and was found to be effective in... 

While deriving the dynamic batch-reactor models in Tables 7.3 and 7.4, the equal-reactivity-of-functional-groups assumption was made, so that kp is the rate constant for all forward linear polyamidation reactions and Ay is the rate constant for all reverse hydrolysis reactions involving amide links on linear chains. Let the rate constant for the forward cychzation reaction be Ay and the rate constant for hydrolysis of an amide link on cyclic oligomers be A . In practice all of these rate constants depend on the reactor temperature and... 

The protein amino acids are the basic building blocks for all peptide chains (amino acid polymers and oligomers) and protein chains (a protein is a large polypeptide), which make up the structure of an enormous number of biological molecules including enzymes. The chains are held together by peptide links (amide... 

Peptoids are oligomers of N-substituted glycines. Hence, the principal difference between peptides and peptoids is the location of the amino acid side chains with respect to the backbone. While in peptides 6 the side chains are attached to the a-carbon of the amino acids, in peptoids 7 they are linked to the amide nitrogens of the peptide backbone (Scheme 4) [42,43] Similar to amide-alkylated or reduced peptides (see Section 4.3.7.2.2), peptoids lack the peptide bond CO-NH, and are, therefore, less susceptible to proteolytic degradation. Consequently, peptoids are attractive molecules for the generation of combinatorial libraries. 

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