Biopolymer uses

Proteias, amino acids bonded through peptide linkages to form macromolecular biopolymers, used as chiral stationary phases for hplc iaclude bovine and human semm albumin, a -acid glycoproteia, ovomucoid, avidin, and ceUobiohydrolase. The bovine semm albumin column is marketed under the name Resolvosil and can be obtained from Phenomenex. The human semm albumin column can be obtained from Alltech Associates, Advanced Separation Technologies, Inc., and J. T. Baker. The a -acid glycoproteia and ceUobiohydrolase can be obtained from Advanced Separation Technologies, Inc. or J. T. Baker, Inc. 

Stuting, H. H., Krull, I. S., Mhatre, R., Krzysko, S. C., and Barth, H. G., High performance liquid chromatography of biopolymers using on-line laser lightscattering technique, LC-GC, 7, 402, 1989. 

Fernandez et al. (2007) have characterized the rheological behavior of the mashed potatoes with added biopolymers using steady shear measurements. Fresh and frozen/thawed mashed potatoes present shear thinning with yield stress (Canet et al., 2005a), and dynamic shear data reveal weak gel-like behavior in potato purees (Alvarez et al., 2004). The effects are strongly... 

Fig. 5. Structures of the most important chiral modifiers. Not shown are the sugars and biopolymers used. In some cases the naturally occuring compound was derivatized for best effects but very often this was not even necessary.

The structure determination of biopolymers using NMR spectroscopy usually involves interactions of protons[25,1221. Typically, interactions of protons (nuclear Over-... 

The structure determination of biopolymers using NMR spectroscopy usually involves interactions of protons[216,33. Typically, interactions of protons (nuclear Overhauser effect, NOE) that are close in space but separated by several subunits of the biopolymer are used to establish the folding of the backbone. Distance restraints are then used to compute a structure which is checked by back-calculation of the NOE spectra and comparison with experimental results 361. For large and highly flexible systems molecular dynamics is invaluable for scanning the conformational space. 

Hydrogel micro- and nanoparticles composed of biopolymer matrixes have gained a lot of attention in recent years due to their application in drug delivery and tissue engineering [10,14,45 17], The biopolymers used for these purposes are nontoxic,... 

The typical biopolymers used for the preparation of micro- and nanogels are polysaccharides (Scheme 11) cellulose (CL), chitosan (CS), hyaluronan (HA), heparin, pullulan (PuL), dextran, and gelatin - a proteinaceous polyamolytic gel obtained by partial hydrolysis of collagen. Gelatine microgels are addressed by Landfester and Musyanovych in another chapter of this issue [5] and will thus not be discussed further here. 

Table 4-1 Principal Biopolymers Used in Foods and their Classification Based on Origin ...

Bailey, T. L. and Elkan, C. (1995) Unsupervised learning of multiple motifs in biopolymers using EM. Machine Learning 21, 51-80. 

Edible films and coatings are thin materials made from biological macromolecules (biopolymers).1 The main biopolymers used in preparing biofilms are polysaccharides2 and proteins.3,4 Among the most studied polysaccharides are pectin, cellulose and derivatives, alginates, carrageenan, chitosan and starch.1 5... 

After direct high-resolution structural measurements on proteins became practicable, interest in crystalline amino acids decreased, but became renewed in attempts to simulate the distribution of electronic charge density in biopolymers using amino acids and simple peptides as model systems, to derive some transferable parameters and potentials [2-15]. Another research direction involved these systems and their packing patterns to mimic selected folds and interaction patterns of biopolymers. Typical molecular conformations and patterns of hydrogen bonds and packing in the structures of crystalline amino acids have been reviewed [16-19]. Similar analyses were performed for small peptides [18, 20-22]. 

Figure 19.2 Scientific publications according to the type of biopolymer used in drug delivery in the last 30 years.

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. 

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