What is "mannoheptulose"

n. (context biochemistry English) A hexokinase inhibitor found in avocados.

Mannoheptulose is a hexokinase inhibitor. It is a heptose, a monosaccharide with seven carbon atoms. By blocking the enzyme hexokinase, it prevents glucose phosphorylation. As a result, the breakdown of glucose is inhibited. It is found as D-mannoheptulose in avocados.

Mannoheptulose has been reported to inhibit insulin secretion from pancreas. This inhibition occurs because when mannoheptulose is present the glycolysis is inhibited (because there is no production of glucose-6-P) therefore no increase in ATP concentration which is required to close the KATP channel in the beta cells of the pancreas causing a diminution of calcium entry and insulin secretion.