L-阿拉伯糖,  L-Arabinose

L(+)-Arabinose is a pentose monosaccharide whose transcription is regulated by Ara-C proteins and is a substrate for L-arabinose dehydrogenase, galactose dehydrogenase. It is not fermented by yeast. Used as a one-way or reversible switch for protein expression. It is also used to make arabinosyl nucleosides. L-Arabinose is used as a substrate to identify, differentiate and characterize pentose sugar isomerase(s). L-Arabinose is used in the bioproduction of L-ribose. L-Arabinose is the naturally occurring isomer and is a constituent of plant polysaccharides. Most bacteria contain an inducible arabinose operon that codes for a series of enzymes and transporters that allows L-arabinose to be used as the sole carbon source in microbial culture.

L-Arabinose, also known as L-arabinopyranose, belongs to the class of organic compounds known as pentoses. These are monosaccharides in which the carbohydrate moiety contains five carbon atoms. L-Arabinose exists as a solid, very soluble (in water), and a very weakly acidic compound (based on its pKa). L-Arabinose has been found in human prostate tissue, and has also been detected in multiple biofluids, such as urine, blood, and cerebrospinal fluid. L-Arabinose exists in all eukaryotes, ranging from yeast to humans. L-Arabinose has been linked to the inborn metabolic disorders including ribose-5-phosphate isomerase deficiency.

L-arabinopyranose is the six-membered ring form of L-arabinose. It has a role as an Escherichia coli metabolite and a mouse metabolite.