Glucose optical properties

All carbohydrates can exist in either of these two forms and the prefix of D or L only refers to the configuration around the highest numbered asymmetric carbon atom. Enantiomers have the same name (e.g. D-glucose and L-glucose) and are chemically similar compounds but have different optical properties. The majority of naturally occurring monosaccharides, whether they be aldoses or ketoses, are of the D configuration. 

The latest findings of amide-based rotaxanes focus on their chemistry and stereochemistry. The optical properties of an axle bearing chiral glucose stoppers are significantly influenced by rotaxanation - Cotton effects are amplified and the maxima of the CD spectra are shifted bathochromically [71]. 

It has been known for almost 200 years that starch gives a deep blue color when a solution of potassium iodide and iodine is added [47]. More than a century later it was suggested that the complex consisted of a helical polysaccharide, with triiodide in the center of the helix [48]. Using flow dichroism, it was demonstrated that the triiodide was stacked in a linear structure, as required for the helical model [49]. Another study of the optical properties of crystals of the amylose-triiodide complex showed it to be consistent with a helical structure [50] and X-ray diffraction showed the triiodide complex gave the dimensions of a unit-cell of a helix with six glucose residues per turn [51]. This confirmed a helical structure for the amyiose complex with triiodide that predated the helical models proposed by Pauling for polypeptides [52] and the double helical model for DNA by Watson and Crick [53] by 10 years. 

Optical properties, optimum mechanical properties and suturability, and permeability to glucose and albumin were evaluated... 

Many of the biological and pharmaceutical compounds are chiral In nature. These compounds contain at least one asymmetric carbon atom or are molecularly as5mimetric. These have identical physical and chemical properties and differ only in their spatial configuration or in their optical properties. It is usual that Just one isomeric/enantiomeric form of these compounds is biologically active. For example, it is the L-isomers of amino acids which one finds in proteins and the D-isomer is biologically rejected. It is the D-glucose, not L-glucose that has been preferred by life. 

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