L-Rhamnose monohydrate(6155-35-7)

Carbohydrate compound: rhamnose, also known as mannose-methyl sugar, is a kind of methylpentose, which has two isomers, L-type and D-type[ α] D16.5 is -8.25 °, L-rhamnose[ α] D15 is+9.1 °. L-rhamnose is a kind of deoxhexose, namely 6-deoxy-L-mannose, which is a component of plant cell wall and a variety of glycosides. α Formula: colorless crystal. Crystallization from aqueous solution is a crystal containing crystalline water. Melting point 105 ℃. Soluble in water and methanol. It has optical activity and rotation change. The abundance in marine plankton is generally greater than arabinose. It also exists in seawater, particulate matter and sediment. It can exist in the form of dissociation or combination. Rhamnose α- Type and β- Two types: α- Type A, component of multiple glycosides. The melting point is 82~92 ℃, and the rotation will be changed. Optical rotation[ α] D20-7.7°→+8.9°。 β- Type A, which forms needle-like crystals from acetone. The melting point is 122~126 ℃. Optical rotation[ α] D20+31.5 °, and soon α- Same type. β- Type A is hygroscopic, and it becomes α- Type crystal. The sweetness is 33% of sucrose. Rhamnose is widely distributed in plants as a kind of micro sugar. It can be found in many plant glycosides (such as quercetin, isohesperidin, etc.), polysaccharides, especially pectin and colloid, as well as in lacquertree toxin. Rhamnose can be used to determine the permeability of the intestine, can be used as a sweetener, can reduce Fehling solution, and react with sodium amalgam to produce rhamnitol. It can be hydrolyzed from Xanthrhamnin and Quercetin.