Copper, complex with polysaccharides

A spectrophotometric method that does not use condensation with sulfuric acid was proposed by Mopper and Gindler [157]. The method used the copper (I) complex with 2,2-bicinchoninate to form a colour with simple sugars, with a hydrolysis step which is included to make simple sugars from the polysaccharides. Thus the analysis of two aliquots, one of them hydrolysed, would yield values for both simple and combined sugars. 

Additives that specifically interact with an analyte component are also very useful in altering the electrophoretic mobility of that component. For example, the addition of copper(II)-L-histidine (12) or copper(II)-aspartame (54) complexes to the buffer system allows racemic mixtures of derivatized amino acids to resolve into its component enantiomers. Similarly, cyclodextrins have proven to be useful additives for improving selectivity. Cyclodextrins are non-ionic cyclic polysaccharides of glucose with a shape like a hollow truncated torus. The cavity is relatively hydrophobic while the external faces are hydrophilic, with one edge of the torus containing chiral secondary hydroxyl groups (55). These substances form inclusion complexes with guest compounds that fit well into their cavity. The use of cyclodextrins has been successfully applied to the separation of isomeric compounds (56), and to the optical resolution of racemic amino acid derivatives (57). 

Again, similar to the simple formazans (5), those of the ozone-oxidized polysaccharides readily form complex salts with heavy metals. The probable structure of a copper complex obtained from the formazan of ozone-oxidized cellulose is ... 

Like the simple formazans, the formazans of oxidized polysaccharides form complexes with heavy metal salts with ease. On warming the formazans of oxidized cellulose, starch, dextrin, dextran, or inulin with copper, cobalt, nickel, or uranium salt solutions, their characteristically-colored metal complexes are obtained. The presence of carboxyl groups in the polysaccharide formazans frequently facilitates complex formation. ... 

Maxim extracted a sample of dry fat-free bacilli with acidulated water. The extract was concentrated and the protein removed. The cell residue was treated with water at 80° and the extract removed as before. A third extract was made in alkaline solution by tryptic digestion. The purest product was obtained from the first extraction by precipitation with alcohol. Glycogen was removed from this product by repeated precipitation with alcohol and strong acetic acid. Polysaccharides were obtained from the second and third extracts by precipitation of the copper and uranium complexes in alkaline solution in the cold. A purified product was obtained by elimination of the copper and uranium. 

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