Gelatin chemical structure

In a similar vein, a series of papers published between 2002 and 2008 contains spectacular claims of highly enantioselective asymmetric additions of water to styrenes, unsaturated carboxylic acids, or simple terminal alkenes [34-Al]. The catalysts used are of the heterogeneous type and based on chiral biopolymers such as wool, gelatin, or chitosan as solid supports (sometimes in combination with silica or ion-exchange resins) that are doped with transition metal salts. This series of papers contains spectacular claims, insufficient experimental data, and erroneous chemical structures for the biopolymers used. As earlier work from the same group of authors on asymmetric catalysis on bio-polymeric supports is irreproducible [42], one is well advised to await independent confirmation of those results. 

Gelatin is the product of denaturation or disintegration of collagen I, lacking cystine in acidic environment. The representation of the chemical structure of gelatin can be seen in Figure 31.10. 

Chemical structure - Interactions between the characteristic groups ofBC and gelatin [57] - Weak intermolecular hydrogen bonds [18]... 

Fig. 167. Chemical structures of the most important amino adds of collagen and gelatin...

All SCL basically consist of hydrophilic polymers that maintain then-gel structure, with the ability to swell and not dissolve by intermolecular crosslinking. Therefore, natural polymers, such as agarose and gelatin, are potential candidates for its material. However, currently commercially available SCL are made only of copolymers of methacrylic acid derivatives, mainly PHEMA, and several other monomers because of stability and safety concerns. Lenses with a water content of 30-40 % are made mostly of PHEMA and those with water contents of70-80 % are made of copolymers ofN-vinyl pyrrolidone (NVP), acrylamide (AAm), HEMA, and methacrylic acid (MA). There are also poly(vinyl alcohol) derivatives. Table 2 shows the names and chemical structures of various SCL components [6]. 

Fig. 7.11 Possible chemical structure of (a) gelatin, (b) the luminescent ionogel, and (c) the ionic liquid (Reproduced from Ref. [58] by permission of the Royal Society of Chemistry)...

In the present work results of phosphorus-containing polypeptides on the base of some substrates (peptides, gelatin and fish collagen) synthesis research are presented. The chemical structure of a product, sorption properties and thermal-oxidative degradation are investigated. 

Fig. 42 Photocurable gelatin for application to femtosecond laser microfabrication, a Chemical structures of styrene-derived gelatin, b photogelation mechanism by formation of cross-linked gelatin networks via intermolecular crosslinking and intramolecular polymerization...

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