Wiktionary
xylulose
n. (context carbohydrate English) The ketopentose ''(3R,4S)-1,3,4,5-Tetrahydroxypentan-2-one''
Wikipedia
Xylulose
Xylulose is a ketopentose, a monosaccharide containing five carbon atoms, and including a ketone functional group. It has the chemical formula . In nature, it occurs in both the L- and D- enantiomers.