Octoses

Octoses are a class of monosaccharides that contain eight carbon atoms. Like other monosaccharides, they have the general formula C8H16O8. Octoses are reducing sugars, meaning they can act as reducing agents. They can exist in both open-chain and cyclic forms.

The two main types of octoses are aldosoctoses and ketosoctoses, depending on the position of the carbonyl group. Aldosoctoses contain an aldehyde group at the end of the carbon chain, while ketosoctoses have a ketone group within the chain.

Naturally occurring octoses are relatively rare compared to hexoses like glucose. Some examples of octoses found in nature include L-glycero-D-galacto-octose and L-glycero-D-manno-octose, which are components of certain bacterial lipopolysaccharides. These complex carbohydrates play important roles in the structure and immune response of bacteria.

The study of octoses is primarily within the field of carbohydrate chemistry and biochemistry. Their synthesis and the biological roles of the few known natural octoses are areas of ongoing research. While not as common as simpler sugars, octoses contribute to the diversity of carbohydrate structures and their associated biological functions.