beta-D-Fructopyranose (7660-25-5)

 Levulose (7660-25-5) is a simple monosaccharide found in many foods. It is a white solid that dissolves readily in water. Honey, tree fruits, berries, melons, and some root vegetables, contain significant amounts of the fructose derivative sucrose (table sugar). Sucrose is a disaccharide derived from the condensation of glucose and fructose.Crystalline fructose and high-fructose corn syrup are often confused as the same product. Crystalline fructose, which is often produced from a fructose-enriched corn syrup, is indeed the monosaccharide. High-fructose corn syrup, however, is usually considered to be a mixture of nearly equal amounts of fructose and glucose.and it is a 6-carbon polyhydroxyketone. It is an isomer of glucose, i.e. both have the same molecular formula (C₆H₁₂O₆), but they differ structurally. It typically adopts acyclic structures owing to the stability of its hemiketal. In contrast, aldoses such as glucose, tend to form a six-membered ring. This 5-member ring is formally called D-fructofuranose. Alternatively, the OH group on the sixth carbon may attach to the carbonyl carbon to form a 6-member ring (D-Fructopyranose). In solution, fructose exists as an equilibrium mixture of 70% fructopyranose and 30% fructofuranose.Excess fructose consumption has been hypothesized to be a contributing cause of insulin resistance, obesity,elevated LDL cholesterol and triglycerides, leading to metabolic syndrome. Short-term tests, lack of dietary control, and lack of a non-fructose consuming control group are all confounding factors in human experiments. However, there are now a number of reports showing correlation of fructose consumption to obesity,especially central obesity which is thought to be the most dangerous kind of obesity.