Anomeric bond

In the carbohydrate polymers discussed so far there is variation in positional or anomeric bonding between different types of polymers, but not... 

One of the most abundant compounds in nature is cellulose, the structural material of plants. It is a glucose polymer and is produced in simply enormous quantities (about 1015 kg per year). Each glucose molecule is joined to the next through the anomeric bond (Cl) and the other end of the molecule (C4). Here is that basic arrangement. 

Nqtice that the anomeric bonds are all equatorial. This means that the cellulose molecule is linear in general outline. It is made rigid by extra hydrogen bonds between the 3-OH groups and the ring oxygen atoms—like this. 

Figure 1. Theoretical potential-energy curves for rotation about the anomeric bond from ah initio Hartree-Fock 431-G calculations on dimethoxymethane. is the glycosidic O-5-C-l-O-l-CH i torsion angle. is the C-5-0-5-C-1-0-1 torsion angle and is 60° for a-D-pyranosides, 180° for fl-v-pyranosides (see...

Mean C-O-C Bond Angles (Degrees) and C-O Bond Lengths (pm) in Carbohydrate Structures as a Function of the Torsion Angle ( ) About the C-l-O-1 (Anomeric) Bond"... 

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