Dimeric glycinate

In all cases, glycine oligomers were obtained, from the dimer up to the decamer yields were pressure dependent. The rate of polymerisation increased during the first 8 days and then remained constant until the 31st day. The authors conclude from their experimental results that abiotic polymerisation reactions during diagenesis were more likely to have occurred in deep-lying sediments than in the primeval ocean (Ohara et al 2007). 

Dihydroxyacetone forms dimeric ketosylamines when it reacts with primary amines at low temperatures. However, the reaction of dihydroxyacetone with amino acids apparently generates pyruvaldehyde (23) as an intermediate for several products, including allomaltol (5-hydroxy-2-methyl-4-pyranone). In contrast to other amino acids, glycine reacts with dihydroxyacetone to yield a preponderance of butanedione. 

Dimer with Ag—Ag bond (2.88 A) similar to metallic Ag. Silver atoms bridge centrosymmetric pairs of carboxy-groups forming dimers of glycine. 

Employing experimental supersaturated solution diffusion coefficient data and the cluster di sion theory of Cussler (22), Myerson and Lo (27 attempted to estimate the average cluster size in supersaturated glycine solutions. They estimated an average cluster size on the order of two molecules. Their calculations indicated that while the average cluster size was small, large clusters of hundreds of molecules existed, only there were very few of them. Most of the molecular association was in the form of dimers and trimers. 

The substitution of Leu9 by alanine, ethyl glycine, and its fluorinated derivatives within the hydrophobic core generally decreases the overall thermal stability of the dimer as shown by melting points, which are lowered by 14.9-22.3 K (Fig. 9a). 

By carefully adjusting the distances between two sialoside residues in a number of divalent clusters. Click and Knowles [105] have obtained dimer 104 having the two sialic acid 5.7 nm apart. Compound 104 was 100-fold more potent than methyl a-sialoside (Neu5Aca2Me) in influenza virus inhibitions and 500-fold more potent in the case of polyomia virus. Alternatively, sialyl-a-(2,6)-/3-LacNAc dimers (105) branched at different positions of synthetic peptides, including compact glycine-rich and helical proline-rich peptides, afforded clusters which were only 8- and 4-fold more potent, respectively, than the corresponding monovalent trisaccharide [106]. 

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