Saccharide polymers

Figure 9.1 Polymer-polymer interactions assisted by boronic acid-diol reaction (a) boronic acid-appended polymer-hydroxylated polymer interaction, (b) boronic acid-appended polymer-saccharide interaction, and (c) boronic acid-functionalized molecule-hydroxylated polymer...

Polymer support and the active site of bonding Type of polymer-saccharide bond and its cleavage Method of coupling successive saccharide units Synthesis achieved References... 

Polystyrene, incorporating Polymer-saccharide C-1 Bromide (Koenigs- Isomaltose Frechet and Schuzerch,... 

Polystyrene, (soluble), incorporating an acid chloride group Polymer-saccharide (C-6) ester". Alkaline hydrolysis (NaOMe-Dioxane) C-1 Bromide viacw-1,2-orthoester Guthrie er a/., 1971, 1973... 

Polystyrene incorporating an o-nitrobenzyl alcohol group (insoluble) Polymer-saccharide glycoside. Photolysis of polymer O-nitro-benzyl glycoside at 320 nm Isomaltose Zehavi and Patchomik, 1973... 

Polystyrene (insoluble), incorporating chloromethyl or mer-captomethyl groups Polymer-saccharide thio-glycoside formed via the thio sugar C-1-Chloride propanol-KOH Isomaltose Chiu and Anderson, 1976... 

The separation was carried out on a TSKgel Amide-80 column 4.6 mm i.d. and 25 cm long with a mobile phase consisting of a 80% acetonitrile 20% water mixture. The flow rate was 1 ml/min and the column was operated at an elevated temperature of 80°C. The saccharides shown were 1/ rhamnose, 2/ fucose, 3/ xylose, 4/ fructose, 5/ mannose, 6/ glucose, 7/ sucrose and 8/ maltose. The analysis was completed in less than 20 minutes. These types of separations including other biomonomers, dimers and polymers are frequently carried out employing refractive index detection. 

Early in the 1950s, Stacey was successful in his negotiations to have a 60Co source of y-rays installed in his laboratory. Then, in collaboration with Barker and Bourne, a series of investigations of the effects of y-radiation on saccharides was started. Both polymer formation from simple sugars and the degradation of polysaccharides were studied. 

Monosaccharides, the molecular units of the saccharides, are carbohydrate molecules containing between three and six carbon atoms. Oligosaccharides contain small chains of two to ten monosaccharide units, and polysaccharides contain long-chain polymers of monosaccharides. 

Several other organoboron polymers have been developed by various synthetic strategies and utilized to construct polymeric sensing systems for cations, dopamine, saccharides, and so on. Fabre and co-workers have reported the preparation of a conjugated trifluoroborate-substituted polythiophene system for sensing cations such as... 

Boronic acid-containing polyaniline has also been utilized in diabetes-related research. One such polymer (23) (Fig. 17) has been observed to exhibit a linear near-infrared optical response to saccharides.43 The polymer was prepared by the copolymerization of aniline with 3-aminophenylboronic acid using lOmM (NH4)S208 in 1M HC1. The films were observed to undergo changes in the absorption spectra on addition of saccharides at pH 7.2. 

A further development [27] is the formation of so-called sugar-acrylate copolymers in which acrylic acid is copolymerised with glucose or other saccharides. Unlike other sequestering agents these polymers are said to be readily biodegradable, this being the main reason for their development. 

Now, this tentative description of the development of a correlation, later to become information from bases to the synthesis of proteins, by no means solves the problem of the origin of this code nor does it bring into focus the fact that the very proteins which were produced are responsible for the synthesis of the basic metabolic units, formaldehyde and acetic acid and then the amino acids and bases and finally the polymers by catalysts which are the polymers themselves. We do state, however, that the set of reactions quite probably give the most kinetically stable products. Now, the amounts of the different amino acids, lipids, saccharides... 

In Chapters 3 and 4, we referred to the basic reactions leading to the classes of biological polymers DNA (RNA), proteins, saccharides and long-chain hydrocarbons. Each class has a specific functional value. Here we shall not comment further on the special properties these polymers introduce in aiding cell survival including... 

Even though the short oligosaccharide segment made of seven units may not be considered as a true polymer chain, the chemistry devised by them should be easily applicable to longer saccharidic chains. Liu and Zhang used the Michael reaction for coupling a dextran (Dex) with an amino-functionalized terminal and acrylolyl end-capped PCL [146]. Sun et al. also synthesized Dex-b-PCL by disulfide bond formation [147]. 

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