Heptose
Heptoses are monosaccharides, whose carbon skeleton containing seven carbon atoms. They all have the molecular formula C7H14O7 and a molar mass of 210.18 g / mol. They differ in the kind of the carbonyl function. If it is a keto group, then one speaks of ketoheptoses, with an aldehyde group they are called Aldoheptosen. There are 32 stereoisomeric Aldoheptosen and 16 stereoisomeric ketoheptoses.
Occurrence and use
Heptoses play only a minor role in nature. Among the few naturally occurring heptoses include:
- The D- sedoheptulose that occurs as an intermediate in the pentose phosphate pathway as sedoheptulose -7 -phosphate and is significantly involved in the regeneration of the D -ribulose in the Calvin cycle.
- The D- manno- heptulose, which is found in the fruit of avocado and, as hexokinase - inhibitor is used. An oral or intravenous administration of D- Manno- heptulose leads to decreased insulin secretion, thereby preventing a too rapid fall in blood sugar levels.
- The D- talo - heptulose that can be extracted from the avocado fruit.
- D- allo- heptulose, which can be obtained from the avocado plant.
In addition, some components of the heptoses are lipopolysaccharides (LPS).
Structure of the main ketoheptoses
Mannoheptulose
Taloheptulose
Alloheptulose
Structure of the main Aldoheptosen
Mannoheptose