Conformational descriptors

Constitutional, property-based, 2D topologi- 1,084 cal, and 3D conformational descriptors... 

Monosaccharides, di- and oligosaccharides, and polysaccharides have cumulative conformational descriptors. Because polysaccharides contain as subunits the monomers and dimers, the information on the subunits is usually of interest in the description of the larger molecules as well. However, once the issue of the ring conformation can be regarded as settled, the variables of primary interest for a disaccharide become the torsion angles about the bonds that form the interresidue linkages. 

There are, however, some exceptions that one must note as they apply to large classes of chemical substances. Some classes of biologically active molecules have conformation descriptors that are a part of the chemical substance name, for example, D-glucose (as an example of carbohydrate nomenclature) or L-alanine . Conformational descriptors such as boat or chair cyclohexane are not used. 

The twist-chair conformation was also seen intact when thiol substitution was intfoduced at anomeric center with 2,3,4,5-di-O-isopropylidene protecting group, namely, ethyl 2,3 4,5-di-0-isopropylidene-l-thio-p-D-glucoseptanoside 102 [49]. Positive signs and closer torsion angles of 53.5 for C6-06-C1-C2 and 35.7 for 06-C1-C2-C3 led to assign the conformational descriptor... 

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