L-Rhamnose monohydrate powder is extracted from the hydrolytic liquid of quercetin. As the rare monosaccharide existed in the nature, it can be used for assaying intestinal permeability, and it can be used as sweetener.
It is a naturally occurring deoxy sugar. It can be classified as either a methyl-pentose or a 6-deoxy-hexose. Rhamnose occurs in nature in its L-form as L-rhamnose (6-deoxy-L-mannose). This is unusual, since most of the naturally occurring sugars are in D-form. Exceptions are the methyl pentoses L-fucose and L-rhamnose and the pentose L-arabinose. Rhamnose can be isolated from Buckthorn, poison sumac, and plants in the genus Uncaria. Rhamnose is also produced by microalgae belonging to class Bacillariophyceae.