L-쓰레오-펜툴로스

L-xylulose is a clear liquid. It is a ketopentose, meaning that it has five carbon atoms and a ketogroup at carbon C-2. It has a molecular formula of C5H10O5 and a molar mass of 150.13 g/mol. Xylulose is almost colorless and it forms syrup. The formation of crystals has not been reported (Budavari, 1996). Both D- and L - enantiomers of xylulose are found as intermediates in metabolic pathways of prokaryotes as well as eukaryotes. Both forms are rare in nature (Doten and Mortlock, 1985b).

In 1933 a synthetic procedure for producing small amounts of D- and L -xylulose was introduced. In this method D- or L-xylose is epimerized to the corresponding diastereomer. The isomerization of xylose in pyridine leads to the production of xylulose (Touster, 1962). This enzyme catalyzes the production of L-xylulose from xylitol using either PQQ (pyrroloquinoline quinone) or FAD (flavin adenine dinucleotide) as prosthetic group, and L-xylulose is accumulated in the medium (Adachi et al., 1999; Adachi et al., 2001).